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  • Potential of defatted marama flour-cassava starch composites to produce functional gluten-free bread-type dough
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-24
    Patricia M. Nyembwe, Henriëtte L. de Kock, John R.N. Taylor

    Marama bean is a drought-tolerant oilseed legume. Isolated marama bean protein has high foaming capacity, strong dough extensibility and good elasticity characteristics. The dough properties of composites of defatted marama flour (DMF) and cassava starch (CS) were compared with wheat flour dough with the aim of determining the potential of DMF as a functional nutritious gluten-free ingredient in bread. DMF-CS doughs with similar strength to wheat flour dough could be produced. However, they had much shorter Mixolab development time and stability. Alveography revealed that the DMF-CS doughs could inflate into a bubble, with the 33:67 DMF-CS ratio having the most similar bubble size, extensibility and deformation energy to wheat flour dough; with a higher proportion of DMF (57:43) these parameters were lower. Rheofermentometry showed that the DMF-CS composites could also hold gas produced by yeast fermentation. Confocal laser scanning microscopy revealed that as the proportion of DMF to CS was increased, the DMF protein tended to aggregate rather distribute throughout the dough, probably because the highly hydrophilic marama protein and pectin had great affinity for each other. Nevertheless, defatted marama flour appears to have considerable potential as a functional gluten replacement for making protein- and fibre-rich gluten-free bread.

    更新日期:2018-02-24
  • Effectiveness of vital gluten and transglutaminase in the improvement of physico-chemical properties of fresh bread
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-24
    Fatma Boukid, Eleonora Carini, Elena Curti, Gloria Bardini, Emanuele Pizzigalli, Elena Vittadini

    Transglutaminase (TG) and vital gluten (VG) were tested as improver agents in bread. The experimental design evaluated TG (0, 0.05, 0.1, 0.2 g/100 g flour), VG (0 and 1 g/100 g flour), and wheat flour strength (FS: weak -WF, medium -MF, and strong -SF). Bread specific volume, texture, color, moisture content and water activity were assessed and elaborated with multivariate statistical analysis (MANOVA). TG had a significant (p ≤ 0.001) impact on bread specific volume, color, texture and water status, while VG significantly (p ≤ 0.001) impacted crust color and texture. A significant (p ≤ 0.05) synergic effect (TGxVG) was observed on texture, crust color and water activity, MANOVA showed different effects, depending on flour strength. Optimal addition levels for best bread quality (low hardness and high specific volume) were selected for each flour: WF 0.2 g/100 g flour TG and 1 g/100 g flour VG; MF, 0.1 and 0.2 g/100 g flour of TG with 1 g/100 g flour VG; SF 0.1 g/100 g flour TG with 1 g/100 g flour VG.

    更新日期:2018-02-24
  • Effect of germination with sodium selenite on the isoflavones and cellular antioxidant activity of soybean (Glycine max)
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-24
    Marco A. Lazo-Vélez, Daniela Guardado-Félix, Jonnatan Avilés-González, Irasema Romo-López, Sergio O. Serna-Saldívar

    Isoflavones profiles and cellular antioxidant activity (CAA) of soybeans (Glycine max) germinated for different times with several sodium selenite (Na2SeO3) concentrations were assessed. The experiments were performed using central composite design and isoflavones evaluated by HPLC–UV and HPLC-MS-TOF. Malonylated genistein and malonylated daidzein glycosides were the main isoflavones associated to the soybean sprouts. Soybeans germinated for 48 h at 20 °C with a frequent spraying of water containing less than 32 mg/L of Na2SeO3 per liter contained the optimal concentrations of selenium (Se), total isoflavones and cellular antioxidant activity. This research demonstrated that Se-enriched soybean sprouts are a good source of both dietary Se and isoflavones and potentially can be used to formulate new functional foods.

    更新日期:2018-02-24
  • Preparation of pomegranate peel extract powder and evaluation of its effect on functional properties and shelf life of curd
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-23
    S. Sandhya, Kaushik Khamrui, Writdhama Prasad, C.T. Manoj Kumar

    A study was conducted to prepare pomegranate peel extract (PPE) powder and evaluation of its effect on functional properties and storage stability of curd. The extraction was carried out with ethanol and water and the extracted samples were analysed for anti-oxidant activity and total phenolic content (TPC). Ethanol based extract had significantly (p < 0.05) higher anti-oxidant activity and TPC as compared to aqueous extract. Hence, ethanol based extract was selected for powder preparation. It was mixed with drying aids viz. whey protein concetrate-70 (WPC-70) and skim milk powder (SMP) to avoid stickiness during drying. The WPC-70 based PPE powder showed higher anti-oxidant activity and TPC than SMP based PPE. Both PPE powders were incorporated into curd at different concentrations (0.5, 1 & 1.5%). Anti-oxidant activity and TPC of curd increased with increase in PPE concentration, however, sensorial attributes decreased at higher PPE concentration. Curd with 1% PPE powder showed considerable anti-oxidant activity and acceptable sensory attributes. During storage, PPE added curd shown resistance to increase in microbial count, change in acidity and whey syneresis. The shelf life of the PPE added curd was increased by 6 days as compared to control sample at 5 °C.

    更新日期:2018-02-23
  • Okara: A soybean by-product as an alternative to enrich vegetable paste
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-23
    Rafaiane Macedo Guimarães, Thamara Evangelista Silva, Ailton Cesar Lemes, Marussa Cássia Favaro Boldrin, Marco Antônio Pereira Silva, Fabiano Guimarães Silva, Mariana Buranelo Egea

    Okara is the residue of hydrosoluble extract from soybean used for producing tofu and soydrink and presents high nutritional value. Therefore, it has important characteristics that make it an excellent alternative to being incorporated into “pâté”, i.e., a soft mixture of vegetables transformed into paste to which various flavorings are added. As a result, it has enhanced sensory properties. The aim of this study was to investigate the application of okara on the development of pâté formulations in order to yield a product with good acceptability and nutritional quality. Three formulations were prepared from the wet soybean residue, which showed high moisture (80.77%–81.42%), low lipid (5.62%–7.62%) and low calorie (95.14–108.14 kcal) contents. The sample with the lowest content of okara (34 g/100 g) showed the highest average in the acceptance test (8.0) and was also considered the tasters’ favorite one. It was significantly different from the others in the preference ranking test. The food product enriched with okara had β-carotene (0.411mg/100 mL), compounds with antioxidant activity and isoflavones (0.15 μmol/gFM) in its composition. The process developed by this study enabled to yield a vegetable paste enriched with okara, an agroindustrial by-product, as an interesting alternative to a new food product.

    更新日期:2018-02-23
  • New monovarietal grape seed oils derived from white grape bagasse generated on an industrial scale at a winemaking plant
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-23
    Susana Boso, Pilar Gago, José-Luis Santiago, Emilio Rodríguez-Canas, María-Carmen Martínez

    This paper reports the composition of previously uncharacterized oils from seeds of the white grape varieties Albariño, Caíño Blanco and Loureira (Vitis vinifera L.). All three oils were obtained by cold extraction from bagasse-derived seeds collected at a white winemaking plant in northwestern Spain. These oils met the Codex Alimentarius criteria for edible vegetable oils. All had high linoleic acid contents and contained long chain fatty acids such as linolenic and eicosenoic acids. The majority phytosterols were β-sitosterol and apparent β-sitosterol. Among the vitamin E-associated molecules, γ- and α-tocotrienol were the most common. Organoleptically, the three oils were very different. The oil from the variety Loureira in particular stood out in terms of its aromatic richness and high sensorial quality. The present results show that the seeds of these varieties, which are available in large quantities in white winemaking bagasse (which unlike in red winemaking is removed before must fermentation and thus retains its natural qualities), can be used to produce high quality oils with properties beneficial to human health.

    更新日期:2018-02-23
  • Extreme thermal stability of Lactococcus lactis bacteriophages: Evaluation of phage inactivation in a pilot-plant pasteurizer
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-23
    Natalia Wagner, Sönke Matzen, Hans-Georg Walte, Horst Neve, Charles M.A.P. Franz, Knut J. Heller, Philipp Hammer

    Thermal inactivation of highly heat-stable Lactococcus lactis phages P680 and P1532 of the 936 group and P635 of the c2 group was investigated in a pilot-plant pasteurizer after suspension of the phages in raw milk (107 pfu/ml). The heat-sensitive reference phage P008 was tested as a control. The titers of the phages P008 and P635 decreased ≥99.99% after heating for 32 s at 75 °C and 80 °C, respectively. To achieve a similar inactivation of ≥99.99%, phages P680 and P1532 had to be treated for 39 s at temperatures of 95 °C and 97.5 °C, respectively. D- and z-values for thermal inactivation were calculated for each of the phages. When comparing thermal inactivation data of phages in the pilot-plant pasteurizer obtained in this study with literature data on phage heat inactivation in stainless-steel test tubes in a water bath, the pilot-plant pasteurizer was notably more efficient.

    更新日期:2018-02-23
  • Effects of micro-nano bubbles on the nucleation and crystal growth of sucrose and maltodextrin solutions during ultrasound-assisted freezing process
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-22
    Zhiwei Zhu, Da-Wen Sun, Zi Zhang, Yifei Li, Lina Cheng

    The effects of micro-nano bubbles (MNBs) on the ultrasound-assisted freezing process of sucrose and maltodextrin solutions were investigated and different freezing characteristics of both nucleation period and crystal growth period were analyzed. Results showed that the introduction of MNBs was effective for the acceleration of freezing process, including the ice nucleation and crystal growth of both sucrose and maltodextrin solutions. Under optimal combination conditions, both sucrose and maltodextrin solutions with MNBs achieved a remarkable reduction in the supercooling degree and freezing time (Tn = −1.24 ± 0.09 °C, tp = 92 ± 3.88 s and t = 230 ± 4.82 s for sucrose solution, and Tn = −1.97 ± 0.13 °C, tp = 102.9 ± 8.62 s and t = 240.2 ± 3.72 s for maltodextrin solution) as compared with conventional immersion freezing (Tn = −7.87 ± 4.65 °C, tp = 126 ± 17.86 s and t = 303 ± 28.12 s for sucrose solution without MNBs, and Tn = −8.24 ± 4.73 °C, tp = 127 ± 18.12 s, t = 303.83 ± 17.86 s for maltodextrin solution without MNBs). This study suggested that the introduction of MNBs was a feasible method for enhancing ultrasound-assisted freezing process.

