Effectiveness of air disinfection by ozonation or hydrogen peroxide aerosolization in dairy environments Food Control (IF 3.667) Pub Date : 2018-10-15 Fabio Masotti, Lisa Vallone, Silvia Ranzini, Tiziana Silvetti, Stefano Morandi, Milena Brasca
Indoor air of dairy industry acts as a source or vehicle of microbial contamination affecting both food safety and product shelf life. This research focused on both the monitoring of the air microbial load in selected areas of a dairy factory and in evaluating the effect of air disinfection through ozonation or chemical aerosolization by hydrogen peroxide. The air microbial load was weekly monitored in the autumn/winter season after the routinely applied sanitation procedures. Air samplings, through impaction method, were carried out in 3 critical areas (cheese making, storage and packaging). Total bacteria, moulds and yeasts resulted in mean counts of 161 (± 154) MPN m-3, 228 (± 234) MPN m-3, and 137 (± 439) MPN m-3, respectively. The dairy location exhibiting the lowest contamination was the storage cell. A large variability of microbial loads characterized the packaging area. Mycobiota pattern consisted in 11 species of moulds isolated and identified through mycological and molecular techniques. The isolates observed in the indoor air mainly consisted of Cladosporium spp., Alternaria spp., and Penicillium spp.. The yeast community was mainly represented by Cryptococcus spp., Debaryomyces spp., Bulleromyces spp., and Sporobolomyces spp.. Both ozonation and hydrogen peroxide aerosolization were effective techniques in the inactivation of airborne microorganisms. After air treatment only residual fungi were identified. We verified that their occurrence was promoted by environmental recontamination.
A pilot study for an innovative approach highlighting Actin and COI mRNAs as potential biomarkers of quality of the edible crustacean Nephrops norvegicus (Linnaeus, 1758) Food Control (IF 3.667) Pub Date : 2018-10-13 Caterina Costa, Annalisa Pinsino, Rosa Bonaventura, Roberta Russo, Francesca Zito, Valeria Matranga
Widely appreciated in gastronomy, many harvested and farmed Crustacean species are a great economic resource in the fishery business, throughout the world. Factors like pollutants and/or improper management in on-board/on-shore practices may adversely affect their edible quality and shelf-life. Recent studies from applied scientific research have been supporting the fishing industry and trading companies, in order to improve post-harvest practices and offer a safe and competitive product of high quality. Here, we developed an innovative molecular approach to get basic information on crustacean quality by using the European lobster Nephrops norvegicus (Linnaeus, 1758). For the first time, we investigated muscle-exudates of thawed lobsters for the presence of nucleic acids and analysed mRNA targets selected at NCBI to test their potential use as biomarkers of quality in frozen-thawed seafood. By RT-PCRs and sequencing we validated small amplicons of Actin, Cytochrome oxidase subunit 1 (COI), Calpain M, Prophenoloxidase (ppo) and Crustin-like antimicrobial peptide. In comparative One Step RT-PCR and/or One Step RT-qPCR assays, we analysed their amplification profiles at 1, 4 and 7 days after thawing (a.t.), in lobsters maintained to checked temperatures from capture. Based on amplification efficiency (AE), inversely correlated to the time after thawing and loss of RNA targets integrity, we identified new highly sensitive, species specific early indicators of quality. Our results highlight the advantage of using amplicons from exudates in different food science applications including authenticity/traceability, and provide new insights for the development of scientific tools applicable to crustacean quality monitoring on industrial-scale.
Impact of drivers of change, including climatic factors, on the occurrence of chemical food safety hazards in fruits and vegetables: a Bayesian Network approach Food Control (IF 3.667) Pub Date : 2018-10-13 Yamine Bouzembrak, Hans J.P. Marvin
The presence and development of many food safety risks are driven by factors within and outside the food supply chain, such as climate, economy and human behaviour. The interactions between these factors and the supply chain are complex and a system or holistic approach is needed to reveal cause-effect relationships and to be able to perform effective mitigation actions to minimise food safety risks. In this study, we demonstrate the potential of the Bayesian Network (BN) approach to identify and quantify the strength of relationships and interactions between the presence of food safety hazards as reported in Rapid Alert System for Food and Feed (RASFF) for fruits and vegetables on one hand, and climatic factors, economic and agronomic data on the other. To this end, all food safety notifications in RASFF (i.e. 3,781 notifications) on fruits and vegetables originating from India, Turkey and the Netherlands were collected for the period 2005-2015. In addition, climatic factors (e.g. temperature, precipitation), agricultural factors (e.g. pesticide use, fertilizer use) and economic factors (e.g. price, production volumes) were collected for the countries of origin of the product concurrent with the period of food safety notification in RASFF. A BN was constructed with 80% of the collected data using a machine-learning algorithm and optimised for each specific hazard category. The performance of the developed BN was determined in terms of accuracy of prediction of the hazard category in the evaluation set comprising 20% of the total data. The accuracy was high (95%) and the following factors contributed most: product category, notifying country, yearly production, number of notification, maximal residue level (MRL) ratio, country of origin, and the annual agricultural budget of a country. The assessment of the impact of interactions within the BN showed a significant interaction between the presence and level of a hazard as reported in RASFF and several drivers of change but at present, no definite conclusions can be drawn regarding the climatic factors and food safety hazards.
Fruit infected with Paecilomyces niveus: A source of spoilage inoculum and patulin in apple juice concentrate? Food Control (IF 3.667) Pub Date : 2018-10-13 Megan N. Biango-Daniels, Abigail B. Snyder, Randy W. Worobo, Kathie T. Hodge
Paecilomyces niveus has long been recognized as an important heat-resistant mold (HRM) causing spoilage in thermally processed apple products. With the recent discovery that P. niveus causes an apple disease called Paecilomyces rot, there is a need to evaluate the possibility that the spores can be introduced via infected fruit and survive thermal processing to contaminate apple products. Previously, research characterizing P. niveus survival and spoilage has been based on simple inoculation of cultured ascospores directly into juice. To determine whether ascospores formed in infected fruit survive through thermal processing with rotating vacuum evaporation (2.5 h, 70 °C), apples infected with P. niveus were used to make apple juice concentrate. Viable P. niveus was quantified in samples taken throughout the apple juice concentrate process: in cider, centrifuged juice, apple solids, and in juice made from concentrate. Additionally, the concentration of the mycotoxin patulin was determined in a subset of samples. Results show that P. niveus survived juice concentration. The thermal process used significantly reduced P. niveus (P = 0.0017); from an average of 5.5 log CFU L−1 in the initial cider made from diseased fruit to an average of 1.5 log CFU L−1 in single strength apple juice diluted from concentrate. Ascospores were observed at a greater abundance than intact asci throughout the concentration process. Patulin concentrations at all stages of apple juice concentration exceeded the United States’ regulatory defect action level of 50 ppb. This is the first report that apples infected with P. niveus can survive and remain viable in finished apple products and that patulin is produced in these apples. It raises important questions about the use of damaged and infected fruit as a source of HRM which contribute to spoilage and mycotoxins in apple juice concentrate.
Effect of heating rates on thermal destruction kinetics of Escherichia coli ATCC25922 in mashed potato and the associated changes in product color Food Control (IF 3.667) Pub Date : 2018-10-13 Xiaoxi Kou, Rui Li, Lihui Zhang, Hosahalli Ramaswamy, Shaojin Wang
In this study, the influence of heating rate on thermal inactivation kinetics of Escherichia coli ATCC 25922 in mashed potato and the associated changes in product color was evaluated. Five heating rates (0.1, 0.5, 1.0, 5.0 and 10.0 °C/min), three final temperatures (55, 57 and 60 °C) and five holding times (0, 5, 10, 30 and 60 min) were precisely controlled by a unique heating block system. Results showed that the slower heating rates (<1.0 °C/min) gave significantly higher D-values presumably attributable to heat-adaption during slow heating, and had a more detrimental effect on the color change. L∗ values decreased while a∗ values increased at lower heating rates to reach the target temperature and subsequent holding time. High correlation between microbial lethality and L* & a* values suggested that color change during thermal process could be used as an indicator not only for food quality change but also for the microbial inactivation (food safety). Therefore, heating rates during thermal treatment could have a significant effect on thermo-tolerance of surviving microorganisms and product quality. Results of this study could be useful for evaluation and optimization of thermal pasteurization.
Authentication of ready-to-eat anchovy products sold on the Italian market by BLAST analysis of a highly informative cytochrome b gene fragment Food Control (IF 3.667) Pub Date : 2018-10-12 Alice Giusti, Lara Tinacci, Carmen G. Sotelo, Pier Luigi Acutis, Nicola Ielasi, Andrea Armani
In this study, 111 ready-to-eat anchovy products were collected on the Italian market. The products were molecularly identified through a BLAST analysis of a highly informative cytb fragment amplified by a newly designed primer pair for the genus Engraulis spp. and the mislabelling rate was assessed. In addition, the labels were analysed in the light of the current EU law. Despite only one mislabelling case was observed (mislabelling rate 0.9%), which involved the substitution of the European anchovy (Engraulis encrasicolus) with the low-valuable Peruvian/Chilean anchoveta (Engraulis ringens), the molecular technique developed in this study was proved as suitable tool for detecting species in processed anchovy products. It could be therefore applied to carry out more extensive EU survey aimed at evaluating the mislabelling rate of such products, still poorly covered by a targeted and clear legislation system.
Effect of Deacetylation Degree on Properties of Chitosan Films Using Electrostatic Spraying Technique Food Control (IF 3.667) Pub Date : 2018-10-12 Chenjun Zhuang, Yu Zhong, Yanyun Zhao
Chitosan (CH) films at 4.4 kDa with different deacetylation degree (DD, 81.0, 88.1 and 95.2%) and concentration (0.9, 1.2 and 1.5%) were prepared using electrostatic spraying (ES) system. The effects of DD and concentration on film-forming solution properties, ES-atomization effects, and film performances were investigated. Results indicated that surface tension and viscosity of CH solution declined with the increase of DD, while solution conductivity displayed the opposite trend. The spray angles of film-forming solution during ES were in the range of 10.6-14.2 °, and the average median diameters of droplet sizes were all ranged from 6.4 to 13.9 μm. The spray angle and droplet size generally reduced with increasing DD, and thus more complete, rougher and more crystalline microstructures of CH films were observed by SEM, AFM and XRD. CH films at 88.1 and 95.2% DD had better water barrier property and tensile strength. In addition, antibacterial capacities of CH films against L.innocua and E. coli were enhanced with DD. The results could provide guidance on the application of ES technology to improve the commercial food safety such as, fruits, vegetables, poultry, meat, and seafood.
