Hao Jingyi, Lei Yuqing, Gan Zhilin, Zhao Wanbin, Shi Junyan, Jia Chengli, Sun Aidong
College of Biological Sciences and Biotechnology, Beijing Forestry University, No. 35 Qinghua East Road, Haidian District, Beijing 100083, China.
Beijing Key Laboratory of Food Processing and Safety in Forestry, No. 35 Qinghua East Road, Haidian District, Beijing 100083, China.
Foods. 2021 Dec 8;10(12):3053. doi: 10.3390/foods10123053.
With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly ( ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.
随着高静水压（HHP）技术在食品工业中的广泛应用，出现了与食品产品相关的安全问题，从而导致潜在的食品安全危害。为了解决这些问题，本研究探讨了原儿茶酸（PCA）和HHP对O157:H7的协同杀菌作用及机制。在大于200 MPa时，PCA（1.25 mg/mL处理60分钟）加HHP处理具有显著的协同杀菌作用，且与压力呈正相关。在500 MPa下联合处理5分钟后，菌落数下降了约9.0 log CFU/mL，而单独的HHP和PCA处理分别导致菌落数下降4.48和1.06 log CFU/mL。从机制上讲，当O157:H7暴露于PCA加HHP的协同压力下时，细胞膜的完整性和形态受到破坏，通透性增加。在细胞内部，协同处理还靶向超氧化物歧化酶、过氧化氢酶和ATP酶等酶的活性，当暴露于高压时，这些酶的活性受到显著抑制（≤0.05）。此外，圆二色光谱分析表明，协同处理导致DNA结构发生变化，表现为特征吸收峰的红移。因此，PCA加HHP的协同处理由于对多个靶点具有良好的杀菌效果，可作为一种去污方法。