    更新日期:2018-02-23
  • Global transcriptomic Acid Tolerance Response in Salmonella Enteritidis
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-21
    Shuangfang Hu, Yigang Yu, Donggen Zhou, Rong Li, Xinglong Xiao, Hui Wu

    Salmonella is a major foodborne pathogen throughout the world and able to resist extreme acid stress such as stomach gastric juice after mild acid adaptation, which makes it a potential hazard in food industry. We conducted a comparative transcriptomic analysis by high-throughout RNA-seq to elucidate the Acid Tolerance Response (ATR) in Salmonella Enteritidis. Among these 554 differentially expressed genes (DEGs) identified in this study, the expression of 280 DEGs were up-regulated and 274 DEGs were down-regulated. First, S. Enteritidis tried to survive the adverse environment by reducing the energy-consuming metabolisms and maintaining essential processes as an energy conservation strategy. Second, ATR S. Enteritidis underwent damages in DNA, an oxidization damage result in an iron-lacking circumstance and so on. Thus DEGs related to Fe/S cluster biogenesis, stress response regulating proteins and transport proteins were responsive to acid stress to repair damage caused by acid and ROS. Last, to balance extra protons, by increasing the intracellular NAD (+)/NADH ratio, S. Enteritidis could also decline the protein acetylation level by promoting the consumption of acetyl coenzyme A via TCA, to prevent the intracellular pH from further decline under acid stress.

    更新日期:2018-02-22
  • In vitro evaluation of prebiotic activity, pathogen inhibition and enzymatic metabolism of intestinal bacteria in the presence of fructans extracted from agave: A comparison based on polymerization degree
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-21
    Ricardo García Gamboa, Rosa Isela Ortiz Basurto, Montserrat Calderón Santoyo, Jorge Bravo Madrigal, Blanca Elizabeth Ruiz Álvarez, Marisela González Ávila

    The prebiotic effect of fructans is well known, including their beneficial influence on health. This study shows agave fructans impact as potential prebiotics, depending on their structure and polymerization degree (PD). The growth of seven probiotics and three pathogens was estimated by turbidimetric analysis and the latter (Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes) were submitted to growth inhibition tests in the presence of metabolites produced by probiotics. Lactobacillus casei and L. paracasei growth was optimal when supplemented with agave fructans. L. casei was grown in the presence of the extracted fractions obtained from Agave salmiana spp. crassipina (optical density (O.D.) 1.09 ± 0.02, 0.98 ± 0.03, 0.98 ± 0.07, low, medium and high PD, respectively), A. salmiana var. liso (0.85 ± 0.13), A. atrovirens (0.79 ± 0.03) and A. tequilana spp. (0.89 ± 0.03). The growth of L. paracasei was optimal when supplemented with those fractions obtained from the A. salmiana (O.D. 1.12 ± 0.02, 1.18 ± 0.02, 1.13 ± 0.007, low, medium and high PD, respectively) and A. tequilana var. cenizo (1.18 ± 0.01 and 1.15 ± 0.02, medium and high PD, respectively) species. Both bacteria were tested in order to assess enzyme activity using API ZYM galleries after they were grown on agave fructans. The results show an increase of five enzymes (cysteine-arylamidase, α-chymotrypsin, β-galactosidase, N-acetyl-β-glucosaminidase and α-fucosidase).

    更新日期:2018-02-21
  • Effects of various polysaccharide clarification agents and reaction time on content of polyphenolic compound, antioxidant activity, turbidity and colour of chokeberry juice
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-21
    Sabina Lachowicz, Jan Oszmiański, Stanisław Kalisz

    Chokeberry juice is a good source of health-promoting nutrients, and can be a suitable supplement for a healthy diet. Therefore, the aim of this study was to investigate the changes that occur during clarification using different polysaccharides-based clarification agents (chitosan, xanthan gum (XG), carboxymethylcellulose (CMC), agar-agar (AA), carob gum (locust bean gum, LBG), β-cyclodextrin (BCD), guar gum (GG)), their doses and reaction time on the phenolic compounds (UPLC-PDA-FL), turbidity, change of colour (CIEL*a*b*) and antioxidant activity (ABTS and FRAP) of chokeberry juice. Low turbidity and high antioxidant activity and contents of polyphenol compounds were obtained in chokeberry juice with addition of clarification agents as AA, CMC and XG. The colour of these juices were attractive, intensive red and without browning after reaction time and storage. The dose of clarification agents and after reaction time (1, 5, 16 h) significantly influenced increase in the quality of the finally products. These clarification agents after 5 months storage were also well influenced the stability of clarification process and of of physical and bioactive parameterising the centrifuged chokeberry juice. This study suggests that AA, CMC and XG can be used as a clarifying aid of chokeberry juices.

    更新日期:2018-02-21
  • Cyclic low dose UV-C treatments retain strawberry fruit quality more effectively than conventional pre-storage single high fluence applications
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-20
    Leidy C. Ortiz Araque, Luis M. Rodoni, Magalí Darré, Cristian M. Ortiz, Pedro M. Civello, Ariel R. Vicente

    UV-C irradiation has been shown to reduce fruit decay and delay ripening. Based on an expected higher impact and applicability, UV irradiation treatments have been almost exclusively done before storage at relatively high doses. We evaluated the influence of the pattern of repeated short dose UV-C exposure on quality maintenance of strawberry fruit. Strawberries were subjected to the following treatments: Single-step UV: single 4 kJ m−2 irradiation prior to storage; two-step UV: two consecutive 2 kJ m−2 UV irradiations at harvest and after 4 days of storage and multi-step UV: five 0.8 kJ m−2 after 0, 2, 4, 6 and 8 days of storage respectively. A non-irradiated group was left untreated. Samples were stored at 0 °C for 13 days. All UV-C treatments decreased decay, weight loss and softening. The quality retention was higher in fruit subjected two-step and multi-step UV-C. Multiple low dose UV exposure reduced calyx browning more efficiently. Repeated low UV-C dose decreased mold and yeast counts to a higher extent. Multi-step UV treated fruit showed higher alcohol insoluble residue. Two-step UV-C treated fruit showed the highest sensorial scores. Repeated low dose UV-C treatments are more effective in preventing strawberry fruit than conventional single high-fluence pre-storage irradiation.

    更新日期:2018-02-21
  • HTST puffing in order to produce crispy banana - The effect of the step-down treatment prior to air-drying
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-20
    Carla I.A. La Fuente, Celso C. Lopes

    Banana snacks were produced by HTST puffing. Experiments were performed as follows: an initial pulse at 150 °C for 15 min + step-down treatment from 150 to 70 °C + air-drying at 70 °C. The aim of this work was to study the effect of this step-down treatment on banana snack attributes: crispness, shrinkage, color and structural morphology. Two variables were evaluated. The first was the magnitude of temperature reduction, named as amplitude. The second was the residence time at this temperature, named as cycle time. Results showed that an amplitude of 10 °C and cycle time of 7.5 or 10 min, lead to a gradual reduction of temperature. Banana snacks from these step-down treatments resulted in a highly porous structure, higher number of peaks in the force-deformation curve (an indicative parameter of crispness), less volume loss and, less color degradation. Thus, these treatments were shown to be an adequate alternative in relation to the conditions with the sudden reduction of temperature.

    更新日期:2018-02-21
  • Cistus ladanifer L. essential oil as a plant based preservative against molds infesting oil seeds, aflatoxin B1 secretion, oxidative deterioration and methylglyoxal biosynthesis
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-20
    Neha Upadhyay, Vipin Kumar Singh, Abhishek Kumar Dwivedy, Somenath Das, Anand Kumar Chaudhari, Nawal Kishore Dubey
    更新日期:2018-02-21
  • Effect of a physical pre-treatment and drying on carotenoids of goji berries (Lycium barbarum L.)
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    A. Fratianni, S. Niro, M.D.R. Alam, L. Cinquanta, M. Di Matteo, G. Adiletta, G. Panfili

    In order to evaluate the influence of an abrasive pre-treatment and drying at 50 °C, 60 °C, 70 °C of goji fruits (Lycium barbarum L.), changes in colour and carotenoids were studied. An extraction method was modified and adapted to assay the main carotenoid esters and saponified carotenoids of goji berries, before and after treatments. Goji berries were confirmed as a high source of zeaxanthin, with zeaxanthin-dipalmitate at about 2 g/kg dry weight. The reliability of the analytical method was confirmed by the high quantitative recoveries, about 100%, a higher repeatability than reference methods and a good reproducibility (lower than 5%). After drying, significant but small carotenoid losses (15–20%) were observed in both pre-treated and treated samples. The xanthophyll esters confirmed to be more stable than free carotenoids. The drying process significantly modified colour, in both pre-treated and untreated samples, however, pre-treatment reduced drying time and thus better preserved the colour of the goji berries for a drying temperature up to 60 °C.

