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  • Impact of long bottle aging (10 years) on volatile composition of red wines micro-oxygenated with oak alternatives
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-15
    María del Alamo-Sanza, Ignacio Nevares, Ana Martínez-Gil, Pilar Rubio-Bretón, Teresa Garde-Cerdán

    The adding of wood pieces together with small amounts of oxygen to simulate the processes for aging red wine in barrels is the most common alternative to oak barrels. The evolution of these wines aged with alternatives in bottle has not been examined in depth as they are considered to be for rapid consumption. This paper presents for the first time the evolution in bottle for 10 years of the same wine aged in oak barrels and subjected to diverse alternative aging processes using different woods. Wines subjected to this alternative have evolved after 10 years in the bottle in a similar way to those aged in barrels. Wines aged in barrels retain significantly higher levels of blue tonalities than those treated with chips + FMOX and the loss of compounds responsible for red is almost double in wines treated with alternatives than in those aged in barrels. Wines aged in barrels showed higher concentrations of cis- and trans-whiskylactones than those treated with alternative products. In both the cis/trans whisky lactone ratio has been around 2 in wines aged in French oak, and over 5 in wines aged in American oak. Adequate oxygen management during treatment with oak alternatives provides long-life wines.

    更新日期:2018-11-16
  • Irvingia gabonensis seed fat as hard stock to formulate blends for trans free margarines
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-16
    J. Yamoneka, P. Malumba, G. Lognay, C. Blecker, S. Danthine

    In order to formulate trans-free margarines, Irvingia gabonensis seed fat (IGF) was blended with a liquid oil which was either rapeseed oil (RO), groundnut oil (GNO), palm super olein (PSO) or Dacryodes edulis pulp oil (DPO). All the binary fat blends were evaluated in terms of melting behavior by Differential Scanning Calorimetry and p-NMR. Based on their melting behaviors by p-NMR, four blends (IGF/RO 30:70, IGF/GNO 30:70, IGF/GNO 20:80 and IGF/RO 20:80) were selected as having melting profiles closed to those of fat extracted from commercial margarines and literature data. Some physical properties of the selected fat blends such as solid fat content, hardness (by penetration) test, microstructure using an optical microscope and polymorphism using X-Ray Diffraction were evaluated. Those four trans-free fat blends showed similar hardness and solid fat content (SFC) than fats extracted from commercial bakery margarine, baking margarine and table margarine during storage experiments. All those four fat blends showed β’ crystals as stable polymorphic form, which is desirable for margarines. Therefore, those four fat blends are suitable to formulate trans-free margarines with desirable textural properties.

    更新日期:2018-11-16
  • Decrease of microbial community diversity, biogenic amines formation, and lipid oxidation by phloretin in Atlantic salmon fillets
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-15
    Jing Wang, Jie Fang, Lina Wei, Ying Zhang, Hong Deng, Yurong Guo, Chingyuan Hu, Yonghong Meng

    Phloretin is a naturally occurring flavonoid that has antimicrobial and antioxidant activities. The objective of this study is to examine the feasibility of using phloretin as a preservative for salmon fillets. Salmon samples were dipped in phloretin solution (2 mg/mL and 4 mg/mL), stored at 4 °C for three days. The effect of phloretin on the quality of salmon fillets was investigated during storage time. The results showed that phloretin reduced microbial species diversity and the relative abundance of bacterial community composition in genus level in salmon fillets. Specific spoilage organisms (Pseudomonas, Photobacterium, and Shewanella), Acinetobacter, Flavobacterium, and Chryseobacterium were identified as dominant bacteria in salmon fillets during storage time. Besides, phloretin inhibited the growth of test microorganisms, in particular, Gram-positive bacteria including Listeria monocytogenes, Staphylococcus aureus, and Bacillus subtilis. When dipped into 4 mg/mL of phloretin, phloretin showed growth inhibitory effects against Pseudomonas and Photobacterium by 1.6 and 0.7 logarithmic, respectively; and total viable bacteria counts were decreased. Notably, the formation of biogenic amines was retarded by 18.84 times and lipid oxidation measured by thiobarbituric acid-reactive substances (TBARS) was reduced by 3.23 times compared to control samples. Overall, phloretin is promising as a natural preservative to improve seafood safety.

    更新日期:2018-11-15
  • Reduction of Listeria innocua in fresh-cut Chinese cabbage by a combined washing treatment of sweeping frequency ultrasound and sodium hypochlorite
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-15
    Evans Adingba Alenyorege, Haile Ma, Ishmael Ayim, Joshua Harrington Aheto, Chen Hong, Cunshan Zhou

    The investigation compared the efficiency of single treatments and their combinations in reducing Listeria innocua on fresh-cut Chinese cabbage. Samples were inoculated and treated separately with sweeping frequency ultrasound (SFUS; 28 ± 2–68 ± 2 kHz) and sodium hypochlorite solution (NaOCl; 20–100 mg/L) and their combinations. Treatments were evaluated based on attainable bacterial reduction and treatment synergy. The L. innocua population in the samples reduced to 0.36–0.95 and 0.22–1.29 log CFU/g after treatment with NaOCl and SFUS respectively. The combined application of 40 ± 2 kHz SFUS and 100 mg/L NaOCl accomplished a 3.35 log CFU/g reduction of L. innocua, exhibiting an additional 2.06 log CFU/g reduction compared to single treatments, without causing adverse quality changes to leaf colour, texture, pigments and microstructure. L. innocua population reduction in Chinese cabbage was frequency-dependent rather than NaOCl concentration. Synergistic reductions of L. innocua were recorded in 85% of the combined treatments, though most of the values are below 1.0 log-cycle. The maximum synergistic values of 1.14 or 1.20 log CFU/g were achieved when 40 ± 2 kHz SFUS and 100 mg/L NaOCl or SFUS 68 kHz and 100 mg/L NaOCl were combined respectively.

    更新日期:2018-11-15
  • Rheological and textural properties of gluten-free doughs and breads based on fermented cassava, sweet potato and sorghum mixed flours
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-15
    Orissa Charlène Monthe, Lidwine Grosmaire, Richard Marcel Nguimbou, Layal Dahdouh, Julien Ricci, Thierry Tran, Robert Ndjouenkeu

    In this study, the fermented cassava-sweet potato-sorghum mixed flours have been used to produce GF bread using xanthan gum as substitute of gluten. The "constrained mixture design" was used to evaluate the effect of flour proportions on the rheological and textural properties of dough and bread. The pasting properties of flour blends reveal high peak viscosity (750–1076 cP) for blends containing more than 70% cassava flour. Sweet potato and sorghum flours lead to a drop in the peak viscosity in the blend when substituted at 30 and 20% respectively. According to the response surface of the Linear Visco elasticity (LVR G′), 5% of sorghum proportion appears as the critical threshold beyond which the decrease in the proportion of cassava flour makes it possible to increase the solid character of the dough (LVR G′ increases). Analysis of the textural properties (hardness, adhesiveness, elasticity, cohesiveness and chewiness) of the crumb of the fresh and stored breads allowed obtaining an optimal flour formulation made of 75% fermented cassava, 20% sweet potato flour and 5% sorghum. This study demonstrated feasibility of fermented cassava-sweet potato-sorghum mixed flours in GF bread making.

    更新日期:2018-11-15
  • On the nature of the optimum cleaning concentration for dairy fouling: High NaOH concentrations inhibit the cleavage of non-covalent interactions in whey protein aggregates
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-15
    Liyuan Fan, Xiao Dong Chen, Ruben Mercadé-Prieto

    The dairy industry has long known that highly concentrated alkaline solutions should not be used to clean whey protein rich fouling deposits. At >0.1 mol L−1 NaOH dissolution and cleaning rates decrease markedly to very low values, particularly at low-mid temperatures. It is shown here that it is caused by the incapacity of the hydroxide ion to destroy non-covalent interactions between protein aggregates at at high alkali concentrations. HPLC is used to quantify the breakdown kinetics of soluble whey protein isolate (WPI) aggregates. Results show that the large aggregates kinetic constant is strongly reduced at >0.25 mol L−1 NaOH, but also at higher protein concentrations. Moreover, large aggregates become increasingly stable for long times at ≥0.5 mol L−1 NaOH. The kinetic analysis predicts that large protein aggregates would be fully stable at 0.085–0.105 g WPI/g solution, explaining the dissolution threshold observed in macroscopic swelling studies.

    更新日期:2018-11-15
  • Effect of confectionery solutes on the rheological properties of fish (Oncorhynchus mykiss) gelatin
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-13
    Deniz Damla Altan Kamer, Ibrahim Palabiyik, Nuray Olcay Işık, Fazli Akyuz, Ahmet Sukru Demirci, Tuncay Gumus

    In this study, gelatin was extracted from the skin of rainbow trout (Oncorhynchus mykiss) and gelation performance was studied with confectionery solutes at different concentrations (0, 10, 20, 40, 60 g/100 mL) as an alternative to mammalian gelatin. Rheological measurements were used to characterise the gelling and melting temperature and the gel modulus. Sorbitol and sucrose addition positively affected the gelation, texture, thermal and rheological properties due to changes of structural properties of the gelatin investigated by FTIR analysis. Addition of sugar or polyol enhanced the formation of triple helix structure and more junction zones were formed between proteins. Notably, gel strength increased from 828 Pa to 2317 Pa and 1996 Pa with the addition of 10 g/100 mL sorbitol and sucrose, respectively. Sorbitol had more significant effects than sucrose, probably due to its higher conformational degrees of freedom. Melting temperature increased from 17.5 °C to 22 °C and 22.1 °C by sorbitol and sucrose addition, respectively. These data suggested that the addition of sorbitol and sucrose triggered the formation of more junction zones which caused to increase in hardness and chewiness values. The enhanced properties of fish gel solutions with confectionery solutes showed the potential for use of this fish gelatin in gummy like candies.

