新型琼脂扩散法检测食品中天然防腐剂ε-聚赖氨酸含量

A Novel Agar Diffusion Assay for Qualitative and Quantitative Estimation of ε-Polylysine in Foods

为分析食品中ε-聚赖氨酸(ε-poly-L-lysine,ε-PL)含量,建立一种新型琼脂扩散法,并对分析条件进行优化,验证在检测食品中ε-PL含量时的有效性。结果表明,质量分数0.002%亚甲基蓝、0.75%琼脂、ε-PL溶液pH值为2.0、牛津杯加液量750μL时检测结果最佳。本方法允许检测橙汁中ε-PL最低含量为2 mg/kg、糕点和猪肉火腿中最低为10 mg/kg。这种新型琼脂扩散法具有操作简便、使用成本低、专一性高等优点,可以广泛应用于ε-PL生产企业和食品工业。

A novel agar diffusion assay was developed, optimized, and validated for the analysis of ε-polylysine(ε-PL) in foods. Results showed that the optimum assay conditions were 0.75% agar, 0.002% methylene blue, pH of ε-PL solution adjusted to 2.0 and 750 μL of ε-PL solution allowed to diffuse on agar plate. This method allowed detection of ε-PL at levels as low as 2 mg/kg in orange-juice, and 10 mg/kg in cake and pork ham. This proposed agar diffusion assay can be widely used in ε-PL-production and food industry because of its simplicity, cost-effectiveness, and high specificity.