    更新日期:2018-02-21
  • Improving lipid oxidation inhibition in cooked beef hamburger patties during refrigerated storage with encapsulated polyphosphate incorporation
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    B. Kılıç, A. Şimşek, J.R. Claus, E. Karaca, D. Bilecen

    This work evaluated the influence of added encapsulated (e) polyphosphates (PP; sodium tripolyphosphate, STP; sodium pyrophosphate, SPP) levels (0, 0.25, 0.5%) on lipid oxidation inhibition in beef patties during 120 d refrigerated storage. STP incorporation led to lower (P < 0.05) cooking loss (CL) compared to SPP, caused similar CL with control. Added ePP level had no impact on CL. Although ePP level was not a factor on manufacturing day, increasing eSTP or eSPP level increased or decreased pH respectivelly at the end of storage (P < 0.05). Although PP type and ePP level did not influence some physico-chemical (fat, texture, fatty acids) parameters, STP increased moisture, ash and redness and decreased protein, lightness and yellowness compared to control and SPP incorporated patties (P < 0.05). Regardless of encapsulated or not, SPP enhanced lipid oxidation reduction rate compared to STP (P < 0.05). Using 0.25% ePP provided lower (P < 0.05) lipid oxidation than 0.5% unencapsulated PP. Hovewer, 0.5% ePP had no further impact on advancing lipid oxidation inhibition.

    更新日期:2018-02-21
  • Use of high pressure homogenization to reduce milk proteolysis caused by Pseudomonas fluorescens protease
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Miguel Meirelles de Oliveira, Bruno Ricardo de Castro Leite Júnior, Alline Artigiani Lima Tribst, Marcelo Cristianini

    The growth of proteolytic microorganisms in raw milk is favored when the milk is stored at abusive refrigeration temperatures for many days. The proteases produced, especially by Pseudomonas genus, are heat resistant, and can induce problems in dairy products on a long term basis, such as age gelation in milk processed by UHT systems. This work evaluated the impact of high pressure homogenization (HPH) processing at 100 and 150 MPa on milk proteolysis during storage, considering that this emerging technology can alter the structure of the milk constituents and enzyme activity. HPH (up to 150 MPa) was incapable of inactivating the Pseudomonas protease and did not alter the occurrence of proteolysis in skimmed milk. On the other hand, positive effects of HPH were observed for standard milk (3% fat) samples, with reductions in proteolysis of 29 and 51% for samples processed at 100 and 150 MPa, respectively. The practical impact of this effect was delays in age gelation of at least 23 (100 MPa) and 40 days (150 MPa) for milk with 3% fat. A microstructural evaluation inferred that fat globule fragmentation and its subsequent adsorption by protein was the main factor responsible for the reduction in milk proteolysis.

    更新日期:2018-02-21
  • Effects of ozone-enriched storage atmosphere on postharvest quality of black mulberry fruits (Morus nigra L.)
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Nadide Tabakoglu, Hakan Karaca

    Ozone, a popular agent for food industry, was examined to extend the shelf life of fresh mulberry fruit. Changes in quality parameters of mulberries were investigated during storage in cold rooms with ambient air and ozone atmospheres (0.64 and 5.14 mg m−3) for 6 days at 2 °C and 95% RH. The selected quality parameters were the counts of total aerobic mesophilic bacteria (TAMB), Enterobacteriaceae, yeast-mold, weight loss, and the contents of ascorbic acid and total monomeric anthocyanins. On the first sampling day, the numbers of all microorganisms tested were significantly lower in the samples stored in 5.14 mg m−3 ozone atmosphere compared to that in air (p < 0.05). However, at the end of the storage period the counts of TAMB and yeast-mold in the samples stored in air and ozone were not significantly different (p > 0.05). The case was different for Enterobacteriaceae where the counts in the samples stored in 5.14 mg m−3 ozone atmosphere were significantly lower than the other samples (p < 0.05). Weight loss was less severe in the samples stored in ozone atmosphere compared to the control samples. Ozone in the storage atmosphere did not have any detrimental effect on anthocyanins and ascorbic acid contents of the fruit.

    更新日期:2018-02-21
  • In vitro bioaccessibility and physicochemical properties of phytosterol linoleic ester synthesized from soybean sterol and linoleic acid
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Fuming Yang, Samson A. Oyeyinka, Weili Xu, Ying Ma, Shaobo Zhou

    Phytosterols are bioactive components capable of reducing cholesterol level in serum and reducing risk of arteriosclerosis. In this study, conditions for the synthesis of maximum yield of phytosterol linoleic ester (PLE) was optimized and the physicochemical properties and in vitro bioaccessibility of the PLE were assessed. Under the optimized condition of 1:1.1 mol ratio of phytosterol and linoleoyl chloride at 80 °C for 1.5 h, the conversion rate of phytosterol reached 96.1%. Its solubility in oil increased 20 times, up to 33.8%. Also, peroxide value of PLE was much lower than linoleic acid (32.9 and 47.0 mmol/kg), which means better oxidative stability. Bioaccessibility of PLE was affected by time, concentration of bile extract, and dissolved medium. It was 4.93% alone, increased by 2.5 times compare to phytosterol; or 53.46% in oil, under the condition of 40 mg/mL bile extract for 120 min. In conclusion, under the tested condition, phytosterol conversion rate, its solubility in oil and bioaccessibility were improved significantly. The method showed great potential in manufacture high quality and quantity of PLE.

    更新日期:2018-02-21
  • Biogenic amine formation and bacterial contribution in Cheonggukjang, a Korean traditional fermented soybean food
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Ah Ran Jeon, Jae Hoan Lee, Jae-Hyung Mah

    To evaluate the safety of Cheonggukjang, 60 different samples collected from 8 provinces all across the country were analyzed for biogenic amine contents by HPLC. The aromatic vasoactive amine (β-phenylethylamine and tyramine) contents in some Cheonggukjang samples exceeded safe levels for consumption. Bacterial and enterococcal counts of Cheonggukjang samples were 9.70 ± 0.43 and 6.00 ± 1.52 Log CFU/g, respectively, and strains of Bacillus (n = 433) and Enterococcus (n = 55) isolated from Cheonggukjang samples were tested for biogenic amine production in assay media. Histamine and putrefactive amines (putrescine and cadaverine) were detected more abundantly in cultures of Bacillus strains, while tyramine was detected in larger quantities in cultures of Enterococcus strains. Subsequently, strains selected based on their specific abilities to produce the aforementioned respective biogenic amines were applied to soybeans to undergo fermentation, and biogenic amine contents in the soybeans were measured during the fermentation period. Unexpectedly, Bacillus strains produced slightly lower levels of histamine, but significantly higher levels of β-phenylethylamine and tyramine than Enterococcus strains. Altogether, this study suggests that Bacillus species are as significant as Enterococcus species for biogenic amine production in Cheonggukjang, including tyramine, and should be controlled accordingly for the reduction of biogenic amine contents in the food.

    更新日期:2018-02-21
  • Improving design of thermal water activity cell to study thermal resistance of Salmonella in low-moisture foods
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Ravi Kiran Tadapaneni, Jie Xu, Ren Yang, Juming Tang

    Water activity (aw) influences the thermal resistance (D-value) of pathogens in low-moisture foods (LMF). However, the influence of food matrices on aw at elevated temperatures is complicated. A recent study reported that a novel thermal water activity cell (TAC) could be used to control aw of LMF using LiCl solution (select molality) during the isothermal determination of D-values of Salmonella. This research proposed a new version of TAC (TAC-II) that could significantly reduce the time to establish the moisture-equilibrium between LMF and LiCl solutions during D-value measurements. Wheat flour (WF) samples inoculated with Salmonella (aw at room temperature = 0.45) were treated in TAC-II at 80 °C under controlled relative humidity (RH) (45%) provided by LiCl solution (9.37 mol kg−1). Results showed that the moisture-equilibrium was established to the controlled RH condition at 80 °C in <4 min for tests with TAC-II, as opposed to >14 min for TAC. The D-value of Salmonella in WF treated in TAC-II at 80 °C (20.7 ± 1.1 min) was significantly higher (p < 0.05) than the reported D-values of Salmonella obtained from TAC and conventional test-cells. TAC-II offers to improve our understanding of the isolated effect of aw (corresponding RH) at high temperatures on the D-values of Salmonella in LMF.

    更新日期:2018-02-21
  • Characterization of rosemary and thyme extracts for incorporation into a whey protein based film
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Mariana A. Andrade, Regiane Ribeiro-Santos, M. Conceição Costa Bonito, Margarida Saraiva, Ana Sanches-Silva

    Active packaging is designed to interact with foods by releasing active components with biological properties, allowing the extension of foods shelf-life, being aromatic plants a source of active compounds. The main goal of this research was to develop a biodegradable whey protein based film, incorporated with an aromatic plant extract. Ethanolic extracts from rosemary and thyme were obtained from three commercial brands. The DPPH* scavenging activity assay showed that the rosemary extracts presented the highest antioxidant capacity. Thyme acetone extract had the highest antioxidant activity in the β-carotene bleaching assay. Three different mixtures of rosemary and thyme extracts with the highest antioxidant capacity showed a lower antioxidant capacity than the single extracts. The content of carnosic acid, carnosol and rosmarinic acid was determined in the three rosemary extracts, having the extract from the brand C shown the highest phenolics content. The extract showed antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes and Clostridium perfringens. For the active film, 1% of the rosemary extract was incorporated into the whey protein film. The film presented antimicrobial activity against L. monocytogenes and S. aureus.

    更新日期:2018-02-21
  • Effect of initial 5 days fermentation under low salt condition on the quality of soy sauce
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-19
    Nguyen Xuan Hoang, Sophia Ferng, Ching-Hua Ting, Ying-Chen Lu, Yu-Fong Yeh, Yi-Ru Lai, Robin Yih-Yuan Chiou, Jean-Yu Hwang, Cheng-Kuang Hsu

    A two-stage moromi fermentation method was employed to the soy sauce making in order to shorten the overall fermentation time. At the first stage, the koji was mixed with 10% brine solution and incubated at 40 °C for 5 days. The second fermentation stage was conducted under three different treatments, including reduced temperature from40 °C to 30 °C, outdoor without temperature control, and indoor ambience temperature up to 3 months with the brine content increased from 10% to 18%. The increases of total nitrogen (TN) and amino nitrogen (AN) contents were mainly occurred at the first stage while maintain constant during the second stage. Both TN and AN values satisfied the requirement of first-grade soy sauce of Taiwan. Unlike TN and AN, the reducing sugar and total acid contents still increased with fermentation time during the second stages. Since most of the changes of these biochemical properties occurred within 5 days’ moromi fermentation, the use of high temperature and low salt fermentation condition in the first stage was very important to rapid fermentation process of soy sauce.

