Effect of pH on the antimicrobial activity and oxidative stability of oil-in-water emulsions containing caffeic acid
Effect of pH on the antimicrobial activity and oxidative stability of oil-in-water emulsions containing caffeic acid
复制标题
DOI：
10.1111/j.1750-3841.2007.00387.x
复制
发表时间：
2007-06-01
影响因子：
3.9
通讯作者：
Gordon, M. H.
中科院分区：
文献类型：
--
作者：
Almajano, M. P.;Carbo, R.;Gordon, M. H.
食品中的抗氧化特性取决于各种参数。其中包括 pH 值以及与食物成分（包括蛋白质或金属离子）的相互作用。食品成分会影响抗氧化稳定性，也会影响微生物的特性及其活力。本文介绍了不同介质中 pH 对咖啡酸抗氧化和抗菌特性影响的研究。使用水包油乳液作为模型系统，研究的 pH 值分别为 3、5（有或没有磷酸盐缓冲液）和 9。研究了咖啡酸、牛血清白蛋白 (BSA) 和 Fe (III) 的混合物对乳液样品氧化变质的影响。结果表明，BSA 的存在提高了咖啡酸的抗氧化活性。该效果取决于 pH 值，并受铁离子存在的影响。抗菌特性也依赖于 pH 值。确定了在 pH 值 5 至 7 范围内抑制某些微生物所需的咖啡酸最低浓度。 0.41% (w/w) 的咖啡酸浓度足以在 pH 值 5 至 7 范围内抑制一些所研究微生物的生长。然而，需要高于 0.4% 的近中性 pH 浓度才能抑制培养基中的一些微生物，包括单核细胞增生李斯特氏菌、大肠杆菌和金黄色葡萄球菌。
Antioxidant properties in food are dependent on various parameters. These include the pH value and interactions with food components, including proteins or metal ions. food components affect antioxidant stability and also influence the properties of microorganisms and their viability. This paper describes an investigation of the effect of pH on the antioxidant and antibacterial properties of caffeic acid in different media. The pH values studied, using an oil-in-water emulsion as model system, were 3, 5 (with and without phosphate buffer), and 9. Effects of mixtures of caffeic acid, bovine serum albumin (BSA), and Fe (III) on oxidative deterioration in the emulsion samples were studied. The results show that the antioxidant activity of caffeic acid was increased by the presence of BSA. This effect was pH dependent and was affected by the presence of iron Ions. Antibacterial properties were also pH dependent. The minimum concentration of caffeic acid required to inhibit some microorganisms in the pH range of 5 to 7 was determined. A concentration of 0.41% (w/w) caffeic acid was enough to inhibit the growth of some of the studied microorganisms in the pH range of 5 to 7. However, near-neutral pH concentrations higher than 0.4% were needed to inhibit some microorganisms, including Listeria monocytogenes, E. coli, and Staphylococcus aureus, in the medium.