QUALITY PRESERVATION OF COMMERCIAL FISH BALLS WITH ANTIMICROBIAL ZEIN COATINGS

To enhance the practical application of active edible coatings in the food industry, edible zein coatings incorporated with nisin (54.4 AU/cm2) or nisin/ethylenediaminetetraacetic acid (EDTA; 568 mu g/cm2) were used to preserve the quality of commercially manufactured fish balls. The microbial load, total basic volatile nitrogen (TVB-N) content and weight loss were served as quality indicators. The increase of microbial load of fish balls coated with antimicrobial zein during a 15-day refrigeration storage period was less than 1 log cfu/g, while the microbial load increased about 3 log cfu/g for the control group without the coating treatment. The formation of TVB-N was significantly (P < 0.05) reduced when fish balls were coated with antimicrobial zein. With or without antimicrobial agent, coated fish balls exerted significantly (P < 0.05) less weight loss than uncoated fish balls. PRACTICAL APPLICATIONS Although edible coatings or films containing bioactive substance have been intensively studied over the last few decades, most of these, still, have not had widespread commercial applications because the majority of studies were conducted with food-simulated systems or food samples produced in laboratory. The fish balls commercially manufactured in a fishery product factory was used to demonstrate the efficacy of antimicrobial edible coating will enhance the confidence of food manufactures to apply the technology in their products.