    更新日期:2018-02-19
  • Effects of different milling methods on physicochemical properties of common buckwheat flour
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-17
    Didi Yu, Jincheng Chen, Jie Ma, Huaxing Sun, Yanqiu Yuan, Qian Ju, Yuzhao Teng, Mo Yang, Wenhao Li, Kaori Fujita, Eizo Tatsumi, Guangzhong Luan

    Physicochemical properties of common buckwheat flour processed using a high-speed universal grinder (UGBF), wet-milling (WMBF) and a stone mill (SMBF) were investigated and compared, since there is scarce information concerning the effect of different milling methods on physicochemical properties of common buckwheat flour. The results showed that WMBF had lower average particle size and damaged starch content than other samples. Scanning electron microscopy (SEM) observations showed that WMBF had more intact granular structures compared to UGBF and SMBF. The bulk densities of UGBF and SMBF increased as the particle size decreased, whereas WMBF exhibited a reverse trend according to bulk density analysis. Wet-milling method caused a significant lowering of the total flavonoid content. Colour measurements revealed that WMBF exhibited higher L* value compared to other samples. Differential scanning calorimeter (DSC) analysis showed that WMBF had significantly lower Tp but higher ΔH compared to UGBF and SMBF. Rapid Visco Analyzer (RVA) measurements showed that the suspension viscosity of SMBF and WMBF was higher than UGBF. Furthermore, among different buckwheat flour, WMBF showed the highest water absorption index (WAI) value and swelling power (SP) value but the lowest water solubility index (WSI) value and water binding capacity (WBC) value.

    更新日期:2018-02-19
  • Effect of drying and extrusion processing on physical and nutritional characteristics of bilberry press cake extrudates
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-17
    Evelina Höglund, Lovisa Eliasson, Gabriel Oliveira, Valérie L. Almli, Nesli Sozer, Marie Alminger

    Mild drying and extrusion processing of side streams from berry juice production can enable retention of valuable compounds in the food chain and reduce waste production. The aim of this study was to evaluate the applicability of using hot air (HA) and microwave assisted hot air (MWHA) drying combined with extrusion for conversion of bilberry press cake into value-added extruded food products. Bilberry press cake was dried at 40 °C by HA and MWHA drying to a moisture content of 17 g/100 g. A twin screw extruder (average feed rate 72 g/min, temperature profile 135-128-89-69 °C) was used to extrude products containing organic wholegrain rye flour and 10% or 25% dried bilberry press cake powder. A consumer panel (n = 15) evaluated four extrudates on hedonic and Just-About-Right (JAR) scales, with a main focus on texture properties. The results indicate that different drying techniques implied a difference in processing time (40% reduction with MWHA drying). However, the retention of total phenolics and physical characteristics of extruded snacks containing bilberry powders were independent of drying techniques. In sum, powder of bilberry press cake can be incorporated in cereal based extruded snacks with enhanced phenolic content and potential for palatable sensory properties.

    更新日期:2018-02-19
  • Biotechnological potential, probiotic and safety properties of newly isolated enterocin-producing Enterococcus lactis strains
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-17
    Olfa Ben Braïek, Morandi Stefano, Cremonesi Paola, Smaoui Slim, Hani Khaled, Ghrairi Taoufik

    Eight lactic acid bacterial (LAB) strains were newly isolated from fresh shrimps (Penaeus vannamei and Palaemon serratus) and characterised by phenotypic and molecular tests. These isolates, identified as Enterococcus lactis producing the enterocins A, B and/or P, displayed interesting antagonistic activities against pathogenic bacteria and fungi. Regarding biotechnological properties, E. lactis strains had generally great redox potentials, good proteolytic activities (P < 0.05) and medium acidification rates. Evaluated by the API ZYM system, two strains named Q1 and 4CP3 exhibited good enzymatic activities: leucine, valine and cystine arymalidases, Naphthol-AS-BI-phosphohydrolase and β-galactosidase. For probiotic assessment, the examined strains were found to resist low pH and bile salts with presence of gastric and digestive enzymes. Likewise, they indicated potentialities of adhesion and colonisation in the intestines. All strains were sensitive to clinically important antibiotics and no PCR signals were detected for any of the common antibiotic resistance genes such as vanA and vanB for vancomycin. Furthermore, virulence traits including the presence of virulence factors, haemolysin and gelatinase, were not detected. This work suggests that our E. lactis strains can be considered as promising candidates for future applications as a starter, adjunct or protective cultures or could constitute new potential probiotics.

    更新日期:2018-02-19
  • Quantitative determination of epoxy stearic acids derived from oxidized frying oil based on solid-phase extraction and gas chromatography
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-17
    Ying Liu, Yuanpeng Wang, Peirang Cao, Yuanfa Liu

    An improved preparation method based on solid phase extraction (SPE) for determination of epoxy fatty acids derived from oleic acid in frying oils was developed. A three-step separation of fatty acid methyl esters (FAMEs) by SPE on a silica gel column was proposed, and quantification by gas chromatograph with a fiame ionization detector (GC-FID) was performed. The limits of detection (LODs) of trans- and cis-epoxy stearic acid (ESA) were 6.32 and 13.09 μg/mL, respectively. And the limits of quantification (LOQs) ranged from 20.87 to 43.19 μg/mL with recoveries ranging from 89.32% to 107.08%. Good reproducibility was observed, with an intraday relative standard deviations of 0.93–2.35%, and an interday relative standard deviations of 2.44–11.68%. Results showed total levels of ESAs in different oil samples were in the range of 235.65–5916.05 mg/kg, and the contents of ESAs increased with the increase of frying time. Thus, combining the improved sample preparation method for ESAs analysis with the separation on a fused-silica capillary column using GC is highly useful for determination of ESAs in frying oils.

    更新日期:2018-02-17
  • Enzymatic preparation and facile purification of medium-chain, and medium- and long-chain fatty acid diacylglycerols
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-16
    Guanghui Li, Jiazi Chen, Xiang Ma, Zhen Zhang, Ning Liu, Yong Wang

    High purity diacylglycerols (DAG) rich in medium-chain fatty acid diacylglycerols (MCD) and medium- and long-chain fatty acid diacylglycerols (MLCD) were prepared via the enzymatic esterification of monoacylglycerols (MAG) with caprylic acid followed by molecular distillation (MD), solvent fraction and low-temperature centrifugation. The content of DAG in the crude product was 44.8 ± 0.1%, under the selected esterification conditions, which were MAGs/caprylic acid mole ratio of 1:3, reaction temperature of 65 °C, reaction time of 30 min and enzyme load of 5 wt.%. Subsequently, the one-step MD and solvent fraction in methanol/ethanol increased the DAG content to 61.3 ± 0.8%. Eventually, the product containing 86.6 ± 0.6% of DAG with 39.3 ± 1.3% of MCD and 47.3 ± 0.6% of MLCD was obtained by the methanol crystallization at 0 °C with a water content of 9 wt.% and a 1:3 ratio of glycerides/methanol (v/v) followed by the centrifugation separation at 0 °C.

    更新日期:2018-02-16
  • Effects of probiotic strains, Lactobacillus plantarum TN8 and Pediococcus acidilactici, on microbiological and physico-chemical characteristics of beef sausages
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-16
    Sirine Ben Slima, Naourez Ktari, Mehdi Triki, Imen Trabelsi, Asehraou Abdeslam, Hafedh Moussa, Iskandar Makni, Ana Maria Herrero, Francisco Jiménez-Colmenero, Claudia Ruiz-Capillas, Riadh Ben Salah

    This study was undertaken to evaluate the effects of a combination of probiotic strains namely, Lactobacillus plantarum TN8 and Pediococcus acidilactici MA 18/5M and dietary fiber on microbiological and physico-chemical characteristics of sausages stored at 4 °C up to 12 days. L. plantarum TN8 might be a potential food additive in the meat industry as a probiotic agent. Microbial counts revealed a decrease in Enterobacteriaceae of inoculated sausages, which reached values below 2 log CFU/g in the stored product. Reformulated sausages recorded good textural attributes and improved sensory features. At the end of storage period, sausages with different probiotic strains decreased the b* color parameter and cooking loss when compared with control samples. Sensorial and color parameters could be used for constructing regression models to predict overall acceptability. On the other hand, the free fatty acid profile was significantly affected by probiotic strains. Overall, the inclusion of two probiotic strains and fiber improved the hygienic quality and sensorial features of sausages.

    更新日期:2018-02-16
  • Characteristics of fermented coffee inoculated with yeast starter cultures using different inoculation methods
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-16
    Ana Paula Pereira Bressani, Silvia Juliana Martinez, Suzana Reis Evangelista, Disney Ribeiro Dias, Rosane Freitas Schwan

    This study aimed to evaluate the behavior of yeasts as starter cultures for dry-processed coffee. Saccharomyces cerevisiae CCMA 0543, Candida parapsilosis CCMA 0544, and Torulospora delbrueckii CCMA 0684 were separately inoculated into coffee by directly spraying the cherries on a terrace or in buckets for 16 h before sun drying. Samples were collected and analyzed by qPCR (inoculum persistence), HPLC and GC-MS. Sensory analysis was performed on the roasted coffee. All treatments directly inoculated with yeasts showed high citric and malic acid concentrations. Caffeine, chlorogenic acids and trigonelline concentrations varied between the methods of inoculation. A total of 217 volatile compounds were identified. After roasting, volatile compounds corresponding to caramel flavor were detected in samples inoculated with Saccharomyces cerevisiae CCMA 0543 D. Fruity flavor (apple, cherry) compounds were observed in samples inoculated with Candida parapsilosis CCMA 0544 D. Saccharomyces cerevisiae CCMA 0543 inoculated in buckets obtained the highest score in the coffee cupping. Direct inoculation of Candida parapsilosis CCMA 0544 showed the best results when compared to the bucket method, while Torulospora delbrueckii CCMA 0684 showed good results for both inoculation methods evaluated.

