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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]

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]

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]