Using laboratory-simulated retail conditions, a variety of retail case blower temperatures were selected to determine their influence upon the surface temperature of displayed rib eye steaks, bacterial growth and steak shelf life. Steak surface temperature was found to be significantly correlated with blower temperature and exceeded the temperature of the incoming blower air by 9 C. Furthermore, bacterial generation time and steak shelf life were significantly and inversely related to blower temperature. Shelf life was also dependent upon the initial psychrotrophic bacterial load. Retail blower temperature could be easily adjusted to reduce steak surface temperature to 2 C, and thereby extend the visual shelf life from 3.8 to 8.2 days. From a practical standpoint, these results indicate that a relatively simple temperature adjustment by the retailer could improve the microbial quality and more than double the shelf life of meats on display.
1Scientific Paper No. 402, Lacombe Research Station, Research Branch, Agric. Canada.