    更新日期:2018-02-16
  • Effects of polyols on gelation kinetics, gel hardness, and drying properties of alginates subjected to internal gelation
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-15
    Asli Can Karaca, Ibrahim Gokce Erdem, M. Mehmet Ak

    This study investigates the influence of polyols (glycerol, sorbitol, mannitol and isomalt) on thickening of sodium alginate solutions, hardness and drying kinetics of calcium alginate gels and their glass transition temperature (Tg) after drying. Two alginate samples with 30% and 63% guluronate were used to prepare gels by internal gelation based on release of calcium ions from CaCO3 by hydrolysis of glucono-delta-lactone. The lag period, determined from viscosity-time plots, for the low-G alginate was about 13 min less than that for the high-G alginate. Presence of polyols did not influence the lag period values. The hardness value for high-G gels was about 100 g greater than that of low-G gels. Addition of isomalt resulted in gels with higher hardness values compared to other polyols. Presence of polyols had a significant effect on residual moisture and Tg of alginate films. Initial drying rates were the same for all samples but gels containing glycerol had high residual moisture (∼3.5 g/100 g) and produced very flexible films, whereas mannitol containing samples had low moisture (∼0.2 g/100 g) and produced brittle films. Tg of the films varied from −88 °C to 35 °C and decreased upon polyol addition.

    更新日期:2018-02-15
  • Influence of different organic materials on chlorine concentration and sanitization of slightly acidic electrolyzed water
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-15
    Hyeon-Yeong Jo, Charles Nkufi Tango, Deog-Hwan Oh

    The objective of the present study was to determine the effect of organic materials on chlorine concentration through in vitro assays to identify the most critical organic material affecting the sanitization of slightly acidic electrolyzed water (SAEW) during washing process. Organic materials (100–1000 mg/L) were added into SAEW solution and consumption of free chlorine was recorded. Inactivation of pathogens was performed in present of these organic materials. Depletion of free chlorine and sanitization efficacy of SAEW were determined during vegetables and meats samples washing processes. Results of this study showed that protein compounds had more detrimental effects on sanitization efficacy than lipids and carbohydrates. In the presence of carbohydrate and lipid compounds, pathogen population were decreased below the detection limits within 3 min. However, SAEW effect was decreased with increasing protein concentration. During simulation of washing processes, free chlorine was more quickly consumed in reactions containing organic materials for meats compared to those for vegetable produce. However, such difference in chlorine depletion did not significantly influence bacterial reduction between meats and vegetable produce. These results indicate that the optimization of SAEW washing should consider both the amount and the type of organic materials constituting the fresh produce.

    更新日期:2018-02-15
  • Smart technique for accurate monitoring of ATP content in frozen fish fillets using fluorescence fingerprint
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-14
    Mario Shibata, Gamal ElMasry, Keisuke Moriya, Md. Mizanur Rahman, Yuki Miyamoto, Kazuya Ito, Naho Nakazawa, Shigeki Nakauchi, Emiko Okazaki

    The aim of the present study was to develop a fast and nondestructive method based on fluorescence fingerprints (FFs) to predict the ATP content in frozen fish meat frozen at early stages after death using fillets of horse mackerel (Trachurusjaponicus) as a model. Fifty-six fish were sacrificed instantly, stored in ice for different periods (0–48 h), and then filleted and frozen. The fluorescence fingerprints of the frozen fillet samples were acquired using fluorescence spectrophotometer with fiber probe installed inside a freezer. Subsequently, the ATP-related compounds of the same samples were determined using HPLC. Finally, four different models based on partial least squares (PLS) were developed to predict ATP contents from HPLC and the FFs data. The best PLS model with a correlation coefficient (R2) of 0.88 and root mean square error estimated by cross validation (RMSECV) of 0.97 μmol/g was obtained when the most important combinations of excitation-emission wavelengths were used for prediction. This methodology offers a simple and rapid approach to detect the ATP contents in frozen fish nondestructively without thawing the sample during the assessment that could be applied during any stage of fish marketing, facilitating quality control activities and the determination of fishery market price.

    更新日期:2018-02-14
  • Multiplex PCR to discriminate bovine, porcine, and fish DNA in gelatin and confectionery products
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-14
    Sharmin Sultana, M.A.Motalib Hossain, I.S.M. Zaidul, Md Eaqub Ali

    Gelatin is widely used in many confectionery products such as gummy, candies, pastilles and marshmallows. However, the acceptance of gelatin in consumer goods largely depends on its animal origins. The main sources of gelatin are pig, cow and fish collagens that have differential acceptance in Halal, Kosher and Hindu foods. Currently, several simplex and duplex PCR assays are available for the determination of gelatin origins but those methods are not only time-consuming and costly but also cannot reveal all information in a single assay platform. For the first time, we documented here a tetraplex PCR assay involving eukaryotic, fish, bovine, and porcine control for the simultaneous detection of these species by a single, easy and reliable approach. The assay was optimized under pure and mixed gelatin matrices and validated by PCR product sequencing. Finally, 38 halal branded confectionery items were screened and 33, 2 and 3 of them yielded positive bands for bovine, porcine and eukaryotes, respectively. The detection limit was 0.1 to 0.001 ng DNA extracted from pure and mixed gelatins. The study is potentially useful in monitoring and certifying halal, kosher and vegetarian issues in processed foods, pharmaceuticals and cosmetics.

    更新日期:2018-02-14
  • Inhibitory effect of glucose oxidase from Bacillus sp. CAMT22370 on the quality deterioration of Pacific white shrimp during cold storage
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-14
    Defeng Xu, Lijun Sun, Caihong Li, Yaling Wang, Riying Ye

    The retarding effect of glucose oxidase (GOD) from Bacillus sp.CAMT22370 on the quality degradation of Litopenaeus vannamei was investigated in comparison with the commonly used preservatives of sodium sulfite (SS), phytic acid (PA) and vitamin C (Vc) during 5 days of storage at 4 °C. The quality parameters of sensory (appearance, color, odd, elasticity and overall sensory score), physicochemical (total volatile basic nitrogen (TVB-N), pH, protease and polyphenol oxidase (PPO) activity, texture (hardness, gumminess, chewiness, adhesiveness, springiness and cohesiveness) and bacteriological characteristics (total aerobic counts (TAC) and Pseudomonas spp. counts (PBC)) were periodically detected and analyzed. The results indicated that the selected preservatives of SS, PA, Vc and GOD could improve the overall sensory score, reduce the increase of TVB-N, pH, proteinase and PPO activity, enhance the texture properties and inhibit the microbial growth at remarkable or significant level (p < 0.05) versus the control group of distilled water. Moreover, GOD treatment displayed more desirable retarding effect on quality degradation than that of SS, PA and Vc. Therefore, GOD treatment may be a promising alternative for maintaining the storage quality and extending shelf life of L. vannamei during cold storage.

    更新日期:2018-02-14
  • Essential oil components inhibit biofilm formation in Erwinia carotovora and Pseudomonas fluorescens via anti-quorum sensing activity
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-13
    Ying Zhang, Jie Kong, Yunfei Xie, Yahui Guo, Yuliang Cheng, He Qian, Weirong Yao

    The effect of 10 essential oil (EO) components on biofilm formation for vegetable spoilage Erwinia carotovora and Pseudomonas fluorescens at sub-MICs were investigated. Chromobacterium violaceum CV026 (CV026) was selected as quorum sensing (QS) biosensor bacterium. The swimming, swarming, twitching motility, exopolysaccharide (EPS) production and biofilm formation were determined. All tested EO components showed QS inhibition of CV026, E. carotovora and P. fluorescens. Biofilms were inhibited by all EO components by inhibiting their motilities and EPS production. Salicylic acid and thymol showed the best inhibitory effect on biofilm formation of P. fluorescens (37.61%) and E. carotovora (47.24%) respectively. Hexanal as QS inhibitor for biofilm formation was first reported, with inhibition ratio of 25.86% and 20.18%, which was confirmed by scanning electron and fluorescence microscopy. Inhibition of biofilm formation by anti-QS EO components could be novel intervention strategy to enhance safety and quality of vegetables in the food industry.

    更新日期:2018-02-13
  • Extraction of phenolic compounds with antioxidant potential from coconut (Cocos nucifera L.) testa and identification of phenolic acids and flavonoids using UPLC coupled with TQD-MS/MS
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-13
    M. Arivalagan, T.K. Roy, A.M. Yasmeen, K.C. Pavithra, P.N. Jwala, K.S. Shivasankara, M.R. Manikantan, K.B. Hebbar, S.R. Kanade

    Coconut testa, a brown skin covering of a coconut endosperm, is a rich source of phenolics. It is one of the by-products obtained in the coconut processing industries and currently underutilized despite being rich in phenolic compounds. A study was conducted to identify the suitable solvent system for maximum extractability of total phenolic content (TPC) and total flavonoid content (TFC) with antioxidant potential from the testa. Individual phenolic acids and flavonoids of different solvent extracts were also determined using UPLC-H class coupled with TQD-MS/MS. The TPC and TFC ranged from 4.9-167 mg GAE/g and 8.84–115 mg QE/g defatted testa, respectively; significant differences were observed for various solvent systems studied. Acidification of solvents significantly increased the extractability of TPC and reduced the extractability of TFC. A total of 28 phenolics comprising 16 phenolic acids and 12 flavonoids were identified. Protocatechuic acid, p-coumaric acid and ferulic acid are the major phenolic acids identified whereas, catechin, apigenin and kaempferol are the major flavonoids identified. In summary, this study proved that coconut testa is a natural source of multiple phenolics acids and flavonoids with potent antioxidant capacity, and it can be used as a natural source of antioxidants.

