Plasma Research Group, School of Food Science and Environmental Health, Dublin Institute of Technology, Ireland.
School of Chemical Engineering, UNSW, Sydney, Australia.
Food Microbiol. 2017 Sep;66:48-54. doi: 10.1016/j.fm.2017.04.002. Epub 2017 Apr 5.
Brochothrix thermosphacta is the predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta, taking microbial and food environment factors into consideration, and investigated the shelf-life of lamb chop after in-package plasma treatment in modified atmosphere. Community profiling was used to assess the treatment effects on the lamb microflora. ACP treatment (80 kV) for 30s inactivated B. thermosphacta populations below detection levels in PBS, while 5 min treatment achieved a 2 Log cycle reduction using a complex meat model medium and attached cells. The antimicrobial efficacy of plasma was reduced but still apparent on lamb chop surface-inoculated with high concentrations of B. thermosphacta. Lamb chop treated under modified atmosphere exhibited reduced microbial growth over the product shelf-life and community profiling showed no evident changes to the microbial populations after the treatment. The overall results indicated potential of ACP to enhance microbial control leading to meat storage life extension through adjusting the modality of treatment.
生孢食酸菌是肉类中的主要腐败微生物，控制其在加工环境中的生长对于保持肉类产品的质量非常重要。大气压冷等离子体（Atmospheric cold plasma，ACP）在控制食品中致病菌和腐败微生物方面具有重要的应用价值。本研究考虑了微生物和食品环境因素，确定了介电阻挡放电大气压冷等离子体（Dielectric barrier discharge atmospheric cold plasma，DBD-ACP）对生孢食酸菌的控制潜力，并研究了包装内等离子体处理对气调包装羊排货架期的影响。采用群落分析评估了处理对羊排微生物群落的影响。ACP 处理（80 kV）30 s 可使 PBS 中生孢食酸菌的数量降低至检测水平以下，而在复杂的肉模型培养基和附着细胞中，5 min 的处理可降低 2 Log 个循环。等离子体的抗菌效果在高浓度生孢食酸菌接种的羊排表面有所降低，但仍有明显效果。在气调包装下处理的羊排，在产品保质期内微生物生长受到抑制，处理后群落分析显示微生物种群没有明显变化。总体结果表明，ACP 具有增强微生物控制的潜力，通过调整处理方式，可以延长肉类的储存寿命。
