Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Sandy Bay Campus, Hobart, Tasmania 7005, Australia.
Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Sandy Bay Campus, Hobart, Tasmania 7005, Australia.
Meat Sci. 2017 Sep;131:34-39. doi: 10.1016/j.meatsci.2017.04.021. Epub 2017 Apr 22.
This report builds on the earlier studies of the shelf-life of chilled Australian vacuum packaged (VP) beef primals (striploin and cube roll), products distinguished in the global marketplace for unusually long shelf-life. Notable findings in those studies were a shelf-life of at least 26weeks at -0.5°C, low microbial counts, and relatively high sensory scores. However, growth rates for total viable counts (TVC) and lactic acid bacteria (LAB) varied among the different abattoirs. The present study adds to these findings, by providing greater definition about temporal changes in bacterial communities using terminal restriction fragment length polymorphism (TRFLP) and clone library analyses of 16S ribosomal RNA (16S rRNA) gene, and measuring statistical associations among abattoir, beef cut, storage time and sensory attributes. Bacterial communities changed over time, with Carnobacterium spp. typically predominating (29-97%) at the end of storage. Variation in TRFLP profiles showed that different Carnobacterium strains predominated in different abattoirs, and that additional variation was due to the presence of other taxa typical of VP meat microbiomes. TRFLP-based community structure correlated significantly (P≤0.01) with sensorial characteristics, such as vacuum integrity, confinement odour, and intact pack appearance of beef. This study shows that Carnobacterium spp. predominate on extended shelf-life VP beef primals, while other taxa may produce subtle effects on shelf-life duration.
本报告是对先前关于冷藏澳大利亚真空包装（VP）牛肉原切（牛里脊和牛臀肉卷）保质期的研究的扩展，这些产品以异常长的保质期在全球市场上脱颖而出。这些研究中的显著发现是，在-0.5°C 的温度下，保质期至少为 26 周，微生物数量低，感官评分相对较高。然而，总活菌数（TVC）和乳酸菌（LAB）的增长率在不同的屠宰场之间存在差异。本研究通过使用末端限制性片段长度多态性（TRFLP）和 16S 核糖体 RNA（16S rRNA）基因的克隆文库分析，对细菌群落进行更具体的时间变化定义，并测量屠宰场、牛肉切割、储存时间和感官属性之间的统计关联，进一步扩展了这些发现。细菌群落随时间发生变化，最终通常以食酸菌属（Carnobacterium spp.）为主（29-97%）。TRFLP 图谱的变化表明，不同的食酸菌属菌株在不同的屠宰场中占优势，而其他分类群的存在是 VP 肉微生物组的典型变化。基于 TRFLP 的群落结构与感官特征（如真空完整性、封闭气味和牛肉包装完整性）显著相关（P≤0.01）。本研究表明，食酸菌属在延长保质期的 VP 牛肉原切中占优势，而其他分类群可能对保质期持续时间产生微妙影响。
