No abstract

No abstract

In this research, the antioxidant and antibacterial characteristics of the chitosan (CH) coating incorporated with lemon verbena essential oil (LVEO) and extract (LVE) on the quality of the rainbow trout packed by vacuum packaging at 4°C were investigated. Samples evaluated include the following: Control, VP, CH, CH‐LVE 2%, CH‐LVEO 1%, and CH‐LVE 1%‐LVEO 0.5% for 16 days at 3 days intervals. All of the samples significantly reduced Psychrotrophic bacteria, total viable counts, Enterobacteriaceae, and H2S producing bacteria as compared with control during keeping time. Thiobarbituric acid reactive substance, peroxide value, total volatile basic nitrogen, and pH value were detected lower in all of the samples than control. CH incorporated with LVE and LVEO gave an agreeable effect on sensory characteristics. Samples containing CH‐LVE 1%‐LVEO 0.5% was often in priority by sensory assessors. Generally, LV can be applied as a substitution for chemical preservatives in fish meat.

No abstract

No abstract

Incorporation of natural ingredients antioxidants in edible fats can profitably affect their oxidative stability during production and storage. The purposes of the current work were to assess the antioxidant and antimicrobial effect of walnut kernel septum membranes hydroalcohol extract (WHE) in traditional butter (TB). Antioxidant characterization of the extract was screened through methods of DPPH, reducing power and total phenolic assays. After preparation of traditional butter from yogurt, WHE was incorporated into TB at three different concentrations; 0.05%, 0.1% and 0.5% and compared with a control, BHT and tocopherol treated samples (200 mg of BHT and tocopherol/kg). Microbiological studies ( Staphylococcus aureus , Coliforms, Psychrotrophic bacteria, yeasts and molds) were done during 90 days of storage time. Changes in Anisidine value (AV), acid value, peroxide value (PV) free fatty acids (FFA), Schaal and Totox value were monitored at 45-day intervals. Sensory evaluation was done using 10 semi-trained panelists based on the 5-point hedonic scale. It was found that the total phenolic content of WHE was 368.86 mg GAE/g. The BHT had higher antioxidant activity than WHE inhibiting 92.3% of the DPPH radical at 600 μg/mL. Peroxide value of TB treated with tocopherol, BHT and WHE 0.5% was 0.29 ± 0.07, 0.39 ± 0.07 and 0.52 ± 0.04 respectively. Furthermore, the WHE incorporated butter has shown low levels of free fatty acids, Schaal and Totox value when compared to control treatment. The WHE 0.5% incorporated sample had the most antimicrobial activity and it inhibited the growth of all the microorganisms (except Staphylococcus aureus ) used in the study. Among the treated TB, the samples treated with the control and WHE 0.05% had the highest sensory attributes score. The study showed that WHE could be an excellent natural origin of antimicrobial and antioxidant agents which can be used in butter.

The effects of Zataria multiflora essential oil (ZEO) alone and in combination with probiotic bacterium Lactobacillus acidophilus PTCC 1643 on the growth and stability of Escherichia coli O157 in cheese were investigated during storage time. The effect of different concentrations of ZEO (0, 50, 75, and 150 ppm) and L. acidophilus, on E. coli O157 count, pH and sensory characteristics in a manufactured cheese were determined. Various concentrations of the ZEO alone and in combination with L. acidophilus significantly decreased the E. coli O157 enumerations, compared to the control group (p < .01). Also pH decline, the number of E. coli O157 also decreased in cheese samples. The synergistic effects on the stability of E. coli O157 was not observed in different treatments of ZEO and L. acidophilus. The addition of ZEO and probiotics in samples showed a synergistic trend on the reduction of E. coli and significantly improved sensorial properties.Practical applicationsLactobacillus spp. are widely used as probiotic species in fermented foods. Zataria multiflora essential oil (ZEO) is applied in food industries to prolong shelf life of the products with desired sensorial characteristic. The association of Escherichia coli O157 in the Iranian probiotic white‐brined cheese and the antimicrobial effect of ZEO are particular concern to the dairy plants. The aim of current work was to study the effects of ZEO alone and in combination with probiotic Lactobacillus acidophilus PTCC 1643 on the growth and stability of E. coli O157 in cheese during the storage period. The significant (p < .05) synergistic inhibitory effect of the ZEO and probiotic on E. coli O157 shown in this study which emphasizes ZEO function in the food industry.

In this study, antibacterial, antioxidant, and anticancer effects of Cu nanoparticles (CuNPs) fixed on cellulosic walnut shell material were investigated. Firstly, three types of walnut shell-supported copper nanoparticles with various sizes (CuNP-WS1 15-22 nm, CuNP-WS2 60-80 nm and, CuNP-WS3 aggregated of metallic nanoparticles) were synthesized. Antibacterial properties of CuNPs were studied on three strains of bacteria; Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes. DPPH (1, 1-Diphenyl-2-picrylhydrazyl) method was used to examining antioxidant properties. Cytotoxic effects of the synthesized nanoparticles on the cancer cell line were studied. Antimicrobial properties of CuNPs showed that these nanomaterials affect both Gram-positive and Gramnegative bacteria. The antioxidant properties of CuNPs increased significantly by increasing the concentration to 10%. CuNPs appeared to have a dose-dependent cytotoxic effect on K562 cells. However, the IC50 of the synthesized nanoparticles against the K562 (25.24 AE 5 μg/mL) cancer cells was lower significantly (P < 0.01) of the IC50 of these compounds against PBMCs (42.54 AE 6.2 μg/mL).