    更新日期:2018-02-13
  • Quality assessment of ready-to-eat asparagus spears as affected by conventional and sous-vide cooking methods
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-13
    Maria Gonnella, Miriana Durante, Sofia Caretto, Massimiliano D'Imperio, Massimiliano Renna

    Asparagus represents a nutritious and refined food being very popular to consumers. The effects on the quality of spears cooked by conventional (boiling, steaming and microwaving) and different sous vide (using hot water or microwave) methods were analyzed. Physical, chemical and sensory traits were compared. Microwaving caused the largest weight change, the highest dry weight increase and the highest Total Color Difference in cooked samples compared to raw asparagus spears. Sous vide-microwaving showed an increase in greenness (the highest value of h°), better than the raw spears, and the lowest reduction in chlorophyll contents. After sous vide microwawing violaxanthin increased by about 42%, while after steaming neoaxanthin decreased by about 57%. Following sensory analysis, all cooked samples generally resulted acceptable (scores > 5 in a 1–9 hedonic scale), nevertheless sous vide-microwaved asparagus satisfied consumer acceptability more than the other cooked samples, especially when compared to steamed samples. Results indicate the sous vide-microwaving technique as optimal to preserve several traits, including the organoleptic ones, essential for the quality of cook-chilled asparagus spears. They also provide product-specific information usually required for cooking process strategies in the industrial area of ready-to-eat vegetables.

    更新日期:2018-02-13
  • Effects of garlic (Allium sativum) supplemented fish diet on sensory, chemical and microbiological properties of rainbow trout during storage at −18 °C
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-13
    Mustafa Öz

    In the present study, garlic (Allium sativum) was added at 0.0% (G1-Control), 1.0% (G2), 1.50% (G3), and 2.0% (G4) to rainbow trout feed for a feeding period of 90 days. After the feeding process, the trout were harvested and stored in a deep freezer at −18 °C, and changes in chemical, microbiological and sensory parameters were examined periodically. During the storage period, the highest peroxide values (PV), free fatty acids (FFAs), The thiobarbituric acid reactive substances (TBARS) were observed in the control group, while the lowest values were noted for those fed on 1.50% and 2.0% garlic feed. During storage, significant differences were not observed in the total volatile basic nitrogen (TVB-N) content of rainbow trout. The highest values in microbial count were observed in the control group.

    更新日期:2018-02-13
  • Nutritional quality and techno-functional changes in raw, germinated and fermented yellow field pea (Pisum sativum L.) upon pasteurization
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-13
    Zhen Ma, Joyce I. Boye, Xinzhong Hu

    Yellow field peas were subjected to soaking (SY), germination (SGY), fermentation (SFY), fermentation and pasteurization (SFPY), combined germination and fermentation (SGFY), as well as SGFY upon pasteurization (SGFPY). Soaking generally had a negligible impact on the proximate composition and nutritive quality of field peas except that a 23.4% reduction in trypsin inhibitor activity (TIA) was observed. Both germination and fermentation led to a significant reduction in starch content by 11.2–11.7%. Processed peas including SFY, SFPY, SGFY, and SGFPY exhibited higher in vitro protein digestibility (IVPD) values (P < 0.05) of 87.80–89.16%, which was further strengthened by the negative correlation between IVPD and antinutrients including tannin and TIA. The electrophoretic profile of their protein hydrolysates confirmed the IVPD results where the above four treatments resulted in an extensive degradation and breakdown of pea seed's storage proteins with the peptide subunits appeared at molecular weight <16 kDa. SFY, SFPY, SGFY, and SGFPY also showed higher levels of digestible starch (114.1–257.7 g/kg) which agreed with their DSC gelation temperatures and the most distinguishable alternations on their microstructure. The fermentation of germinated peas led to an enhanced nutritional property, the following pasteurization process further changed the starch crystalline organization and protein resembling structure of field peas.

    更新日期:2018-02-13
  • Techno-functional properties of yoghurts fortified with walnut and flaxseed oil emulsions in guar gum
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-12
    Waqas N. Baba, Kaunser Jan, Hilal A. Punoo, Touseef Ahmed Wani, Mohd Masarat Dar, F.A. Masoodi

    The present study aimed at fortification of yoghurt with walnut and flaxseed oils using guar gum. Both the oils were added separately at a concentration of 2% along with two different concentrations of guar gum (0.025% and 0.05%). Fortified yoghurt samples were studied for functional, rheological, microbial and antioxidant properties. Fatty acid profile and oxidative shelf-life of the product was also determined. The addition of oil increased syneresis, antioxidant activity and malondialdehyde formation in yoghurts while the microbial count decreased. Gum addition, significantly (P < 0.05) decreased pH, syneresis, and increased the oxidative stability, antioxidant activity of yoghurt samples while no significant (P > 0.05) effect on microbial content was seen. All yoghurt samples showed pseudo plastic flow behavior with yield stress that increased with increase in gum and oil concentration. Gum and oil addition increased G′, G″, and composite viscosity of yoghurt samples. Walnut fortified yoghurt samples showed significantly (P < 0.05) higher MUFA and PUFA levels among all the samples. Walnut oil fortification showed higher sensory parameters and superior overall quality characteristics than flaxseed oil fortification. Hence, walnut oil is a better option for fortification of yoghurts with essential fatty acids than flaxseed oil.

    更新日期:2018-02-13
  • Characterisation of the Turkish and Slovenian extra virgin olive oils by chemometric analysis of the presaturation 1H NMR spectra
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-12
    İbrahim Sani Özdemir, Çağdaş Dağ, Damjan Makuc, Erdal Ertaş, Janez Plavec, Somer Bekiroğlu

    Monovarietal extra virgin olive oils from 3 major Turkish cultivars (Gemlik, Ayvalık, Memecik) and 1 Slovenian cultivar (Bianchera) were analysed by standard and presaturation proton NMR experiments. In the latter method, signals arising from major lipid fractions upfield of 5.6 ppm were suppressed and, compared to standard proton experiment, considerable improvement was achieved in the intensities of the signals downfield of 5.6 ppm. For each sample, specific data sets were achieved by replacing the 0.04-ppm integration buckets in the region of 5.6–10.0 ppm of standard proton spectra with that of presaturation experiment values. Multivariate statistical analyses showed that olive oils of different olive cultivars could be effectively classified based on their one-dimensional proton NMR profiles. The buckets containing the signals belonging to protons of aldehydes (9.0–10.0 ppm), phenolic compounds (6.0–7.0 ppm), terpenes (4.0–5.0 ppm) and diacylglycerols (3.8–4.2 ppm) were the major discriminants of the oils used in the study.

    更新日期:2018-02-12
  • Influences of fermentation parameters on lovastatin production by Monascus purpureus using Saccharina japonica as solid fermented substrate
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-10
    Sharmin Suraiya, Jang-Ho Kim, Jin Yeong Tak, Mahbubul Pratik Siddique, Cho Ja Young, Joong Kyun Kim, In-Soo Kong
    更新日期:2018-02-10
  • Gomphrena globosa L. as a novel source of food-grade betacyanins: Incorporation in ice-cream and comparison with beet-root extracts and commercial betalains
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-10
    Custódio Lobo Roriz, João C.M. Barreira, Patricia Morales, Lillian Barros, Isabel C.F.R. Ferreira

    Currently, there are some examples of natural colourants with commercial use. However, these colourants are usually under-exploited, besides being obtained from a reduced number of plant or algal species. Accordingly, we propose using betalains obtained from an alternative plant species, Gomphrena globosa, which have a powerful colouring activity besides being strong antioxidants, as a novel ice-cream colourant. For comparison purposes, other ice-cream formulations were prepared, namely without colourants, added with commercial betalain or with Beta vulgaris extract. Besides evaluating the colour parameters L*, a* and b*, the nutritional parameters, individual sugars and fatty acids profiles were also studied. These parameters were evaluated throughout time, up to a maximum of 60 days of freeze (-22 °C) storage. Betacyanin quantification of each formulation was also performed to determine its maintenance along storage. In general, ice-creams prepared with G. globosa were similar (considering nutritional, colour, individual sugars and fatty acids profiles) to those including B. vulgaris extract, thereby validating the suitability of this alternative plant as a source of food colourants, particularly as ice-cream colourants. Furthermore, the positive effects induced by the addition of this natural colourant were maintained throughout storage time, as indicated by the markers distribution in the linear discriminant analysis.

    更新日期:2018-02-10
  • Characterization of olive pomace extract obtained by cyclodextrin-enhanced pulsed ultrasound assisted extraction
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-10
    Petra Albahari, Mario Jug, Kristina Radić, Sanja Jurmanović, Mladen Brnčić, Suzana Rimac Brnčić, Dubravka Vitali Čepo

    Cyclodextrin enhanced pulsed ultrasound assisted extraction procedure was developed for obtaining olive pomace extract rich in bioactive polyphenols, principally oleuropein, tyrosol, and hydroxytyrosol. 20-minute extraction using 12 mm probe at 100% output intensity was selected as optimal for the extraction of olive pomace polyphenols, using 60% ethanol at 1:40 solvent to solid ratio. Addition of cyclodextrins to extraction solvent (especially randomly-methylatedbeta cyclodextrin and hydroxypropyl-beta cyclodextrin) significantly affected extraction yields, stability and the appearance (colour and particle size distribution) of obtained extracts. Extracts obtained under optimized conditions contained 887 mgkg-1 of hydroxytyrosol, 1117 mgkg-1 of tyrosol and 1744 mgkg-1 of oleuropein. In comparison to conventional solvent extraction, application of ultrasound-assisted extraction resulted in significantly higher yields, reduced extraction time and solvent consumption.