    更新日期:2018-11-14
  • Effect of heat treatment on denaturation of whey protein and resultant rennetability of camel milk
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-14
    Almaz Genene, Egon Bech Hansen, Mitiku Eshetu, Yonas Hailu, Richard Ipsen

    The effect of varying heat treatments (65 °C/30 min, 72 °C/30 s, 75 °C/5 min, 85 °C/5 min, 90 °C/5 min) on the degree of whey protein denaturation and rennetability of camel milk was investigated. Bovine milk was used for comparison. In camel milk α-lactalbumin exhibited less denaturation than in bovine milk following heat treatment for 90 °C/5 min and 67% α-lactalbumin was un-denatured as compared to the initial raw milk content, whereas this was only 5% in bovine milk. Camel serum albumin, however, showed substantial denaturation with increase in heat treatment. The gelation time as well as the time to reach maximal gel strength was significantly increased with heat treatment. Camel milk preconditioned to 40 °C exhibited a short gelation time (6 min) which increased to 14 min for milk treated at 65 °C/30 min. Heat treatments at 72 °C/30 s for camel milk resulted in loss of coagulation properties, i.e. very low gel strength or no coagulation within 60 min. A heat treatment process of 65 °C/30 min or 72 °C/30sec is thus recommended, when making cheese from camel milk.

    更新日期:2018-11-14
  • The impact of E-beam treatment on the microbial population and sensory quality of hard annatto-coloured cheese
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Raquel Velasco, M. Isabel Cambero, Juan A. Ordóñez, M. Concepción Cabeza

    The effects of E-beam radiation on microbiota, colour, texture and sensorial properties of hard annatto-coloured cheese during storage at 4 and 14 °C were studied. Doses of up to 2 kGy provoked a decrease in the total bacterial number, although microbiota recovery to initial levels during storage, even under refrigeration temperature, was observed. However, a higher temperature (14 °C) was required to detect bacterial growth in cheese treated at 3 kGy. Moreover, the effects of the dose on the hardness, springiness, cohesiveness and colour parameters were interdependent of the storage conditions. According to the combined effects of E-beam treatment and storage conditions, multivariate cluster analysis allowed treated cheeses irradiated at 0–1 kGy (cluster 1) to be distinguished from those irradiated at 2–3 kGy (cluster 2), which were stored at 4 °C for 28 days. Cluster 3 included irradiated cheeses (1–3 kGy) stored at a higher temperature (14 °C). Although off-odour and off-flavours arose immediately after treatment, they disappeared progressively during storage at doses lower than 2 kGy. Nevertheless, consumers could detect changes in the colour derived from the radiation at 2 kGy, however, those changes may be unimportant because of the wide colour ranges of commercial annatto-coloured cheeses.

    更新日期:2018-11-13
  • Ultrasound assisted extraction of bioactive compounds from pomegranate (Punica granatum L.) peel
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-13
    Parvin Sharayei, Elham Azarpazhooh, Shahin Zomorodi, Hosahalli S. Ramaswamy

    Ultrasound-assisted extraction (UAE) technology was used for extracting effective components from pomegranate (Punica granatum L.variety SisheKape-Ferdos) peel (POP). A response surface method was used to investigate the effects of independent process variables (ultrasonic amplitude (power control, UA): 20, 60 and 100%, and ultrasonic exposure time (UET): 5, 10 and 15 min) on the yield (Y) and antioxidant characteristics: total phenolic compounds (TPC), 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DPPH), ferric reducing-antioxidant power (FRAP), half maximal of radical-scavenging activity (IC50) of aqueous pomegranate peel extract. According to Derringer's desired function approach, the optimal conditions based on both individual and combinations of all process variables were UA 60% and UET 6.2 min, and at this optimum condition, the predicted maximum values of Y, TPC, DPPH, FRAP, and IC50 of the pomegranate peel extract (POPx) were 13.1%, 42.2 mg GA/g, 88.8%, 1824.6 μmol Fe2+/g, and 0.51 mg/mL, respectively. The experimental values were in a good agreement with the predicted values. Also, at optimal conditions, the minimum inhibitory concentration (MIC) of the extract (mean diameter of inhibition zone: 17.7 mm) showed that it had antifungalhttp://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/antibiotics activities against Aspergillus niger.

    更新日期:2018-11-13
  • Characterization of nanoliposomes containing bioactive peptides obtained from sheep whey hydrolysates
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Ana Paula Folmer Corrêa, Diego Bertolini, Nathalie Almeida Lopes, Flávio Fonseca Veras, Gustavo Gregory, Adriano Brandelli

    Whey is recognized by the excellent nutritional and functional properties of its proteins, which can be hydrolyzed to peptides with an array of biological activities. In this work, sheep whey was treated with a novel proteinase from Bacillus sp. P7, resulting in hydrolysates with antioxidant and angiotensin-converting enzyme I (ACE-I) inhibitory activity. The hydrolysates were purified by gel filtration chromatography on Sephadex G-25 and the active fractions were subjected to ultrafiltration through 10 kDa cut-off membranes. The fraction enriched in bioactive peptides was encapsulated into phosphatidylcholine liposomes, which were characterized and evaluated by their ability to maintain biological activities. The physicochemical parameters of the liposomes showed constant values during 30 days, with mean diameter around 166 nm and zeta potential −17 mV. Both antioxidant and ACE-I-inhibitory activities were detected in the liposome preparations. In addition, the residual antioxidant activity was 87% after 30 days storage, suggesting the bioactive peptides are stable in this formulation. Liposome encapsulated peptides may offer the possibility of application in areas such as food science and technology, in order to increase the nutritional value and shelf life of food products, as well as for the development of functional foods.

    更新日期:2018-11-12
  • Cooking quality, biochemical and technological characteristics of bran-enriched pasta obtained by a novel pasta-making process
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Roberto Ciccoritti, Francesca Nocente, Daniela Sgrulletta, Laura Gazza

    The present research was focused on the set up of an innovative technological wheat transformation process, based on micronization and air classification of partially debranned kernels, able to naturally increase the potential nutritional value of pasta. The overall aim was to increase the bran content in pasta, without neglecting the palatability aspect. Enriched pasta was obtained from three durum wheat cultivars adding to semolina two different ratio of coarse and fine flour fractions (25 and 50 g/100 g, respectively). Enriched pasta resulted to be increased up to 53% in soluble polyphenols, to 121% in alkylresorcinols and to 64% in arabinoxylans, reaching the values of 138 μg/g, 206 μg/g and 3 g/100 g, respectively. Noteworthy, enriched pasta showed an increase up to 113% in dietary fiber (6 g/100 g) and to 20% of resistant starch (0.53 g/100 g), along with a good cooking quality, as determined by sensory analysis. The novel technological process allowed to produce pasta with a high content of bioactive compounds, naturally present in durum wheat, and minimal effects on sensory properties, contributing to satisfy the demand of consumers for healthy natural products. The complete technological process and pasta products are subject of a patent.

    更新日期:2018-11-12
  • Characterization of ascorbic acid microencapsulated by the spray chilling technique using palm oil and fully hydrogenated palm oil
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Juliana Domingues dos Santos Carvalho, Vivian Boesso Oriani, Glazieli Marangoni de Oliveira, Míriam Dupas Hubinger

    The aim of this work was produce and characterize solid lipid microparticles (SLMs) with different proportions of fully hydrogenated palm oil (FHPO) and palm oil (PO) as wall material (WM) to encapsulate ascorbic acid (AA), using the spray chilling technique. The microparticles were evaluated for surface morphology (SEM), size distribution and mean diameter, polymorphism, encapsulation efficiency, thermal behavior, DSC, and for release profile. The mean particle diameter ranged from 97.80 to 181.29 μm and the micrographs revealed spherical particles and rough surfaces. The encapsulation efficiency ranged from 80.22 to 93.51% and it was influenced by increases in the concentration of PO in each formulation and by the particle size. All the lipid microparticles presented high thermal resistance and had crystalline behavior β′, proving that after atomization the particles preserved the original polymorphic forms of their constituent materials. Moreover, SLMs gradually released ascorbic acid in aqueous medium, following Higuchi kinetic.

    更新日期:2018-11-12
  • Components and antibacterial activity of a novel essential oil from the nutrient broth of Eremothecium ashbyii H4565
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Feng He, Ke Li, Xiaohong Zhang, Ying Yang, Yuanping Fang, Fu Xiang

    Food spoilage is a global issue, and millions of people suffer from food-borne infections. So it is urgent to search for novel, effective and safe antimicrobial agents. A novel essential oil was obtained from Eremothecium ashbyii H4565, which was identified and conserved in the China Center for Type Culture Collection. The chemical components of the essential oil were analyzed by gas chromatography-mass spectrometry. The results showed that 22 components were identified, and the major compounds were geraniol, citronellol, phenylethyl alcohol, longifolene, linalool and nerolidol. By disc diffusion assay and double-broth dilution method, the essential oil exhibited antibacterial activities against food spoilage microbes, such as Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Zygosaccharomyces bailii, Saccharomyces cerevisiae, and Candida utilis. The minimum inhibition concentrations of the essential oil against these microorganisms were 15.6, 15.6, 15.6, 15.6, 7.8, 7.8, 31.2, 15.6, and 31.2 μg/mL, respectively. Based on the results of electron microscopy, protein and DNA leakage, and cytoplasmic membrane permeability, the possible mechanism was indicated that the possible targets of the essential oil were cell wall and cytoplasmic membrane. Therefore, it was suggested that essential oil might be used as a potential antimicrobial agent in food.

