婴儿配方食品中叶酸测定

采用微生物法测定婴儿配方食品中的叶酸。本文法采用干酪乳酸杆菌（ATCC7469），婴儿配方食品中的叶酸含量取决于干酪乳酸杆菌的反应程度。首先制备基础培养基包括酸解酪蛋白溶液等6种溶液。其次配制其他（包括盐溶液等）10种溶液，最后制备培养基和维持液。对干酪乳酸杆菌菌株进行了转接激活；测定开始制备出叶酸标准溶液；样品经过系列处理与叶酸标准溶液加入干酪乳酸杆菌培养；通过划分滴定数值绘制标准曲线，从标准曲线中通过插补鉴定每一个样品的NaOH毫升数。通过公式计算出样品叶酸的含量。

The determination of folic acid in infant formula

This is a microbiological method for determination of folic acid in infant formula. The method use Lactobacillus casei (ATCC7469)The content of infant formula sample is according to reaction of Lactobacillus casei. First is basal medium preparation, including acid hydrolyzed casein solution and so on 6 solutions. Secondly, confect other solutions including salt solution I and so on 10 solutions. At last prepare culture and maintenance medai. After that, inject and active the speice. Before start testing, prepare folic acid standard solutions The sample treated and folic acid standard solution were inject into cells. Prepare standard concentration-response curse by plotting titration values, determine amount of NaOH for each level of assay solution by interpolation from standard curve. Calculate folic acid content of sample with formula.