鲜切菠萝在贮藏过程中的致病菌风险分析

Risk analysis of pathogenic bacteria in fresh-cut pineapple during storage

中文关键词:  鲜切菠萝  贮藏  致病菌  16S rDNA

英文关键词:fresh-cut pineapple  storage  pathogens  16S rDNA

中文摘要:

      目的 分析鲜切菠萝中致病菌在不同温度及抑菌处理条件下的生长变化情况, 评估其食品安全风险, 查找降低风险的因素。方法 采用16S rDNA测序并结合平板计数法分析鲜切菠萝在贮藏中细菌组成和数量变化, 并查找疑似致病菌, 最后以致病菌快速检测片确认鲜切菠萝中的致病菌。结果 用5个不同产地的原料制作的鲜切菠萝中均含有蜡样芽孢杆菌、金黄色葡萄球菌、李斯特菌、志贺氏菌、阪崎肠杆菌5种致病菌。这些鲜切菠萝经室温贮藏后仅金黄色葡萄球菌消失; 经4℃贮藏6 d后上述5种致病菌均未消失。经10 mg/kg ClO2处理后, 鲜切菠萝中细菌数量大幅降低, 但蜡样芽孢杆菌和阪崎肠杆菌仍能检出; 继续于室温贮藏5 d后, 仅金黄色葡萄球菌消失; 继续于4℃贮藏9 d后, 仅李斯特菌消失。经1%壳聚糖处理后, 在短时间内鲜切菠萝中致病菌已低至无法检出, 但继续在室温贮藏5 d, 则仅金黄色葡萄球菌和李斯特菌消失; 继续于4℃贮藏9 d后, 仅李斯特菌、志贺氏菌和阪崎肠杆菌消失。结论 鲜切菠萝存在多种致病菌风险; 无论在室温或4℃贮藏大部分致病菌仍能存活甚至生长; 10 mg/kg ClO2处理不能消除这些风险; 1%壳聚糖处理能显著降低各种致病菌数量, 但残留的致病菌仍能缓慢生长, 并可能最终导致食品安全危害。

英文摘要:

      Objective To analyze the growth changes of pathogenic bacteria in fresh-cut pineapple under different temperature and inhibition treatment conditions, assess their food safety risk, and find factors to reduce the risk. Methods The 16S rDNA sequencing combined with plate counting was used to analyze the changes in bacterial communities and number of fresh-cut pineapples in storage and to search for suspected pathogenic bacteria, and finally the pathogenic bacteria in fresh-cut pineapples were confirmed by rapid pathogen detection tablets. Results In the fresh-cut pineapple made from the raw materials planted at 5 different zones, 5 pathogens including Bacillus cereus, Staphylococcus aureus, Listeria, Shigella and Enterobacter sakazakii were found. Only Staphylococcus aureus disappeared after storage at room temperature. All the 5 pathogens survived after storage at 4℃ for 6 days. The treatment with 10 mg/kg ClO2 significantly decreased the bacterial population in fresh-cut pineapple, but Bacillus cereus and Enterobacter sakazakii could still be detected. However, when the fresh-cut pineapple was stored at ambient temperature for 5 days after the ClO2 treatment, only Staphylococcus aureus disappeared, and when stored at 4℃ for 9 days after the ClO2 treatment, only Listeria disappeared. After 1% chitosan treatment, the pathogenic bacteria in fresh-cut pineapple were low to undetectable within a short period of time, but only Staphylococcus aureus and Listeria disappeared after continued storage at room temperature for 5 d. After continued storage at 4°C for 9 d, only Listeria, Shigella and Enterobacter sakazakii disappeared. Conclusion Fresh-cut pineapples are at risk for a variety of pathogenic bacteria, most pathogenic bacteria can still survive or even grow whether stored at room temperature or 4°C. 10 mg/kg ClO2 treatment cannot eliminate these risks. 1% chitosan treatment can significantly reduce the number of various pathogenic bacteria, but residual pathogenic bacteria can still grow slowly and may eventually lead to food safety hazards.