Dong Qingli, Tu Kang, Guo Liyang, Li Hongwen, Zhao Yan
Key laboratory of Food Processing & Quality Control of Ministry of Agriculture, College of Food Science and Technology, Nanjing Agricultural University, PR China.
Food Microbiol. 2007 Sep;24(6):624-32. doi: 10.1016/j.fm.2006.12.003. Epub 2007 Jan 12.
Clostridium sporogenes is considered to be a non-toxingenic equivalent of proteolytic Clostridium botulinum, and it also causes food spoilage. The effects of temperature (16.6-33.4 degrees C), pH value (5.2-6.8) and concentration of sodium chloride (0.6-7.4%) on the growth parameters of C. sporogenes spores were investigated. The growth curves generated within different conditions were fitted using Baranyi function. Two growth parameters (growth rate, GR; lag-time, LT) of the growth curves under combined effects of temperature, pH and sodium chloride were modeled using a quadratic polynomial equation of response surface (RS) model. Mathematical evaluation demonstrated that the standard error of prediction (%SEP) obtained by RS model was 1.033% for GR and was 0.166% for LT for model establishing. The %SEP for model validation were 43.717% and 5.895% for GR and LT, respectively. The root-mean-squares error (RMSE) was in acceptable range which was less than 0.1 for GR and was less than 8.0 for LT. Both the bias factor (B(f)) and accuracy factor (A(f)) approached 1.0, which were within acceptable range. Therefore, RS model provides a useful and accurate method for predicting the growth parameters of C. sporogenes spores, and could be applied to ensure food safety with respect to proteolytic C. botulinum control.
生孢梭菌被认为是蛋白水解型肉毒梭菌的无毒等效物，它也会导致食物变质。研究了温度（16.6 - 33.4摄氏度）、pH值（5.2 - 6.8）和氯化钠浓度（0.6 - 7.4%）对生孢梭菌孢子生长参数的影响。使用Baranyi函数拟合不同条件下生成的生长曲线。利用响应面（RS）模型的二次多项式方程对温度、pH和氯化钠联合作用下生长曲线的两个生长参数（生长速率，GR；延迟期，LT）进行建模。数学评估表明，RS模型在建立模型时，GR的预测标准误差（%SEP）为1.033%，LT的预测标准误差为0.166%。模型验证时，GR和LT的%SEP分别为43.717%和5.895%。均方根误差（RMSE）在可接受范围内，GR小于0.1，LT小于8.0。偏差因子（B(f)）和准确度因子（A(f)）均接近1.0，在可接受范围内。因此，RS模型为预测生孢梭菌孢子的生长参数提供了一种有用且准确的方法，可用于确保在控制蛋白水解型肉毒梭菌方面的食品安全。
