Effects of Chitosan Coatings Incorporated with Garlic Oil on Quality Characteristics of Shrimp

Abstract

AbstractThe effect of chitosan‐based edible coatings (CC) incorporated with garlic (Allium sativum) oil at 0.5, 1.0 and 1.5% on shrimp (Parapenaeus longirostris) meat quality was investigated during refrigerated storage (4C) for 11 days. CC application resulted in lower pH (P < 0.05) as compared with the uncoated control. Reductions in aerobic plate counts (APC) up to 2 log units were promoted by CC. Combined effect of garlic oil (GO) and CC was observed. CC resulted in lower APC with GO (P < 0.05) toward the end of storage. CC reduced total volatile base nitrogen and trimethylamine nitrogen contents in comparison with C (P < 0.05), with no significant effect of GO incorporation (P > 0.05). Antioxidant activity of CC was only apparent during the earlier periods of storage, while GO accelerated lipid oxidation as measured by thiobarbituric acid value. CC application with or without GO generally resulted in higher lightness (L*), and lower redness (a*) and yellowness (b*) values. Minimum concentration of GO incorporation (0.5%) into chitosan coating could be useful in extending the shelf life of shrimp meat during refrigerated storage.Practical ApplicationsApplication of edible films and coatings with natural active compounds for enhancing storage stability of food products is a promising active packaging approach. Several biopolymers with the inclusion of antimicrobial and/or antioxidant active agents have been tested in vitro; however, limited studies have been conducted for real food applications of these antimicrobial/antioxidant packaging systems. Chitosan, commercially produced from processing the waste of crustaceans, is an important biopolymer that possesses antimicrobial and antioxidant activity as well as enormous economic value. In the current study, chitosan coatings with the inclusion of garlic oil (GO) were applied to shrimp meat as an alternative natural method to extend shelf life. The obtained results suggest that chitosan coatings with minimum concentration of GO (0.5%) addition could be used as a natural antimicrobial and antioxidant packaging system for preservation of shrimp meat in a fresh state during refrigerated storage.