    更新日期:2018-11-12
  • Texture improvement and deformation inhibition of hot air-dried apple cubes via osmotic pretreatment coupled with instant control pressure drop (DIC)
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Xiao Li, Jinfeng Bi, Qinqin Chen, Xin Jin, Xinye Wu, Mo Zhou

    To inhibit the shrinkage and deformation as well as improve texture properties of hot air (HA) dried apple cubes, osmotic pretreatment and/or instant control pressure drop (DIC) coupled with HA were investigated. Shrinkage and deformation of apple cubes with dimension of 1.5 cm at classic HA drying process of 80 °C were analyzed, when moisture content reduced to 0.60 g/g d.b., it showed significant deformation including cell and pore collapse. Only osmotic pretreatment or DIC combined with HA could not improve the appearance and texture properties of apple cubes at the same time. However, osmotic pretreatment and DIC combined with HA (MD/MCC + HA + DIC) could significantly increase crispness (57–64) and reduce hardness (138–145 N) of apple cubes, and inhibit the deformation by increasing the volume by 1.6 times compared with that of HA dried ones. MD/MCC + HA + DIC could be an emerging combined technology to obtain dried products with good appearance and texture properties.

    更新日期:2018-11-12
  • Tracing the melamine migration from three-piece tin cans into food simulants during coating process
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Mi Li, Yuhao Fan, Zhigang Liu, Yunfei Xie, Yahui Guo, Yuliang Cheng, He Qian, Weirong Yao

    Melamine is commonly used to manufacture the coating of three-piece tin cans. It may migrate into food in the course of storage, threatening the health of consumers. This work aimed to trace the migration of melamine into food simulants (acetic acid, 3% v/v; ethanol, 10% v/v) during coating of three-piece tin cans in order to propose the critical points for food contamination. High-performance liquid chromatography–tandem mass spectrometry was used to detect melamine in samples. The results indicated that the amount of melamine migrating in the overlay–spray process (step 8) is the largest, significantly higher than that of the other processes (P ≤ 0.05). It was also found that the main source of melamine in the packaging of metal containers is the coating. Therefore, the selection of coatings and the optimization of the process can reduce the migration of melamine.

    更新日期:2018-11-12
  • Effects of small laccase from Streptomyces coelicolor on the solution and gel properties of whey protein isolate
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Wei Quan, Chong Zhang, Meixia Zheng, Zhaoxin Lu, Haizhen Zhao, Fengxia Lu

    Laccase from Streptomyces coelicolor (SLAC) can catalyze protein cross-linking without any phenolic acid assistance, and its effects on the solution and gel properties of whey protein isolate (WPI) were investigated in this study. WPI solution (5% w/v) was catalyzed by SLAC at 60 °C for 10 min at different enzymatic activities (0–20U). Results showed that, cross-linked by SLAC, the foaming capacity and emulsifying activity properties of WPI solution were improved. SLAC treated solutions had more negative charge in zeta potential, indicating more stable in protein solutions. SLAC-modified increased the apparent visicosities of WPI solutions. Rheological results showed that SLAC-treated WPI gels had higher dynamic storage modulus (G′) and took longer gelation time, compared to control (0U). SLAC treatment improved the strength of WPI gels and increased their water holding capacity (WHC). The results indicate that suitable SLAC catalysis could be used to modify whey protein isolate to improve its solution and gel properties.

    更新日期:2018-11-12
  • Effect of frying oils’ fatty acid profile on quality, free radical and volatiles over deep-frying process: A comparative study using chemometrics
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Ying Liu, Jinwei Li, Yajun Cheng, Yuanfa Liu

    The effects of frying oils’ fatty acid profile on quality, free radical and volatiles over deep-frying process were investigated, using oils with different fatty acid composition. Results showed oxidative stability of frying sunflower oil (SO) were higher than that of frying palm oil (PO). Meanwhile, free radicals in frying oils increased over frying time, and amounts of free radicals in SO were higher than those in PO. Our further analysis on fatty acid composition showed oleic and linoleic acid decreased significantly with the increasing frying time, indicating unsaturated fatty acid of oils degraded under frying process, while no significant change of saturated fatty acids was observed. Results of volatiles indicated that totals of 27 main volatile compounds were found in both frying oils but their content distributed differently in two oils. Chemometrics analysis showed that (E,E)-2,4-octadienal, (E)-2-decenal, 2-undecenal, 1-heptanol, 1-octanol, 2-undecanol, 3-hepten-2-one, 1-undecanol, octanoic acid, nonanoic acid, octane, dodecane and tetradecane was highly correlated with AV, POV, p-AV, PCs and free radical in frying PO, while (E)-2-hexenal, 1-nonen-3-ol, 2-dodecanol,3-methyl-3-buten-2-one, 4-methyl-2-hexanone, pentanoic acid and nonadecane was highly correlated with quality indices in frying SO, indicating these volatiles may be proposed as potential indicators for evaluating lipid oxidation of corresponding frying oil.

    更新日期:2018-11-12
  • The antibacterial mechanism of pterostilbene derived from xinjiang wine grape: A novel apoptosis inducer in Staphyloccocus aureus and Escherichia coli
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Xueyan Ren, Peipei An, Xin Zhai, Shuo Wang, Qingjun Kong

    Antibiotic overuse has caused concerns owing to the emergence of antibiotic resistant microorganisms and the accompanying decreased bacteria-inhibiting effectiveness of proffered treatments. Pterostilbene, derived from XinJiang wine grape, is a natural polyphenol, and has attracted considerable attention for its promising antifungal effects. However, its inhibitory activities and mechanisms of action against bacteria are still unknown. In this study, pterostilbene inhibited the growth of Gram-positive Staphyloccocus aureus and Gram-negative Escherichia coli effectively. Electron microscope observations showed that the morphological structures of S. aureus and E. coli were significantly damaged by pterostilbene. Cells became irregular, shriveled, and lysed, while nucleic acids and proteins leaked, and DNA content decreased. Furthermore, confocal laser scanning microscopy experiments revealed that bacteria treated with pterostilbene produced reactive oxygen species, and the cytomembrane potential increased. To further clarify the molecular mechanism, changes in the expression levels of four genes in two bacteria were confirmed by qRT-PCR. Pterostilbene cause the up-regulation of DinF (an oxidative stress gene). An associated down-regulation of PaL, MtgA, and NagA (genes involved in cell wall synthesis) is also attributed to pterostilbene treatment. This is the first time that the mechanism of pterostilbene against S. aureus and E. coli is presented in literature.

    更新日期:2018-11-12
  • Complex formation, physicochemical properties of different concentration of palmitic acid yam (Dioscorea pposita Thunb.) starch preparation mixtures
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Xia Li, Xiaoxiao Gao, Jun Lu, Xinhui Mao, Ying Wang, Deming Feng, Jingguo Cao, Luqi Huang, Wenyuan Gao

    The starch-palmitic acid complex was prepared by the reaction of different concentrations (0.1%–5.0%) of palmitic acid and yam starch. In order to find out the effects of concentration of palmitic acid on the properties of the complex, the physicochemical properties, morphological properties, freeze-thaw stability, antioxidant activity and bile acid binding capacity of complexes were studied. It was found that with the increase of palmitic acid concentration, the complex index of starch-fatty acid increased first and then decreased. When the concentration of palmitic acid was 2%, the complex index was the highest (26.39%). The crystal type has gradually changed from Ca type into mixtures of V-type pattern and B-type pattern when introduced palmitic acid. The water binding capacity, solubility, swelling power and paste clarity were decreased, while the content of resistant starch and freeze-thaw stability were obviously increased. Compared with the native starch, the antioxidant activity and bile acid binding capacity of the complex were significantly increased. All the result showed that the concentration of palmitic acid has a great influence on the physicochemical properties of modified starch and the starch-palmitic acid complexes have higher ability of controlling cholesterol and improving the anti-oxidant activity than native yam.

    更新日期:2018-11-12
  • Optimal pH of zinc protoporphyrin IX formation in porcine muscles: Effects of muscle fiber type and myoglobin content
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Jun-ichi Wakamatsu, Mofassara Akter, Fumika Honma, Toru Hayakawa, Haruto Kumura, Takanori Nishimura

    This study investigated the effects of pH, muscle fiber type, and precursor levels on zinc protoporphyrin IX (ZnPP) formation in porcine skeletal muscles. ZnPP formation could be classified into three distinct groups with pH optima of 4.75, 5.5, or both. The effects of temperature and incubation time on ZnPP formation at the new optimal pH 4.75 differed significantly from those at pH 5.5 reported in previous studies. Protoporphyrin IX (PPIX) formation at pH 4.75 nearly coincided with that of ZnPP, suggesting that the latter strongly affects the former, as observed at pH 5.5. The amount of ZnPP formed at pH 4.75 was related to the ratio of type I muscle fibers. Although myoglobin degradation occurred at pH 4.75, no decrease in heme content corresponded to the formation of ZnPP and PPIX. These results demonstrate that ZnPP and PPIX are formed by two independent mechanisms in porcine skeletal muscles whose optimal pH values are 5.5 and 4.75.

