Kim N H, Lee N Y, Kim S H, Lee H J, Kim Y, Ryu J H, Rhee M S
Department of Food Bioscience and Technology, Korea University, Seoul, Korea.
Food Microbiology Division, National Institute of Food and Drug Safety Evaluation, Osong, North Chungcheong Province, Korea.
J Appl Microbiol. 2015 Jul;119(1):139-48. doi: 10.1111/jam.12815. Epub 2015 Apr 22.
To develop a mild blanching method with calcium salts to ensure microbiological safety and quality of fresh-cut spinach.
The antimicrobial efficacy of eight calcium salts was evaluated on Escherichia coli O157:H7 at 45-65°C and calcium hydroxide (Ca(OH)2 ) showed the greatest synergistic antimicrobial effect with heat. Combinations of low temperature treatments (45, 55, 65°C), time (20, 40, 60 s) and Ca(OH)2 (0·25, 0·50, 0·75%) were applied for E. coli O157:H7 disinfection on fresh-cut spinach to develop a predictive model using a Box-Behnken experimental design. A suitable quadratic model was produced (R(2) = 0·98, P < 0·001) and the optimum condition (64·9°C with 0·52% Ca(OH)2 for 42·4 s) was drawn by reducing 6·6 log CFU g(-1) of E. coli O157:H7 on fresh-cut spinach. Blanching at 61·9°C with 0·52% Ca(OH)2 for 41·7 s can inactivate E. coli O157:H7 on spinach by 5·4 log CFU g(-1) . The new method was comparable to the CDC recommendation for safe spinach cooking (71·1°C, 15 s; 5·0 log CFU g(-1) reduction) with lower levels of weight loss of the spinach (P < 0·05).
This study suggests an efficient spinach blanching method for E. coli O157:H7 disinfection.
This blanching method will enhance microbiological safety of fresh-cut produce while minimizing the use of energy and chemicals.
开发一种使用钙盐的温和热烫方法，以确保鲜切菠菜的微生物安全性和质量。
评估了八种钙盐在45 - 65°C对大肠杆菌O157:H7的抗菌效果，氢氧化钙（Ca(OH)₂）与热显示出最大的协同抗菌作用。采用Box-Behnken实验设计，将低温处理（45、55、65°C）、时间（20、40、60秒）和Ca(OH)₂（0.25%、0.50%、0.75%）的组合应用于鲜切菠菜上的大肠杆菌O157:H7消毒，以建立预测模型。生成了一个合适的二次模型（R² = 0.98，P < 0.001），通过将鲜切菠菜上的大肠杆菌O157:H7减少6.6 log CFU g⁻¹得出最佳条件（64.9°C，0.52% Ca(OH)₂，42.4秒）。在61.9°C用0.52% Ca(OH)₂烫漂41.7秒可使菠菜上的大肠杆菌O157:H7失活5.4 log CFU g⁻¹。新方法与美国疾病控制与预防中心（CDC）关于安全菠菜烹饪的建议（71.1°C，15秒；减少5.0 log CFU g⁻¹）相当，但菠菜的重量损失较低（P < 0.05）。
本研究提出了一种有效的菠菜热烫方法用于大肠杆菌O157:H7消毒。
这种热烫方法将提高鲜切农产品的微生物安全性，同时最大限度地减少能源和化学品的使用。
