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The present study aimed to produce sulfur dioxide release sheets based on cellulose acetate (CA) film for using in control of mold growth during fruits storage. For this purpose, first CA film was prepared, and the sodium metabisulfite (MBS) salt was fixed on its surface. Further, the effect of temperature (5, 15 and 25 °C), relative humidity (75, 85 and 95%), and the concentration of MBS (30, 40 and 50% by weight) on the release rate of sulfur dioxide was evaluated after 0.5, 2, 4, 6, 16, and 24 h. The results revealed that the temperature and relative humidity significantly affected the release of sulfur dioxide gas in which the highest gas release was observed at the temperature of 25 °C and relative humidity of 95% (3.64 mmol/L). Also, rising the amount of MBS increased the release rate of sulfur dioxide, significantly. The highest release of sulfur dioxide (4.25 mmol/L) was achieved at a concentration of 50% salt. In the next step, the prepared sheets were laminated to control the release of sulfur dioxide. Paper with a thickness of 30 μm and polyethylene film with a thickness of 25 μm were used to laminate the film. The results revealed that laminating the sheets as single or double side slowed down the release rate of sulfur dioxide from the sheets, and thus, its releasing was controlled. The results also showed that the rate of gas release and its control were higher in dual release sheets. The presence of sodium metabisulfite salt in CA sheet was confirmed through FTIR, XRD and SEM analyses. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the efficiency of sulfur dioxide release sheets on the basis of acetate cellulose film to control the growth of molds, especially botrytis cinerea, during the storage period of kiwifruit. For this purpose, the storage of kiwifruit inoculated with botrytis cinerea in the presence of one and dual sulfur dioxide releasing sheets (containing 30 and 50% metabisulfit salts, respectively) on the acetate cellulose bed was investigated. After 15 days of storage (9 days in cold store and 7 days in ambient temperature), the least bursting and crushing (4.5%) was obtained in the presence of single-stage sheets that were placed on the surface and bottom of the packages. Also, in the ninth day, mold was not observed in the 60% of packages in the presence of sulfur dioxide releasing sheets. On the 15th day, the amount of total sugar, acidity, firmness, residual sulfur, and soluble solids in packaged kiwis in the presence of two dual releasing sheets placed on the surface and bottom of packages were, respectively, 9.9 g/100 g, 1.09%, 4.75 N, 0.24 mg/g and 12.21%. In general, it can be said that sulfur dioxide releasing sheets have an effective function on cold storage in increasing the shelf life of fruits, especially fruits that are attacked by gray mold. [ABSTRACT FROM AUTHOR]

Microwave- assisted extraction is efficiency technic for extraction bioactive compounds and valuable in biological compounds that lead to accelerating the food heat processing, better extraction and quality, time decreasing and amount of solvent without decomposition of heat sensitive compounds that is applicable in both laboratory and industrial scales. The aim of this study, optimization of extraction was using response surface method and Face-center design, in order to investigate the effect of time (60-120 Sec), power (300-700 W) and ethanol percentage (40-80 %) on the yield of polyphenol,, and also the antioxidant activity and optimization of extraction process. The results showed that, model fitting was suitable. The phenolic content was decreased by increasing the ethanol concentration, significantly. Simultaneous increase of extraction time and power, resulted in significant increase of total phenolic, contents (P<0.05). Maximum yield of antioxidant compounds is achieved with extraction time of 120 sec, extraction power of 300 W and ethanol percentage of 80%. Under these conditions, the values have been assayed: 25.37(mg/100 g) for quercetin, 53.60% for DPPH free radical scavenging activity, extraction efficiency, 77.76%, and 47.43 (mg/kG) for total polyphenol and 416.79 (µm/g) for ferric ion reducing antioxidant power. As a result, Microwave assisted extraction method by two friendly environment solvent (water and ethanol) in different concentrations for extraction of bioactive compounds and antioxidant of onion by-products can used at a shorter extraction time and energy saving. [ABSTRACT FROM AUTHOR]

