瞬时高压对嗜热脂肪芽孢杆菌的杀灭效果

Effect of Instantaneous High Pressure on Bacillus stearothemophilus Reductions

本文研究了不同作用压力和处理次数下瞬时高压(IHP)对嗜热芽孢杆菌的杀灭效果,以及食品基质对IHP杀菌的影响。结果表明:①瞬时高压作用对嗜热芽孢杆菌具有较好的杀灭效果,随着处理压力的提高,嗜热芽孢杆菌的致死率上升;提高进料温度,嗜热芽孢杆菌的致死率略有升高。进料温度10、25、40℃下分别处理一次时,随着处理压力从80MPa上升到120MPa,对嗜热芽孢杆菌的致死率分别从54.13%、53.81%、54.39%上升到74.12%、74.52%、74.96%。②瞬时高压对嗜热芽孢杆菌的致死率随着处理次数的增加而上升,且增加处理次数比提高作用压力的效果要好的多。室温(25℃)下,采用在100、110、120MPa下分别对样品处理3次,100MPa下处理三次的致死率分别为67.6%、74.13%、77.95%,110MPa下分别为71.34%、76.89%、80.74%,120MPa下分别为74.52%、79.58%、82.08%。③食品基质对瞬时高压下的菌体有保护作用,在一定浓度范围内,基质浓度愈高,对菌体保护作用愈强。在菌液中添加消毒豆奶,浓度为0、1.5、3、4.5、6g/100g,进料温度为25℃,工作压力分别为100、110、120MPa进行瞬时高压处理。结果100MPa下对菌体的致死率从67.60%下降到65.73%,110MPa下从71.34%下降到69.12%,120MPa下从74.52%下降到72.36%。

The article studied the killing effects of Instantaneous High Pressure on Bacillus stearothermophilus considering different pressures, times of dealing and the influences of the food substances. The results of the experiments were as follows. （1）Instantaneous High Pressure has better effects on killing Bacillus stearothermophilus. With the increase of pressure, the killing rate of Bacillus stearothermophilus increases, but the killing rate of Bacillus stearothermophilus increases a little with the increase of feed-in temperature. When dealing at the temperature 10, 25 and 40℃ respectively for once every time, and with the pressure rising from 80MPa to 120MPa, the killing rate increases from 54.13%, 53.81% and 54.39% to 74.12%, 74.52%, 74.96% respectively. （2）With the increase of dealing time, the killing rate of Instantaneous High Pressure on Bacillus stearothermophilus also increases, and the result is more satisfactory with the increase of the dealing times instead of the pressure. Under 25 ℃, when the pressure of 100, 110 or 120MPa is applied respectively to the sample treated from one to three times respectively, the killing rate of 100MPa is respectively 67.6%, 74.13% and 77.95%; that of 110MPa 71.34%, 76.89% and 80.74% respectively and that of 120MPa 74.52%, 79.58% and 82.08% respectively. （3） Food matrix can protect the bacteria from the treatment of Instantaneous High Pressure. To certain concentration, the higher the concentration of food matrix is, the stronger the effect of bacteria-protection. For instances, the disinfected soy milk was added to the bacteria liquid, with different concentrations as 0, 1.5, 3, 4.5 and 6g/100g respectively, while the bacteria was treated with Instantaneous High Pressure with the feed-in temperature 25℃ and the work pressure 100, 110 and 120MPa respectively. The results showed that the killing rates of Bacillus stearothermophilus dropps from 67.6% to 65.73% under 100MPa, from 71.34% to 69.12% under 110MPa and from 74.52% to 72.36% under 120MPa.