    更新日期:2018-11-12
  • Oxidation products from omega-3 and omega-6 fatty acids during a simulated shelf life of edible oils
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-12
    Marina S. Nogueira, Bianca Scolaro, Ginger L. Milne, Inar A. Castro

    Nutritional guidelines recommend reduced intake of saturated fatty acids to prevent cardiovascular disease. Polyunsaturated fatty acids (PUFA) are proposed as substitutes for saturated fats. PUFA, however, are more susceptible to lipid peroxidation resulting from environmental free radical than saturated fats. We hypothesize that toxic lipid peroxidation products could be generated during shelf storage in dietary sources of PUFA prior to consumption. Therefore, the oxidative stability of six edible oils rich in omega-3 and omega-6 PUFA was evaluated by simulating transport, storage and consumption conditions that these oils typically receive. 2-Propenal (acrolein); 2-butenol; (E,E)-2,4-heptadienal; (E,E)-3,5-octadien-2-one; (Z,Z)-3,6-nonadienal and (E,E)-2,4-decadienal were identified as potentially toxic products resulting from the oxidation of PUFA in omega-3 rich oils from marine sources while propan-2-one; 2-butanol; (E,E)-2,4-heptadienal; (E,E)-3,5-octadien-2-one and (E,E)-2,4-decadienal were identified in omega-3 PUFA rich oils from vegetable sources. Hexanal, (E)-2-heptenal, (E,E)-2,4-neptadienal, nonanal and 2-undecenal were identified from omega-6 rich oils. All samples showed increased oxidation with some lipid oxidation products exceeding recommended limits at the time of consumption. These findings highlight the importance of examining the oxidative stability of commercially available edible oils. The physiological implications of the chronic intake of reactive aldehydes, such as acrolein, through the consumption of dietary oils deserve further investigation.

    更新日期:2018-11-12
  • In-vitro digestion by simulated gastrointestinal juices of Lactobacillus rhamnosus cultured with mulberry oligosaccharides and subsequent fermentation with human fecal inocula
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-09
    Erna Li, Hua Yang, Yuxiao Zou, Hong Wang, Tenggen Hu, Qian Li, Sentai Liao

    In the present study, mulberry oligosaccharides were produced from mulberry polysaccharide by physical ultrasonic hydrolysis, chemical acid hydrolysis and enzymatic hydrolysis. The impact of the oligosaccharides on the growth four probiotic bacteria—Lactobacillus plantarum, Leuconostoc mesenteroides, Lactobacillus casei and Lactobacillus rhamnosuswas examined. The oligosaccharides produced from β-mannanase hydrolysis had the greatest effect on the growth of L. rhamnosus (252% of the number of cells compared with medium without the hydrolyzate). The enzymatically-prepared mulberry oligosaccharides (EMPS) were superior to the untreated mulberry polysaccharide and commercially available prebiotics (isomaltooligosaccharides and galactooligosaccharides). L. rhamnosus was cultured with EMPS and then subjected to tolerance tests with artificial gastrointestinal fluids. Bacteria remained viable. Subsequently, simulated-digested L. rhamnosus cultured with EMPS was used in in vitro fermentation with human gut microbiota from fecal inoculum. After 48 h of the incubation, in the experimental group (with pretreated L. rhamnosus), the ratio of Bacteroidetes to Firmicutes was 0.848, compared with 0.659 in the control group (saline instead of L. rhamnosus), suggesting that L. rhamnosus and constituents in EMPS were capable of regulating the growth of intestinal microorganisms. Our results inform the potential for the development of mulberry oligosaccharides as a prebiotics or synbiotics.

    更新日期:2018-11-10
  • Effects of high pressure processing (HPP) on quality attributes of tilapia (Oreochromis niloticus) fillets during refrigerated storage
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-09
    Laura Suemitsu, Marcelo Cristianini

    Fish fillets are extremely perishable in refrigerated conditions, so the use of technology is necessary to extend its shelf life. The present work aimed at evaluating high pressure processing effects on colour, texture, microbiological quality and sensory quality of tilapia fillets. Samples were pressurized at 100, 200, 300 or 400 MPa for 1 or 3 min. Colour parameters L* and whiteness of samples processed at 300 and 400 MPa were significantly higher (p < 0.05) than control samples. Both hardness and compression force of pressurized samples did not significantly differ (p > 0.05) from control. Counts of psychrotrophic microorganisms were significantly reduced (p < 0.05) on samples pressurized at 300 and 400 MPa. Samples processed at 200 MPa were preferred (p < 0.05) by assessors on sensory evaluation of fillets appearance. Colour, texture and microbiological analysis of samples kept at refrigerated storage (5 °C) for 1 wk showed that HPP at 400 MPa for 3 min was efficient to preserve tilapia fillets. The study has shown that HPP might be a suitable process for fish conservation, but influence on tilapia fillets appearance acceptance due to changes in colour may difficult its commercialization, so further research about these effects is needed.

    更新日期:2018-11-10
  • The role of microbes in free fatty acids release and oxidation in fermented fish paste
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-09
    Yanshun Xu, Lin Li, Wenshui Xia, Jinhong Zang, Pei Gao

    To better understand the role of fermentative microorganisms in lipid changes during the processing of fermented fish, sterile fish paste with or without the antioxidant tert-butylhydroquinone (TBHQ) was used to investigate the roles of three strains isolated from traditional fermented fish in free fatty acid (FFA) liberation and lipid oxidation. The results showed that the addition of 0.03% TBHQ had no significant influence (P > 0.05) on the strain growth but could effectively inhibit fatty acid oxidation. Staphylococcus xylosus 135 demonstrated the highest liberation of FFAs, followed by Saccharomyces cerevisiae 31, with its released FFAs being almost all polyunsaturated fatty acids (PUFA). Furthermore, the highest amount of PUFA oxidation in FFAs was observed in the samples inoculated with Staphylococcus xylosus 135 (802 mg/kg DM), followed by Lactobacillus plantarum 120 (476 mg/kg DM) and Saccharomyces cerevisiae 31(388 mg/kg DM). The results suggested that Staphylococcus xylosus may play a major role in the lipolysis and lipid oxidation during the processing of fermented fish. Lactobacillus plantarum also contributed to the fatty acid oxidation although it had no obvious lipolysis ability.

    更新日期:2018-11-10
  • Biogenic amines producing and degrading bacteria: A snapshot from raw ewes' cheese
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-10
    Fabrizia Tittarelli, Giorgia Perpetuini, Paola Di Gianvito, Rosanna Tofalo

    Tyramine and histamine are considered the most toxic biogenic amines (BAs) and are often found in high concentrations in in fermented foods, such as cheese, and beverages. Their control is critical to assure food safety. Recently the use of food borne BAs degrading bacteria has been proposed. The aim of this study was to isolate bacteria from Incanestrato di Castel di Monte, a raw ewe's cheese, unable to produce histamine and tyramine and, at the same time, able to degrade them. Twenty-four strains with different BAs-producing and degrading abilities were isolated. Twelve strains produced tyramine, while none of them histamine in agreement with molecular data which showed the absence in these strains of hdc gene. Only 2 strains did not degrade tyramine, while the others showed a degradation % ranging from 3.83 ± 0.15 to 62.45 ± 3.98. Tyramine degradation % varied from 6.23 ± 012 to 70.74 ± 2.15. The most interesting strains appeared to be A422 (L. casei), and A143 (E. casseliflavus), since they show a quite high % of degradation of both BAs, and did not show decarboxylase activity. Selected bacteria could be used as starter culture to reduce tyramine and histamine concentration in raw milk cheeses.

    更新日期:2018-11-10
  • Effect of hydrocolloid addition on dimensional stability in post-processing of 3D printable cookie dough
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-10
    Hyun Woo Kim, Il Joo Lee, Sea Mi Park, Jang Ho Lee, Minh-Hiep Nguyen, Hyun Jin Park

    This paper provides a solution to the problem of the deformation of 3D printed cookie products during post-processing such as baking. The influence of the incorporation of hydrocolloids on the dimensional stability of the cookie dough during temperature variations was investigated. Methylcellulose and xanthan gum were blended in mass fractions of 0.5, 1, 2, and 3 g/100 g dough basis. In dynamic viscoelasticity experiments, during the temperature sweep, the cookie doughs with methylcellulose showed losses in storage modulus (G′) and loss modulus (G″) that were comparable to those of the control samples. Although the incorporated xanthan gum exhibited high structural retention owing to its high shear modulus, its low extrudability resulted in a high extrusion hardness and poor 3D printing performance. In the post-processing, sufficient dimensional stability was observed even with a xanthan gum incorporation of 0.5 g/100 g. Moreover, the heat-resistant 3D printable cookie samples with 0.5 g/100 g xanthan gum exhibited a texture profile having a hardness and fracturability similar to those of the control cookies.

    更新日期:2018-11-10
  • Influence of fermented and unfermented Agaricus bisporus polysaccharide flours on the antioxidant and structural properties of composite gluten-free cookies
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-10
    Abdellatief A. Sulieman, Ke-Xue Zhu, Wei Peng, Hayat A. Hassan, Amer Ali Mahdi, Hui-Ming Zhou
    更新日期:2018-11-10
  • Evaluating endogenous protease of salting exudates during the salting process of Jinhua ham
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-09
    Chang-Yu Zhou, Dao-Dong Pan, Yun Bai, Chun-Bao Li, Xing-Lian Xu, Guang-Hong Zhou, Jin-Xuan Cao

    Strategies are being pursued with the aim of reducing salt content of dry-cured ham. To evaluate the effect of salting on protease activities, sixteen hams were randomly assigned into two groups (LS group and HS group), and two different levels of NaCl were used to dry-cure green ham. The LS group of 8 hams were salted with 6% salt (w/w), whereas the HS group of 8 hams were salted with 8% salt. The exudates were collected separately at 1, 2 and 7 d of the salting stage. The activities and contents of protease in the exudates were investigated. The intense activities of calpains, cathepsin B and L were observed at 1, 2 and 7 d of salting stage in both LS and HS group. The increased contents of 80 and 76 kDa fragments implied that there was a dramatic release of calpain from ham tissues; lower release rates of cathepsin B and cathepsin L led to high residues in LS group, which may be responsible for the intense degradation of proteins and flavor development of dry-cured ham. This paper provides new insights into the study of biochemical changes of Jinhua ham induced by endogenous protease during the salting stage.

