九头芥梅干菜提取物抗菌活性及其在猪肉保鲜中的应用

Antimicrobial Activity of Pickled and Dried Mustard Extracts and their Application in Pork Preservation

摘要:

研究了九头芥梅干菜乙醇提取物及其石油醚、乙酸乙酯萃取物和萃余物对枯草芽孢杆菌、大肠杆菌、金黄色葡萄球菌和黑曲霉的抗菌性能，以及乙酸乙酯萃取物对鲜猪肉的保鲜作用。分别用滤纸片法和连续稀释法测定了各样品对测试菌的抑菌圈大小和最低抑菌浓度。用菌落总数、硫代巴比妥酸反应物值（TBARS）、挥发性盐基氮（TVB-N）和pH值等指标评价了乙酸乙酯萃取物对猪肉的保鲜效果。结果表明各样品对黑曲霉无明显的抑制作用，但对三种细菌却有较强的抑菌作用，其中乙酸乙酯萃取物的抑菌性能最强，其对枯草芽孢杆菌、金黄色葡萄球菌和大肠杆菌的最低抑菌浓度分别为0.1、0.1和3 mg/mL。浓度为3和5 mg/mL的乙酸乙酯萃取物能有效地减缓4 ℃下贮藏猪肉的菌落总数、pH、TVB-N和TBARS值的增加。与对照组相比，可以延长猪肉的保鲜期3~6 d。

Abstract:

Anti-microbial activity of ethanolic crude extract and three kinds of solvent sub-fractions (petroleum ether fraction [PEF], ethyl acetate fraction [EAF], and the residual fraction [RF]) from pickled and dried mustard extract against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Aspergillus niger were investigated. The effect of EAF on pork preservation was also studied. The inhibition-zone diameter and minimum inhibition concentration (MIC) of various samples against all tested strains were determined using agar disk diffusion method and broth dilution method, respectively. The effect of EAF on pork preservation was evaluated by total plate counts, pH, total volatile basic nitrogen (TVB-N) content, and thiobarbituric acid-reactive substance (TBARS) content. The results showed that all samples had no obvious antimicrobial activity against Aspergillus niger, but they exhibited strong antibacterial activities against the other three bacteria tested. Among all fractions, EAF showed the strongest antibacterial activity, and its MIC against Bacillus subtilis, Staphylococcus aureus, and Bacillus coli was 0.1, 0.1, and 3 mg/mL, respectively. EAFs at concentrations of 3 and 5 mg/mL could effectively reduce the total plate counts, TVB-N, pH, and TBARS values of pork stored at 4 ℃. Compared with the control group, treatment of pork samples with EAF could extend its shelf life by 3~6 days.