School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, Shaanxi, China.
Sci Rep. 2022 Nov 7;12(1):18856. doi: 10.1038/s41598-022-23309-3.
This study investigated the mechanism of membrane damage by protocatechualdehyde (PCA) against Micrococcus luteus and assessed effects of PCA on the sensory and physicochemical properties of pork. The mechanism of PCA inhibition on M. luteus was studied by determining the minimum inhibitory concentration (MIC) based on membrane potential, intracellular ATP concentration, intracellular pH, confocal laser scanning microscopy (CLSM), and field emission gun scanning electron microscopy (FEG-SEM). The results showed that the MIC of PCA against M. luteus was 1.25 mg/mL. Hyperpolarization of the bacterial cell membrane, a decrease in the intracellular ATP concentration, and intracellular pH indicated that PCA damaged the cell membrane of M. luteus. FEG-SEM observation revealed that PCA could cause surface collapse, cell membrane rupture, and content outflow of M. luteus. Additionally, PCA was found to inhibit increases in the total number of colonies, the thiobarbituric acid reactive substances (TBARS) value growth rate, and moisture mobility in raw pork. Additionally, it improved the color and texture of raw pork, all of which effectively prolonged its shelf life. This study will encourage the application of PCA as a natural antibacterial agent in the food industry.
本研究旨在探讨原儿茶醛（PCA）对藤黄微球菌的膜损伤机制，并评估 PCA 对猪肉感官和物理化学特性的影响。通过测定基于膜电位、细胞内 ATP 浓度、细胞内 pH 值的最小抑菌浓度（MIC），采用激光共聚焦扫描显微镜（CLSM）和场发射枪扫描电子显微镜（FEG-SEM）研究 PCA 对藤黄微球菌的抑制机制。结果表明，PCA 对藤黄微球菌的 MIC 为 1.25mg/mL。细菌细胞膜的超极化、细胞内 ATP 浓度的降低和细胞内 pH 值表明 PCA 破坏了藤黄微球菌的细胞膜。FEG-SEM 观察显示，PCA 可导致藤黄微球菌表面塌陷、细胞膜破裂和内容物流出。此外，PCA 还能抑制生猪肉总菌落数、硫代巴比妥酸反应物（TBARS）值增长率和水分迁移率的增加，同时改善生猪肉的颜色和质地，有效延长其货架期。本研究将鼓励 PCA 在食品工业中作为天然抗菌剂的应用。