    更新日期:2018-11-09
  • High hydrostatic pressure treatment improves physicochemical properties of calcium- and soybean protein-added peach juice
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-09
    Carlos A. Manassero, Francisco Speroni, Sergio R. Vaudagna

    Calcium- and soybean proteins-added peach beverages were prepared and subjected to high hydrostatic pressure (HHP, 600 MPa, 5 min) in order to evaluate their physicochemical properties (protein solubility, physical stability, viscosity and color). Calcium addition decreased protein solubility and destabilized the beverage. Solubilizing effect of HHP was detected only for non-calcium-added beverages. Nevertheless, HHP treatment stabilized calcium-added beverages, with a greater effect in samples with 10 mmol L−1 CaCl2. HHP treatment increased viscosity of calcium-added beverages, which could contribute to their increase in physical stability. This work provides information that may be useful in the handling of functional foods, since physicochemical properties such as physical stability was improved by HHP in a drink with improved nutritional value (incorporation of proteins and calcium).

    更新日期:2018-11-09
  • Protective cultures against foodborne pathogens in a nitrite reduced fermented meat product
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-08
    Ivana Nikodinoska, Loredana Baffoni, Diana Di Gioia, Beatriz Manso, Lourdes García-Sánchez, Beatriz Melero, Jordi Rovira

    In the present work, a combined hurdle approach for fermented meat preservation was investigated. Challenge tests were performed in Chorizo sausage model using the maximum allowed NaNO2 amount (150 mg/kg), a reduced amount (75 mg/kg) and no nitrite, with and without protective cultures inoculation. Cocktail strains of L. monocytogenes and Salmonella spp. were used as indicator strains. In a nitrite reduced sausage model, L. monocytogenes growing trend did not significantly change (p > 0.05) when compared with that containing higher nitrite concentration (150 mg/kg NaNO2). The addition of L. plantarum PSC20 significantly lowered L. monocytogenes growth when compared with control batches without PCS20 (p < 0.05), obtaining 3.84 log cfu/g and 2.62 log cfu/g lower counts in the batches with 150 mg/kg NaNO2 and 75 mg/kg NaNO2 respectively. None of the protective cultures demonstrated in situ antagonistic activity against Salmonella spp. This work pointed out that the reduction of nitrites with the combined use of a protective culture could be a feasible approach to control L. monocytogenes growth in fermented meat foods.

    更新日期:2018-11-08
  • Storage time assessment and shelf-life prediction models for postharvest Agaricus bisporus
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-08
    Yuan Song, Qiuhui Hu, Yuanyue Wu, Fei Pei, Benard Muinde Kimatu, Anxiang Su, Ning Ma, Yong Fang, Wenjian Yang

    Rapid senescence and short shelf-life of fresh Agaricus bisporus can cause serious economic losses. Sometimes even illegal additives are used to maintain the freshness of A. bisporus. This misconduct can bring health risks to consumers. Therefore, it is meaningful to establish shelf-life prediction model for taking necessary measures to reduce the losses, and establish storage time assessment model to evaluate the true postharvest storage duration of A. bisporus to prevent commercial misconduct. We developed storage time assessment model and shelf-life prediction model based on mushroom texture (hardness, gumminess, chewiness), signal of water mobility and typical flavor. With the extension of storage time, all the qualities of A. bisporus showed a decreasing tendency at different temperatures. Quality decreases were proven suitable to the first-order kinetic model. Gumminess was a more accurate index to assess how long postharvest A. bisporus has already been stored (the storage time), whereas chewiness was a more precise index to predict how long postharvest A. bisporus can be stored (the shelf-life). These mathematical models can be useful to assess the storage time and predict the shelf-life of fresh A. bisporus during distribution chain and storage under a temperature range of 4–20 °C.

    更新日期:2018-11-08
  • Effect of heat treatment and packaging technology on the microbial load of lightly processed seafood.
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-08
    Nanna Abel, Bjørn Tore Rotabakk, Jørgen Lerfall

    Increasing demands for lightly processed seafood stresses the need for development of non-intensive processing methods that ensures a safe product. The limitation to the shelf life of seafood is often ascribed to microbial activity. An experiment was design to investigate the influence of heat-treatments in combination with packaging technologies (vacuum (VAC), modified atmosphere (MA) packaging, or soluble gas stabilization (SGS)) on the microbial survival of inoculated species. Fish patties were inoculated with either Brochothrix thermosphacta or Listeria innocua before heat-treatment, packaging, and storage at 2ᵒC for 16 days. Increased heat-treatment lowered the bacterial load throughout the storage and type of packaging technology affected the bactierial load significantly. VAC-samples had a significantly higher bacterial load than MA- and SGS-packaged samples, regardless of heat-treatment (L. innocua: 8.7 ± 0.1, 8.3 ± 0.1, 8.2 ± 0.1logCFU/g, B. thermosphacta: 9.9 ± 0.1, 9.2 ± 0.1, 8.6 ± 0.1 logCFU/g, respectively) at end of storage. Furthermore, use of SGS significantly increased the bacterial inhibition by heat (0.5–0.6logCFU/g) and extended the lag phase of B. thermosphacta, as well as decreasing the growth rate of both inoculum species. It is concluded that use of SGS can fulfill the consumers’ demand of fresh, lightly processed seafood with a prolonged shelf life.

    更新日期:2018-11-08
  • The beneficial effects of grape seed, sage and oregano extracts on the quality and volatile flavor component of hairtail fish balls during cold storage at 4 °C
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-08
    Weiliang Guan, Xingchen Ren, Yujin Li, Linchun Mao

    Fishy odor was always generated in hairtail fish balls, decreasing the quality and reducing commercial acceptance. Improving the flavor of hairtail fish balls is a challenge in recent seafood industry. Extracts from sage leaves, oregano leaves and grape seeds (SOG) were proved to be effective in reducing the fishy odor in hairtail fish balls. The primary antioxidants were catechin, epicatechin and rosmarinic acid in SOG with the antioxidant capacity of 0.09 ± 0.01 mg gallic acid equivalents (GAE)/mL. Gas chromatography mass spectrometry (GC-MS) showed that about 50% volatility off-flavor compounds including aldehydes, ketones, alcohols and hydrocarbons, were reduced by the application of SOG. Inhibition of fishy odor by SOG was directly related with the reduced thiobarbituric acid reactive substances value (TBARs value) and total volatile basic nitrogen (TVB-N), which was likely due to the decreased lipid oxidation and bacteria growth, respectively. These results suggested the beneficial potential for SOG in inhibiting fishy odor formation and improving flavor of hairtail fish balls during storage.

    更新日期:2018-11-08
  • Evaluation of non-isothermal inactivation on survivals of pathogenic bacteria by predictive models
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-08
    Jae-Hyun Yoon, Areum Han, Jeong-Yeup Paek, Sun-Young Lee

    This study was conducted to examine thermal resistances of Escherichia coli O157:H7, Cronobacter sakazakii, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes upon exposure to non-isothermal inactivation at various heating rates (HRs) between 1.0 °C and 9.0 °C/min. Bacterial cultures were re-suspended in tryptic soy broth without dextrose and treated with non-isothermal inactivation processing (to maximally 60 °C) at different HRs. Predictive models were used to determine fundamental kinetic parameters that describe characteristic behaviors of these bacteria under dynamic environments. At a HR of 9.0 °C/min, viable numbers of these organisms declined below the detection limits (<1.0 log CFU/ml). In contrast, E. coli O157:H7, C. sakazakii, and S. Typhimurium survived at levels of <2.5 log CFU/ml at HRs of 1.5–6.0 °C/min. Under non-isothermal processing, the thermal tolerances increased with slow HRs. Lag time (LT) and δ from the modified Gompertz and the Weibull survival functions were significantly (p < 0.05) higher at the lower HRs. The Weibull distribution showed reliable goodness-of-fits ranging from 0.889 to 0.999, indicating that this equation model was shown to be effective in predicting survival kinetics of these bacteria under non-isothermal inactivation conditions at different HRs. In conclusion, slow HRs resulted in higher thermal tolerances of these bacteria under non-isothermal processing.

    更新日期:2018-11-08
  • Gamma irradiation as pre-fermentative method for improving wine quality
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-07
    Marin Mihaljević Žulj, Luna Maslov Bandić, Ivana Tartaro Bujak, Ivana Puhelek, Ana Jeromel, Branka Mihaljević

    Merlot and Traminer (Vitis vinifera L.) grapes were subjected to gamma irradiation at the panoramic 60Co source at four doses (670, 1300, 2000, 2700 Gy) and wines were produced from the irradiated grapes. HPLC analysis of musts have shown a negative impact of irradiation on the amino acids content. However, Merlot wines produced from irradiated grapes demonstrated better extraction of the coloring matter. The concentrations of anthocyanins increased with the increasing absorbed irradiation dose, while flavonols and flavanols were not affected by irradiation. Irradiation with doses up to 2000 Gy increased concentrations of fruity-floral aroma compounds, especially monoterpens and C13 norisoprenoids in wines, while a maximal dose of 2700 Gy expressed more the toasty and caramel notes due to higher concentrations of furfural and furfuryl alcohols. Results obtained suggest that ionizing irradiation might be a suitable method for grape treatment since better chemical properties in wine could be achieved.

