Teixeira Januana S, Repková Lenka, Gänzle Michael G, McMullen Lynn M
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
Front Microbiol. 2018 Aug 27;9:1979. doi: 10.3389/fmicb.2018.01979. eCollection 2018.
Pressure treatment of ready-to-eat (RTE) meats extends the shelf life and reduces risks associated with . However, pressure reduces numbers of on ham by less than 5 log (CFU/g) and pressure effects on other meat microbiota are poorly documented. This study investigated the impact of pressure and RTE meat microbiota, with or without nisin and rosemary oil, on survival of after refrigerated storage. Ham was inoculated with a 5-strain cocktail of alone or with a cocktail of RTE meat microbiota consisting of , , , and . Products were treated at 500 MPa at 5°C for 1 or 3 min, with or without rosemary extract or nisin. Surviving cells were differentially enumerated after pressure treatment and after 4 weeks of refrigerated storage. After 4 weeks of storage, products were also analyzed by high throughput sequencing of 16S rRNA amplicons. Pressure treatment reduced counts of by 1 to 2 log (CFU/g); inactivation of RTE meat microbiota was comparable. Counts of increased by 1-3 log (CFU/g) during refrigerated storage. RTE meat microbiota did not influence pressure inactivation of but prevented growth of during refrigerated storage. Rosemary extract did not influence bacterial inactivation or growth. The combination of nisin with pressure treatment for 3 min reduced counts of and meat microbiota by >5 log (CFU/g); after 4 weeks of storage, counts were below the detection limit. In conclusion, pressure alone does not eliminate or other microbiota on RTE ham; however, the presence of non-pathogenic microbiota prevents growth of on pressure treated ham and has a decisive influence on post-pressure survival and growth.
即食（RTE）肉类的压力处理可延长保质期并降低与之相关的风险。然而，压力使火腿上的[细菌名称]数量减少不到5个对数（CFU/g），且压力对其他肉类微生物群的影响记录较少。本研究调查了压力以及RTE肉类微生物群（添加或不添加乳酸链球菌素和迷迭香油）对冷藏储存后[细菌名称]存活的影响。火腿单独接种由[细菌名称1]组成的5菌株混合物，或接种由[细菌名称1]、[细菌名称2]、[细菌名称3]和[细菌名称4]组成的RTE肉类微生物群混合物。产品在5°C下于500 MPa处理1或3分钟，添加或不添加迷迭香提取物或乳酸链球菌素。在压力处理后以及冷藏储存4周后，对存活细胞进行差异计数。储存4周后，还通过16S rRNA扩增子的高通量测序对产品进行分析。压力处理使[细菌名称]数量减少1至2个对数（CFU/g）；RTE肉类微生物群的失活情况相当。在冷藏储存期间，[细菌名称]数量增加了1 - 3个对数（CFU/g）。RTE肉类微生物群不影响[细菌名称]的压力失活，但可防止其在冷藏储存期间生长。迷迭香提取物不影响细菌的失活或生长。乳酸链球菌素与3分钟压力处理相结合可使[细菌名称]和肉类微生物群数量减少>5个对数（CFU/g）；储存4周后，数量低于检测限。总之，单独的压力并不能消除RTE火腿上的[细菌名称]或其他微生物群；然而，非致病性微生物群的存在可防止[细菌名称]在压力处理过的火腿上生长，并对压力处理后的存活和生长具有决定性影响。
