LED蓝光与柠檬酸对大肠杆菌的协同抗菌作用

The synergistic antibacterial effect of LED blue light and citric acid against Escherichia coli

为了开发新型食品抗菌方法,研究了LED蓝光辐照强度、柠檬酸质量浓度和温度3个因素对营养肉汤中大肠杆菌O157:H7抗菌性能的影响。结果表明:LED蓝光在低温(12℃)下对大肠杆菌O157:H7的抗菌效果优于室温(25℃),且抗菌效果随着光照剂量的增加而增强;柠檬酸在低温下对大肠杆菌O157:H7的影响较弱,但在室温下可明显减缓其生长速率;与空白对照组相比,在使用4 072.3J/cm^2光照剂量的LED蓝光照射后,大肠杆菌O157:H7的数量在低温下可减少(2.60±0.19)lg CFU/mL,而在室温下仅减少(0.67±0.12)lg CFU/mL;加入柠檬酸后,显著增强了LED蓝光的抗菌效果,在使用2 471.0J/cm^2光照剂量的LED蓝光照射后,大肠杆菌O157:H7的数量在低温下可减少(5.13±0.11)lg CFU/mL,在室温下可减少(3.08±0.11)lg CFU/mL。

In order to develop a novel antibacterial method of food, the influences of the illumination intensity of LED blue light, the mass concentration of citric acid and temperature on the antibacterial property of Escherichia eoli O157 ： H7 in nutrient broth were studied. The results demonstrated that under low temperature （12℃）, the effect of LED blue light on the antibacterial property of Escherichia coli O157 ： H7 was better than that under room temperature （25℃）, and the antibacterial efficiency increased with the increase of illumination intensity. Under low temperature, the influence of citric acid on E. coli O157：H7 was weak, but under room temperature it could obviously slow down its growth rate. Compared with the control group, after exposure to the LED blue light with an illumination intensity of 4 072.3 J/cm2 , the number of E. coli O157：H7 under the low temperature decreased by （2.60 ± 0.19 ） lg CFU/mL, while the number only decreases by （0.67±0.12） lg CFU/mLunder the room temperature . After adding citric acid blue light was significantly enhanced. light with E. coli 0 illumination intensity the antibacterial effect of LED After exposed to the LED blue 2 471.0 J/cm2 , the number of 157：H7 under the low temperature decreased by （5.13 ± 0.11） lg CFU/mL,while it decreased by （3.08±0.11） lg CFU/mL under the room temperature.