Microbial and Organoleptic Qualities of Lamb Liver During Storage at 0 or 3°C.

Lamb liver samples from a commercial abattoir were packed separately and stored under aerobic conditions at 0 and 3°C for 8 d. Both surface microbiological [aerobic plate count (APC)] at 30°C, APC at 7°C, Enterobacteriaceae , Pseudomonas , and lactic acid bacteria counts and organoleptic analysis ("overall appearance", "odor", and "visible surface colonies") were performed on days 0, 3, 6, and 8. All microbial groups (except lactic acid bacteria) showed differences in the growth between 0 and 3°C. Both at 0 and 3°C, a statistical correlation was demonstrated between organoleptic spoilage and the increase in APCs at 30°C, APCs at 7°C, and Pseudomonas (r ≥ 0.9; p < 0.0001). When these three parameters reached 106-107 CFU/cm2, visible surface colonies appeared, which made the product rejectable. Among the three organoleptic parameters studied, this is the first to determine organoleptic spoilage and has hence enabled us to establish a shelf life of up to 6-7 d and up to 4-5.5 d for samples stored at 0 and 3°C, respectively. Off-odors were detected 2 d later since the three counts had already reached levels higher than 108 CFU/cm2.