Effect of Film Oxygen Transmission Rate on Lean Color and Microbiological Characteristics of Vacuum-Packaged Beef Knuckles.

Seventy-two beef knuckles were packaged (n = 12) in each of six different bag types with oxygen transmission rates (OTR) of 1, 10, 12, 13, 30 and 400 cc/m2/24 h at 4°C and 100% relative humidity to study brown discoloration of knuckles during refrigerated storage. Knuckles in bag types of OTR of 1 and 12 cc did not discolor as compared to those in bags with higher OTR (30 and 400 cc) probably due to differences in oxygen tension in the package and in the types of bacteria present. Deterioration of lean color of knuckles in some bag types of low OTR appeared associated with large percentages of Leuconostoc mesenteroides in the microflora.