Gas chromatography-mass spectrometry based profiling reveals six monoglycerides as markers of used cooking oil Food Control (IF 3.667) Pub Date : 2018-10-10 Guodong Cao, Cheng Ding, Dongliang Ruan, Zhaobin Chen, Huiqin Wu, Yanjun Hong, Zongwei Cai
Under deep frying conditions, edible oil will release a variety of deterioration chemicals that have been implicated in many diseases. Unscrupulous traders may refine used cooking oil and adulterate it as qualified edible oil, thus posing threats to public health. This research aimed to discover the chemical markers of used cooking oil by using gas chromatography-mass spectrometry (GC-MS) based profiling. Our results suggested that six monoglycerides could be used as endogenous markers to discriminate used cooking oil from fresh edible oil. Accumulation behaviors of those markers in continuous heating process were observed. A quantitative GC-MS method was further developed for the six monoglycerides with good accuracy, precision and reproducibility. This method enabled the authentication of commercial olive oil adulterated with 1% deep fried oil. Abnormally high levels of the monoglycerides markers had also been determined in 116 gutter oil samples. Therefore, quantitation of six monoglycerides markers by GC-MS could be a promising approach for elucidating the degradation state of edible oil, authenticating commercial oil products adulterated with used cooking oil, as well as screening of gutter oil.
Species specific marker peptides for meat authenticity assessment: A multispecies quantitative approach applied to Bolognese sauce Food Control (IF 3.667) Pub Date : 2018-10-11 Barbara Prandi, Martina Varani, Andrea Faccini, Francesca Lambertini, Michele Suman, Andrea Leporati, Tullia Tedeschi, Stefano Sforza
Food frauds are a critical issue in the field of food safety and quality. Given the high added value, and the complexity of the matrix, processed meat products are among those most susceptible of adulteration. Despite all the efforts made by the official control authorities and by the food industry to counteract these frauds, the undeclared replacement of meat species with cheaper ones is still widespread. The meat species allowed for food consumption are many, and their specific and accurate detection in highly processed food products requires very sensitive and selective analytical methods. In this work, a LC-MS method was developed to identify and quantify eight different meat species (duck, rabbit, chicken, turkey, buffalo, equine, deer and sheep) in a complex food matrix, such as Bolognese sauce. After protein extraction and trypsin digestion, a species-specific peptide marker for each species was chosen for qualification and quantification. The method was validated on real Bolognese sauce samples prepared in an industrial environment, showing a good sensitivity (LOD 0.2–0.8% on whole finished product) and the possibility, using specifically defined calibration lines, to quantify the amount of meat present coming from different species.
Systematic Review of Mycotoxins in Food and Feeds in Turkey Food Control (IF 3.667) Pub Date : 2018-10-11 Nurhan UNUSAN
Mycotoxins are toxic natural contaminants of food and feeds and are produced by various fungi from Aspergillus, Alternaria, Fusarium, and Penicillium genera. Molds and their toxins have attracted much attention worldwide due to the important economic losses related to their effects on human health and domestic and international trade. Although more than 400 mycotoxins have been identified, most studies have focused on aflatoxins, ochratoxin A, fusarium toxins, zearalenone, patulin, and trichothecenes owing to their relationships with food safety and economic losses. In Turkey, the dramatic variations in climatic conditions among regions have facilitated the spread of various foodborne mycotoxins. Accordingly, in this systematic review, a summary of the occurrence and contamination levels of foodborne mycotoxins in Turkey was provided. Based on our literature review, mycotoxin levels were shown to exceed the limits designated by the European Union in apple juice (35%), milk (21%), dairy products (12%), dried fruits and vegetables (11%), herbs (10%), cereal and cereal products (2%), nuts (1%), and feeds (1%). Thus, there is a need for additional studies on the mycotoxin prevalence in all types of foods and feeds throughout Turkey, and education programs on mycotoxin management are important for reducing the prevalence of mycotoxin contamination.
Can lactic acid bacteria be an efficient tool for controlling Listeria monocytogenes contamination on cheese surface? The case of Gorgonzola cheese Food Control (IF 3.667) Pub Date : 2018-10-10 Stefano Morandi, Tiziana Silvetti, Battelli Giovanna, Milena Brasca
Gorgonzola is an Italian blue-veined, mould-ripened PDO cheese obtained using pasteurised cow's milk. Like other mould cheeses, Gorgonzola rind represents a suitable substrate for the growth of Listeria. In this study, we proposed the use of lactic acid bacteria (LAB) to limit the growth of L. monocytogenes on Gorgonzola surface during ripening process. A total of 23 LAB strains were screened by agar disk diffusion test and microplate turbidometric growth inhibition assays for their antimicrobial activity against two L. monocytogenes and two L. innocua biotypes isolated from Gorgonzola rinds. The anti-Listeria activity differed among the LAB strains and it was Listeria biotype-dependent. Amongst them, Carnobacterium SCA, SCB, Lactobacillus plantarum NA18, Lb. sakei SCC, Lactococcus lactis FT27, N16 and SV77 were selected for their marked anti-Listeria activity and a challenge test was performed to evaluate their effect on the development of L. monocytogenes and L. innocua artificially inoculated on Gorgonzola rinds at 6 and 55 days of ripening and maintained at 4 and 8 °C. Five strains (Carnobacterium SCB, Lb. sakei SCC, Lc. lactis FT27, N16 and SV77) showed notable inhibition when low level of Listeria contamination (102 CFU/g) occurred during the first stage of ripening (6 days) and L. monocytogenes cells were maintained below the EC limit (<102 CFU/g) for 60 days. Differently, when Listeria was inoculated on the cheese surface at the end of ripening process (after 50 days; pH: 6.7), only Lc. lactis FT27 exerted a significant inhibition on the growth of the two Listeria species if the cheese was strictly maintained at 4 °C. This research underlined that the susceptibility of Listeria biotypes to LAB antimicrobial activity is strain-dependent, thus a blend of different LAB strains could represent an effective tool to develop protective culture for blue-veined cheeses.
Some genotypic and phenotypic characteristics of biofilm formation of emetic toxin producing Bacillus cereus strains Food Control (IF 3.667) Pub Date : 2018-10-08 Eun-ji Park, Mohammad Shakhawat Hussain, Shuai Wei, Minyeong Kwon, Deog-Hwan Oh
The objectives of this study were: 1) to determine biofilm formation abilities of 11 emetic toxin producing Bacillus cereus strains along with two reference strains ATCC 14579 and KCTC 13153 on stainless steel and plastic coupons; 2) to examine the correlation between biofilm formation ability and genotypic and phenotypic characteristics of four selected strains. Crystal violet assay results indicated that the biofilm formation behavior was highly variable depending on strain and surface. Cell enumeration and scanning electron microscopy (SEM) analysis showed complex cell clusters with extracellular polymeric substances (EPS) for high biofilm forming strains and single layer of cell clusters with few EPS for low biofilm forming strains. Phenotypic characteristics of planktonically grown cells such as hydrophobicity were positively correlated with biofilm formation behavior. However, antibiotic susceptibility of B. cereus strains was not correlated with biofilm formation, although resistance to benzalkonium chloride showed a clear correlation with biofilm formation ability. Expression levels of two genes spo0A and abrB involved in the regulation of cell differentiation and mobility of B. cereus were positively correlated with biofilm formation. Results of this study indicate that multiple factors are involved in biofilm formation by emetic toxin producing B. cereus.
Successive detection of benzoic acid and total parabens in foodstuffs using mercaptosuccinic acid capped cadmium telluride quantum dots Food Control (IF 3.667) Pub Date : 2018-10-08 Kanlaya Prapainop, Wid Mekseriwattana, Weena Siangproh, Orawon Chailapakul, Kriangsak Songsrirote
An approach for the determination of benzoic acid (BA) and total paraben content using mercaptosuccinic acid capped CdTe quantum dots (MSA-CdTe QDs) as an optical probe is presented. The levels of these preservatives in the samples of liquid foodstuff could be determined by both visible and fluorescent detection methods. For the analysis of paraben content, sample hydrolysis under alkaline conditions was required in order to obtain p-hydroxybenzoic acid (PHBA) prior to the addition of MSA-CdTe QDs. Both BA and PHBA could be quantified by their quenching of QD fluorescence, owing to the formation of hydrogen bonds between the carboxylic acid groups of the MSA-CdTe QDs and the analytes. Reverse-phase C18 solid phase extraction cartridge was exploited to reduce sample loss and organic solvent consumption in the sample preparation steps. The developed approach was successfully applied for the determination of the BA and total paraben content found in orange juice, soft drink, energy drink, beer, coconut milk, and fish sauce, giving a limit of detection of 0.3 mg/L for BA analysis, and 0.1 mg/L for PHBA (hydrolyzed form of parabens) analysis, with a linearity range from 1.0 mg/L to 500.0 mg/L. Since the concentrations of most preservatives added to products are controlled and regulated by raw, therefore, quality control is necessary to monitor the levels of these agents in products to better ensure the safety of customers.
Impartial assessment of oil degradation through partitioning of polar compounds in vegetable oils under simulated frying practice of fast food restaurants Food Control (IF 3.667) Pub Date : 2018-10-08 Azmil Haizam Ahmad Tarmizi, Elina Hishamuddin, Raznim Arni Abd Razak
Measurement of total polar compounds (TPC) is recognised as one of the objective indicators to gauge oil resistance against high temperature. Dependency to TPC measurement alone in arbitrating the quality and safety of oils can be misleading especially for those oils that are rich with significant amount of natural diacylglycerols (DAG). In fact, the results generated could be at the higher side when the analysis protocol involves excessive drying. Method modification has been established to isolate and quantify the individual polar compound fractions without the involvement of drying stage to protect the integrity of samples and therefore produce credible results. Performance of the established method is validated with the DAG quantified from the acylglycerols analysis. A series of vegetable oils, i.e. palm olein (POo), soybean oil (SBO), canola oil (CAN) and sunflower oil (SFO), were subjected to 9 days of intermittent frying, 8 h day-1 and 144 frying cycles. The transient of TPC across frying time was coincided with polymerised triacylglycerols (PTAG) following the linear model with coefficient of determination (R2) greater than 91% while DAG and oxidised triacylglycerols (OxTAG) showed good regression with the quadratic model (R2 > 0.97). Oils with equal amount of polyunsaturated fatty acids (PUFA) were found to have similar rate of combined PTAG and OxTAG. Whilst liquid oils have similar OxTAG contents with POo, they were much distressed with polymeric reaction given that their PTAG levels were 1.6 to 2.4 folds higher than POo. Blending liquid oils with POo has been proven to moderate the level of PTAG when similar frying conditions were applied.
