Application of Tragacanth gum impregnated with Satureja khuzistanica essential oil as a natural coating for enhancement of postharvest quality and shelf life of button mushroom (Agaricus bisporus).

The effect of Tragacanth gum (TG) coating incorporated with 100, 500 and 1000ppm Satureja khuzistanica essential oil (SEO) on the postharvest quality and shelf life of button mushroom (Agaricus bisporus) stored at 4±1°C for 16days was investigated. Weight loss, firmness, browning index (BI), total phenolics, ascorbic acid, microbial and sensory quality were measured. The results indicated that treatment with TG containing SEO (TGSEO) maintained 92.4% tissue firmness, and reduced microorganism counts, such as yeasts and molds and Pseudomonas, compared to uncoated samples. Furthermore, mushrooms treated with TGSEO coating exhibited up to 57.1% decreased in BI, significantly higher levels of total phenolics (85.6%) and ascorbic acid accumulation (71.8%) than control and its efficiency was better than that TG coating alone. Sensory evaluation demonstrated the capability of TGSEO coating for preserving the quality of mushroom during the storage. The results obtained endorse that application of TGSEO coating might be a simple and effective technique for prolonging their postharvest shelf life of mushroom by up to 16days.

Chitosan-cinnamon essential oil nano-formulation: Application as a novel additive for controlled release and shelf life extension of beef patties.

In this study cinnamon essential oil-incorporated chitosan nanoparticles (CEO-CSNPs) were produced by an emulsion-gelation method. Size, zeta potential and polydispersity index of the formed nanoparticles were 235.6nm, 25.1mV and 0.33, respectively. In vitro release evaluation showed an initial burst effect, followed by a slow CEO release during 104h (at pH∼5). Different formulations of patties including control, samples containing free and encapsulated CEO and ascorbic acid were analyzed for physicochemical characteristics, microbial growth and sensorial attributes during 8days of storage at 4°C. Both free and encapsulated CEO decreased the microbial population of patties compared to the control (p<0.05) throughout the experiment. On the 8th day, the best formulations in TBARS test were AA-0.05 (0.05% of ascorbic acid) and 0.1-EN-CEO (0.1% of encapsulated CEO). During storage, the color parameters of the patties containing encapsulated CEO changed slightly whereas color and metmyoglobin content significantly decreased in samples containing free CEO and control. Free CEO had an unfavorable impact on color and odor but the incorporation of encapsulated CEO improved the consumer acceptability. The principle component analysis clearly distinguished 6 formulation groups based on physicochemical characteristics.

Comparison of tea and sesame seed oils as two natural antioxidants in a fish oil model system by radical scavenging activity.

Tea and sesame seed oils, two natural antioxidants at 5% and 10% levels, were added to carp (Cyprinus caprio) and common kilka (Clupeonella cultiventris caspia) oils, and the peroxide value and thiobarbituric acid were evaluated after 13 days at 60 degrees C (oven test). The results showed that the antioxidant effects of tea and sesame seed oils in the two aforementioned fish oils were statistically similar. In addition, the radical scavenging activity (RSA) of tea and sesame seed oils (extracted with two solvents:n-hexane and benzene) and their methanolic extract (methanol-soluble phase), ethanolic extract (ethanol-soluble phase) and lipid fraction (non-soluble in methanol or ethanol) were evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical method. The results revealed that the RSA of sesame seed oil was higher than that of tea seed oil (IC(50) = 52 mg and 45 mg, respectively). In addition, among ethanolic and methanolic extracts, the RSA of the ethanolic extract of sesame seed oil (IC(50) = 65 ml and 68 ml in n-hexane and benzene solvents, respectively) and of the ethanolic extract of tea seed oil in benzene solvent (IC(50) = 73 ml) were the highest. Also, the RSA in the lipid fraction, non-soluble phase of sesame seed oil was the highest (IC(50) = 74 mg and 81 mg in n-hexane and benzene solvents, respectively). Furthermore, after 6 days at 60 degrees C the RSA values of tea and sesame seed oils were the same.