INFLUENCE OF DIFFERENT FORMULATIONS OF ALGINATE-BASED FILMS IN THEIR ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY IN MEAT SLICES

Abstract

In the current study, the antibacterial and antioxidant effects of three formulated alginate-based edible coats on refrigerated beef were investigated. The formulated coats included 2 organic acids (OAs) based (T1 and T2) and one nisin-OAs based (T3). Control and coated beef slices were sampled immediately (zero time) and then periodically for 15 days of storage at 1  C. The antibacterial effects of coating were assessed by aerobic plate count (APC), Enterobacteriaceae and coliforms count. Peroxide value (POV) and catalase (CAT) activity were applied as indexes of oxidation. Moreover, the cupper sulphate test and pH were used as freshness indexes. The coats appeared efficient antibacterials. By coating, APC didn't exceed 6 log cfu/g 15 for days of storage with OAs-based coats more significant. T1 and T2 were more effective against enteric bacteria where the load of Enterobacteriaceae and coliforms were reduced to undetectable levels for 15 days. The coats also successfully functioned as antioxidants. POV of coated slices significantly reduced where their values were 2.27, 1.87, 2.27 and 2.20 (meq/kg) for control, T1, T2 and T3, respectively after 15 days of storage. Nisin-OAs-based coats appeared the most antioxidant defense mechanism in stored beef where CAT levels were 0.005, 0.010, 0.007 and 0.044 U/g for control, T1, T2 and T3, respectively at end of 15 days of storage. According to freshness indexes, coated slices continued fresh for at least 3 days in excess to control with nisin-OAs coating the most effective. The obtained data indicate that studied coats can be effectively applied to improve the marketability of beef and preserve its