Comprehensive analysis of multi-class mycotoxins in twenty different species of functional and medicinal herbs using liquid chromatography–tandem mass spectrometry Food Control (IF 3.667) Pub Date : 2018-10-08 Hyun-Deok Cho, Joon Hyuk Suh, Shi Feng, Taeyong Eom, Junghyun Kim, Seung Muk Hyun, Junhee Kim, Yu Wang, Sang Beom Han
Effects of natural and synthetic antioxidants on changes in 3-MCPD esters and glycidyl ester in palm olein during deep-fat frying Food Control (IF 3.667) Pub Date : 2018-10-06 Yu Hua Wong, Kok Ming Goh, Kar Lin Nyam, Imededdine Arbi Nehdi, Hassen Mohamed Sbihi, Chin Ping Tan
The effects of selected antioxidants on the changes of the quality properties and 3-monochloropropane-1,2-diol (3-MCPD) esters and glycidyl ester (GE) contents in refined, bleached, and deodorized (RBD) palm olein during the deep-fat frying (at 180°C) of potato chips were studied. The frying duration was 100 min in five antioxidant systems for three consecutive days. The antioxidants used were butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butylhydroquinone (TBHQ), oleoresin rosemary and sage extract. Both the frying oil and the oil extracted from the fried potato chips were analyzed for the 3-MCPD esters and GE content, acylglycerol composition, free fatty acid (FFA) content, p-anisidine value (p-AV), and specific extinction coefficient K232 and K268. Generally, TBHQ and oleoresin rosemary showed significantly lower levels of 3-MCPD esters and GE. The order of effectiveness of the selected antioxidants in the frying oil and fried potato chips was BHT < BHA < sage extract < oleoresin rosemary < TBHQ. Antioxidants reduce the 3-MCPD esters and GE levels by inhibiting the formation of radical intermediates.
Modification of aluminum surfaces with superhydrophobic nanotextures for enhanced food safety and hygiene Food Control (IF 3.667) Pub Date : 2018-10-06 Jun Kyun Oh, Shuhao Liu, Matthew Jones, Yagmur Yegin, Li Hao, Tamra N. Tolen, Nirup Nagabandi, Ethan A. Scholar, Alejandro Castillo, T. Matthew Taylor, Luis Cisneros-Zevallos, Mustafa Akbulut
As a result of frequent outbreaks occurring due to poor hygiene and improper sanitation of processing environments, there has been an increasing demand for the development of food-contact surface materials that intrinsically inhibit and reduce likelihood of potential microbial adherence and biofilm formation. Herein, we report the synergistic utilization of surface nanotexturing and chemical modifications with nonpolar functional groups on aluminum surfaces to produce coatings having bacterial super-repellant and mud anti-fouling characteristics. Using these coatings, the attachment of Salmonella Typhimurium LT2 and Listeria innocua as pathogen surrogates was reduced more than 99.0%, compared to the bare aluminum surfaces. In addition, the coating strongly resisted the adhesion of mud, showing a 10-fold reduction in the area of mud adhesion upon submerging in mud solution. Moreover, this method is both versatile and scalable, involving inert and biocompatible building blocks. Overall, this study contributes to the field of food safety through the design and development of novel coatings for achieving improved food safety and hygiene.
The Effectiveness Of Regulatory Maximum Levels For Fumonisin Mycotoxins In Commercial And Subsistence Maize Crops In South Africa Food Control (IF 3.667) Pub Date : 2018-10-06 Gordon S. Shephard, Hester-Mari Burger, John P. Rheeder, Johanna F. Alberts, Wentzel C.A. Gelderblom
The fumonisins are carcinogenic mycotoxins that have been implicated in various adverse human health effects. Recently, the Codex Alimentarius Commission set maximum levels (MLs) for fumonisin mycotoxins at 4000 µg/kg for raw maize and 2000 µg/kg for maize flour and maize meal and these have been incorporated into South African health regulations. The MLs are intended to be health protective such that fumonisin exposures will be below the provisional maximum tolerable daily intake (PMTDI) of fumonisin of 2 µg/kg body weight/day set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). South Africa has an extensive commercial maize farming industry as well as a large subsistence farming population reliant on home-grown maize. The available data on fumonisin contamination levels indicates that these MLs are readily met by the commercial crop. However, the situation in subsistence farming areas such as in the Eastern Cape Province region is of concern. The daily consumption of large amounts of highly fumonisin-contaminated home-grown maize is of relevance mainly due to rudimentary milling, which is not subject to the reduction in mycotoxin contamination associated with commercial milling. Analysis of historical fumonisin data from the Eastern Cape region indicates that approximately 12.8% of raw maize and 25% of the rural locally produced flour would not meet the respective MLs of 4000 µg/kg ML and 2000 µg/kg. Further analysis shows that given the high maize intake levels of this population, only prohibitively low MLs for raw maize of around 100 to 300 µg/kg would be health protective for different age groups in this area. Based on this analysis, the lowering of fumonisin exposure in subsistence farmers requires an integrated approach and cannot be achieved purely by regulatory means.
Reduction of Ochratoxin A in Direct Steam Injected Oat-based Infant Cereals with Baking Soda Food Control (IF 3.667) Pub Date : 2018-10-04 Hyun Jung Lee, Bon-Jae Gu, Girish Ganjyal, Dojin Ryu
Ochratoxin A (OTA) is a possible human carcinogen with its potent nephrotoxicity and has been found in many agricultural commodities particularly in oats and its processed foods including oat-based infant cereals. While OTA is stable under most thermal processing conditions, alkaline pH can increase the reduction of OTA. In this study, the effect of direct steam injection (DSI) process along with the absence and presence baking soda (0.5% and 1% of solid contents) on the reduction of OTA in oat-based infant cereals was investigated. Food-grade oat flour was spiked with OTA (100 μg/kg) and equilibrated overnight followed by preparation of slurry by adding water to reach 5% solid content. Then the slurry was processed by DSI at 85°C and 121°C followed by spray drying at 210ºC. Greater reduction of OTA in DSI processed oat-based infant cereals was observed at higher process temperature to result in 20-28% reduction. In addition, the reduction of OTA increased with increasing amounts of baking soda. These results suggest that OTA may be reduced significantly by DSI process, which can be applied to commercial production of oat-based infant cereals. Baking soda may also help to reduce OTA amount in cereal-based infant cereals during thermal processing.
Analysis of RASFF notifications on food products contaminated with Listeria monocytogenes reveals options for improvement in the rapid alert system for food and feed Food Control (IF 3.667) Pub Date : 2018-10-04 Stefanie Lüth, Idesbald Boone, Sylvia Kleta, Sascha Al Dahouk
Tools for supranational communication of food safety risks like the European Rapid Alert System for Food and Feed (RASFF) play an increasingly important role in consumer protection along global supply chains. They allow for a coordinated response to emerging public health threats such as Listeria monocytogenes (Lm), the causative agent of the foodborne disease listeriosis. As a result of disease severity and the rising number of human listeriosis cases in Germany since 2011, an effective reporting system on Lm contamination in food products has become more crucial than ever to counteract this trend. Therefore, we analysed RASFF notifications on food products contaminated with Lm and distributed in Germany, 2001 to 2015, assessed trends in the reported data and addressed options for improvement in the current notification system.In RASFF Lm notifications concerning Germany from 2001 to 2015, there was often a discrepancy between country of origin and notifying country, indicating that the food safety risk was not always recognised at the earliest possible time point of the product's life span. In addition, in our dataset, most Lm notifications were driven by official controls when the respective product was already on the market. However, starting in 2005, there was an increasing trend for company's own checks. This trend of making food manufacturers accountable for the detection and notification of contaminated products in the production line is a first step into the right direction as it might help to reduce the number of contaminated food products that enter the market.Besides its function as a reporting tool, the RASFF may also facilitate the identification of risk factors associated with Lm contamination so that the problem can be tackled at its root. Unfortunately, information about packaging and food processing was only mentioned in a minority of Lm notifications. Hence, risk factors cannot be easily identified. In the future, a comprehensive database including additional metadata together with the RASFF notification should be established.Although a solid basis for the surveillance of Lm, there is still room for improvement in RASFF to speed-up the flow of information. This might help to identify food safety risks that can be harmful to European consumers much faster, more effectively prevent the spread of risk bearing food products and consequently reduce the burden of listeriosis.
Effect of temperature on inactivation kinetics of three strains of Penicillium paneum and P. roqueforti during bread baking Food Control (IF 3.667) Pub Date : 2018-10-04 Marcelo V. Garcia, Arthur Kael Rodrigues da Pia, Luísa Freire, Marina V. Copetti, Anderson S. Sant’Ana
In this study, the inactivation kinetics of strains of Penicillium paneum and P. roqueforti were determined during bread baking. Three strains of P. paneum (PR03, PR04, and PR05) and P. roqueforti (PR06, PR11, and PR67) were used. Baking conditions were based on those used in baking industries (160 °C, 190 °C and 220 °C). The inactivation curves did not follow first-order kinetic, and as the primary model, the Weibull model was used with the fixed p-value. The t4D value was also determined, and the secondary model was built using the log δ as a function of the baking temperature. Lower values of δ and t4D were obtained at 220 °C, and the values of this parameter were different (p<0.05) among the three P. paneum strains at 160 °C and 220 °C. Two strains of P. roqueforti (PR06 and PR11) showed the highest values of t4D at 190 °C and 220 °C (10.2 and 8.18 min. respectively). The results of this study demonstrate that the different baking temperatures of the bread making process may result in the survival of fungi in the product, which may be vital in limiting the shelf life of these products. The quantification of fungal inactivation during bread baking is critical for the design of thermal process aiming to balance quality and microbiological stability of industrialized loaves of bread.
