Putrefactive Amine Changes in Relation to Microbial Counts of Ground Beef During Storage

Seven amines currently found in ground beef, 1,3 diaminopropane, histamine, cadaverine, putrescine, spermine, spermidine and tyramine, were evaluated as indicators of total bacterial, psychrotrophic and coliform counts in raw ground beef stored for 12 d at 4, 7 and 10°C. At 2-d intervals, amines were analyzed by extraction with 0.6 N HC104, separation by ion exchange column chromatography, and detection by ninhydrin. Lysine decarboxylase positive bacteria (LD+) during storage at 4°C were also studied. Correlation and regression analysis were used to determine the relationship of amine concentration to bacterial count. The percentage of lysine decarboxylase-positive bacterial colonies increased until the 6th day of storage and then decreased until the 12th day. Total and psychrotrophic bacterial counts ranged from 102 to 109 bacteria/g and were correlated significantly with putrescine, 1,3 diamino-propane, tyramine, cadaverine and spermidine. Cadaverine was the only amine that correlated significantly with...