[关键词]
[摘要]
紫外辐射食没子酸抑菌液(UVC-GA)是通过紫外线短波(UV-C)辐照没食子酸(GA)开发一种新型光诱导增强GA抑菌的方法,将UV-C辐照GA 12 h形成新型UVC-GA抑菌液,E. coli O157:H7减少量达3.57 log cfu/mL,比GA显著高22.33倍。UVC-GA的抑菌活性受辐照时间、波长和pH的影响,60 min辐照后使E. coli O157:H7减少4.42 log cfu/mL,比紫外线中波UVB-GA和紫外线长波UVA-GA显著高64.25%和223.47%,pH 3下比pH 7和pH 11分别高94.23倍和87.62倍。UVC-GA加入苯磺酸(BSA)后抗菌活性显著降低至0.63 log cfu/mL(p<0.05),说明UVC-GA内的醌类化合物增强了其抗菌活性。加入活性氧(ROS)猝灭剂,UVC-GA比二甲基亚甲砜(DMSO)和甘露醇处理组比UVC-GA抗菌效果显著降低了4.56%和8.15%(p<0.05),且UVC-GA内有过氧化氢的生成及E. coli O157:H7氧化应激水平增加,表明ROS在UVC-GA的抗菌作用中也起着一定的作用。结果表明,UVC-GA可有效抑制牡蛎肉质表面E. coli O157:H7,正确处理UV-C辐照的GA可作为一种新型抑菌液应用于牡蛎或其它食品的抑菌。
[Key word]
[Abstract]
A novel ultraviolet-irradiated gallic acid antibacterial solution (UVC-GA) was developed using a new method of light-induced enhancement of GA antibacterial activity through exposing gallic acid (GA) to UV-C for 12 h. The GA solution obtained after UVC-GA for 12 h could reduce E. coli O157: H7 by 3.57 log cfu/mL (which was 22.33 times higher than that of GA. The antibacterial activity of UVC-GA solution was affected by the irradiation duration, wavelength and pH. After 60 min of irradiation, UVC-GA reduced E. coli O157: H7 by 4.42 log cfu/mL, which was significantly higher than UVB-GA and UVA-GA by 64.25% and 223.47%; The reduction of E. coli O157: H7 by UVC-GA at pH 3 was 94.23 and 87.62 times, respectively, higher than those at pH 7 and pH 11. The addition of benzenesulfinic acid (BSA) to UVC-GA lowered E. coli O157: H7 to 0.63 log cfu/mL (p<0.05), indicating that quinone compounds in UVC-GA enhanced its antibacterial activity. The addition of reactive oxygen species (ROS) quencher to UVC-GA significantly (p<0.05) reduced the antibacterial effect by 4.56% and 8.15%, respectively, compared with those of the DMSO-treated group and the mannitol-treated group (p<0.05). The generation of hydrogen peroxide and the increase of E. coli O157: H7-induced oxidative stress indicated the contribution of ROS to the antibacterial effect of UVC-GA. The results showed that UVC-GA could effectively inhibit E. coli O157:H7 on the surface of oyster flesh, and correctly treated UV-C irradiated GA can be used as a novel antimicrobial solution for sterilization of oyster products and other foods.
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[基金项目]
广西重点研发计划项目(2018AB45010);广西科技重大创新项目(AA17204095-4);广西重点实验室自主创新项目(AA19204095-1)