From purchase to consumption of bivalve molluscs: A qualitative study on consumers’ practices and risk perceptions Food Control (IF 3.667) Pub Date : 2018-10-03 S. Crovato, G. Mascarello, S. Marcolin, A. Pinto, L. Ravarotto
Worldwide bivalve production has increased significantly in recent years. Bivalve meat is recommended in dietary regimens due to the benefits associated with their consumption but, at the same time, is internationally recognized as a potential vehicle for outbreaks of foodborne disease. To reduce food risk exposure, consumers must pay close attention when purchasing, handling and consuming bivalves. This study aimed to collect information on consumers' perceptions and practices related to bivalve purchasing, managing and consumption at home. A focus group methodology was adopted to better understand consumers' food practices and risk perceptions regarding molluscs. Four focus groups involving 42 consumers were conducted in Veneto and Marche region. The core analysis was then applied to each focus group discussion in order to identify, categorize and rank the information collected. The most important factors that came to light during the focus groups concerned the personal reasons for preparing bivalves at home; the place of purchase; the elements guiding consumers when purchasing bivalves; the bivalve preparation, cooking and storage conditions at home; the consumption of raw molluscs and the health risks; the consumers’ categories most at risk; and the production chain control by the authorities. The data reported in the article can provide useful information to public authorities working on food safety for developing effective risk communication strategies.
Development of a sensitive sandwich ELISA specific to 2S albumin (Ana o 3), as a stable protein marker for cashew nut residue detection in pre-packaged food products Food Control (IF 3.667) Pub Date : 2018-10-02 Yiqing Zhao, Xin Sun, Christopher Marquis, Nanju Alice Lee
In this study, a cashew allergen, Ana o 3 (2S albumin), was used as a protein marker to develop two sensitive and specific sandwich ELISAs (denoted as CAS-ELISA-2 and Ano3-ELISA-1) with the limits of detection (LOD, determined as a concentration that yield 20% of maximum colour development) at 0.04 and 0.06 mg protein kg−1, respectively. The ELISAs were highly specific to cashew nut with very low cross-reactivity with pistachio, pecan, almond, peanut, and hazelnut. Assay validation on the model cookies observed lower cashew protein recovery of 40.2–44.9% with the CAS–ELISA–2 assay and 25.2–79.8% with the Ano3–ELISA–1 assay. Both assays exhibited a limit of quantitation (LOQ) of 40 mg protein kg−1 cookies. While for the model chocolate, the acceptable protein recoveries were obtained with both CAS–ELISA–2 (74.0–87.7%) and Ano3–ELISA–1 (62.8–136.2%). The LOQ of 4 mg protein kg−1 chocolate were achieved.
Analysis of food safety compliance in Warsaw nurseries Food Control (IF 3.667) Pub Date : 2018-10-02 Joanna Trafialek, Agnieszka Domańska, Wojciech Kolanowski
The aim of this study was to assess the degree of conformity with food safety hygiene requirements in children's nurseries in Warsaw over a period of 11 years and to predict the expected time to achieve full conformity. The survey was carried out in 55 nurseries using a specially designed check list containing questions regarded GMP/GHP and HACCP documentation and practice. The results showed that the level of compliance with both GMP/GHP and HACCP standards was high in respect of documentation. However, it was much lower in the case of practice, especially HACCP. Although a constant increase in compliance with HACCP criteria was observed over the evaluated period, improvement was slow and inadequate. In 2017, compliance of HACCP practice reached only a 3.4 score. Based on food safety system improvements acquired so far, achievement of its full compliance with requirements was optimistically expected during 3 years. Regular monitoring of compliance level and prediction of its conformity are of practical importance to improve food safety system management and to indicate the corrective actions which are necessary to eliminate the risk.
Growth and Survival of Bacillus cereus from Spores in Cooked Rice – One-Step Dynamic Analysis and Predictive Modeling Food Control (IF 3.667) Pub Date : 2018-09-28 Cheng-An Hwang, Lihan Huang
Bacillus cereus is a spore-forming foodborne pathogen that can produce toxins causing emetic or diarrheal intoxication. Food poisoning caused by B. cereus is a significant public health concern as it is frequently associated with the consumption of starch-based food products, which are a staple food worldwide. The objective of this study was to investigate the growth and survival of B. cereus in cooked rice under changing temperatures between 1 and 48°C. A one-step dynamic analysis was used to directly construct a tertiary model to describe the growth and survival of B. cereus and estimate the kinetic parameters.The results of one-step dynamic analysis showed that the minimum, optimum, and maximum growth temperatures were 8.2, 37.6, and 46.8°C, respectively, with an optimal specific growth rate of 2.21 ln CFU/g/h or 0.96 log CFU/g/h. These parameters agreed well with the reported typical growth kinetics of this microorganism. In addition, this study found that the populations of B. cereus decreased gradually at the rate of 1.21 × 10-3 ln CFU/g/h per °C or 1.2 × 10-3 log CFU/g/h per °C below the minimum growth temperature.The tertiary model was validated using three dynamic growth and survival curves. The results showed that the root-mean-square-error of the predictions was 0.5 log CFU/g, suggesting that the model is reasonably accurate in predicting the growth of B. cereus in cooked rice. The results of this study can be used to predict the growth and survival of B. cereus and assess its risk in cooked rice or other starch-based products exposed to a relatively wide temperature range during manufacturing and distribution.
Removal of cadmium from rice by Lactobacillus plantarum fermentation Food Control (IF 3.667) Pub Date : 2018-09-28 Qixiao Zhai, Yue Guo, Xiaoshu Tang, Fengwei Tian, Jianxin Zhao, Hao Zhang, Wei Chen
Cadmium (Cd) contamination in rice has become a serious food safety concern in developing countries. Microbial fermentation has been demonstrated as a promising method for removing Cd from rice. The present study evaluated the effects of Lactobacillus plantarum fermentation on Cd levels in rice and analyzed the modes of Cd removal. Fermentation by 10 strains of L. plantarum exhibited varied Cd removal capacities, which could be related to variations in the Cd-binding and acid-producing abilities of the strains. In light of the relatively superior Cd removal (over 80%) using fermentation by L. plantarum CCFM8610, the procedure was optimized, and the predicted Cd removal percentage reached 93.37%. L. plantarum CCFM8610 fermentation induced alterations in the physicochemical properties of rice such as reductions in the protein, lipid, and ash contents; appearance of a porous micro-morphology; alteration of the crystal structure of rice starch granules; and improved gelatinization properties. These results suggest that fermentation by L. plantarum strains is an effective means of removing Cd from rice and could be considered as a strategy for the development of Cd-free rice-based foods.
Multifunctional alkyl ferulate esters as potential food additives: Antibacterial activity and mode of action against Listeria monocytogenes and its application on American sturgeon caviar preservation Food Control (IF 3.667) Pub Date : 2018-09-29 Yu-gang Shi, Li-qing Bian, Yun-jie Zhu, Run-run Zhang, Shi-yin Shao, Yu Wu, Yue-wen Chen, Ya-li Dang, Yue Ding, Hao Sun
The alkyl ferulate esters were prepared through lipase-catalyzed reactions by using green deep eutectic solvent-water binary mixtures. Antibacterial effects screening of alkyl ferulate esters against Listeria monocytogenes demonstrated that hexyl ferulate (FAC6) exerted both bacteriostatic and bactericidal effects on Listeria monocytogenes (minimum inhibitory concentration: 0.1 mM, minimum bactericidal concentration: 0.2 mM). The antibacterial mechanism of FAC6 were further investigated to provide more information on practical applications as a multi-functional food additive. The growth curves and time-kill assay also showed the occurrence of cell lysis and significant inhibition of the growth of L. monocytogenes caused by FAC6. PI uptake analysis and massive leakage of cell constituents (K+, proteins and nucleotide) demonstrated that the membrane integrity and permeability were undermined by FAC6. Alterations in morphology and membrane hyperpolarization of L. monocytogenes cells treated with FAC6 further clearly confirmed that it disrupted the cell membrane. Meanwhile, FAC6 interacted with membrane proteins and affected the protein expression system, causing a significant change in contents, constitution and conformation of membrane proteins. Moreover, FAC6 could bind to L. monocytogenes DNA grooves to form complexes. Overall, this research highlights the effectiveness of FAC6 against L. monocytogenes, suggesting that FAC6 with both antioxidant and antibacterial activities can be used as an effective and safe multifunctional food additive for American (Amer) sturgeon caviar preservation.
A nano-carrier platform for the targeted delivery of nature-inspired antimicrobials using Engineered Water Nanostructures for food safety applications Food Control (IF 3.667) Pub Date : 2018-09-29 Nachiket Vaze, Georgios Pyrgiotakis, Lucas Mena, Robert Baumann, Alexander Demokritou, Maria Ericsson, Yipei Zhang, Dhimiter Bello, Mary Eleftheriadou, Philip Demokritou
Despite the progress in the area of food safety, foodborne diseases still represent a massive challenge to the public health systems worldwide, mainly due to the substantial inefficiencies across the farm-to-fork continuum. Here, we report the development of a nano-carrier platform, for the targeted and precise delivery of antimicrobials for the inactivation of microorganisms on surfaces using Engineered Water Nanostructures (EWNS). An aqueous suspension of an active ingredient (AI) was used to synthesize iEWNS, with the ‘i’ denoting the AI used in their synthesis, using a combined electrospray and ionization process. The iEWNS possess unique, active-ingredient-dependent physicochemical properties: i) they are engineered to have a tunable size in the nanoscale; ii) they have excessive electric surface charge, and iii) they contain both the reactive oxygen species (ROS) formed due to the ionization of deionized (DI) water, and the AI used in their synthesis. Their charge can be used in combination with an electric field to target them onto a surface of interest. In this approach, a number of nature-inspired antimicrobials, such as H2O2, lysozyme, citric acid, and their combination, were used to synthesize a variety of iEWNS-based nano-sanitizers. It was demonstrated through foodborne-pathogen-inactivation experiments that due to the targeted and precise delivery, and synergistic effects of AI and ROS incorporated in the iEWNS structure, a pico-to nanogram-level dose of the AI delivered to the surface using this nano-carrier platform is capable of achieving 5-log reductions in minutes of exposure time. This aerosol-based, yet ‘dry’ intervention approach using iEWNS nano-carrier platform offers advantages over current ‘wet’ techniques that are prevalent commercially, which require grams of the AI to achieve similar inactivation, leading to increased chemical risks and chemical waste byproducts. Such a targeted nano-carrier approach has the potential to revolutionize the delivery of antimicrobials for sterilization in the food industry.
