选取食品中主要的致腐致病菌鼠伤寒沙门氏菌、荧光假单胞菌、单核增生李斯特菌、金黄色葡萄球菌及粪肠球菌等,测定月桂酸单甘油酯(GML)和其它常见防腐剂在中性(p H 7.2)及弱酸性(p H 5.7)条件下对它们的抑制效果(以最低抑制浓度表示),结果表明GML在中性及弱酸性条件下能有效抑制革兰氏阳性菌(单核增生李斯特菌及金黄色葡萄球菌),最低抑制质量浓度低于25μg/m L,其抑制活性在弱酸性条件下有所增强。以GML为主体,与其它保鲜剂复配,测定复配体系在两种p H条件下的抑菌增效作用,结果GML与乳酸的复配效果最佳。该研究结果为开发适用于中性或弱酸性食品的安全、高效复配防腐剂奠定了基础。
Fatty acids and derivatives(FADs)are resources for natural antimicrobials.In order to screen for additional potent antimicrobial agents,the antimicrobial activities of FADs against Staphylococcus aureus were examined using a microplate assay.Monoglycerides of fatty acids were the most potent class of fatty acids,among which monotridecanoin possessed the most potent antimicrobial activity.The conventional quantitative structure-activity relationship(QSAR)and comparative molecular field analysis(CoMFA)were performed to establish two statistically reliable models(conventional QSAR:R2=0.942,Q 2 LOO=0.910;CoMFA:R 2=0.979,Q 2=0.588,respectively).Improved forecasting can be achieved by the combination of these two models that provide a good insight into the structureactivity relationships of the FADs and that may be useful to design new FADs as antimicrobial agents.
