MARKETING AND PRODUCTS Changes in the Lipid Fractions and Bacteriological Counts in Chilled Broil~er Meat

ABSTRACT Samples of broiler muscle were taken either for bacteriological determinations or were sampled aspetically for storage at either 0 or 6 C. In muscle stored at 6 C total colony-forming units increased from 10 · to 107 after 4 days of storage and presumptive coliform counts from 102 to 10'; 82 % of these samples were rejected organoleptically at this time. On storage at 0 C, colony-forming units began to approach 107 after 16 days storage, at which time 88 % of the samples were organoleptically rejected. Oxidation of polyunsaturated fatty acids proceeded slowly at both temperatures with significant increases observed only after 30 days storage, when leg muscles oxidized more rapidly than breast muscles. Lipolysis of phospholipids was observed in leg muscles and, to a lesser extent, in breast muscles. Free fatty acid levels increased more at 6 than at 0 C, particularly after 30 days storage. Hydrolysis of both phosphatidyl ethanolamine and phosphatidyl choline were observed. This study demonstrates that lipolysis occurs on chilled storage of chicken meat concurrent with oxidation and that these changes do not appear to be as important as bacteriological factors in the deterioration of chilled broiler meat. (Key words: broiler, chilled meat, oxidation, lipolysis, bacteriological counts