婴幼儿乳粉和米粉中阪崎克罗诺杆菌的耐受性研究

发布时间：2019/11/4 15:49:24     浏览次数：1140

杨保伟.婴幼儿乳粉和米粉中阪崎克罗诺杆菌的耐受性研究[J].中国食品学报,2019,19(9):45-52
婴幼儿乳粉和米粉中阪崎克罗诺杆菌的耐受性研究
Studies on Tolerance of Cronobacter sakazakii Isolated from Infant Milk Powder and Rice Cereal
  
DOI：
中文关键词: 婴幼儿乳粉  米粉  阪崎克罗诺杆菌  耐热  耐酸碱

英文关键词: powdered infant and baby formula（PIBF）  baby rice cereal（BRC）  Cronobacter sakazakii  anti-thermal  anti-acid （alkaline）

 以婴幼儿乳粉和米粉中分离到的15株不同基因型的阪崎克罗诺杆菌为材料，研究其对不同温度、酸碱度和微波的耐受性以及对枯草杆菌二联活菌颗粒（商品名：妈咪爱）和产乳酸菌素乳酸菌的敏感程度。采用平板计数法检测阪崎克罗诺杆菌在不同处理后的存活率，衡量菌株的耐受性；采用皿内抑菌法检测妈咪爱和产乳酸菌素乳酸菌对阪崎杆菌的抑制作用。结果表明：70 ℃处理20 min后，15株阪崎克罗诺杆菌的存活率均低于0.11%，对阪崎克罗诺杆菌的致死作用明显高于50 ℃和60 ℃（P＜0.01）。阪崎克罗诺杆菌经pH 4.0、pH 6.0和pH 8.0条件处理20 min后，部分菌株被致死，pH 4.0时的存活率明显低于其它2组（P＜0.01）。微波处理2 min后，大部分供试菌株的死亡率超过99%，菌株间存活率无显著性差异（P＞0.05）。产乳酸菌素乳酸菌和妈咪爱对供试菌株均有一定的抑制作用，部分菌株对其的敏感程度具有极显著差异（P＜0.01）。结论：阪崎克罗诺杆菌的耐受性和敏感程度存在差异，采用适当的条件处理能有效防止阪崎克罗诺杆菌对婴幼儿食品的污染。

   The tolerance ability of 15 Cronobacter sakazakii isolates with different genotypes that recovered from powdered infant and baby formula （PIBF） and baby rice cereal （BRC） to different temperature， pH， and microwave， and the susceptibility to Mamiai and lactobacillus-producing lactobacillus was studied to perform some reference for infant and baby food safety. Plate counting method was employed to calculate the survival rate， which was used as the index to evaluate the tolerance ability of the bacteria， after heat， pH and microwave treatment. The rate of the diameter of the inhibition zone and the cup that put the anti-bacteria or the width of the inhibition zone to Cronobacter sakazakii was used to evaluate the susceptibility of Cronobacter sakazakii to Live Combined Bacillus Subtilis and Enterococcus Faecium Granules with Multivitamines （Product name： Mamiai） and lactobacillus. Results： The survival rate of 15 Cronobacter sakazakii isolates indicated the lethal effect of 70 ℃ was significantly higher than those of 50 ℃ and 60 ℃ （P<0.01）. The survival rates were all less than 0.11% after the isolates were treated at 70 ℃ for 20 min. A certain lethal effect was shown after treated on condition of pH 4.0， pH 6.0 and pH 8.0 for 20 min， and the survival rate of pH 4.0 treatment was significantly lower than those of the other two groups （P<0.01）. The mortality rate of majorities of the tested strains was as high as 99% after treated by microwave for 2 min， and no significant difference was found among the survival rate of the strains（P>0.05）. Lactobacillus-producing lactobacillus and Mamiai had a certain degree of inhibition to Cronobacter sakazakii， and the susceptibility of some strains was significant different （P<0.01）. Conclusion： The tolerance and susceptibility of the Cronobacter sakazakii strains were different， appropriate methods could be taken to prevent Cronobacter sakazakii contamination from infant and baby foods.