抗菌蓝光对鲜牛奶杀菌后味觉和脂质组的影响

Effect of antibacterial blue light on taste character and lipidomics offresh milk after sterilization

抗菌蓝光(400~480 nm)是近年来新型的非热杀菌新技术,具有杀菌谱广、安全性好等优势,在食品杀菌领域具有良好潜力。该文采用415 nm蓝光,对鲜牛奶中污染频率高的大肠杆菌进行杀菌研究。因此论文针对牛奶最易氧化的脂质成分,研究了蓝光杀菌后牛奶脂质组变化,同时分析了牛奶味觉特性和过氧化物丙二醛(malondialdehyde, MDA)。结果显示,蓝光对牛奶中大肠杆菌杀灭效果好,82.08 J/cm^(2)剂量时可完全杀灭。杀菌后鲜牛奶酸、甜、苦、涩等多个感官特性无统计学差异;MDA水平也无影响。牛奶的脂质组分析显示,蓝光杀菌前后鲜牛奶的脂质组成、相对含量、尤其是不饱和脂质均无统计学差异,结果表明,415 nm蓝光不会改变鲜牛奶中的脂质组分。因此415 nm蓝光照射可有效杀灭鲜牛奶中大肠杆菌,且不影响牛奶脂质和风味。

Antibacterial blue light(400-480 nm)is a novel non-thermal sterilization technology,possessing multiple advantages such as a wide bactericidal spectrum and good safety,and thus has good potential in the field of food sterilization.Therefore,the present work employed 415 nm blue light to inactivate Escherichia coli,a common contaminating bacterium in fresh milk.The hypothetical bactericidal mechanism widely recognized was associated with cellular oxidative damage,however,there was almost no research on whether these intracellular peroxides caused the oxidation of lipids in fresh milk.Therefore,the present work focused on lipid molecules in milk,the most easily oxidized components,and investigated the effect of blue light on lipidomics change after blue light inactivation,additionally,it evaluated the changes in the taste character of fresh milk and the content of lipid peroxide MDA.Results showed that blue light had an efficient bactericidal effect against E.coli in fresh milk,and could completely kill them under an irradiation dose of 82.08 J/cm^(2).After sterilization,there was no statistical difference in taste characteristics of fresh milk such as acidity,sweetness,bitterness,and astringency.Besides,blue light had no statistical impact on malondialdehyde levels.Furthermore,comparative lipidomics of fresh milk before and after blue light sterilization revealed that there were no statistical changes in the composition and relative content of lipids,especially unsaturated lipids,thus 415 nm blue light did not change the lipid profiles in the fresh milk.The present study showed that 415 nm blue light could effectively kill E.coli in fresh milk without affecting the taste character and lipid composition of fresh milk.