该研究探讨了茶树精油对单增李斯特菌的抑制效果及其在冷鲜猪肉保鲜中的应用。测定了茶树精油对单增李斯特菌的最小抑菌浓度（Minimal Inhibitory Concentration, MIC），观察了细菌的生长曲线以及细胞微观结构的变化，并分析了茶树精油处理的猪肉在冷藏期间其菌落总数、总挥发性盐基氮含量、硫代巴比妥酸反应物值、pH值、颜色和质构的变化情况。结果表明：茶树精油对单增李斯特菌的MIC为4.0 mg/mL，且不同茶树精油处理组均对单增李斯特菌具有明显的抑制效果，茶树精油破坏了单增李斯特菌细胞膜和细胞壁结构的完整性，引发细胞内容物外渗，从而导致菌体死亡。此外，在贮藏期间（0~12 d），MIC、2MIC和4MIC茶树精油处理组的菌落总数与对照组相比分别下降了1.18、1.37和1.56 log CFU/g，且TVB-N值和TBARS值均未超过最大阈值，茶树精油有效抑制了猪肉中微生物的生长，延缓了猪肉含氮化合物降解、脂肪氧化、色度和品质的变化。结果表明，茶树精油可抑制单增李斯特菌的生长，并延长冷鲜猪肉的货架期3 d左右，可作为冷鲜猪肉的保鲜剂。

This study investigated the inhibitory effect of tea tree essential oil on Listeria monocytogenes and its application in the preservation of chilled fresh pork. The minimum inhibitory concentration (MIC) of tea tree essential oil against Listeria monocytogenes was determined, and the bacterial growth curve and the changes in cell microstructure were observed. The changes in the total bacterial count, total volatile basic nitrogen content, thiobarbituric acid reactive substances content, pH, color, and texture of the pork treated with the tea tree essential oil during refrigeration were analyzed. The results showed that the MIC of tea tree essential oil against Listeria monocytogenes was 4.0 mg/mL, and different treatments with tea tree essential oil exhibited a significant inhibitory effect on Listeria monocytogenes. The tea tree essential oil damaged the structural integrity of the cell membranes and cell walls of Listeria monocytogenes, causing the release of internal cellular contents and ultimately the death of bacteria. Compared with the control group, the total colony number of MIC, 2MIC and 4MIC of the tea tree essential oil treatment groups decreased by 1.18, 1.37 and 1.56 log CFU/g, respectively, and the values of TVB-N and TBARS did not exceed the maximum threshold during storage (0~12 days). Therefore, tea tree essential oil effectively inhibited the growth of microorganisms in pork, delayed the degradation of nitrogen-containing compounds, fat oxidation, color and quality changes in the pork. The results showed that tea tree essential oil could inhibit the growth of Listeria monocytogenes and extend the shelf life of chilled fresh pork for about 3 days, and can be used as a preservative for chilled pork.

国家自然科学基金资助项目（32172320）；广东省自然科学基金资助项目（2021A1515011068）