title: Microbial growth, communities and sensory characteristics of vacuum and modified atmosphere packaged lamb shoulders.
abstract: 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/cm(2) for VAC lamb and 4-6 log10 CFU/cm(2) 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.
authors.affiliation: Food Safety and Innovation, South Australian Research and Development Institute, Adelaide, South Australia 5001, Australia.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kiermeier
authors.forename: Mark
authors.initials: M
authors.lastname: Tamplin
authors.forename: Damian
authors.initials: D
authors.lastname: May
authors.forename: Geoff
authors.initials: G
authors.lastname: Holds
authors.forename: Michelle
authors.initials: M
authors.lastname: Williams
authors.forename: Alison
authors.initials: A
authors.lastname: Dann
mesh_terms: D000818:Animals; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D018857:Food Packaging / Q000295:instrumentation / Q000379:methods*; D061353:Food Storage; D008460:Meat / Q000032:analysis* / Q000382:microbiology*; D009812:Odorants / Q000032:analysis*; D012756:Sheep
keywords: 454 Pyrosequencing; Gompertz growth model; Lactic acid; Shelf-life; Terminal restriction fragment length polymorphism; pH