    更新日期:2018-11-07
  • Dipeptidyl peptidase-IV, α-amylase, and angiotensin converting enzyme inhibitory properties of novel camel skin gelatin hydrolysates
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-07
    Priti Mudgil, Baboucarr Jobe, Hina Kamal, Maitha Alameri, Noura Al Ahbabi, Sajid Maqsood

    Antidiabetic and antihypertensive activities of novel camel skin gelatin hydrolysates (CSGHs) were reported for the first time. Effect of different proteolytic enzymes, time of hydrolysis and enzyme: substrate (E/S) ratio on the bioactive properties (antidiabetic and antihypertensive) was explored. Results revealed that CSGHs exhibited highly potent inhibitory activity against dipeptidyl peptidase IV (DPP-IV), pancreatic α-amylase (PA) and angiotensin-I converting enzyme (ACE) compared to non-hydrolyzed camel skin gelatin. All three enzyme combinations used produced highly potent PA inhibitory hydrolysates while for DPP-IV inhibitory property, enzymes protease and alcalase-protease (A/P) in combination produced more potent hydrolysates than alcalase generated hydrolysates. Moreover, alcalase and protease generated hydrolysates were highly active in inhibiting ACE activity in comparison to their combination AP (P < 0.05). However, no significant effect of E/S ratio and time of hydrolysis on production of DPP-IV, PA and ACE inhibitory peptides were observed. These findings suggest that both enzymes i.e. alcalase and protease alone or in combination were capable of hydrolyzing camel skin gelatin to produce hydrolysates with highly potent antidiabetic and antihypertensive properties. The present study presents the first report on the production of camel skin gelatin hydrolysates with strong antidiabetic and antihypertensive potential.

    更新日期:2018-11-07
  • Ellagitannins in wines: Future prospects in methods of analysis using FT-IR spectroscopy
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-07
    Marianthi Basalekou, Stamatina Kallithraka, Petros A. Tarantilis, Yiorgos Kotseridis, Christos Pappas

    Wine aging in wooden barrels can alter a wine's sensory features through the extraction of wood phenols such as lignins, volatile phenols and hydrolysable tannins. Among the hydrolysable tannins, ellagitannins have been found not only to modify a wine's sensory character but also to generate new products with compounds already present in wines. For this reason, their quantification is of high importance. However, ellagitannin analysis requires the use of sophisticated equipment and many preparative steps, making their quantification in wines cost effective and laborious. In this study, the feasibility of FT-IR spectroscopy coupled with chemometrics for the quantification of ellagitannin concentration in wines was examined for the first time. Partial Least Squares regression was used to construct calibration models, using the fingerprint region of the spectrum, 1821-950 cm−1 (first derivative in range). The correlation coefficient (R2) was found 0.93, the Root-Mean-Square Error of Calibration RMSEC was 1.17 and the Root-Mean-Square Error of Prediction, RMSEP was 1.57. The results indicate that FT-IR could be used for a quick, non destructive and economical estimation of a wine's total ellagitannin content.

    更新日期:2018-11-07
  • Potential antimicrobial activity of honey phenolic compounds against Gram positive and Gram negative bacteria
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-07
    Francisco Javier Leyva-Jimenez, Jesus Lozano-Sanchez, Isabel Borras-Linares, M. Luz Cadiz-Gurrea, Elaheh Mahmoodi-Khaledi

    This study is focused on the potential antimicrobial activity of honey phenolic compounds against Gram positive and Gram negative bacteria. For this purpose phenolic compounds were isolated from 33 Iranian honeys obtained from different botanical and geographical origins using solid-phase extraction (SPE). Characterization of honey extracts was carried out by HPLC-DAD-ESI-QTOF/MS. Minimum inhibitory concentration (MIC) and inhibition zone were used to determine the antimicrobial capacity of honey phenolic extracts against Gram positive (Staphylococcus aureus and Enterococcus faecalis) and Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The results shown that E. coli was the most sensitive bacteria and P. aeruginosa the most resistant strain. Moreover, five phenolic extracts shown lower MIC values than the whole honey pointing out that honey phenolic fraction may exert antimicrobial activity by itself and be a source of bioactive compounds to develop functional ingredients.

    更新日期:2018-11-07
  • A novel method for rapid quantitative evaluating formaldehyde in squid based on electronic nose
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-07
    Dong-Chen Gu, Wei Liu, Yu Yan, Wei Wei, Jian-hong Gan, Ying Lu, Zao-Li Jiang, Xi-Chang Wang, Chang-Hua Xu

    The aim was to establish a rapid and quantitative detection method of formaldehyde in squid based on electronic nose for screening massive samples. Identification of volatile compounds in squid with different formaldehyde content by electronic nose were mainly depended on eight sensors. Besides, the diversities of volatile constituents in squid with increasing contents of aldehydes and aromatic compounds were validated by GC-MS results. Moreover, to build a qualitative discrimination model for estimating whether formaldehyde in squid over standard limit or not, DFA and SIMCA based on PCA were used to analyze electronic nose data for semi-quantitative determination of formaldehyde content in squid. Finally, a rapid quantitative prediction model based on electronic nose and PLS was established (R2 = 0.9266).To verify the accuracy of quantitative model, t-test was employed and no significant difference between predicted values and true values was found. This approach showed well potentiality to provide a rapid, nondestructive and quantitative method for detecting formaldehyde residue in food.

    更新日期:2018-11-07
  • Evaluation of the DNA damage protective activity of the germinated peanut (Arachis hypogaea) in relation to antioxidant and anti-inflammatory activity
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Apinun Limmongkon, Jintana Pankam, Thapakorn Somboon, Pakwuan Wongshaya, Phatcharaporn Nopprang
    更新日期:2018-11-05
  • Xanthan gum biosynthesis using Xanthomonas isolates from waste bread: Process optimization and fermentation kinetics
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Ahmet Sukru Demirci, Ibrahim Palabıyık, Demet Apaydın, Mustafa Mirik, Tuncay Gümüs
    更新日期:2018-11-05
  • Effects of alginate-glycerol-citric acid concentrations on selected physical, mechanical, and barrier properties of papaya puree-based edible films and coatings, as evaluated by response surface methodology
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    M. Rangel-Marrón, E. Mani-López, E. Palou, A. López-Malo

    The development of edible coatings is an interesting strategy to reduce the use of conventional packaging materials and extend the shelf life of minimally processed fruits. The potential of papaya puree (PP) as a base for formulating edible films and coatings containing alginate (0.5–1.0 g/100 mL), glycerol (0.8–1.5 g/100 mL), and citric acid (0.5–1.0 g/100 mL) was evaluated. A Box–Behnken experimental design was used to determine the effect of independent variables on selected physical and mechanical properties, water vapor permeability (WVP) of PP edible films (PPEFs), and the surface solid density (SSD) and water vapor resistance of PP coating solutions (PPCSs) applied to papaya cubes. Furthermore, the PPEFs and PPCSs were optimized and validated using response surface models. Alginate-citric acid and glycerol-citric acid interactions significantly affected the SSD. The highest puncture strength of PPEFs was 17.94 MPa, with the highest concentration of alginate, whereas the WVP increased with higher concentrations of glycerol and citric acid. The optimum concentrations of alginate, glycerol, and citric acid for PPCSs and PPEFs were predicted to be 0.50, 1.32, and 0.59 g/100 mL, and 0.78, 0.80, and 0.50 g/100 mL, respectively. The mean average relative percent deviations between the experimental and predicted values were less than 10%.

    更新日期:2018-11-05
  • A multi-scale approach for pasta quality features assessment
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Agoura Diantom, Elena Curti, Eleonora Carini, Fatma Boukid, Monica Mattarozzi, Yael Vodovotz, Maria Careri, Elena Vittadini

    Pasta industry has introduced in the market new pasta formulations to respond to consumers' nutritional/health needs. The resulting macromolecular, mesoscopic, and microscopic changes induced in pasta need to be evaluated. In this work, a multi-scale screening of physico-chemical properties was performed on commercial pasta formulations (wheat semolina, whole wheat semolina, veggie, gluten free). Pasta samples showed significantly (p ≤ 0.05) different properties: wheat semolina and whole flour samples had a more pronounced viscoelastic behaviour (Dynamic Mechanical Analysis), higher hardness (Texture Analysis) and higher mobility of the more rigid protons (1H Nuclear Magnetic Resonance); veggie pasta had the highest frozen water content and higher 1H T2 molecular mobility; gluten free pasta showed a larger rigid population (Population C). This study indicated the ability of a multi-scale approach in discriminating pastas' formulation. In particular, besides physico-chemical properties, 1H NMR was able to properly discriminate pastas’ formulations.

