College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Int J Food Microbiol. 2010 Jan 31;137(1):81-7. doi: 10.1016/j.ijfoodmicro.2009.10.004. Epub 2009 Oct 13.
Apple juice was pasteurized by high pressure carbon dioxide (HPCD) at 20MPa with CO(2) concentration of 4.5-5.3% and mild heat (MH) at atmospheric pressure. Microbial inactivation and stability of natural microorganisms in apple juice were investigated. The temperatures were 37, 42, 47, 52, 57 and 62 degrees C, treatment time was 30min, and storage temperatures of pasteurized apple juice were 2 and 28 degrees C. The aerobic bacteria (AB) treated by MH at 62 degrees C and by HPCD at > or =52 degrees C were almost totally inactivated, the microbial counts were<10CFU/mL. The yeasts and moulds (Y&M) treated by MH at > or =57 degrees C and by HPCD at > or =42 degrees C were totally inactivated. HPCD increased the susceptibility of these natural microorganisms to temperature and enhanced their microbial inactivation. The AB in apple juice treated by HPCD at > or =52 degrees C and the Y&M treated by HPCD at > or =57 degrees C, the AB and the Y&M treated by MH at 62 degrees C showed a better stability during storage at 2 and 28 degrees C, but apple juice treated by HPCD at < or =47 degrees C was characterized with high microbial counts of the AB> or =2.75x10(3)CFU/ml. A viable but non-culturable (VBNC) state of the Y&M treated by MH at 57 degrees C and by HPCD at 42, 47 and 52 degrees C was observed during storage at 28 degrees C. Apparently the proper temperature of HPCD treatment of apple juice at 20MPa and stored at 2 and 28 degrees C was greater than or equal to 52 degrees C, while for MH treatment the proper temperature increased to 62 degrees C in this study.
苹果汁采用高压二氧化碳（HPCD）在 20MPa 下，二氧化碳浓度为 4.5-5.3%，温和加热（MH）在大气压力下进行巴氏杀菌。研究了苹果汁中天然微生物的微生物失活和稳定性。温度分别为 37、42、47、52、57 和 62°C，处理时间为 30min，巴氏杀菌苹果汁的储存温度为 2 和 28°C。MH 处理的需氧菌（AB）在 62°C 和 HPCD 处理的 >或=52°C 几乎完全失活，微生物计数<10CFU/mL。MH 处理的 >或=57°C 和 HPCD 处理的 >或=42°C 的酵母菌和霉菌（Y&M）完全失活。HPCD 增加了这些天然微生物对温度的敏感性，并增强了它们的微生物失活。AB 在 HPCD 处理的 >或=52°C 和 HPCD 处理的 >或=57°C 的 Y&M 中的稳定性，AB 和 Y&M 在 MH 处理的 62°C 下在 2 和 28°C 下储存时表现出更好的稳定性，但在 HPCD 处理的 <或=47°C 的苹果汁中 AB 的微生物计数>或=2.75x10(3)CFU/ml。在 28°C 下储存时，观察到 MH 处理的 57°C 和 HPCD 处理的 42、47 和 52°C 的 Y&M 处于存活但不可培养（VBNC）状态。显然，在 20MPa 下对苹果汁进行 HPCD 处理并在 2 和 28°C 下储存的适当温度大于或等于 52°C，而在 MH 处理下，本研究中适当温度升高到 62°C。
