Abstract
Extracts of gamma-irradiated (at dose levels of 0, 4, 8 and 12kGy) mushrooms (Agaricus ostreatus)(EIM) were prepared to be used as natural antioxidant and antimicrobial agents for extending the shelf life of meat products. The properties of EIM-added minced beef balls (BB) were studied during refrigerated storage (4 degrees C). The antiradical potential of EIM against DPPH radicals and the antioxidant trait of EIM in a beta-carotene-linoleate model system were studied. The anti-microbial properties of EIM against bacterial strains including Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsilla penumoneae, Pseudomonas aeruginosa and Salmonella Typhumurium as well as fungal strains including Aspergillus niger and Penicillium expansum were studied. The EIM from mushroom treated with 8 kGy had the highest antioxidant and antimicrobial properties. Thus, the 8-kGy-EIM treatment was added with BB at levels of 3, 6 and 9% (w/w). The BB treated with 3, 6 and 9% concentrations were evaluated as rejected by a trained panel after 9, 12 and 15 days of refrigerated storage, while the control sample was rejected after only 6 days. It is anticipated that EIM could be applied as natural antioxidant and antimicrobial agent to extend the shelf fife of meat products.