Application of X-ray for inactivation of foodborne pathogens in ready-to-eat sliced ham and mechanism of the bactericidal action Food Control (IF 3.667) Pub Date : 2018-09-28 Ga-Lam Cho, Jae-Won Ha
The aim of this study was to investigate the effect of X-ray irradiation in reducing the population of Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes in ready-to-eat (RTE) sliced ham and to verify the mechanisms underlying the lethal effect of X-ray irradiation. In addition, the effect of the X-ray treatment on food quality was determined by measuring color and texture changes. Sample surfaces were inoculated with cocktails of three pathogens and subjected to X-ray irradiation, with doses ranging from 0.2 to 0.8 kGy. After 0.8 kGy of X-ray irradiation, the numbers of S. Typhimurium, E. coli O157:H7, and L. monocytogenes were reduced by 5.7, 7.2, and 6.9 log CFU/g, respectively, without generating sublethally injured cells with potential to recover. The mechanism of X-ray-associated lethality was determined using fluorescent staining. We confirmed that the primary factors contributing to the lethal effect of X-ray treatment are related to intracellular enzyme inactivation and damage to cellular DNA rather than disruption of the cell membrane. Following X-ray irradiation, color values and textural characteristics of sliced ham products were not significantly altered compared to that of the control. The results of this study suggest that X-ray irradiation can be potentially used as a novel non-thermal process for inactivating foodborne pathogens in post-packaged RTE deli food products without compromising product quality.
Large-scan-area sub-terahertz imaging system for nondestructive food quality inspection Food Control (IF 3.667) Pub Date : 2018-09-28 Gyeongsik Ok, Hee Jun Shin, Min-Cheol Lim, Sung-Wook Choi
A subwavelength transmission imaging system based on Bessel–Gauss beam focusing in the 140 GHz frequency band (λ = 2.14 mm) was constructed for food quality inspection purposes. The system employed a low-cost beam source for imaging via mechanical raster scanning, and the high resolution (0.75 λ) focusing module had an extended depth of focus (12.6 λ) and supported a large scan area (800 × 400 mm2, 30 min scan time). The performance of the proof-of-concept system was nondestructively investigated by using a variety of food products, such as chocolate bars, dried laver, red ginseng, and walnuts.
Staphylococcus aureus carriage among food handlers in a pasta company: Pattern of virulence and resistance to linezolid Food Control (IF 3.667) Pub Date : 2018-09-28 Daniela Bencardino, Luca Agostino Vitali
This study aimed at monitoring and characterize the Staphylococcus aureus carriage status of employees in a pasta company in order to evaluate the associated risk factors. Food handlers (n = 21) were sampled between 2013 and 2015 through nasal and hand swabs to determine the colonization status. Seven out of 21 employees (33%) were contaminated with S. aureus and the prevalence decreased to 9.5% over the last year. Only two persistent carriers were identified. Twenty-eight strains were isolated from both hand and nasal samples. Each of them was resistant to at least one class of antibiotics and the multidrug resistance strains were isolated from the nose. The highest resistance rate was observed towards penicillin G (79%) and to linezolid (64%) confirming the rapid spread of linezolid resistant strains recently described in Italy. The dominant toxin gene was sem (93%), which is usually not among the most prevalent, whereas the primary agr group was the agrIII (43%) and the most frequent spa type was t030 (39%). These results combined with the genomic macrorestriction analysis revealed high genetic diversity. The increased virulence, antibiotic resistance and molecular variability of isolates highlighted the importance of monitoring activity in food company to assess the potential associated risk of foodborne diseases.
Provision of microbiologically safe food for vulnerable people. Food Control (IF 3.667) Pub Date : 2018-09-27 Barbara M. Lund
In Europe and North America up to 20% of the population is particularly susceptible to foodborne and other sources of infection because of age, pregnancy, illness, treatment or medication. These people may be in hospitals, nursing homes, long-term care homes or living in the community. In order to control the microbiological safety of food, including that supplied to vulnerable people, food businesses must have in place a Food Safety Management System based on Hazard Analysis and Critical Control Point principles, Good Manufacturing Practice and Good Hygienic Practice. Vulnerable people should be advised about measures to maintain food safety and should be advised of, and supplied with, a diet in which lower-risk foods are substituted for higher-risk foods. The main microorganisms responsible for the burden of foodborne disease are discussed, examples of outbreaks in healthcare settings are given, and factors leading to outbreaks are discussed.
The mode of action of bacteriocin CHQS, a high antibacterial activity bacteriocin produced by Enterococcus faecalis TG2 Food Control (IF 3.667) Pub Date : 2018-09-25 Shuo Cao, Fangkun Zhao, Renpeng Du, Huazhi Xiao, Ye Han, Zhijiang Zhou
This study aims to examine the inhibitory effects of the bacteriocin CHQS, produced by Enterococcus faecalis TG2, and its mode of action against Listeria ivanovii DSMZ 20750T, which is one of the pathogens sensitive to CHQS. The minimum inhibitory concentration, minimum bactericide concentration and time-inhibition curves were measured to confirm the strong effects of CHQS on L. ivanovii DSMZ 20750T, and its antibacterial mode of action was studied by observing the changes in cell membrane permeability, integrity, and proton motive force. The minimum inhibitory concentration and minimum bactericide concentration of CHQS were 26.74 ng/mL and 107.30 ng/mL, respectively, demonstrating that CHQS exhibited significantly strong and rapid antibacterial efficacy towards L. ivanovii DSMZ 20750T. The results showed that CHQS led to the leakage of K+ and electrolytes, the massive release of ATP and UV-absorbing materials, and the collapse of the proton motive force. The micrographs of scanning electron and transmission electron microscopy demonstrate the severe cellular destruction and release of intracellular substances induced by bacteriocin CHQS. Collectively, this study reveals the antibacterial activity and mode of action of CHQS against L. ivanovii DSMZ 20750T and demonstrates the mode of action of the inhibition by bacteriocins.
Early warning modeling and analysis based on a deep radial basis function neural network integrating an analytic hierarchy process: A case study for food safety Food Control (IF 3.667) Pub Date : 2018-09-25 Zhiqiang Geng, Dirui Shang, Yongming Han, Yanhua Zhong
Food safety is vital to the national economy and livelihood of people. Therefore, effective food safety warnings are helpful to the healthy and sustainable development of society. Focused on the early warning modeling for a certain scale of complex food safety inspection data, this paper proposes a novel early warning modeling method based on the deep radial basis function (DRBF) neural network that integrates an analytic hierarchy process (AHP). First, the AHP based on the entropy weight is used to obtain the risk fusion results of the inspection data as the expected output of the DRBF. Then, the DRBF model based on the autoencoder is used to build the early warning model, implementing feature learning to acquire the high-level representation of the food inspection data. Finally, the category data of sterilized milk from the food safety inspection data of a province in China is taken as a case study. Comparing the experimental results of the radial basis function (RBF) neural network, the back propagation (BP) neural network and the improved multilayer BP, the proposed DRBF model is found to have a better generalization ability and a better generalization effect for the complex food safety inspection data. Furthermore, the proposed early warning model is used to predict and analyze the risk of the inspection data from early September 2014. The results could be helpful for relevant departments to carry out early warning work and provide a scientific basis for guidance, thereby promoting the improvement of the food quality and reducing food risks.
Inactivation of Listeria monocytogenes on paperboard, a food packaging material, using 410 nm light emitting diodes Food Control (IF 3.667) Pub Date : 2018-09-22 Vinayak Ghate, Einat Zelinger, Hagit Shoyhet, Zvi Hayouka
Light emitting diodes of wavelength 410 nm were used to inactivate Listeria monocytogenes on paperboard, an increasingly popular food packaging material. The integrity of the cell membranes was examined using differential fluorescent staining. Scanning electron microscopy (SEM) was used to obtain a deeper understanding of L. monocytogenes stain formation on paperboard and the damage caused to the cells by the LEDs. While the planktonic L. monocytogenes population could be completely inactivated following a brief lag phase that lasted about 20 min, the illumination of the sessile population left some persisters despite immediate commencement of the inactivation. Planktonic populations of inocula sized 3, 5 and 7 log CFU/mL were reduced below the detection limit in 54, 80 and 84 min respectively, whereas it took 120 and 390 min to reach constancy in the sessile populations of inocula sized 5 and 7 log CFU/cm2. The number of membrane-damaged cells was seen to increase with the illumination time. SEM images provided evidence of the protection conferred by the stain on the underlying cells. This study demonstrates that blue LEDs have the potential to reduce the risk of contamination from paperboard cartons under refrigeration conditions.
Detection of Shiga toxin-producing Escherichia coli, stx1, stx2 and Salmonella by two high resolution melt curve multiplex real-time PCR Food Control (IF 3.667) Pub Date : 2018-09-22 Prashant Singh, Yuejiao Liu, Joseph M. Bosilevac, Azlin Mustapha
In the United States, Shiga toxin-producing Escherichia coli (STEC) O157 and six non-O157 serogroups O26, O45, O103, O111, O121 and O145 are considered adulterants in non-intact beef. Further, Salmonella is responsible for one of the highest numbers of foodborne infections worldwide. Multiple foods, especially meats, are routinely tested for these pathogens using methods like PCR. However, with such a large group of organisms, multiplexing using probe-based PCR assays is expensive due to the need for differently labeled oligonucleotide probes and sophisticated instrumentation. The aim of this study was to design low-cost multiplex real-time PCR assays for the detection of seven STEC serogroups, stx1, stx2 genes and virulent Salmonella. Two multiplex real-time PCR melt curve assays with internal amplification controls (IAC) were standardized. The first assay detected E. coli O121, E. coli O145, E. coli O157, stx1, and stx2. The second assay targeted E. coli O26, E. coli O111, E. coli O103, E. coli O45, and Salmonella. Ground beef and beef trim inoculated with 5-27 CFU/325 g of STEC and 9-36 CFU/325 g of Salmonella could be detected following an 8-10 h enrichment at 40oC ± 2°C in buffered peptone water containing 8 mg/L vancomycin. The assays showed reproducible results for beef products with different fat contents. These assays do not rely on fluorescent-labeled probes or immunomagnetic beads, yet accurately detect seven STEC serogroups, seven stx gene subtypes and Salmonella, making them suitable for routine testing of STEC and Salmonella in beef.