    更新日期:2018-02-10
  • Growth factors affecting gas production and reduction potential of vegetative cell and spore inocula of dairy-related Clostridium species
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-10
    Tiziana Silvetti, Stefano Morandi, Milena Brasca

    Cheese late blowing defect caused by the Clostridium growth results in flavour and texture flaws and huge economical losses. The aim of this study was to evaluate simultaneously the influence of pH (6.50, 5.75, 5.00), NaCl (0, 1, 2, 4%) and temperature (10, 12, 15, 20, 37 °C) on gas production and reduction potential (Eh) of vegetative cell and spore inocula of dairy related clostridia (Clostridium beijerinckii, C. butyricum, C. sporogenes and C. tyrobutyricum). Clostridia showed a high reduction capacity in milk (Eh7min < −280 mV in 24 h). Spores exposed to harsh environment generated cells less sensitive to adverse conditions. A temperature ≤15 °C was effective in preventing the gas formation by vegetative cells for over 70 days, but a combination of temperature ≤15 °C, pH ≤ 5.00 and osmotic stress (NaCl 2%) or a temperature ≤ 10 °C was necessary to avoid spores outgrowth and gas production. Gas production resulting from C. tyrobutyricum spore germination and growth was not affected by acidity and salt concentration at 20 °C. Some strains of C. sporogenes were capable of producing gas even at 12 °C, pH 5.00 and 1% of NaCl. A ripening temperature below 10 °C represents a potential strategy to prevent LBD occurrence.

    更新日期:2018-02-10
  • Synthesis of nano curcumin using black pepper oil by O/W Nanoemulsion Technique and investigation of their biological activities
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-10
    Fariba Moghaddasi, Mohammad Reza Housaindokht, Majid Darroudi, Mohammad Reza Bozorgmehr, Abbas Sadeghi

    Curcumin is an important biologically active polyphenolic compound that has been found to contain the ability of a wide range of beneficial biological activities. The aim of this study was to develop a method for the preparation of curcumin nanoparticles (Nano-CUR) with a view to improve its aqueous-phase solubility and examine the effect on its biological properties. Nano-CUR were prepared in black pepper oil (BP oil) as an oil phase and Tween 80 as the surfactant. Nano-CUR was prepared by a modified microemulsion technique and was found to have a narrow particle size distribution in the ranges of 8–26 nm. Nano-CUR was obtained with a spherical shape and mean particle size of 15.7 ± 3.55 nm when the following optimal conditions were adopted as water/oil (5:1) and oil/surfactant (1:9). Unlike curcumin (bulk), Nano-CUR is readily dispersed in aqueous media. The FTIR spectrum indices can be used in order to differentiate nano and non-nano emulsion solutions. Antioxidant activity tests were applied to the Emulsion components, Nano-CUR, and also to Tween 80 + BP oil. Results demonstrated that Nano-CUR has maximum antioxidant activity. In vitro cytotoxicity effect of Nano-CUR was also investigated, which was detected in the treated Neuro2A cells to be up to 15.6 μg/mL.

    更新日期:2018-02-10
  • Effect of ultra-high pressure homogenization on cream: Shelf life and physicochemical characteristics
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Daniela Rodarte, Anna Zamora, Antonio-José Trujillo, Bibiana Juan

    The ultra-high pressure homogenization (UHPH) effect on microbial and physicochemical shelf life of cream during storage at 4 °C were studied and compared with a conventional homogenization-pasteurization treatment. Cream samples were processed using UHPH at 300 MPa with an inlet temperature of 40 °C. Furthermore, a sample was also submitted to UHPH after the addition of 1.5% (w/v) of sodium caseinate. Ultra-high pressure homogenized samples were compared with homogenized-pasteurized (15 MPa, 55 °C; 65 °C, 30 min) cream sample and an untreated sample, which was used as a control. UHPH was efficient in reducing the total bacteria, reaching reductions of 6 log cfu/mL compared to raw samples. Enterobacteriaceae were completely eliminated in creams treated by UHPH and conventional homogenization-pasteurization. Microbial results suggest a shelf life between 29 and 36 days for UHPH-treated creams. Furthermore, no creaming was observed in cream samples treated by UHPH with caseinate throughout 29 days of storage, being a very stable cream over time.

    更新日期:2018-02-10
  • Polarized projective mapping as a rapid sensory analysis method applied to South African Chenin Blanc wines
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Christine Wilson, Jeanne Brand, Wessel du Toit, Astrid Buica

    To test the applicability of Polarized Projective Mapping (PPM) to dry South African Chenin Blanc wines, one Projective Mapping and four PPM experiments were performed using expert judges. PM was used to create an initial product map for comparison with PPM results and to assist in the selection of the three poles. For the purposes of method validation 17 wines were analysed in this set of experiments. As the use of poles as stable references between evaluations allowed, the PPM results from all four PPM experiments were combined in a single statistical analysis. This gave a single figure which compared samples from all evaluations in a global “Global MFA”. In this experiment repetitions, blind duplicates, explained variance, confidence ellipses, and grouping trends were used to establish the consistency of the results. All of these parameters indicated good reliability of the results. PPM consistently separated wooded and unwooded wines with acceptable percentage of explained variance and correct groupings of blind duplicates. The overall groupings were also consistent with those found in PM.

    更新日期:2018-02-10
  • Synergistic effects of combined X-ray and aqueous chlorine dioxide treatments against Salmonella Typhimurium biofilm on quail egg shells
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Shin Young Park, Soo-Jin Jung, Sang-Do Ha

    The current study investigated the synergistic effect of combined X-ray irradiation (0.5, 1.0, 1.5, and 2.0 kGy) and aqueous chlorine dioxide (ClO2) treatment (10, 20, 30, and 50 ppm) on Salmonella enterica serovar Typhimurium biofilms on the surfaces of quail egg shells. The synergistic effect was not dependent on the X-ray irradiation dose or ClO2 concentration. The synergistic reductions of biofilms after X-ray/ClO2 treatment on the egg shells were −0.1–1.1 log CFU/egg. The largest reduction was 1.1 log CFU/cm2 after a 2.0 kGy X-ray and a 20 ppm ClO2 treatment. No significant change (P > 0.05) was observed in the Hunter colors (L*, a*, and b*) and shear force (shell thickness) of the egg shell surfaces after single or combined treatments. Similarly, no significant changes (P > 0.05) were observed in the same parameters on the egg shell surfaces when a combination treatment of minimum X-ray doses/ClO2 concentrations and a combination treatment of maximum X-ray doses/ClO2 concentrations were applied separately. The results indicated that the combination treatment of 2.0 kGy X-ray/20 ppm ClO2 could be used in the egg production, processing, and distribution processes to enhance food safety without causing changes to the egg shell surface color and shell thickness.

    更新日期:2018-02-10
  • Changes in the mutagenicity of heterocyclic amines, nitrite, and N-nitroso compound in pork patties during in vitro human digestion
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Hyeong Sang Kim, Sun Jin Hur

    The objective of this study was to determine the changes in mutagenicity caused by heterocyclic amines (HCAs), nitrite, and N-nitrosodiethylamine (NDEA) in pork patties during in vitro human digestion. The mutagenicity was higher in raw pork patties containing HCAs than in those containing nitrite or NDEA. In cooked pork patties too, the mutagenicity was higher in HCA-containing patties than that in nitrite- or NDEA-containing patties, both before and after in vitro human digestion. However, the mutagenicity of all pork patties decreased after in vitro digestion. In particular, their mutagenicity was drastically reduced during simulated large intestine digestion with enterobacteria, i.e., Escherichia coli and/or Lactobacillus sakei. These results indicate that high amounts of HCAs in pork patties show higher mutagenicity than nitrite and NDEA, although the mutagenicity decreases after in vitro human digestion.

    更新日期:2018-02-10
  • Effect of pectinolytic and cellulytic enzymes on the physical, chemical, and antioxidant properties of blueberry (Vaccinium corymbosum L.) juice
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Muhammad Siddiq, Kirk D. Dolan, Penelope Perkins-Veazie, Julie K. Collins

    Blueberry (Vaccinium corymbosum L.) fruit, rich in anthocyanins, polyphenolics and antioxidant activity, has not been exploited fully for processing into juice. The objective of this study was to investigate the effect of commercial juice extraction enzymes (Cellubrix, Pectinex Ultra SPL, and Crystalzyme) on juice yield, total soluble solids (TSS), juice clarity, HPLC sugars profile, total anthocyanins (ACY), total phenolics (TPH), and antioxidant activity (assayed as FRAP). Enzyme treatments resulted in significantly (p ≤ 0.05) higher juice yield (86.91–87.29 mL/100 g with Pectinex and Crystalzyme as compared 79.45 mL/100 g from control), higher juice clarity, and titratable acidity, and lower extraction loss. However, enzymes treatment had no effect on total soluble solids (°Brix), fructose, glucose, and total sugars. Generally, juice Hunter color values (L, a, and b), Hue angle (h°) and Chroma (C*) were affected positively by the enzymes treatment. As compared to the control (9.69 mg/100 mL), total ACY were significantly higher (11.49–12.90 mg/100 mL) in juice from enzyme-treated macerates; whereas there was no effect on TPH, determined as gallic acid equivalent (96-89‒101.30 mg GAE/100 mL) and FRAP antioxidant activity (3.87–3.97 μmol TE/100 mL). Total ACY, TPH, and FRAP were several-fold higher in the pomace than the juice.

    更新日期:2018-02-10
  • Survey of mycotoxins in beer and exposure assessment through the consumption of commercially available beer in Lleida, Spain
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Xenia Pascari, Jordi Ortiz Solá, Sonia Marín, Antonio J. Ramos, Vicente Sanchis

    A multianalyte method, using a MS/MS detector, was applied for a simultaneous determination of 23 mycotoxins in 64 beer products purchased from the supermarket in Lleida, Spain. The samples varied by their origin, brewing technology, alcohol content, etc. The results showed that 20.3% of the tested samples were mycotoxin contaminated overpassing the limit of detection (LOD). None of the alcohol-free samples (17%) were contaminated with mycotoxins. The most frequently occurring toxin was zearalenone (ZEN), being quantified in 65% of the positive samples, with levels ranging from 8.24 to 62.96 μg/L. Regarding the co-occurrence of mycotoxins, three samples were found to contain two or more mycotoxins simultaneously. A deterministic approach was used to evaluate the contribution of beer consumption to daily intake and the proportion of the established tolerable daily intake (TDI) for ZEN and deoxynivalenol (DON) and its metabolite deoxynivalenol-3-glucoside (DON-3-G).