    更新日期:2018-11-05
  • Effect of extrusion processing and hydrocolloids on the stability of added vitamin B12 and physico-functional properties of the fortified puffed extrudates
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Seema R. Bajaj, Rekha S. Singhal

    An alarming rate of increase in the prevalence of vitamin B12 deficiency has generated the demand for fortified foods therewith. This work focused on the development of vitamin B12 fortified rice extrudates wherein the effect of extrusion variables viz. die temperature (oC), screw speed (rpm) and feed rate (kg/h) on the stability of vitamin B12 and physico-functional properties were evaluated. The stability of vitamin B12 was greatly affected by die temperature and unaffected by screw speed and feed rate. The product with best physico-functional properties as obtained from experimental design (168 °C/229 rpm/4.6 kg/h) gave 54% retention of vitamin B12, while the product with best retention of 77% vitamin B12 (140 °C/150 rpm/4 kg/h) gave extrudates with low expansion ratio, WAI, WSI and high bulk density, hardness, breaking strength index and fracturability. To achieve the desirable combination of high retention of vitamin B12 and best physico-functional properties, hydrocolloids such as guar gum, xanthan gum or carboxymethyl cellulose were added at 5 and 10 g/kg of rice flour. Although all the hydrocolloids improved the physico-functional properties without affecting vitamin B12 stability, carboxymethyl cellulose at 5 g/Kg is recommended for such fortified snacks.

    更新日期:2018-11-05
  • Valorization of coffee parchment waste (Coffea arabica) as a source of caffeine and phenolic compounds in antifungal gellan gum films
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Vicente A. Mirón-Mérida, Jorge Yáñez-Fernández, Brenda Montañez-Barragán, Blanca E. Barragán Huerta

    Coffee parchment waste (CP), which is obtained during dry coffee (Coffea arabica) processing, is a coffee by-product that has been rarely studied nor efficiently utilized. Thus, the extraction conditions, phenolic composition, antioxidant activity of CP extracts, and their application as antifungal additive in gellan gum based films were analyzed in this work as an alternative in bioactive food packaging. Gallic, chlorogenic, p-coumaric, and sinapic acids along with caffeine were identified in the CP extracts by high performance liquid chromatography coupled with diode array detection. The optimum extraction conditions were found at 75 °C with a liquid/solid ratio of 41 using 70% of aqueous ethanol as solvent. The gellan gum film added with CP extract showed growth inhibition against Fusarium verticillioides, Fusarium sp., and Colletotrichum gloeosporioides, especially at the highest CP extract concentration (8 mg cm−2). The addition of the CP extract into a gellan gum film, modified its physicochemical, mechanical and structural properties, when compared with a film in the absence of any additives, and enhanced its potential use for food preservation due to its antifungal activity.

    更新日期:2018-11-05
  • Moringa extract enhances the fermentative, textural, and bioactive properties of yogurt
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-05
    Ting Zhang, Chang Hee Jeong, Wei Nee Cheng, Hyojin Bae, Han Geuk Seo, Michael C. Petriello, Sung Gu Han

    Yogurt is a fermented dairy food produced by lactic acid bacteria (LAB). Moringa oleifera is known for its bioactive properties. The aim of this study was to evaluate the effects of moringa on the fermentation, quality characteristics, and bioactive properties of yogurt. Yogurt was supplemented with 0–0.2% moringa extract (ME; hot water extract, 100 °C, 30 min) and fermented using mixed starter cultures (Streptococcus thermophilus, Lactobacillus acidophilus, and Bifidobacterium longum). Addition of ME to yogurt significantly accelerated the rate of fermentation by promoting growth of LAB. ME reduced syneresis up to 21% and enhanced the water-holding capacity by 17%. The viscosity of 0.2% ME yogurt was approximately 5-fold higher than control yogurt and radical-scavenging activity of ME yogurt increased up to 40% in a dose-dependent manner during the 21 days of cold storage. Sensory testing showed that the addition of 0.05% ME to yogurt did not negatively influence the overall acceptability of the product, compared to the control. The addition of ME to yogurt decreased the oxidative stress and increased the expression of antioxidant proteins in human colon cells. Thus, ME-fermented yogurt maintains the sensory acceptability and exerts positive health benefits because of increased LAB proliferation and enhanced antioxidant properties.

    更新日期:2018-11-05
  • Improvement of protein quality and degradation of allergen in soybean meal fermented by Neurospora crassa
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-02
    Jing Li, Ruo-lin Zhou, Zhi-qing Ren, Ya-wei Fan, Sheng-ben Hu, Cheng-fei Zhuo, Ze-yuan Deng

    The nutrition quality and bioactivity of soybean meal was investigated via solid-state fermentation using Neurospora crassa (NC) alone or Neurospora crassa and saccharomyces cerevisiae (NCSC) together. The optimized fermentation conditions of NC or NCSC were obtained as follow: fermentation temperature (30 °C both), fermentation time (72 h vs 74.7 h), solid-liquid ratio [1:3.5 vs 1:3.0 (g/mL)], inoculation amount (the inoculation amount of fungi/soybean meal (dry weight)) of Neurospora crassa + Saccharomyces [1% (m/m)+0 vs 1% (m/m) +20% (v/m)], initial pH (7.0 both). The protein hydrolysis of fermented soybean meal (FSM) could reach to 10.05% and 8.05% by NC and NCSC, respectively. In fermented soybean meal by NC, the level of total free amino acids (TFAA) increased 13 times (p < 0.05), in vitro digestion rate of protein reached to 95.96%, increased by 37.97% (p < 0.05) compared to soybean meal (SM). In fermented soybean meal by NCSC, the level of TFAA increased 6.76 times than that in SM (p < 0.05). SDS-PAGE results showed that macromolecular proteins were degraded to micromolecular proteins (<14.4 kDa/mw). No stripe of antibody response was observed and IC50 values of allergic reaction were significantly increased. It indicated fermentation improved nutritional quality and antioxidant activity of SM, and may be applied to food materials.

    更新日期:2018-11-05
  • Fast evaluation by quantitative PCR of microbial diversity and safety of Chinese Paocai inoculated with Lactobacillus plantarum NCU116 as the culture starter
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-02
    Tao Xiong, Jiakang Chen, Tao Huang, Mingyong Xie, Yangsheng Xiao, Changgen Liu, Zhen Peng

    Paocai as a traditional side dish in Asia gains its popularity owing to the favorable tastes, which are bestowed by microbial metabolisms. The microorganisms involved in fermentation are mainly lactic acid bacteria and Saccharomyces, while low-quality Paocai may contain spoilage and potentially pathogenic microorganisms such as Escherichia coli. To monitor and control food safety for direct vat inoculation of Paocai, this study intended to develop propidium monoazide based quantitative PCR to enumerate fermentation starter Lactobacillus plantarum NCU116, as well as Saccharomyces and potentially present pathogenic bacteria. Universal and specific primers targeting different microorganisms were designed to identify and quantify total lactic acid bacteria, Lactobacillus plantarum, Saccharomyces, and Escherichia coli by establishment of standard curves, respectively. Plate counting was performed and showed comparable results to quantitative PCR analysis, indicating the applicability and efficiency of absolute quantitative PCR in fast detection of microbial composition in Paocai system. Nitrite as a hazardous substance in Paocai was also investigated by spectrophotometry and reverse transcription quantitative PCR. The mechanism of nitrite synthesis and degradation was studied, revealing nitrite reductase in lactic acid bacteria as an effective enzyme in reducing nitrite present in the fermented vegetable.

    更新日期:2018-11-05
  • Flavored oven bags for cooking meat based on proteins
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-02
    Luciana Di Giorgio, Pablo R. Salgado, Adriana N. Mauri

    This work deals with the activation of protein films with a flavoring and their evaluation as oven bags for cooking meat. Two protein sources, very different in origin, structure and functionality, such as bovine gelatin (BG) and soybean proteins isolate (SPI); and a curry powder were used to prepared films by casting. Curry addition to protein film significantly affected their appearance, activated them with important antioxidant properties and improved their mechanical resistance without modifying their water susceptibility. Oven bags were prepared by heat sealing the films. Those of SPI successfully resisted cooking treatments in both conventional and microwave ovens, while those of BG were disintegrated during cooking possibly due to their higher sensitivity to humidity. Furthermore SPI bags managed to transfer the flavor to chicken meat during cooking, without affecting their texture and water content.

    更新日期:2018-11-05
  • Influence of two different cocoa-based coatings on quality characteristics of fresh-cut fruits during storage
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-02
    Virginia Glicerina, Urszula Tylewicz, Giada Canali, Lorenzo Siroli, Marco Dalla Rosa, Rosalba Lanciotti, Santina Romani

    The aim of this work was to evaluate the effect of two different cocoa-based coatings on some quality characteristics of fresh-cut fruits (grape and apple) during storage. Apples were cut into small pieces before application of cocoa coatings, while for grapes whole berries were used. Fruit samples were immersed in the cocoa dipping to obtain a thin layer of coating and then left to solidify. Coated products were packed in polyethylene terephthalate (PET) trays under atmospheric conditions and stored for 10 days at 6 °C and analysed at 0, 2, 4, 6, 8, 10 days for water activity, moisture, colour, texture, cell viability, microbiological and sensorial quality. Cocoa coatings provided positive effects on sensory properties of analysed fruit samples during storage. In general, coated grapes maintained better quality and microbiological characteristics compared to coated apple samples and uncoated ones showed general better performances mainly in terms of firmness and microbiological spoilage. All coated samples showed a shelf-life similar to uncoated ones, in particular from a microbiological point of view, generally until the 3rd day of storage for apples and the 6th day for grapes. Moreover, coating B showed better performances compared to A in enhancement of the shelf-life of fruits.

