فهرست مطالب seyed roholla javadian

In the present study, the effect of Pullulan coating with watercress extract on the quality and shelf life of fresh beluga sturgeon fillet stored in a refrigerator over a period of 16 days was investigated. First, the watercress extract was extracted by ultrasound and soxhlet (solvent) method and the amount of phenolic compounds and antioxidant activity of the extract (DPPH free radical activity test) were determined. The values of phenolic compounds for soxhlet extract were equal to 586.53 mg gallic acid per gram of dry weight and for ultrasonic extract was 879.57 mg/g dry weight and the antioxidant properties of watercress extracted by ultrasound were significantly higher than soxhlet method (p<0.05), so ultrasound extracts were added to the pullulan coating. Then, 4 treatments were included: control, pullulan coating, pullulan coating + watercress extract 500 ppm, pullulan coating + watercress extract 1000 ppm were analyzed by biochemical parameters such as peroxide value (PV), thiobarbithic acid (TBA), free fatty acid (FFA), total volatile base nitrogen (TVB-N) and pH). The results showed, natural preservation delayed chemical spoilage in compared with control treatment (p<0.05). According to the results pullulan coating + watercress extract 1000 ppm significantly retarded lipid oxidation by decreasing peroxide value and thiobarbituric acid production in the samples and it had the lowest total volatile basic nitrogen and pH (p<0.05). The control treatment had only the allowed chemical range for up to 6 days, but the treatment containing pullulan coating + 1000 ppm extract had the allowed values until the end of the storage period. The final conclusion showed that the coating of pullulan with watercress extract could act as a natural antioxidant, delaying chemical degradation and prolonging the shelf-life of fish fillets.

In the present study, the feasibility of producing superfine fried fish using Carboxymethyl cellulose coated and Anethum graveolens extract was studied. For this purpose, control samples (without any additive), treatment 2: Carboxymethyl cellulose)18 g (, treatment 3: Carboxymethyl cellulose + Anethum graveolens extract 500 ppm, treatment 4: Carboxymethyl cellulose + Anethum graveolens extract of s 1000 ppm and treatment 5: Carboxymethyl cellulose + Anethum graveolens extract of 2000 ppm. Oil absorption, moisture content, peroxide value and Sensory analysis of fried fish were evaluated. The results of physicochemical test showed that Carboxymethyl cellulose + Anethum graveolens extract increased the moisture content and reduced the fat absorption of oil compared to control treatment, and also more effective to delayed lipid oxidation in fried fish fillet by decreasing peroxide. The best results in relation to these parameters were observed in treatment 5 and then in treatment 4. Sensory score of treatment 4 was higher than the sensory rating of treatment 5. In conclusion, the results of this study indicate that the use of Carboxymethyl cellulose and Anethum graveolens extract with a concentration of 1000 ppm can improve the organoleptic properties and oxidation spoilage of Bighead carp (Aristichthys nobilis) fried fillet.

Fish meat is prone to both microbial and chemical spoilage. Therefore, it is desirable to use a preservative with both antioxidant and antimicrobial properties. In this study, at first antioxidant activities of Echinophora cinerea extract at concentrations of 500, 1000, 2000 and 2000ppm and synthetic antioxidant TBHQ (100 ppm), by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) tests was surveyed. The result showed the most DPPH content had showed at TBHQ treatment, 1500 and 2000ppm Echinophora cinerea extract, 82.54, 87.12 and 87.04 percent respectively. However any significant difference not found between them (p≥0.05). Effect of Echinophora cinerea extract at concentrations of 1500 ppm on the shelf life of fish fillets at 4 and 18 ° C (without any extract at 4 °C and 18 °C and 1500 ppm extract of E. cinerea at 4 °C and 18 °C). Total viable counts (TVC), total psychrotrophic counts (TPC), peroxide value (PV), thiobarbituric acid (TBA) and total volatile base nitrogen (TVB-N)) were examined during the 30-day preservation during within 5 days. The result showed E. cinerea extract could decrease TVB-N, PV, TBA, TVC in compare to control group. The final conclusions that the E. cinerea extract might be recommended as a natural preservative to increased shelf life of Aristichthys nobilis fillet.