火龙果酵素中原花青素含量测定方法的建立

采用香草醛-盐酸法对火龙果酵素中原花青素含量进行测定，考察反应温度、反应时间、香草醛质量浓度对溶液吸光度值的影响，并确定火龙果酵素中原花青素含量测定的方法。结果表明，原花青素含量的最适检测条件为1 mL火龙果酵素稀释液，5 mL 5 g/100 mL的香草醛甲醇溶液，4 mL 10%盐酸甲醇溶液，混匀后，35 ℃条件下显色反应20 min，在波长500 nm处测定吸光度值。精密度和重现性试验结果的相对标准偏差（RSD）值分别为1.23%和1.47%；平均回收率为99.5%～104.4%，RSD值为1.21%～2.11%。表明该法操作简便，精密度和重现性良好，准确性高，适用于火龙果酵素中原花青素含量的测定。

Establishment of determination method of proanthocyanidins content in pitaya enzyme

The content of proanthocyanidins in pitaya enzyme was determined by vanillin-HCl method. The effects of reaction temperature, time and vanilline content on solution absorbance values were investigated, and the determination method of proanthocyanidins content in pitaya enzyme was established. The results showed that the optimum detection conditions were pitaya enzyme dilute solution 1 ml, 5 g/100 ml vanillin methanol solution 5 ml, 10% HCl methanol solution 4 ml, after blending, the reaction was carried out at 35 ℃ for coloration 20 min and then absorbance value was detected at the wavelength of 500 nm. The relative standard deviation (RSD) of precision and reproducibility tests results were 1.23% and 1.47%, respectively. The average recovery rate 99.5%-104.4%, RSD was 1.21%-2.11%, which indicated that the method was easy and simple, and had good precision and reproducibility and high accuracy, and was suitable for the determination of proanthocyanidins content in pitaya enzyme.