    更新日期:2018-11-05
  • Dynamic changes in targeted phenolic compounds and antioxidant potency of carob fruit (Ceratonia siliqua L.) products during in vitro digestion
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-03
    Vlasios Goulas, Andriani Hadjisolomou

    Carob fruit is considered as a rich source of phenolics that are linked with potent health effects. The aim of this work was to study the effect of a triple-step digestion on the stability of phenolics and antioxidant potency in carob products. Results showed that the gastric and intestinal steps induced the most significant changes in the stability of pure phenolics; their recovery ranged between 61 and 88% at oral, 40–87% at gastric and 16–57% at intestinal step. Regarding to the carob products, the yield of phenolic contents were ranged from 0.83 to 1.41 for gastric and from 0.43 to 0.82 for intestinal phase. The counterpart yield of antioxidant potency was 0.84–1.66 and 0.48–0.67, respectively. HPLC analysis also disclosed interesting findings; the stability of phenolics is strongly influenced by their chemical structure. In general, the phenolic acids are quite resistant under digestion procedure, whereas the flavonols are mostly degraded when they were subjected into digestion. Results points out that the carob phenolics are degraded, released from food matrix or attached to other food or digestive juice constituents. Furthermore, the critical role of food matrix was underlined as the food components had a protective effect against pH changes and enzymatic activities along digestion.

    更新日期:2018-11-05
  • Complexation of rice proteins and whey protein isolates by structural interactions to prepare soluble protein composites
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-03
    Ren Wang, Pengcheng Xu, Zhengxing Chen, Xing Zhou, Tao Wang

    The main factor limiting the preparation of high value-added rice proteins (RPs) is their low solubility. In this experiment, whey protein isolates (WPIs), which are of high nutritional value, were compounded with RPs at pH 12, and formed RP-WPI complexes by neutralization to pH 7 (pH-cycle). The formation of the protein complexes was studied by fluorescence and ultraviolet (UV) spectra. The results showed that hydrogen bond, hydrophobic force and electrostatic interaction mediated the merging of the two proteins into particulate spheres. Meanwhile the complexes acquired considerable surface charges resisting aggregation of the protein bodies, and the solubility of RPs was increased to more than 50%. The effectiveness of protein interactions by pH-cycle used in this study indicated that the technique may be a versatile approach to improve the functional properties of food proteins.

    更新日期:2018-11-05
  • Effect of roasting treatment on the chemical composition of sesame oil
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-03
    Junmin Ji, Yulan Liu, Longkai Shi, Nannan Wang, Xuede Wang

    Sesame oil is rich in highly concentrated bioactive components including tocopherols, phytosterols and lignans (e.g., sesamolin, sesamin, and sesamol). The chemical composition and quantification of oil extracted from roasted sesame seeds was investigated and compared with unroasted sesame oil in relation to health-promoting and potentially harmful substances (particularly polycyclic aromatic hydrocarbons, abbreviated as PAHs). With roasting, the peroxide value and color development of oils was elevated obviously while the total tocopherols and sesamolin decreased steadily. The acid values in the current experiment were expected to grow as the roasting time increased at the same temperature, and the acid value decreased in the first 30 min of roasting at 160 °C. Increased roasting temperature or time facilitates sesamol formation in sesame oil. The fatty acid profiles are almost independent of roasting conditions. There was a significant increase in PAHs with elevated temperatures and extended times. In general, favorable sensory qualities accompanied by a beneficial healthy composition of sesame oil may be attributed to the treatment by roasting at a temperature from 160 °C to 180 °C and a roasting time of less than 20 min.

    更新日期:2018-11-05
  • Mechanisms of the Escherichia coli and Enterococcus faecalis inactivation by ozone
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-10-31
    Zeynep Girgin Ersoy, Sibel Barisci, Ozge Turkay

    The aim of this study is to investigate the inactivation mechanism of ozone on Escherichia coli and Enterococcus faecalis, which signifies a Gram-negative and a Gram-positive bacterium, respectively. For bacterial inactivation, 1 mg/L ozonated water was used with the contact times of 30 s, 1, 5, 10 and 20 min. The TTC dehydrogenase relative activity of E. faecalis was inactivated after 30 s of ozone treatment; however, 20 min were needed for almost total inactivation of E. coli according to flow cytometry analysis. 30 s of treatment resulted in the release of intracellular components (i.e. DNA and protein) for both types of cells. The rapid increase of K+ leakage after 30 s of treatment for E. faecalis and 5 min for E. coli indicated the deterioration of cell membrane integrity. Due to lipopolysaccharide content in the cell membrane, lipid peroxidation of E. coli peaked within 30 s of ozone treatment. Although the death rate was significantly higher for E. faecalis, more severe cell wall injury in E. coli was detected by TEM. These results indicate that disruption of the cell wall integrity is not the only reason for E. faecalis cell mortality; damage of intracellular components is also required.

    更新日期:2018-11-02
  • Lipase synthesis of isoamyl acetate using different acyl donors: Comparison of novel esterification techniques
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-01
    Mahdieh Zare, Mohammad-Taghi Golmakani, Mehrdad Niakousari
    更新日期:2018-11-02
  • Functional enhancement of ultrafine Angelica gigas powder by spray-drying microencapsulation
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-11-01
    Kyeong-Ok Choi, Dongeun Kim, Jung Dae Lim, Sanghoon Ko, Geun-Pyo Hong, Suyong Lee

    Whole Angelica gigas in a powder form has been limitedly utilized for food applications due to its undesirable processing performance such as low aqueous solubility and dispersibility. Ultrafine Angelica gigas powders were thus microencapsulated with maltodextrin (MD) at different mass ratios (1:1, 1:2 and 1:3, w/w) by spray-drying to enhance their functional characteristics. The microencapsulated Angelica gigas powders had a smaller particle size and a smoother surface than the native ones, and their particle size had a tendency to decrease with increasing proportions of microencapsulating materials. Significantly higher bulk density and lower moisture content (p < 0.05) were observed in the microencapsulated Angelica gigas powders than the native ones. The microencapsulation significantly improved the water solubility and dispersibility of the Angelica gigas powders (p < 0.05). In addition, two fold higher contents of decursin and decursinol angelate were significantly included from the microencapsulated Angelica gigas powders (p < 0.05). The results indicated that the microencapsulation with MD by spray-drying could be effective in enhancing the functional characteristics of Angelica gigas powders, showing the potential uses of the microencapsulated Angelica gigas powders in a food system.

    更新日期:2018-11-02
  • Orange-fleshed sweet potato flour as a precursor of aroma and color of sourdough panettones
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-10-30
    Ana Paula Aparecida Pereira, Maria Teresa Pedrosa Silva Clerici, Marcio Schmiele, Luis Carlos Gioia Júnior, Marina Akemi Nojima, Caroline Joy Steel, Yoon Kil Chang, Glaucia Maria Pastore, Elizabeth Harumi Nabeshima
    更新日期:2018-10-31
  • Quantitative determination of free and esterified phytosterol profile in nuts and seeds commonly consumed in China by SPE/GC–MS
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-10-30
    Mengmeng Wang, Liuquan Zhang, Xiaodan Wu, Yajing Zhao, Lipeng Wu, Baiyi Lu

    Nuts and seeds are well known for their health benefits due to their bioactive compounds, including phytosterols. However, information on phytosterols in nuts and seeds is scare. In this study, the free and esterified phytosterols in 65 nut and seed samples from China were analyzed using solid-phase extraction combined with gas chromatography–mass spectrometry. The compositions of phytosterols were compared and classified by hierarchical cluster analysis. Results showed that the total phytosterols ranged from 15.9 mg/100 g dry weight of chestnuts to 255.2 mg/100 g dry weight of pistachios, and approximately 54.1%–77.2% of the total phytosterols were in the free form. Moreover, 76.1%–96.4% of the total phytosterols belonged to 4-desmethyl sterols, and more than 92.6% belonged to plant sterols. In most nuts and seeds, β-sitosterol was the major phytosterol, accounting for 62.4%–87.1%, except that in pumpkin seed kernel and watermelon seed kernels, the major phytosterol was α-spinasterol (57.7% and 67.8%, respectively). The nut and seed samples were classified into four groups on the basis of the composition of phytosterols. This study revealed the difference of phytosterols between nuts and seeds, which may contribute to their specific health benefits.

    更新日期:2018-10-31
  • Inhibitory of grey mold on green pepper and winter jujube by chlorine dioxide (ClO2) fumigation and its mechanisms
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-10-30
    Mao-run Fu, Xiao-min Zhang, Tong Jin, Bo-qiang Li, Zhan-quan Zhang, Shi-ping Tian

    As a powerful sanitizer, chlorine dioxide (ClO2) has mainly focused on control of bacteria, but little is known about its antifungal effects, especially on postharvest fungi found in vegetable and fruit. This study investigated the effect of ClO2 on Botrytis cinerea growth in vitro and on its disease severity in green pepper and winter jujube. Result showed that ClO2 fumigation reduced disease development of grey mold caused by B. cinerea on green pepper and winter jujube, and the efficiency was positively correlated with ClO2 concentrations. ClO2 treatment directly inhibited mycelial growth, spore germination and germ tube elongation of B. cinerea. To further survey the mechanisms by which ClO2 treatment inhibited hypha growth of B. cinerea, we observed the mycelial morphology and the integrity of the plasma membrane; the results showed that ClO2 treatment resulting in B. cinerea mycelial morphology was strongly affected, and leading to the loss of plasma membrane integrity, causing the cellular leakage. These data showed that ClO2 was effective for controlling grey mold caused by B. cinerea on green pepper and winter jujube, and the antifungal activity of ClO2 could be attributed to the disruption of cell membrane of the fungal pathogen.

    更新日期:2018-10-31
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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