In this study, the changes in the color and some properties of carrot slices were investigated during hot air drying. The carrot slices first underwent an optimized osmotic pretreatment. The sucrose concentration of 60% and the dehydration time of 60 min were found to be as the optimum conditions of the osmotic dehydration. In hot air drying, temperature (60, 70 and 80°C) was taken into account as the independent variable and moisture content, shrinkage, rehydration ratio, total phenolic content, texture and sensory evaluation were considered as the dependent variables. The results revealed that the lowest reduction in total phenolic content was associated with 70°C and the effect of temperature on all of the responses was significant. With increasing temperature, shrinkage, rehydration ratio and texture increased but the moisture content decreased to (11 gr / gr). At the end, the optimum conditions were selected based on the maximum rehydration rate, phenolic compounds, total acceptance and minimum moisture content, shrinkage and stiffness of the texture were determined and the optimum temperature was 70 ° C. [ABSTRACT FROM AUTHOR]

There is a growing demand for fresh cut, value-added and ready-to-use food in households, as well as for widespread use in retail, food services and the various food industries. Amongst vegetables, onions have many medicinal properties and can lead to health. This study evaluated the effect of disinfection methods including; T1: Nisin (50µg mL-1) + Citric Acid (1%), T2: Sodium Hypochlorite (100 mg/L) + Citric Acids (0.25 M) + Sulphuric Acid (eq/L), T3: Calcium Chloride (0.5%) + Ascorbic Acid(1%)+ Citric Acid(1%) +hot water 50°C, T4: Control (without disinfectant) during 21 days storage at 4°C on onion pure. Each week, pH, soluble solids, acidity, weight loss, total phenolic compounds antioxidant activity and microbial tests (total microbial count, total molds and yeasts) were performed on the samples. Statistical analysis of the data by way of a completely randomized factorial design, demonstrated that in all treatments pH was not significant (p > 0.05) while pH increased with increasing of storage days. The lowest TSS (6.44 °Brix) was recorded in T3 (CC+AS+CA) followed by T1 and T4 (control). The lowest weight loss (3.51%) was recorded in T1 followed by (3.77%) in T3, while the highest weight loss (5.89%) was observed for untreated (controlled). The highest TPC (54.01 mg GAE/100 g), lowest total count 0.95 log CFU g-1 and total molds and yeasts 1.40 log CFU g-1 was recorded in T3. [ABSTRACT FROM AUTHOR]

BACKGROUND: The aim of this study was to investigate the effect of lactic fermentation on soy protein gastrointestinal digestive pattern and the influence of protein digesta on human faecal microbiota. Soymilk and soy yogurt were prepared in this study and a novel in vitro dynamic gastrointestinal model was employed to simulate gastric and duodenum digestions. Particle size, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE), and peptide content were monitored at the end of duodenum tract. RESULTS: Ingestion of soy yogurt allowed a rapid drop in pH from 7.0 to 5.0 at simulated duodenal digestion (0–30 min), and resulted in a loss in soluble protein content compared to that of soymilk. The electrophoretic pattern between soymilk and soy yogurt exerted distinctive differences at early stages of duodenal digestion (0–60 min) and resulted in different peptide contents (180 min). Soy yogurt duodenal digesta collected at 180 min (D180), by co‐fermentation with human intestinal flora distribution, allowed a higher population in Bifidobacterium spp., Lactobacillus/Enterococcus spp. and Streptococcus/Lactococcus spp., whereas soy yogurt D30 resulted in lower population in Clostridium and Escherichia coli compared to samples co‐fermented with soymilk digesta. CONCLUSION: The results demonstrated lactic fermentation of soy protein modulated human intestinal microflora and might relate to the different protein digestive behaviours. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This study was focused on investigating the use of pulsed ultrasound-assisted osmotic dehydration (UAOD) for enhancing the infusion with phenolic compounds extracted from grape pomace (GPx) into Aloe vera gel (AVG). The response surface methodology (RSM) was used and a dehydrated product with high antioxidant content was produced. AVG were initially immersed in a sucrose solution of 50° Brix with three levels of GPx (10, 20, 30 v v-1) and subjected to pulsed ultrasound (US) treatment with a probe of 2 cm diameter, two levels of ultrasound amplitude (UA) (50% and 100%), and three immersion time (IT) (30, 135, 210 min). The pulse on and off times were set at 15 min and 1 min, respectively. A multiple regression analysis was carried out to develop second-order polynomial models with high values of determination coefficient (R²>0.81). The optimal conditions were obtained using the Design-Expert software. The best condition obtained for the UAOD optimization was that UA = 59%, 20% grape pomace was extracted in 50% sucrose, IT = 173 min (moisture loss 49.9%, predicted 51.1%), solid gain was 4.3 % (predicted 5.0%), total phenolic content was 30.5 mg g-1 (predicted 31.8 mg g-1), and DPPH radical scavenging activity was 15.3% (predicted 15.0%). UAOD appears to be a promising process for antioxidant incorporation and preparing added value product. [ABSTRACT FROM AUTHOR]