DNA sequences and predicted protein structures of prot6E and sefA genes for Salmonella ser. Enteritidis detection Food Control (IF 3.667) Pub Date : 2018-09-21 Lijun Hu, Robert Stones, Eric W. Brown, Marc W. Allard, Li M. Ma, Guodong Zhang
Genes prot6E and sefA are used as targets for detection of Salmonella enterica subsp. enterica serovar Enteritidis (Salmonella ser. Enteritidis). We investigated variations in these genes across 64 different Salmonella ser. Enteritidis strains isolated from egg and chicken samples, then used Whole Genome Sequence (WGS) data to model the structures of their protein products. Isolates were sequenced using Illumina technologies. Based on the resulting phylogenetic tree, our isolates clustered in 2 distinct clades. All isolates carried prot6E and sefA. Comparative genomic analyses indicated two non-synonymous mutations (Glycine → Serine and Valine → Isoleucine) of prot6E in 11 isolates (9 egg samples, 2 chicken samples). However, SWISS-MODEL was unable to clearly model the protein structure of these two mutations. We identified one non-synonymous mutation (Valine → Glutamic Acid) in the sefA gene in 4 isolates from egg samples. The model for the protein structure of this mutant gene was clearly different from that of the other isolates studied herein. Circular maps of plasmid genomes from two PacBio platform-sequenced Salmonella ser. Enteritidis isolates revealed prot6E gene was located on the tail of the plasmid. Based on the biosynthesis of amino acids - Reference pathway in the KEGG pathway Database, the transition of amino acid from sefA Var. was a transversion from essential amino acid to non-essential amino acid, while that of prot6E Var.1 happened between the conditionally non-essential amino acid, and prot6E Var. 2 occurred between essential amino acids. Properties of these mutated amino acids, such as side-chain polarity or charge, may contribute to the occurrence and rate of mutations in prot6E and sefA. These insights can be used to improve detection methods for Salmonella ser. Enteritidis.
Gaseous chlorine dioxide maintained the sensory and nutritional quality of grape tomatoes and reduced populations of Salmonella enterica serovar Typhimurium Food Control (IF 3.667) Pub Date : 2018-09-21 Lin Wang, Kimberly Sokorai, Vivian C.H. Wu, Xuetong Fan
There have been numerous reports on the effectiveness of gaseous chlorine dioxide (gClO2) in inactivating various human pathogens associated with fresh produce. However, studies dealing with both microbial reduction and impact on quality and nutrients of tomatoes are scarce. In the present study, gaseous chlorine dioxide was evaluated for its effectiveness on populations of Salmonella and native microorganisms on grape tomatoes, and impacts on sensory and nutritional quality. Grape tomatoes, dip inoculated with a cocktail of Salmonella enterica serovar Typhimurium, were treated with three different levels of gClO2 generated by sachets containing sodium chlorite and reducing acids for up to 5 h in 20-L chambers. For the quality study, non-inoculated fruits were treated similarly with the gClO2, and stored for 21 d at 10 °C. Sensory and nutritional quality, and native microflora were measured at 1, 7, 14 and 21 d of storage. Headspace gClO2 concentrations and humidity in the chambers were measured during the treatments. Concentrations of gClO2 in the chamber were relatively stable during the 2.5 and 5 h treatment times. Gaseous ClO2 at 1.9 mg/L for 5 h and 4.3 mg/L for 2.5 and 5 h reduced Salmonella populations from 5.4 log CFU/fruit to a non-detectable level (detection limit 1.70 log CFU/fruit). However, populations of native microflora were not consistently affected by the gClO2 treatments. Furthermore, the treatments did not have any significant effect on appearance, off-odor, firmness, color, or lycopene, and vitamin C contents of grape tomatoes during the 21-d storage. Overall, gClO2 treatments that achieved more than 4 log reductions of Salmonella did not significantly (P>0.05) affect sensory or nutritional quality of grape tomatoes.
The safety evaluations of chilled pork from online platform in China Food Control (IF 3.667) Pub Date : 2018-09-21 Chen-xing Liu, Ying-ping Xiao, Dong-wen Hu, Jian-xin Liu, Wei Chen, Da-xi Ren
This study aimed to investigate the meat quality and safety of chilled pork collected from 45 online stores in China. Total volatile basic nitrogen (TVBN), total viable counts (TVC), and coliform counts of 135 meat samples were analyzed, and the shipment conditions including endpoint temperature, transport time, transport distance and package model were also recorded. Foodborne pathogenic bacteria including Salmonella spp, Staphylococcus aureus (S. aureus), methicillin resistant Staphylococcus aureus (MRSA) and Listeria Monocytogenes (L. monocytogenes) were also detected. The positive rate of Salmonella spp (13.32%), S. aureus (14.81%), MRSA (3.70%) and L. monocytogenes (4.44%) was found for 135 online meat samples. Endpoint temperature is the most important indicator of meat safety; when > 10 °C, the unqualified rates for coliform counts, TVC and TVBN were 60%, 40% and 30%, respectively, which were significantly higher than those at < 4 °C. The vacuum packing model is also found to be better than modified atmosphere (P<0.05); modified atmosphere with an absorbent pad also has benefits for TVC and TVBN control. For the correlations between shipment condition and meat safety, the endpoint temperature has a positive correlation with meat safety, with a significance level of P<0.001. However, no significant correlation was found between transport distance and meat quality. Results of this study showed that meat sold online poses potential hazards, and endpoint temperature control is the most important factor to ensure meat safety sold online in China.
Biogenic amines and free amino acids in craft beers from the Spanish market: a statistical approach Food Control (IF 3.667) Pub Date : 2018-09-21 J.M. Poveda
The concentrations of seven biogenic amines and twenty-three free amino acids and ammonium ion were monitored in different craft beers acquired in the Spanish market. Besides, a statistical approach was conducted using multivariate statistical analysis. The significant differences observed between manufacturing batches, both in the content of free amino acids and biogenic amines, reveal a lack of homogeneity in the production, probably caused by the craft brewing process. A great variability among samples was observed in terms of their content in free amino acids. The main biogenic amine was putrescine, followed by tyramine and histamine; however, the concentrations were below those considered as toxic in alcoholic beverages. Strong negative correlations (P<0.001) were found between pH and some biogenic amines. The differences in the amino acid profile and the content of biogenic amines in beer samples seem to be more related to the raw materials and to the brewery than to the type of brewing. Multivariate statistical analysis could serve as a useful tool for monitoring craft beers quality.
Characterisation and classification of pineapple (Ananas comosus [L.] Merr.) juice from pulp and peel Food Control (IF 3.667) Pub Date : 2018-09-19 G. Difonzo, K. Vollmer, F. Caponio, A. Pasqualone, R. Carle, C.B. Steingass
Large quantities of by-products, such as peels and trimmings, emerge during industrial pineapple (Ananas comosus [L.] Merr.) processing. The latter are further exploited by juice extraction. However, the low-quality juices obtained may be marketed as genuine pineapple juice from pulp or be admixed to the latter, thus adulterating the final product. To identify chemical markers, juice was extracted from edible pulp, from flesh adhered to the peel, and from milled peel. The metabolite pattern in the juices was elucidated by HPLC-DAD-(HR)-ESI-MSn. Unsupervised principal component analysis (PCA) and hierarchical cluster analysis (HCA) as well as supervised partial least squares discriminant analysis (PLS-DA) and PLS regression calculated on the basis of physico-chemical parameters and metabolite profiles enabled the distinction between juices from pulp and those from peel, irrespective of the fruit maturity degree. In addition, selected marker compounds were deduced from the multivariate statistics, permitting the unambiguous distinction between pulp and peel juices as well as the three maturity stages assessed.
Surveillance and characterisation of Cronobacter in powdered infant formula processing factories Food Control (IF 3.667) Pub Date : 2018-09-20 Xiaoyan Pei, Ying Li, Huaning Zhang, Li Zhan, Xiaojie Yu, Guang Lan, Huayun Jia, Ning Li, Dajin Yang, Lingling Mei
Cronobacter had been detected in the powdered infant formula (PIF) in China more frequently in comparison with other developed countries. However, the persistence, dissemination and transmission routes of Cronobacter are not clearly known. As part of the national surveillance program, 6,111 samples were collected and tested for the presence of Cronobacter from eight powdered infant formula production facilities in China between 2013 and 2014. The isolates were further characterized by pulsed-field gel electrophoresis (PFGE), as well as multilocus sequence typing (MLST). From the 6,111 samples, Cronobacter was only isolated in 35 samples, 21 samples from dry-mix processes and 14 samples from combined processes. The prevalence in final products was 2.27% (4/176) and 0.00% (0/89) in samples from dry-mix processes and samples from combined processes, respectively. The 35 Cronobacter isolates were differentiated into 22 pulsotypes, and eight groups of isolates demonstrated the same clonality, suggesting a potential epidemiological link. MLST analysis on 35 isolates revealed that C. sakazakii was the most prevalent species (71.43%), followed by C. malonaticus (25.71%). The most common typeable isolates belonged to sequence type (ST) 7 (18.18%) and ST1 (15.15%).The results of this study showed the Cronobacter contamination along the PIF production process. PIF manufactured with dry-mix processes was frequently contaminated with Cronobacter potentially due to noncompliant materials and/or lack of a sterilization step.
