Lactic acid bacteria are the main bacterial group associated to meat spoilage. Herbal essential oils are promising alternatives that can be used to retard lactic acid bacterial growth and extend shelf life of meat products. In this study, the influence of oregano and rosemary essential oils on the growth of lactic acid bacteria and the physicochemical properties of refrigerated vacuum-packed Tuscan sausage was evaluated. In addition to the control (without the addition of oil), the sausage samples were separately treated with different concentrations of each essential oil (0.05 wt%, 0.1 wt%, 0.2 wt%, and 0.4 wt%). The shelf life was evaluated as the time to the lactic acid bacteria population to reach the levels of 106 and 107 CFU/g. After the addition of 0.05 wt% and 0.1 wt% of essential oil to the sausage, the rosemary essential oil provided a higher extension of the shelf life of the sausages (approximately 3 and 5 days, respectively) than the oregano essential oil (approximately 1 and 3 days, respectively). After adding 0.2 wt% and 0.4 wt% of essential oil, the oregano essential oil resulted in a larger increase of the shelf life of the samples (about 8 and 14 days, respectively) when compared with the rosemary essential oil (about 7 to 11 days, respectively). All the treatments slowed the growth of the lactic acid bacteria but they did not change the maximum bacterial population. New empirical models that relate the shelf life of the sausage and the maximum specific growth rate of the lactic acid bacteria with the oil concentration were obtained. These results can be applied to model the influence of essential oils on the shelf life of different meat products.

中文翻译：

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添加抗菌牛至（Origanum vulgare）和迷迭香（Rosmarinus officinalis）精油对冷藏真空包装托斯卡纳香肠中乳酸菌生长的影响

乳酸菌是与肉类腐败相关的主要细菌群。草本精油是一种很有前途的替代品，可用于延缓乳酸菌的生长并延长肉制品的保质期。本研究评估了牛至和迷迭香精油对乳酸菌生长的影响以及冷藏真空包装托斯卡纳香肠的理化特性。除了对照（不添加油）之外，香肠样品分别用不同浓度的每种精油（0.05 wt%、0.1 wt%、0.2 wt%和0.4 wt%）进行处理。保质期被评估为乳酸菌种群达到 106 和 107 CFU/g 水平的时间。在香肠中加入0.05wt%和0.1wt%的精油后，与牛至精油（分别约 1 天和 3 天）相比，迷迭香精油延长了香肠的保质期（分别约为 3 天和 5 天）。添加 0.2 wt% 和 0.4 wt% 的精油后，与迷迭香精油相比，牛至精油使样品的保质期（分别为约 8 天和 14 天）（约 7 至 11天，分别）。所有的处理都减缓了乳酸菌的生长，但它们并没有改变最大的细菌种群。获得了将香肠的保质期和乳酸菌的最大比生长率与油浓度相关联的新经验模型。