Luciano F B, Hosseinian F S, Beta T, Holley R A
Department of Food Science, Faculty of Agricultural and Food Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
J Food Sci. 2008 Jun;73(5):M214-20. doi: 10.1111/j.1750-3841.2008.00762.x.
Escherichia coli O157:H7 contamination is a significant meat safety issue in many countries. Allyl isothiocyanate (AIT) is a natural compound found to limit the survival of E. coli O157:H7 and other pathogens in meat and meat products. In the present study, it was found that glutathione and cysteine naturally present in meat can interfere with AIT antimicrobial activity. Spectroscopy, HPLC, and LC-MS were used to confirm that glutathione was able to react with AIT and formed a conjugate with no or low bactericidal activity against the tested organisms. The same reaction also occurred at pH values of 4.9 and 5.8 at 25 and 4 degrees C, respectively, which broadly represent storage conditions in raw beef (pH 5.8) and during fermented sausage (pH 4.9) manufacture. Reactions observed help to explain reduction in antimicrobial potency of AIT in food (meat) systems.
大肠杆菌O157:H7污染在许多国家都是一个重大的肉类安全问题。异硫氰酸烯丙酯（AIT）是一种天然化合物，已发现它能限制大肠杆菌O157:H7及其他病原体在肉类和肉制品中的存活。在本研究中，发现肉类中天然存在的谷胱甘肽和半胱氨酸会干扰AIT的抗菌活性。使用光谱学、高效液相色谱法（HPLC）和液相色谱 - 质谱联用（LC - MS）来确认谷胱甘肽能够与AIT发生反应，并形成一种对受试生物无杀菌活性或杀菌活性较低的共轭物。相同的反应分别在25℃和4℃时pH值为4.9和5.8的条件下也会发生，这大致代表了生牛肉（pH 5.8）的储存条件以及发酵香肠（pH 4.9）生产过程中的条件。观察到的这些反应有助于解释AIT在食品（肉类）体系中抗菌效力的降低。