Fate of inoculated Listeria monocytogenes on yellow onions (Allium cepa) under conditions simulating food service and consumer handling and storage Food Control (IF 3.667) Pub Date : 2018-09-18 Vanessa M. Lieberman, Linda J. Harris
Recalls and cases of listeriosis have been associated with the presence of Listeria monocytogenes in fresh-cut refrigerated or frozen onions or associated processing environments. The survival or growth of L. monocytogenes on the outer surface of whole onions and in diced onion was evaluated during simulated retail or consumer storage. Whole and diced yellow onions (Allium cepa) were inoculated with a 6-strain cocktail of L. monocytogenes collected either from agar plates or from broth culture. Marked circles (3.3 cm in diameter) on the outer papery skin of whole onions were spot inoculated (10 μl) at 7 log CFU per circle, dried for 30 min and then stored at 4 or 23 °C for up to 8 weeks. The marked circles or “disks” of the outermost skin layer were excised for sampling. Diced onions were inoculated at 3 log CFU/g and then stored in closed containers at 4 or 10 °C for 28 or 21 days, respectively, or at 23 °C for 38 h. Populations of L. monocytogenes were determined by plating each sample onto both tryptic soy agar and modified Oxford or CHROMagar Listeria agars. At 4 °C, populations of L. monocytogenes on whole onion declined from initial pre-drying levels of 6–7 log CFU/disk to mean levels of 2.39 ± 1.14 log CFU/disk at week 8; at 23 °C, populations declined to below the limit of detection by plating (<0.40 log CFU/disk) and by enrichment in 3, 9, and 12 of 12 samples at weeks 2, 3, and 4, respectively. No significant change in L. monocytogenes populations was observed in diced onion during 28 days of storage at 4 °C. A maximum rate of change of 0.0081 log CFU/g/day; a mean L. monocytogenes population of 6.86 ± 0.44 log CFU/g was observed at 17 days of storage at 10 °C. At 23 °C calculated lag times of 4.7 and 8.6 h, maximum rates of change of 0.15 and 0.16 log CFU/g/h, and maximum L. monocytogenes populations of 6.24 ± 0.07 and 6.10 ± 0.03 log CFU/g after 38 h of storage were observed in diced onion inoculated with agar and broth cultures, respectively. Diced onions support the growth of L. monocytogenes at 10 and 23 °C but not at 4 °C.
Antibacterial activity and mechanism of a laccase-catalyzed chitosan–gallic acid derivative against Escherichia coli and Staphylococcus aureus Food Control (IF 3.667) Pub Date : 2018-09-18 Kangjing Li, Guilin Guan, Junxiang Zhu, Hao Wu, Qingjie Sun
In this paper, the antimicrobial activity and mechanism of a laccase-catalyzed chitosan–gallic acid derivative were evaluated. The results showed that compared to the parent chitosan, the derivative could significantly inhibit the growth of Escherichia coli and Staphylococcus aureus, wherein the latter was more sensitive to the derivative than the former. The chitosan–gallic acid derivative could disrupt the cell membrane of E. coli and S. aureus, resulting in leakage of cytoplasm and an increase in relative conductivity. The morphological changes were manifested by the aggregation of bacterial cells and formation of an irregular shape. Agarose gel electrophoresis showed that chitosan derivatives could enter bacterial cells through damaged cell membranes and inhibit DNA synthesis in the nucleus. In addition, the cytotoxicity was significantly reduced by proper modification of chitosan with gallic acid. The above results indicated that there was a great potential for laccase-catalyzed chitosan–gallic acid derivative for use as a food preservative.
Bactericidal activity of neutral electrolyzed water against Bacillus cereus and Clostridium perfringens in cell suspensions and artificially inoculated onto the surface of selected fresh produce and polypropylene cutting boards Food Control (IF 3.667) Pub Date : 2018-09-17 Hamzah M. Al-Qadiri, Stephanie Smith, Aleksandra Checinska Sielaff, Byju N. Govindan, Mohamed Ziyaina, Nivin Al-Alami, Barbara Rasco
Bactericidal activity of neutral electrolyzed water (NEW) was investigated against endospore forming Bacillus cereus and Clostridium perfringens in cell suspensions and artificially inoculated onto the surface of selected fresh produce items (cherry tomato, miniature cucumber, carrot and parsley) and polypropylene cutting boards at ambient temperature (22 °C). Viable counts of survivors were determined within 0 (untreated control), 1, 3 and 5 min of treatment at ambient temperature using NEW solutions of 60 and 120 mg/L free available chlorine FAC. All treatments showed significant differences (P < 0.05) in bacterial reductions with regard to contact time and concentration used and which maximized after 5 min of treatment at 120 mg/L FAC. For cell suspensions, the extent of reduction (log10 CFU/mL) after 5 min of treatment ranged from 2.11-3.03 for B. cereus and 2.46-3.62 for C. perfringens at 60 and 120 mg/L FAC, respectively. However, when the bacteria inoculated onto the produce items and cutting boards showed greater resistance to NEW treatments compared to cell suspensions. Sterile deionized water did not contribute any significant reduction (P > 0.05) after 5 min of treatment, whereas bacterial viability of the inoculated produce was reduced by 2.11-2.30 and 2.41-3.16 log10 CFU/g when NEW used at 120 mg/L FAC for B. cereus and C. perfringens, respectively. When inoculated cutting boards were sprayed with NEW at 120 mg/L FAC and after 5 min of treatment, cell viability was reduced by 2.33 and 3.06 log10 per 100 cm2 for B. cereus and C. perfringens, respectively. This study showed that NEW could be used as an effective bactericidal treatment alternative to commonly used chemical sanitizers against endospore forming bacteria.
Amplification of 16S rDNA reveals important fish mislabeling in Madrid restaurants Food Control (IF 3.667) Pub Date : 2018-09-17 Jose L. Horreo, Patrick S. Fitze, Alberto Jiménez-Valverde, Jorge Ari Noriega, Maria L. Pelaez
Food fraud encompasses economic fraud and can produce health problems for consumers, as well as conservation problems for the involved species. Nevertheless, few studies tested for mislabeling in restaurants. In this study, we tested for mislabeling of fish species in restaurants. We sampled 77 fish dishes from 53 different restaurants located in 9 different districts of Madrid, Spain. A short fragment of the 16S rDNA was employed for DNA amplification leading to species or genera identification. Results showed that 7 species or genera and almost 30% of the samples were mislabeled. Mislabeling was present in 37% of the sampled restaurants and in 71% of the sampled districts. Mislabeling was common and it was not correlated with a districts’ economic status (i.e. with the official average square-meter price of apartments). The analyses also showed that some species were more prone to be mislabeled than others.
Microbiota of eggs revealed by 16S rRNA-based sequencing: From raw materials produced by different suppliers to chilled pasteurized liquid products Food Control (IF 3.667) Pub Date : 2018-09-17 Damares A.P. Vieira, Lucélia Cabral, Melline F. Noronha, Gileno L.V. Júnior, Anderson S. Sant’Ana
In this study, the microbiota of liquid eggs (raw materials) produced by different suppliers and final products (chilled pasteurized liquid whole eggs and chilled pasteurized liquid egg yolk) (n = 211, pooled in 21 samples) was studied by a 16S rRNA-based amplicon sequencing. The raw material samples were collected from five different egg suppliers (A, B, C, E, and F), whereas the sixth type of raw material was whole shell eggs broken at the egg processing factory. The suppliers were located at different distances (∼100 Km to ∼1500 Km) from the liquid egg processing facility, being subjected to varying practices after egg breaking (pasteurization and addition of hydrogen peroxide), followed by chilled transportation. The results showed that final products presented lower diversity indexes than raw materials suggesting that processing and storage act towards shaping their microbiota. Besides, the transportation distance seemed to influence the microbiota of liquid egg. Proteobacteria and Firmicutes dominated the sequences of 16S rRNA in raw materials and final product samples, while the abundance of classes was found to vary considerably among samples and composite samples. Lactobacillales and Pseudomonadales were the most abundant order in almost all raw material samples, whereas Enterobacteriales was abundant in few raw material samples. The principal genera linked to final products were Pseudomonas, Carnobacterium and less frequently Clostridium. The study highlights that the practices employed by suppliers and transportation distances are key in modulating the microbiota of raw materials and further liquid processed egg products.
Evaluation of the high school food safety curriculum using a positive deviance model Food Control (IF 3.667) Pub Date : 2018-09-17 Taylor Whited, Yaohua Feng, Christine M. Bruhn
Proper food handling practices can help protect consumers from foodborne illness. This study assessed high school students' food safety knowledge and handling practices and evaluated the effectiveness of a new food safety curriculum based on the Positive Deviance model. In phase I, 114 high school students completed a food safety on-line questionnaire assessing their baseline food safety knowledge and food handling practices; in phase II, 53 high school students took a one session class and completed pre- and post- assessment and take-home tasks. The results showed that there is a critical need for an effective high school food safety curriculum. The curriculum increased students' knowledge significantly.
Prevalence and characterization of Staphylococcus aureus and Staphylococcus argenteus in chicken from retail markets in China Food Control (IF 3.667) Pub Date : 2018-09-15 Qiuchun Li, Yang Li, Yuanyue Tang, Chuang Meng, Hanne Ingmer, Xinan Jiao
Staphylococcus aureus (S. aureus) is one of the most common pathogens causing both human and animal infections. Transmission of S. aureus to humans via contaminated food continues to be a health public concern. In the present study, 104 strains including eight MRSA strains were identified from 507 chicken samples (20.5%) in three cities of China. These strains harbored the highest resistance against penicillin (91.4%), followed by tetracycline (64.4%), erythromycin (53.5%), and kanamycin (32.7%). We used spa typing to classify these isolates into 28 types belonging to two lineages including the predominant type t112 (n = 26) and four newly identified spa types. Among the 104 strains, six carried the CRISPR-Cas system, a prokaryotic immune system which protects against foreign genetic elements. Interestingly, rpoB gene sequencing demonstrated that these six initially designated ST2250 strains were in fact S. argenteus, a novel Staphylococcus species genetically closely related to S. aureus. Three Staphylococcus CRIPSR types containing ten spacers identified in these strains have been reported in CRISPR-positive S. aureus. Additionally, 80% of the spacers showed homology to S. aureus phages demonstrating that these conserved spacers were closely related to the phages in the environment of S. argenteus. We speculated that the identical CRISPR types and spacers in both S. argenteus and S. aureus have resulted via exchange of mobile elements between these two species. Emergence of food-borne ST2250 S. argenteus is a potential threat to human public health.
Application of meta-analysis technique to assess effectiveness of HACCP-based FSM systems in Chinese SLDBs Food Control (IF 3.667) Pub Date : 2018-09-15 Yongheng Yang, Lijuan Wei, Jianan Pei
Despite effectiveness of HACCP-based FSM systems in food safety management (FSM) and their common adoption in industrialized food businesses, doubts have been raised on their feasibility in small and/or less developed food businesses (SLDBs) because of barriers such as financial constraints, lack of technical expertise, and insufficient personnel training faced by SLDBs. Uncertainty about their effectiveness, as well as feasibility for SLDBs (including numerous Chinese SLDBs) made them reluctant to adopt these FSM systems. In order to have clear understanding on the effectiveness of HACCP-based FSM systems for SLDBs, this study presented meta-analyses on associations between implementing HACCP-based FSM systems in Chinese SLDBs and levels of their food safety status. Having HACCP-based FSM systems implemented led to significantly higher odds of qualified numbers, with pooled ORs (95% CI) being 10.58 (6.06, 18.49), 8.66 (4.88, 15.35), 6.39 (3.36, 12.18), and 6.65 (4.29, 10.30), respectively, with regard to food products, food handlers' hygiene, employees’ knowledge about food safety and hygiene, and food contacting surfaces & operating environments. Solid evidence on effectiveness of HACCP-based FSM systems in SLDBs should encourage food businesses to adopt these systems for ensuring food safety.
