肉桂醛对猪肉糜中单核细胞增生李斯特菌的 抑制作用及其机制

Antibacterial activity and mechanism of cinnamaldehyde on Listeria monocytogenes in ground pork

中文关键词:  肉桂醛  单核细胞增生李斯特菌  热杀菌  细胞形态

英文关键词:cinnamaldehyde  Listeria monocytogenes  thermal inactivation  cell morphology

中文摘要:

      目的 研究不同温度条件下肉桂醛对猪肉糜中单核细胞增生李斯特菌的抑制作用, 并分析其机制。方法 在不同温度(55、60、65和70 ℃)条件下, 对添加不同浓度肉桂醛的猪肉糜中单核细胞增生李斯特菌的活细胞变化曲线进行测定分析, 并采用扫描电子显微镜技术研究肉桂醛对其菌体形态的影响。结果 在猪肉糜中添加肉桂醛能明显增大单核细胞增生李斯特菌的热失活速率, 缩短热处理的时间, 这种促进作用也随着肉桂醛浓度的增大而逐渐加强。在70 ℃下, 添加有1.0%肉桂醛的猪肉糜样品在0.5 min之内可使得单核细胞增生李斯特菌活细胞的数目从9.03 Log CFU/g迅速减少到2.89 Log CFU/g, 而未添加肉桂醛的对照样品则需要3 min。扫描电子显微镜结果显示, 肉桂醛处理后单核细胞增生李斯特菌的菌体变长, 细胞色泽暗沉。结论 肉桂醛能够显著改变单核细胞增生李斯特菌的形态, 降低其在猪肉糜中的热抵抗能力, 因而加快了其热失活速率。本研究为肉桂醛在食品中食源性致病菌的安全控制领域的应用提供了参考。

英文摘要:

      Objective To clarify the inactivation effect of cinnamaldehyde on Listeria monocytogenes in ground pork under different temperatures, as well as its inactivation mechanism. Methods Under different heat temperatures (55, 60, 65 and 70 ℃), the changing curve of viable cell number of L. monocytogenes in ground pork supplemented with various concentrations of cinnamaldehyde were analyzed. The effects of cinnamaldehyde on the changes of cell morphology were also observed using scanning electron microscope. Results The supplementation of cinnamaldehyde in ground pork significantly increased the thermal inactivation rate of L. monocytogenes, and shortened the time required for thermal inactivation. Moreover, the improvement effect was enhanced along with the increase of cinnamaldehyde concentration. The addition of 1% cinnamaldehyde to ground pork achieved a reduction from 9.03 Log CFU/g to 2.89 Log CFU/g within only 0.5 min at 70 ℃, while 3 min was needed in control sample without cinnamaldehyde supplementation. The scanning electron microscope observation showed that, L. monocytogenes cells treated by cinnamaldehyde became elongated and darker compared with the control cells. Conclusion The cinnamaldehyde can significantly change the morphology of L. monocytogenes, decrease its thermal resistance, thus improving the thermal inactivation rate. The present study offers a reference for the application of cinnamaldehyde in the area of foodborne pathogens control in foodstuff.