【摘要】 研究了添加不同质量分数的肉桂醛(0,0.1%,0.5%和1.0%)后猪肉糜中金黄色葡萄球菌的热失活规律。在肉糜中添加不同浓度的肉桂醛后进行热处理(60～75℃),用选择性培养基进行活细胞计数。结果表明,不同温度条件下,肉桂醛对金黄色葡萄球菌的热失活有明显的促进作用,随着温度和肉桂醛浓度的升高,金黄色葡萄球菌的耐热性逐渐降低。在75℃条件下,肉桂醛使肉糜中金黄色葡萄球菌完全热失活所需的时间从5 min减少到3 min。将试验结果进行动力学模型拟合,多项式拟合作为初级模型,能准确地描述添加肉桂醛后肉糜中金黄色葡萄球菌的热失活规律。在二级模型的拟合中,线性模型具有更高的拟合系数值。通过扫描电镜观察肉桂醛处理条件下金黄色葡萄球菌细胞的形态变化,表明肉桂醛可破坏金黄色葡萄球菌的细胞膜,从而导致胞质泄露而死亡。更多还原

【Abstract】 This paper studied the different concentrations of cinnamaldehyde(0, 0.1%, 0.5% and 1.0%) on the thermal inactivation of Staphylococcus aureus in ground pork ranging from 60 to 75 ℃. Different concentrations of cinnamaldehyde were added in the ground pork samples, then subjected to thermal treatment. The surviving cell number was counted on selective media. The results showed that at different temperatures, cinnamaldehyde promoted the thermal inactivation of S. aureus. Moreover, the thermal resistance of S. aureus decreased along with the increase of heat temperature and cinnamaldehyde concentration. At 75 ℃, cinnamaldehyde supplementation shortened the time needed to reach the non-detectable level of S. aureus in ground pork from 5 min to 3 min. When the inactivation curves were fitted by different kinetic models, polynomial fitting was suitable to describe the thermal inactivation regulation of S. aureus in ground pork added by cinnamaldehyde, where the secondary linear model had the highest coefficient value when different models were compared. When scanning electron microscopy(SEM) was used to observe the morphological changes of S.aureus exposed to cinnamaldehyde, the results revealed that the cinnamaldehyde ruptured the cell membrane, which leaded to the leakage of cytoplasm and might attributed to the promoting effect of cinnamaldehyde on thermal inactivation.更多还原