Effect of cured meat product ingredients on the Penicillium verrucosum growth and ochratoxin A production Food Control (IF 3.667) Pub Date : 2018-09-15 María J. Andrade, Belén Peromingo, Mar Rodríguez, Alicia Rodríguez
Ochratoxigenic penicillia can grow on the cured meat products surface during their ripening. Ingredients added to cured meat products throughout their processing, and specifically of dry-fermented sausages, consist of a potential strategy to prevent or minimise the hazard associated with ochratoxin A (OTA) in these products. The aim of this work was to evaluate the effect of different concentrations of NaCl, KCl and sucrose in a conducive medium on the growth and OTA production by two Penicillium verrucosum strains. In general, there were no statistical differences between their growth rates. Although OTA production was not completely avoided in the presence of KCl and sucrose, it was reduced by comparison with NaCl. The concentration of the ingredients also affected the OTA production by P. verrucosum. These results would mean that the replacement of NaCl with KCl would imply the production of potentially safer cured meat products in terms of the OTA presence, which is of great importance for the current trends to reduce the NaCl levels in this kind of products. Furthermore, the addition of sucrose should be considered one of the approaches of the hurdle technology for minimising OTA accumulation in cured meat products.
Food safety behavior observed in German TV cooking shows Food Control (IF 3.667) Pub Date : 2018-09-17 Jasmin Geppert, Sarah Schulze Struchtrup, Rainer Stamminger, Claudia Haarhoff, Volker Ebert, Severine Koch, Mark Lohmann, Gaby-Fleur Böl
Since a few years, cooking shows have enjoyed great popularity in Germany. Currently, about 60 different formats are broadcasted on German television. In the field of food preparation and nutrition, they represent a significant passive source of information. This study aims to assess food safety practices in German TV cooking shows and to identify potential differences between professional and amateur chefs. With the help of an observational sheet, three trained evaluators examined 100 episodes of eight popular TV cooking shows. On average, the evaluators observed 1.2 hygiene mistakes per minute or one hygiene lapse every 50 seconds. The most common mistakes include the use of unwashed cutting boards, adding ingredients with unwashed hands and wiping dirty hands with tea towels. A lack of handwashing before beginning food preparation and after coughing, sneezing, wiping the nose or sweat or touching their hair, eyes, etc. was also frequently observed. No significant differences between professional and amateur chefs were found for the overall frequency of food safety mistakes, but professional chefs more often complied with specific personal hygiene measures. Findings suggest that little attention is paid to safe food handling practices in German TV cooking shows. However, they may be particularly suited to convey safe food handling practices to a broad audience, not least because of their popularity.
Cabin Crew Food Safety Training: A Qualitative Study Food Control (IF 3.667) Pub Date : 2018-09-14 Ayman Abdelhakim, Eleri Jones, Elizabeth Redmond, Mahmoud Hewedi, Phillip Seaman
This study aims to explore the status of cabin crew food safety training in different airlines. Using the snowballing technique, 26 cabin crew managers, supervisors and trainers (from 20 international airlines) participated in in-depth, structured interviews. The interview schedule was developed to determine and evaluate implementation and perceptions of cabin crew training. Data was analysed using a qualitative content analysis approach. All respondents perceived cabin crew food safety/hygiene issues are important in relation to on-board food-handling, for example: “food safety is always an important issue”. Findings indicated that while most of the airlines (90%) train cabin crew on food safety, different cabin crew roles perceived the same level of food safety training. The results obtained can be used to inform development of future training programmes, methods and evaluation.
High-humidity hot air impingement blanching (HHAIB) enhances drying quality of apricots by inactivating the enzymes, reducing drying time and altering cellular structure Food Control (IF 3.667) Pub Date : 2018-09-12 Li-Zhen Deng, Zhongli Pan, A.S. Mujumdar, Jin-Hong Zhao, Zhi-An Zheng, Zhen-Jiang Gao, Hong-Wei Xiao
Cultivar discrimination, fatty acid profile and carotenoid characterization of monovarietal olive oils by Raman spectroscopy at a single glance Food Control (IF 3.667) Pub Date : 2018-09-12 Silvia Portarena, Chiara Anselmi, Claudia Zadra, Daniela Farinelli, Franco Famiani, Chiara Baldacchini, Enrico Brugnoli
Monovarietal extra virgin olive oils (EVOOs) from Olea europea trees grown in the same experimental orchard have been characterized by Raman spectroscopy combined with chemometrics. Linear discriminant analysis of the EVOO Raman spectra correctly classified up to 94.4% of samples, as a function of the cultivar, at four different maturation stages. The sensitivity of Raman spectroscopy to the oil cultivar is due to the genotypic dependence of the olive oil composition in terms of both carotenoid and fatty acids. Thus, using gas chromatography as the reference technique, models for predicting the oleic, palmitic and linoleic acid content are obtained combining Raman spectra and partial least squares regression analysis. Evidences that a similar approach could be implemented also for carotenoid characterization are provided.
Effect of dielectric barrier discharge plasma on background microflora and physicochemical properties of tiger nut milk Food Control (IF 3.667) Pub Date : 2018-09-12 Aliyu Idris Muhammad, Yang Li, Xinyu Liao, Donghong Liu, Xingqian Ye, Shiguo Chen, Yaqin Hu, Jun Wang, Tian Ding
The microbial and physicochemical properties of tiger nut milk were studied under different dielectric barrier discharge (DBD) plasma exposure time: 2, 4, 6, 8, and 12 min. Following the plasma treatment, a significant reduction in the microflora was observed at 2, 4, 6 and 8 min treatment time with 12 min reaching the undetectable limit. The treatment did not result in any significant change in soluble solids and fat contents. Significant reduction in pH was recorded after 8 and 12 min treatment, whereas heightened titratable acidity and lipid oxidation were noticed in all the treated samples. The protein content decreased significantly in all the treated samples, while peroxidase activity only decreased when the treatment time was extended beyond 4 min. The loss in enzyme activity was due to the oxidation effect plasma reactive species including atomic oxygen, ozone, and hydroxyl radicals, which might have oxidized the amino acid side chain. The findings presented here could be a prelude for the potential application of DBD plasma treatment of tiger nut milk in the food industry.
Co-occurrence of multi-mycotoxins in wheat grains harvested in Anhui province, China Food Control (IF 3.667) Pub Date : 2018-09-12 Wenjing Xu, Xiaomin Han, Fengqin Li
The aim was to evaluate the occurrence of Fusarium mycotoxins in 370 wheat grain samples harvested in 2015 from Anhui province of China. Deoxynivalenol (DON), deoxynivalenol-3-glucoside (D-3-G), 3- and 15-acetyl-deoxynivalenol (3-A-DON and 15-A-DON), nivalenol (NIV), fusarenon-X (FX) and zearalenone (ZEN) were analyzed by a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. The thousand kernel weight of wheat samples was also conducted. DON is the most frequent and abundant Fusarium mycotoxins detected, then followed by D-3-G, NIV, 3-A-DON, ZEN, 15-A-DON and FX. A total of 368 samples are positive for more than one Fusarium mycotoxins analyzed. Moreover, there are positive correlations between DON concentration and other six Fusarium mycotoxins. While, the thousand kernel weight of wheat has a negative correlation with ZEN concentration. These findings suggest an urgent need to monitor contamination of these toxins and raise concern to the high-consuming population of wheat in China.
Influence of high-intensity ultrasound on bioactive compounds of strawberry juice: Profiles of ascorbic acid, phenolics, antioxidant activity and microstructure Food Control (IF 3.667) Pub Date : 2018-09-12 Jin Wang, Jun Wang, Jinghua Ye, Sai Kranthi Vanga, Vijaya Raghavan
Combined antibacterial activities of essential oil compounds against Escherichia coli O157:H7 and their application potential on fresh-cut lettuce Food Control (IF 3.667) Pub Date : 2018-09-11 Wenqian Yuan, Constance Hui Min Teo, Hyun-Gyun Yuk
This study evaluated the antimicrobial activities of combined use of essential oil (EO) compounds against E. coli O157:H7, using the Fractional Inhibitory Concentration (FIC) index and time-kill assay. The mechanisms of enhanced antimicrobial efficacies in EO combinations were evaluated using flow cytometry, and their application potentials as decontamination rinse were assessed using fresh-cut lettuce. Thymol (Thy), carvacrol (Car), trans-cinnamaldehyde (TC), eugenol (Eug) and vanillin (Van) displayed minimum inhibitory concentrations (MICs) in a range of 0.63 – 2.5 mg/mL, whereas citral (Cit) and linalool (Lin) were ineffective (MIC > 10 mg/mL). FIC indices (1.00 – 2.00) suggested additive interactions of all EO combinations, and time kill assay showed enhanced bactericidal activities in Thy/Eug, Car/Eug and TC/Eug combinations. The stronger antimicrobial efficacy in EO combination was attributed to increased membrane damages. Application of Thy/Eug and Car/Eug on fresh-cut lettuce as decontamination rinse caused a significant (P < 0.05) decrease in bacterial count, compared to water rinse, but resulted in color-darkening and texture-softening in treated lettuce.
The role of media reporting in food safety governance in China: a dairy case study Food Control (IF 3.667) Pub Date : 2018-09-10 Xinyi Zhu, Iona Yuelu Huang, Louise Manning
Using dairy products as the case study of interest, the aim of the research is to explore the role of the media in food safety governance in China. Thematic content analysis is used to evaluate government and media reports (n = 233) on dairy related food safety incidents in China between 2004 and 2017 with differences identified between government and media reporting. The data is extracted from an online database (Zhichuchuangwai). The results show that the government performs better on exposing incidents earlier within the 14-year period but the news media plays a complementary role in food safety governance exposing a wider coverage of incidents. This study extends the current literature on the role of the news media in food safety governance in China by focusing on a single food sector (dairy), but on a national scale.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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