Fatemeh Khedri; Ainaz Khodanazary
Abstract
Introduction: The mackerel (Scomberomorus commerson; Scombridae) also known as "Sheer fish" in Persian, is the most popular fish in Iran with the highest economic value. This fish is mainly offered on the Iranian market as skinned and boneless fillets. Major changes occur in proximate, microbiological, ...
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Introduction: The mackerel (Scomberomorus commerson; Scombridae) also known as "Sheer fish" in Persian, is the most popular fish in Iran with the highest economic value. This fish is mainly offered on the Iranian market as skinned and boneless fillets. Major changes occur in proximate, microbiological, chemical and sensory composition of fish fillets during storage in the refrigerator. To preserve the fish fillet, antioxidant additives prior to packaging is a common practice used in food market to extend the shelf life of aquatic products. Currently, synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) frequently have been used prior to packaging. However, recently the consumers’ demand has ben changed to fillets with natural preservatives such as green tea extract (GTE), usually packaged in vacuum packaging (VP). Green tea is a good source of polyphenolic compounds such as catechina having strong antioxidant and antimicrobial properties. Incorporating GTE as a food additive due to its antioxidant activities is a growing interest in the seafood industry. GTE can improve the marketing potential of various seafood products and can effectively be used in the packaging food industry.Materials and method: Mackerel, Scomberomorus commerson was purchased from a local fish market in Abadan city, Khozestan province, Iran. Fish were freshly caught and completely free of additives. The fish samples were kept in ice with a fish/ ice ratio of 1:2 (w/w) and transported to the seafood processing laboratory within one hour. Upon arrival, fish samples were washed in cold water and each sample was carefully filleted by hand. Two fillets were obtained from each fish after removing the head and bone. Mackerel fillet were soaked with 1 g GTE/ L solution at a fillet/solution ratio of 1: 2 (w/v) for 15 min at 4 °C, followed by draining on the screen for 3 min at 4 °C. The trays of containing samples were then vacuum- packaged (VP).Results and discussion:The results indicated that the bacterial experiments (total count and pscychrotrophic bacteria) showed the antibacterial effect of green tea extract. Lipid oxidation value experiments (peroxide and thiobarbituric values) showed lower oxidation value in fillets treated with GTE, compared to fish kept under vacuum packaging without treatment and the control (P
Behrouz Mohammadzadeh; Masoud Rezaei
Abstract
In this research green tea extract was prepared with water and then fishes in whole and gutted fish form was dipped in solutions of green tea extract (600 ppm) for 90 minutes and then were icing. During storage period (16 days), spoilage oxidation (PV, FFA, and TBA), spoilage microbial indices (TVB-N, ...
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In this research green tea extract was prepared with water and then fishes in whole and gutted fish form was dipped in solutions of green tea extract (600 ppm) for 90 minutes and then were icing. During storage period (16 days), spoilage oxidation (PV, FFA, and TBA), spoilage microbial indices (TVB-N, TVC, PVC) and Sensory assessment with interval of 4 days were measured and compared with control treatment. Based on obtained results in all of treatments by passing time the value of all of the indexes (PV, FFA, TBA, TVB-N, TVC and PVC) increased significantly (P < 0/05). But this increase in treatments dipped in 600 ppm solution was performance slowly. Also in gutted fish form was caused higher delay in lipid oxidation and spoilage microbial relate to whole fish form. According sensory assessment results not significantly different among treatments (P > 0/05). In conclusion Obtained results showed that green tea extract with dipping gutted fish in consternation of 600 ppm was suggested for retardation of lipid oxidation and microbial spoilage in rainbow trout during storage in ice.
