食品防腐剂对糕点中金黄色葡萄球菌生长的影响

Effect of food preservatives on the growth of Staphylococcus aureus in cake

中文关键词:  防腐剂  糕点  金黄色葡萄球菌  生长

英文关键词:food preservatives  cake  Staphylococcus aureus  growth

中文摘要:

      目的 研究食品防腐剂对糕点中金黄色葡萄球菌的生长抑制影响。方法 确定各防腐剂临界生长质量浓度后, 应用修正Gompertz方程和修正Logistic方程拟合添加了不同类别防腐剂的糕点中金黄色葡萄球菌的抑制生长曲线, 确定最适初级模型方程及参数。结果 糕点中金黄色葡萄球菌对脱氢乙酸钠、纳他霉素、山梨酸钾均敏感, 参考GB 2760-2014《食品安全国家标准 食品添加剂使用标准》最大使用量, 所得临界生长浓度为脱氢乙酸钠1 mg/mL, 纳他霉素2.4 mg/mL, 山梨酸钾4 mg/mL。2种初级预测模型动力学指标分析结果显示r2均大于0.98, 模型拟合所得最大比生长速率(μmax)依次为山梨酸钾＞脱氢乙酸钠＞对照＞纳他霉素; 3种防腐剂组达到相对最大生长速率所需的时间(xc)相比对照组均延迟; 延滞期(λ)时长依次为山梨酸钾＞脱氢乙酸钠＞纳他霉素＞对照。3种防腐剂组在24 h内菌落数均小于对照组, 至稳定期后最大菌落数(Nmax)依次为山梨酸钾＞纳他霉素＞对照＞脱氢乙酸钠。结论 脱氢乙酸钠、纳他霉素、山梨酸钾等常见食品防腐剂均在延滞期和对数期期间能有效抑制糕点中金黄色葡萄球菌的生长。

英文摘要:

      Objective To study the effects of food preservatives on the growth inhibition of Staphylococcus aureus in cake. Methods The critical growth concentrations of different kinds of food preservatives were determined. The inhibitory growth curve of Staphylococcus aureus in cake with different kinds of food preservatives was fitted by modified Gompertz model (SGompertz) and modified Logistic model (SLogistic), and the primary model and parameters was established. Results Staphylococcus aureus in cake was sensitive to sodium dehydroacetate, potassium sorbate and natamycin according to GB 2760-2014 National food safety standard-Standards for use of food additives, and the critical growth concentrations of sodium dehydroacetate, natamycin and potassium sorbate was 1, 2.4, 4 mg/mL, respectively. Analysis of both of primary predictive models kinetic index showed that the coefficients of determination (r2 ) of the SGompertz equations and SLogistic equations were up to 0.98, and the maximum specific growth rate (μmax) obtained by model fitting was potassium sorbate > sodium dehydroacetate > control group > natamycin. The time required to achieve the relative specific growth rate (xc) in the 3 preservatives groups were longer than those in control group. The shortest Lag time(λ)was in control group, the second was in natamycin group, the third was in sodium dehydroacetate group and the longest was in potassium sorbate group. The number of colonies in the preservative groups were less than that in the control group within 24 hours. The maximum number of colonies(Nmax)at the stationary phase was potassium sorbate > natamycin> control >sodium dehydroacetate. Conclusion Common food preservatives such as sodium dehydroacetate, natamycin and potassium sorbate can effectively inhibit the growth of Staphylococcus aureus in pastry during the delay and logarithmic periods.