摘要:
本实验旨在提出一种使用鼠李糖乳杆菌(Lactobacillus casei)ATCC 7469快速估算食品中叶酸含量范围的测定方法。利用鼠李糖乳杆菌生长过程中对叶酸需求的特异性,使用一次性离心管代替玻璃试管作为培养该菌的容器,将整个培养体系从10 mL缩小到1 mL,将培养时间从24 h缩短为8~12 h。在对得到的吸光度数据简单换算后,得到待测样品叶酸含量范围,并进行方法学考察,与国标法GB 5009.211-2014进行对比,判断其是否具有可行性。结果表明,本实验室条件下,该方法的检出限范围为0.4~0.8 μg/100 g,线性范围为0.01~0.08 ng,回收率范围为82.1%~108.0%。本方法检出限范围可估算出叶酸含量下限范围,线性区间范围可估算出叶酸含量上限范围。相对于国标方法需要2~3 d时间测定,本方法只需1 d时间即可得到叶酸含量范围,其步骤简洁且节约试剂材料。
Abstract:
A method for rapid determination of folic acid content range in food by Lactobacillus casei ATCC 7469 was proposed in this paper. Since folic acid was the specific demand for the growth of Lactobacillus casei,the whole culture system was reduced from 10 mL to 1 mL in disposable centrifuge tubes instead of glass tubes and the incubation time was shortened from about 24 h to 8~12 h. After simple conversion of the absorbance data,the range of folic acid content of the sample was obtained,and the methodological investigation was carried out. The feasibility of the method was compared with the national standard method (GB 5009.211-2014). The results showed that,under the laboratory conditions,the detection limit of this method was 0.4~0.8 μg/100 g,the linear range 0.01~0.08 ng,and the recovery rate 82.1%~108%. The detection limit range of this method could be used to estimate the lower limit range of folic acid content,and the linear range could be used to estimate the upper limit range of folic acid content. Compared with the national standard method,which took 2~3 d for the determination,this method only need 1 d,which had simpler steps,and could savereagent materials.
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