Food safety is of utmost importance to the satisfaction and health of consumers, and control of microbial growth is a key factor to preventing food spoilage.   An Australian study, performed by the Food Safety and Innovation Research and Development Institute took a look at the effects of various types of packaging techniques on the longevity of storage in lamb shoulders. 

The study took bone-in and bone-out cuts of lamb and either vacuum packed (VAC)  them, or modified atmosphere packed  (MAP) them, which is 100% CO₂.   The samples were stored at -0.3°C (31.5°F)  for 12 weeks, then were sensory tested and a total viable count and Lactic Acid Bacteria counts were performed weekly.   The results of the sensory tests were the same between the two products, and the total number of bacteria on were similar as well.  The LAB counts were also similar between products, with the vacuum packed sample increasing more linearly for the first 50 days.  The one noticeable difference between the two techniques was that the vacuum packed sample had an increase in Carnobacterium spp. during the storage time, while the bacteria in the MAP samples remained constant, with C. maltaromaticum and C. divergens being the primary species.   Despite the high bacterial counts, both of the samples were deemed to be acceptable safe for consumption.  Overall, it was determined that both types of packaging are acceptable in preventing spoilage and keeping product quality, but the CO₂ packaging reduces the variability of microbial growth.

While many studies of this sort have been performed in beef  and pork, not as many have been done in lamb.   Lamb is different because the meat tends to have a higher pH (5.6-6.8) and a less uniform surface since lamb carcasses contain more fat covering than  muscle tissue.  Therefore, this study is important in determining the optimum packaging type for lamb retail cuts.