Sensory and microbiological quality evaluation of vacuum-packed sliced cooked chicken breast.: Shelf-life estimation

The shelf-life of vacuum packed, sliced, cooked chicken-breast based on sensory and microbial changes as a function of temperature (2.3, 6.5, 10, 13.5 and 17.7C) was determined. Sensory evaluation and a microbiological study charted the development of lactic acid and psychotropic bacteria and of Brochothrix thermosphacta. Six different sensory methods were used to estimate product shelf-life; of these, the method based on average smell and taste was deemed the most suitable, since these parameters had a greater impact on shelf-life. From a microbiological point of view, mean shelf-life times were estimated at each temperature and compared with the estimates of the tasting panel. In the samples stored at the three lowest study temperatures (2.3, 6.5 and 10C), lactic acid and psychotropic bacteria counts of 10(7)-10(8) cfu/g were not achieved; this agrees with the absence of sensory rejection at the end of the experiment. At 13.5 and 17.7C, mean shelf-life estimated microbiologically was shorter than that estimated using sensory methods. This difference, which here amounted to at least 8 days, is due to the so-called "delayed change", reported in previous experiments with cooked meat products.