HPLC法分析酸奶发酵过程中的有机酸

Analysis of Organic Acids in Yogurt Fermentation Process by HPLC

对高效液相色谱法分析有机酸色谱条件进行了优化，定性分析了D-苹果酸、乳酸、柠檬酸和L-苹果酸并对含量较高的3种有机酸（乳酸、柠檬酸和L-苹果酸）进行了定量检测。结果显示，色谱条件为y（磷酸二氢钾（100mmoVL，pH2．7））：V（甲醇）=97：3，检测波长为21013nm可使乳酸、柠檬酸和L-苹果酸达到很好的分离，相关系数为0．9997～0．9999，样品回收率为98．08％～102．9％，具有较高的重复性和精确度。通过对样品的检测可发现，鲜奶经发酵后乳酸增加至0．96％-1．01％；柠檬酸变化不大，含量在0．12％～0．16％之间波动，L-苹果酸含量由0．007％增加了0．004％～0．18％。

The HPLC conditions of organic acids were optimized, D-malic acid, lactic acid, citric acid and L-malic acid were analyzed, and the content of lactic acid, citric acid and L-malic acid in yoghurt fermentation process were separated and detected. The results showed that the three organic acids could be separated and determined better in the conditions of V（ 100 mmol/L KHzPO4 buffer solution （pH 2.7）） ： V（methanol）=97 ： 3 as mobile phase, and UV detection at 210 nm. The correlation coefficient was from 0.999 7-0.999 9, and the recovery rate of organic acids in yoghurt varied from 98.08% to 102.9%. The method had higher accuracy and veracity. It could be found that lactic acid increased by 0.96%1.01%. The content of cilric acid changed little and fluctuated among 0.12% M）. 16%, L-malic acid content increased from 0.007% by 0.004%~0.18%.