PDF(Pubmed)
Abstract：
Various studies have shown that natural colorants, in addition to their coloring attributes, have valuable biological effects such as antioxidant, anti-inflammation, and anticarcinogenic properties. Moreover, their use as a food colorant can restrict the potential disadvantages of synthetic additives and turn foods into functional products. In this study, in vitro antimicrobial activities of two natural colorants of bixin and curcumin against some important foodborne pathogens: Staphylococcus aureus (S. aureus), Listeria innocua (L. innocua), and Escherichia coli (E. coli) were investigated by disk diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration values were determined by agar dilution and broth microdilution methods. The synergistic activity of the colorants against selected microorganisms was assayed by the checkerboard microdilution method. The results showed that the inhibitory effects of bixin against S. aureus were more pronounced than E. coli and L. innocua. The lowest concentration of curcumin (0.6 mg/mL) in the disk diffusion method was not inhibited by any tested bacteria. However, it was effective at the higher concentrations against three microorganisms, but its diameter of inhibition zones was lower than gentamicin in all concentrations. Synergetic effects were observed by curcumin and bixin combination against S. aureus (FICI ≤ 0.5), but they act as an antagonist against E. coli and L. innocua. The results of the synergy test were confirmed by the isobologram curves.
摘要：
各种研究表明，天然色素，除了它们的着色属性，有价值的生物效应，如抗氧化剂，抗炎，和抗癌特性。此外，它们作为食品着色剂的使用可以限制合成添加剂的潜在缺点，并将食品变成功能性产品。在这项研究中,Bixin和姜黄素两种天然着色剂对一些重要的食源性病原体的体外抗菌活性：金黄色葡萄球菌（S.金黄色葡萄球菌)，无害李斯特菌（L.innocua),和大肠杆菌(E.大肠杆菌)采用圆盘扩散法进行了研究。通过琼脂稀释和肉汤微量稀释方法确定最小抑制浓度和最小杀菌浓度值。通过棋盘微量稀释方法测定着色剂对所选微生物的协同活性。结果表明，比辛对金黄色葡萄球菌的抑制作用明显优于大肠杆菌和无毒乳杆菌。圆盘扩散方法中姜黄素的最低浓度(0.6mg/mL)未被任何测试细菌抑制。然而,它在较高浓度下对三种微生物有效，但是在所有浓度下，其抑制区的直径均低于庆大霉素。姜黄素和比辛组合对金黄色葡萄球菌（FICI≤0.5）观察到协同作用，但它们是大肠杆菌和无毒乳杆菌的拮抗剂。协同作用试验的结果由等效线图曲线证实。
