Solomakos N, Govaris A, Koidis P, Botsoglou N
Laboratory of Hygiene of Foods of Animal Origin, Faculty of Veterinary Medicine, University of Thessaly, 224 Trikalon Street, 43100 Karditsa, Greece.
Food Microbiol. 2008 Feb;25(1):120-7. doi: 10.1016/j.fm.2007.07.002. Epub 2007 Jul 25.
The antimicrobial effect of thyme essential oil (EO) at 0.3%, 0.6%, or 0.9%, nisin at 500 or 1000IU/g, and their combination against Listeria monocytogenes was examined in both tryptic soy broth (TSB) and minced beef meat. Thyme EO at 0.3% possessed a weak antibacterial activity against the pathogen in TSB, whereas at 0.9% showed unacceptable organoleptic properties in minced meat. Thus, only the level of 0.6% of EO was further examined against the pathogen in minced meat. Treatment of minced beef meat with nisin at 500 or 1000IU/g showed antibacterial activity against L. monocytogenes, which was dependent on the concentration level of nisin and the strains used. Treatment of minced beef meat with EO at 0.6% showed stronger inhibitory activity against L. monocytogenes than treatment with nisin at 500 or 1000IU/g. All treatments showed stronger inhibitory activity against the pathogens at 10 degrees C than at 4 degrees C. The combined addition of EO at 0.6% and nisin at 500 or 1000IU/g showed a synergistic activity against the pathogen. Most efficient among treatments was the combination of EO at 0.6% with nisin at 1000IU/g, which decreased the population of L. monocytogenes below the official limit of the European Union recently set at 2logcfu/g, during storage at 4 degrees C.
研究了0.3%、0.6%或0.9%的百里香精油（EO）、500或1000IU/g的乳酸链球菌素及其组合对胰蛋白胨大豆肉汤（TSB）和碎牛肉中单核细胞增生李斯特菌的抗菌效果。0.3%的百里香EO对TSB中的该病原体具有较弱的抗菌活性，而0.9%的百里香EO在碎肉中表现出不可接受的感官特性。因此，仅进一步研究了0.6%的EO对碎肉中该病原体的作用。用500或1000IU/g的乳酸链球菌素处理碎牛肉对单核细胞增生李斯特菌具有抗菌活性，这取决于乳酸链球菌素的浓度水平和所用菌株。用0.6%的EO处理碎牛肉对单核细胞增生李斯特菌的抑制活性比用500或1000IU/g的乳酸链球菌素处理更强。所有处理在10℃时对病原体的抑制活性均强于4℃时。联合添加0.6%的EO和500或1000IU/g的乳酸链球菌素对该病原体表现出协同活性。处理中最有效的是0.6%的EO与1000IU/g的乳酸链球菌素的组合，在4℃储存期间，该组合可将单核细胞增生李斯特菌的数量降至欧盟最近设定的2logcfu/g的官方限量以下。
