Identification and evaluation of volatile compounds of vacuum and modified atmosphere packaged beef strip loins

Beef strip loins were packaged and stored for up to 28 days at 3°C in high-oxygen barrier film under vacuum and in 100% CO 2, 40% CO 2/60% N 2 and 20% CO 2/80% O 2. As storage progressed, loins packaged and stored in 20% CO 2/80% O 2 developed strong off-odors. 1-hexene, methyl thiirane, ethyl acetate, benzene and 1-heptene were detected in these packaged loins beginning at 7 to 14 days of storage. With the exception of 1-hexene, these compounds were not consistently detected in loins stored in vacuum, in 100% CO 2, or in 40% CO 2/60% N 2, and these packaged loins developed much less off-odor during storage than loins packaged and stored in 20% CO 2/80% O 2. A large number of volatile compounds from the headspace of the packaged loins originated from the packaging material. Lactobacillus plantarum became the dominant flora on loins stored under vacuum and under 40% CO 2/60% N 2 while Leuconostoc mesenteroides subsp. mesenteroides predominated in loins stored in 100% CO 2. Pseudomonas putida eventually dominated on loins stored in 20% CO 2/80% O 2.