果品总酸度的测定

Determination of Total Acidity of Fruits

以苹果为实验材料，采用水浴浸提法和超声波辅助提取法提取果酸，通过正交实验优化果酸的提取工艺，并用酸碱滴定法测定总酸度。实验结果表明：水浴浸提法的最佳提取条件为：温度80℃，时间90min，苹果质量15g，果酸含量为4．4763g／kg；超声波辅助提取法的最佳提取条件为：温度70℃，时间30min，苹果质量15g，果酸含量为4．7918g／kg。

In this experiment, apple was used as experimental materials and the tartaric acid of apple was extracted by water bath extraction and ultrasonic-assisted extraction. The extracting technical level was improved by orthogonal experiment. Moreover, acid-base titration was used to determine the total acidity. The results of the experiment showed that the extractive effect of water bath extraction was the best when the temperature was 80℃, the extracting time was 90 minutes, the mass of apple was 15 g, and the tartaric acid content was 4. 476 3 g/kg correspondingly. About the ultrasonic-assisted extraction, the optimum extractive condition was that the temperature was 70 ℃, the time was 30 minutes, the mass of apple was 15 g, and the tartaric acid content was 4. 791 8 g/kg.