The effect of microwave postharvest treatment on peach cv."Mashhad SorkhoSefid" quality in cold storage was optimized using Box-Behnken response surface design coupled with numerical optimization technique. The individual and interactive effect of process variables (microwave power (MP), microwave exposure time (MET) and storage time (ST)) on the quality attributes (decay (%), weight loss (%) and firmness (N)) were studied. The results showed that, MET, MP and ST had significant effect on quality parameters of peaches. The experimental data were analyzed by analysis of variance (ANOVA) and second-order polynomial models were developed using multiple regression analysis. The models developed from the experimental design were predictive and good fit with the experimental data with high coefficient of determination (R2) values. An optimization study using desired function methodology was performed and the optimal conditions were found to be MP; 250.44 w, MET; 49.47 s and ST; 30 days. The corresponding predicted values were 5.18% for decay; 3.35% for weight loss, and 1.25 N for firmness. [ABSTRACT FROM AUTHOR]

In this study, osmotic impregnation technique combined with ultrasonic pretreatment was applied to carrot slices followed by hot air drying in order to production of functional and healthy snack enriched with polyphenolic compounds derived from roselle extract (at least 400 ppm). The purposes of osmotic impregnation‐dehydration process were the maximum amount of dehydration and phenolic compounds diffusion along with the minimum sugar gain. Results revealed that increasing osmotic solution concentration and process time over optimal points, resulted in reduction of phenolic compounds saturation inside the samples. Also, it was found that prolonged ultrasound pretreatment had a damaging effect on fruit tissue microchannels and led to a decrease in the mass transfer rate. The optimal conditions of this stage were osmotic solution concentration of 60% and the process time of 60 min without ultrasonic pretreatment. In the second stage, the results of hot air drying showed that the highest amount in the total phenolic content was achieved at 70°C. Furthermore, among the several models evaluated, Jena & Das model with a determination coefficient of 0.99 and minimum error indexes, was the best fitted to drying experimental data and activation energy for effective diffusivity coefficient was calculated as 35.987 kJ/mol. Practical applications: Due to elevation in consumer's awareness in recent decades about the importance of food composition for healthier life and diseases prevention, demand for functional foods has been increasing. Food enrichment with bioactive compounds like polyphenol compounds from different plant sources is an applicable method for this purpose. In this study, carrot, which is a valuable vegetable itself, was further extended to a more functional food by enrichment with rosella plant extract and then hot air dried to produce a snack which has more nutritional quality than conventional ones. Also, osmotic dehydration results in lower moisture content of carrot slices which helps reduced hot air drying time and lower energy consumption. Overall, results from this research is usable to develop a functional snack based on carrot and rosella extract. [ABSTRACT FROM AUTHOR]

Pulsed electric field (PEF) treatment was used for extracting effective components from Nepeta (Nepeta binaludensis Jamzad). A response surface method was used to investigate the effects of independent process variables (voltage of pulsed electric field (VPEF): 2, 4 and 6 kV cm-1 and number of pulsed electric field (NPEF): 20, 40 and 60 n) on the yield (Y) and antioxidant characteristics: total phenolic compounds (TPC), 1,1- diphenyl -2- picrylhydrazyl free radical scavenging (DPPHsc), ferric reducing-antioxidant power (FRAP), half maximal of radical-scavenging activity (IC50) of Nepeta extract (aerial parts). According to Derringer's desired function approach, the optimal conditions based on both individual and combinations of all process variables were VPEF 6 kV cm-1 and NPEF 60 n. At this optimum condition, the Y, TPC, DPPHSC, FRAP, and IC50 of the extract were found to be 11.36%, 417.85 mg GA g-1, 74.8%, 1688.53 µmol Fe2+ g-1, and 0.32 mg mL-1, respectively. The experimental values were in a good agreement with the predicted values. Also, the extract at optimal conditions of PEF (PEFopt-x) had a higher quantity of chlorogenic acid, caffeic acid, rutin, para-coumaric acid, rosemarinic acid, kaempferol, and apigenin compared with solvent extract. The addition of PEFopt-x to the purified soybean oil at the levels of 6% increased oxidative stability index (2.65 h) close to butylated hydroxy toluene (2.78 h). [ABSTRACT FROM AUTHOR]