Abstract The application of dodecyl gallate (DG) is limited due to its poor stability and water-solubility. A new compound of DG microencapsulated with methyl-β-cyclodextrin (MβCD), MβCD-DG was produced, and the inhibition effects of MβCD-DG against three common foodborne pathogens (Staphylococcus aureus, Bacillus cereus and Bacillus subtilis) were investigated in the study. The antioxidant activity of MβCD-DG was determined by the DPPH method (EC50 = 4.515 ± 0.5 μg/mL). The minimum inhibitory concentration (MIC) of MβCD-DG against these bacteria were 0.11, 0.06 and 0.06 mg/mL, and minimum bactericidal concentration (MBC) were 0.22, 0.11 and 0.11 mg/mL, respectively. The MICs remained steady under different pH values (3.0–9.0) and temperatures (4 and 25 °C), indicating that the anti-bacterial effect of MβCD-DG was independent of pH and temperature. Measurements of permeability of cell wall and membrane, membrane potential, release of cellular contents and observation of cell morphology were carried out to explore the antibacterial mechanism of MβCD-DG. The results indicated that MβCD-DG inhibited S. aureus by increasing the permeability of cell membrane and leakage of cellular contents without obvious cell morphological changes. MβCD-DG may kill B. cereus and B. subtilis by damaging the cell wall and cytoplasmic membrane to make the release of cellular contents. As a novel preservative, MβCD-DG is more efficient than DG and common chemical additives, and is thus worthy of further exploitation in food industry.

中文翻译：

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甲基-β-环糊精微囊化十二烷基没食子酸酯的抗菌活性及作用机制

摘要 没食子酸十二烷基酯（DG）由于其稳定性和水溶性较差，其应用受到限制。制备了一种甲基-β-环糊精（MβCD）微胶囊化DG新化合物MβCD-DG，研究了MβCD-DG对三种常见食源性病原体（金黄色葡萄球菌、蜡状芽孢杆菌和枯草芽孢杆菌）的抑制作用. MβCD-DG的抗氧化活性由DPPH法测定（EC50 = 4.515 ± 0.5 μg/mL）。MβCD-DG 对这些细菌的最低抑菌浓度 (MIC) 分别为 0.11、0.06 和 0.06 mg/mL，最低杀菌浓度 (MBC) 分别为 0.22、0.11 和 0.11 mg/mL。MIC 在不同 pH 值（3.0-9.0）和温度（4 和 25°C）下保持稳定，表明 MβCD-DG 的抗菌作用与 pH 和温度无关。通过测量细胞壁和膜的通透性、膜电位、细胞内容物的释放和细胞形态学观察，探索MβCD-DG的抗菌机制。结果表明，MβCD-DG通过增加细胞膜的通透性和细胞内容物的渗漏来抑制金黄色葡萄球菌，而没有明显的细胞形态变化。MβCD-DG可能通过破坏细胞壁和细胞质膜释放细胞内容物来杀死蜡样芽孢杆菌和枯草芽孢杆菌。MβCD-DG作为一种新型防腐剂，比DG和常见的化学添加剂更有效，值得在食品工业中进一步开发。通过释放细胞内容物和观察细胞形态来探讨MβCD-DG的抗菌机制。结果表明，MβCD-DG通过增加细胞膜的通透性和细胞内容物的渗漏来抑制金黄色葡萄球菌，而没有明显的细胞形态变化。MβCD-DG可能通过破坏细胞壁和细胞质膜释放细胞内容物来杀死蜡样芽孢杆菌和枯草芽孢杆菌。MβCD-DG作为一种新型防腐剂，比DG和常见的化学添加剂更有效，值得在食品工业中进一步开发。通过释放细胞内容物和观察细胞形态来探讨MβCD-DG的抗菌机制。结果表明，MβCD-DG通过增加细胞膜的通透性和细胞内容物的渗漏来抑制金黄色葡萄球菌，而没有明显的细胞形态变化。MβCD-DG可能通过破坏细胞壁和细胞质膜释放细胞内容物来杀死蜡样芽孢杆菌和枯草芽孢杆菌。MβCD-DG作为一种新型防腐剂，比DG和常见的化学添加剂更有效，值得在食品工业中进一步开发。枯草芽孢杆菌通过破坏细胞壁和细胞质膜使细胞内容物释放。MβCD-DG作为一种新型防腐剂，比DG和常见的化学添加剂更有效，值得在食品工业中进一步开发。枯草芽孢杆菌通过破坏细胞壁和细胞质膜使细胞内容物释放。MβCD-DG作为一种新型防腐剂，比DG和常见的化学添加剂更有效，值得在食品工业中进一步开发。