Microbial growth, communities and sensory characteristics of vacuum and modified atmosphere packaged lamb shoulders
Kiermeier, A and Tamplin, M and May, D and Holds, G and Williams, M and Dann, A, Microbial growth, communities and sensory characteristics of vacuum and modified atmosphere packaged lamb shoulders, Food Microbiology, 36, (2) pp. 305-315. ISSN 0740-0020 (2013) [Refereed Article]
Packaging fresh lamb in a vacuum (VAC) versus a 100% CO2 modified atmosphere (MAP) may influence
product shelf-life and the bacterial communities. While VAC is a common packing method and 100%
CO2 MAP is used in some countries, there is little information about how these different techniques
affect the growth of spoilage bacteria and sensory attributes of lamb. The aim of this study was to assess
changes in microbiological and organoleptic properties, and determine differences in microbial communities
by terminal restriction fragment length polymorphism (TRFLP) and 454 pyrosequencing, in
bone-in (BI) and bone-out (BO) MAP- and VAC-packed lamb shoulders stored at -0.3 °C over 12 wk.
VAC and MAP lamb shoulders were acceptable in sensory test scores over 12 wk of storage at -0.3 °C,
despite total viable count (TVC) and lactic acid bacteria (LAB) levels increasing to 8 log10 CFU/cm2 for
VAC lamb and 4-6 log10 CFU/cm2 for MAP lamb. Similar to the sensory results, there were no significant
differences in microbial communities between BI and BO product. However, types of bacteria were
different between VAC and MAP packaging. Specifically, while VAC shoulder became dominated by
Carnobacterium spp. in the middle of the storage period, the MAP shoulder microbial population
remained similar from the start until later storage times.