食品中双歧杆菌快速检测方法的建立

Establishment of Rapid Detection Method of Bifidobacterium in Food

越来越多的双歧杆菌被添加到食品和保健品中,因此双歧杆菌定量检测对食品或保健品的质量控制和监测显得尤为重要。通过试验,我们发现一种双歧杆菌显色培养基,使双歧杆菌能够生长良好,并显蓝色,对保加利亚乳杆菌、嗜酸乳杆菌、嗜热链球菌、沙门氏菌、大肠埃氏菌和金黄色葡萄球菌均有一定的抑制作用,或显白色,从而准确、有效在显色平板上区分开来。结果表明:双歧杆菌使用该显色培养基在36℃培养48 h就可以直接计数,显色清楚,结果易于观察,检测成本明显低于国标的检测方法;该显色培养基具有较高的特异性,通过对200份自然样品的检测评价,试验所建立的方法与国标方法准确性比较,差异无显著性(F=3.794 6,p>0.05)。

More and more bifidobacteria is being added to food and health care products, so detecting the existence and content of bifidobacteria in these products is particularly important for the quality assurance and monitoring. On the optimum Bifidobacterium chromogenic medium, the Bifidobacterium could grow well with characteristic blue color, while other non- bifidobacteria, such as Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Salmonella sp., Escherichia coli and Staphylococcus aureus were inhibited or displayed white color, which demonstrated that the medium selected in this study was accurate and effective. Consequently, after 48 h cultivation at 36 ℃ on the chromogenic medium, the positive samples could easily distinguished with clear blue color and then directly counted, and the detection cost was significantly lower than the national standard test method; The specificity of the chromogenic medium was high, being evaluated by 200 natural samples, with a similar accuracy as the national standard method and there was no significant difference （F=3.794 6,p〉0.05）.