    更新日期:2018-02-10
  • Control of Hanseniaspora osmophila and Starmerella bacillaris in strawberry juice using blueberry polyphenols
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-09
    Claudia Verónica Vallejo, Osvaldo Daniel Delgado, Graciela Celestina Rollán, María José Rodríguez-Vaquero

    The aims of the present work were to isolate and identify the principal yeasts present in spoiled Argentine strawberry juice, identify polyphenols present in four blueberry cultivars and use these blueberry extracts in the control of yeasts using strawberry juice as food system model. Hanseniaspora osmophila and Starmerella bacillaris were identified for the first time in Argentine strawberry juice. The blueberry extracts assayed showed antifungal activity against H. osmophila and S. bacillaris through individual phenolic compounds such as quercetin, kaempferol and chlorogenic, ρ-coumaric and ellagic acid. The cytotoxicity assay demonstrated that the blueberries were not toxic to humans and that they did not modify the sensorial qualities of strawberry juice. No viable S. bacillaris and H. osmophila cells were detected after 7 days in strawberry juice supplemented with 150 μg/ml Blue Crisp or Millennium extract, inoculated with the isolated spoilage yeasts and conserved at 4 °C. This is the first evidence of S. bacillaris and H. osmophila in spoiled Argentine strawberry juice and blueberry extracts could be a good natural and non-toxic alternative to prevent growth of these yeasts. Blueberry extracts could be feasible alternatives to improve the microbiological quality without impact on the organoleptic properties of polyphenol-enriched strawberry juice.

    更新日期:2018-02-09
  • Effect of fermentation and storage on the nutritional value and contents of biologically-active compounds in lacto-fermented white asparagus (Asparagus officinalis L.)
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-08
    Małgorzata Tabaszewska, Aleksandra Gabor, Grażyna Jaworska, Iwona Drożdż

    In this study we determined contents of dry matter, ash, total protein, total sugars, lipids, B-group vitamins and vitamin C, polyphenolic compounds, and flavonoids, as well as active acidity, pH value, and antioxidant activity against ABTS(2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), DPPH (1,1-Diphenyl-2-picrylhydrazyl radical, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) radicals, FRAP (ferric ion reducing antioxidant power) in fresh and lacto-fermented white asparagus stored for 1 and 3 months. In addition, we analyzed the microbiological quality of fermented asparagus. The nutritional value and contents of biologically-active compounds were affected by both the fermentation process and the storage of fermented products. Fermentation had no significant effect on dry matter, total protein and fat contents, but contributed to an increase in ash content and a decrease in total sugars content. Fermentation caused a significant decrease in contents of B-group vitamins, polyphenolic compounds, and dehydroascorbic acid, whereas enhanced ability to reduce iron ions and decreased vitamin content were determined in fermented white asparagus during storage. Fermentation and storage did not affect the radical scavenging ability against DPPH and ABTS nor contents of total polyphenols and total flavonoids.

    更新日期:2018-02-08
  • Whey-grape juice drink processed by supercritical carbon dioxide technology: Physical properties and sensory acceptance
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-08
    Gabriela V. Amaral, Eric Keven Silva, Ana Letícia R. Costa, Verônica O. Alvarenga, Rodrigo N. Cavalcanti, Erick A. Esmerino, Jonas T. Guimarães, Monica Q. Freitas, Anderson S. Sant’Ana, Rosiane L. Cunha, Jeremias Moraes, Marcia C. Silva, M. Angela A. Meireles, Adriano G. Cruz

    The effect of supercritical dioxide carbon technology (SCCD, 14, 16, and 18 MPa, 35 ± 2 °C/10 min) on the physical properties (color, particle size, rheology tests and physical stability) and sensory acceptance (consumer test) of whey grape juice drink was investigated. Lower particle diameter and consistency index as well as a pseudoplastic behavior was obtained suggesting the SCCD technology acted as homogenization step. Regards the sensory test, it was not noted differences for all sensory attributes evaluated, although increased sensory scores were noted for all SCCD beverages. Overall, SCCD technology seems an interesting option to be used at the processing of dairy foods, in particular whey grape juices.

    更新日期:2018-02-08
  • Impact of ultrasonication and pulsed light treatments on phenolics concentration and antioxidant activities of lactic-acid-fermented mulberry juice
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-08
    Emmanuel Kwaw, Yongkun Ma, William Tchabo, Maurice Tibiru Apaliya, Augustina Sackle Sackey, Meng Wu, Lulu Xiao

    This study sought to assess the effect of ultrasonication (28 kHz, 60 W, 15 min), pulsed light (1.213 Jcm−2pulse−1, 360 μs, 3 Hz, 4 s) and their combined usage on the phenolics concentration and antioxidant activities of lactic-acid-fermented mulberry juice (LFMJ). The results showed significant improvement in the total phenolic concentration, total flavonoid concentration, total anthocyanin concentration, antiradical activity against 2,2-diphenyl-1-picrylhydrazyl scavenging activity (DPPH•-SA), 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid radical cation scavenging activity (ABTS•+-SA) and reducing power capacity (RP-CA) in all the non-thermal treated fermented juice compared to the control sample. Among the individual non-thermal treatments, ultrasonication caused a significant (p < 0.05) upsurge in the phenolic and antioxidant properties of the LFMJ compared to the pulsed light treatment. In the case of the combined treatments, the application of pulsed light before ultrasonication (PUT) exhibited the utmost performance. This suggests that PUT technique could successfully be implemented on industrial scale for the processing of LFMJ.

    更新日期:2018-02-08
  • The influence of physical properties of selected plant materials on the process of osmotic dehydration
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-07
    Krzysztof Lech, Anna Michalska, Aneta Wojdyło, Paulina Nowicka, Adam Figiel

    The aim of this study is to examine the influence of selected physical properties of plant materials on the osmotic dehydration process (OD) in salt, sucrose and concentrated chokeberry juice solutions, and to explore the possible relationships between these factors. The study also evaluated the effect of osmotic solutions on the antioxidant capacity of OD samples. The material consisted of 3 cultivars of pumpkin, beetroot, parsley, carrot, celery, radish, black turnip and apple. Concentrated chokeberry juice, sucrose (40 °Brix) and salt (5 g/100 g) were used as osmotic solutions. The process was performed at the temperature of 45 °C for 90 min. The functional relationships between physico-chemical properties of raw material, osmotic solutions, water loss and solid gain and the quality of the osmotically dehydrated products were found. The water loss was higher than the solid gain during osmotic dehydration, regardless of the solution used for the process. For all samples analysed, water activity decreased after the OD process and was the greatest after the application of chokeberry juice concentrate. The solid true density diminished after OD, regardless of the OD solution. A strong influence of the osmotic solution on the antioxidant capacity was noted when chokeberry juice concentrate was used.

    更新日期:2018-02-07
  • Evaluation of wheat flour substitution with amaranth flour on chicken nugget properties
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-07
    Maryam Tamsen, Hajar Shekarchizadeh, Nafiseh Soltanizadeh

    The objective of this study was to investigate the effect of substitution of wheat flour with amaranth flour in batter, chicken paste and all layers of chicken nuggets at 0, 50 and 100% levels. The chemical composition, pH and phenolic compounds of amaranth flour, chemical composition and pH of chicken nugget, chicken paste emulsion stability, texture properties, color, porosity, cooking loss, oil absorption, degree of oxidation and sensory characteristics of produced nuggets were evaluated. Inclusion of amaranth flour significantly increased minerals, fiber, fat, and protein of nuggets. The pH of all nuggets containing amaranth flour was higher than the control. Emulsion stability of paste was the highest in samples with amaranth flour in all layers. All the TPA parameters and cutting force increased by increasing the amount of amaranth in each layer. However, amaranth flour darkened nuggets. The presence of amaranth flour in nuggets significantly increased porosity, oil absorption and cooking loss. TBA value of nuggets containing amaranth flour was lower than control sample during 13 days storage at 4 °C. Sensory evaluation of nuggets showed that substitution of wheat flour with amaranth flour in nuggets did not have significant effect on the overall acceptability of the product.

    更新日期:2018-02-07
  • Performance enhancement of ultrafiltration in apple juice clarification via low-pressure oxygen plasma: A comparative evaluation versus pre-flocculation treatment
    LWT - Food Sci. Technol. (IF 2.329) Pub Date : 2018-02-06
    Haci Ali Gulec, Pelin Onsekizoglu Bagci, Ufuk Bagci

    The aim of this study was to improve ultrafiltration (UF) performance during clarification of raw apple juice through surface modification of commercial polysulfone membranes (US100) by low-pressure oxygen plasma treatment (LP-OPlsT). A Plasma power of 90 W and exposure time of 10 min were determined as the most effective parameters enabling an increase in the ΔGiwi value of the plain membrane from (−) 25 ± 2 mN m−1 to (+) 30 ± 1 mN m−1. Improved hydrophilicity achieved by LP-OPlsT remarkably enhanced the performance of US100 throughout the clarification of raw apple juice without the need of an additional pre-flocculation step. While Rfrev (86%) was the dominant resistance controlling the fouling during UF of raw apple juice through the plain membrane, the contribution of Rfrev to Rt decreased to 56% after pre-flocculation step. LP-OPlsT further decreased this ratio, up to 46%, confirming the charge repulsion between the modified membrane and the foulant particles.

    更新日期:2018-02-06
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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