Hansen T B, Knøchel S
Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark.
Lett Appl Microbiol. 1996 Jun;22(6):425-8. doi: 10.1111/j.1472-765x.1996.tb01195.x.
Heating at slowly rising temperatures is suspected to enhance thermotolerance in Listeria monocytogenes and, since anaerobic environments have been shown to facilitate resuscitation of heat-injured cells of this micro-organism, concern may arise about the possibility of L. monocytogenes surviving in minimally preserved products. The effect of rapid ( > 10 degrees C min-1) and slow (0.3 and 0.6 degrees C min-1) heating on survival of L. monocytogenes in sous vide cooked beef was therefore examined at mild processing temperatures of 56 degrees, 60 degrees and 64 degrees C. No statistically significant difference (P = 0.70) was observed between the tested heating regimes. Since the average pH of beef was low (5.6), and little or no effect was observed, a pH-dependency of heat shock-induced thermotolerance in L. monocytogenes is suggested to account for this result.
缓慢升温加热被怀疑可增强单核细胞增生李斯特菌的耐热性，并且，由于厌氧环境已被证明有助于该微生物热损伤细胞的复苏，因此可能会担心单核细胞增生李斯特菌在最低限度保存的产品中存活的可能性。因此，在56℃、60℃和64℃的温和加工温度下，研究了快速（>10℃/分钟）和缓慢（0.3℃/分钟和0.6℃/分钟）加热对真空包装熟牛肉中单核细胞增生李斯特菌存活的影响。在所测试的加热方式之间未观察到统计学上的显著差异（P = 0.70）。由于牛肉的平均pH值较低（5.6），且未观察到明显影响，因此推测单核细胞增生李斯特菌中热休克诱导的耐热性对pH的依赖性可解释这一结果。
