浊度法测定糖汁中葡聚糖含量检测条件的优化研究

Study on Optimized Dextran Determination Conditions Using Turbidimetric Method

采用浊度法测定含有不同葡聚糖浓度的蔗糖-TCA溶液的葡聚糖含量,分析样液温度、反应时间、蔗糖浓度对测量结果准确性的影响,并优化了检测条件:温度为25℃,反应时间25 min,10%三氯乙酸/蔗汁体积浓度为10 m L/50 m L。此外,糖汁中蔗糖浓度对葡聚糖含量的测定结果也有影响,试验发现蔗糖浓度为8%时,所测得葡聚糖含量与真实值最为接近。用优化了检测条件的浊度法检测混合汁、清汁及糖浆葡聚糖含量,回收率和相对标准偏差分别为97.28%~101.54%和2.65%~3.98%,表明优化浊度法可准确测量糖汁中的葡聚糖含量。

The content of dextran in sucrose TCA solution was determined by turbidimetric method. The effects of sample temperature, reaction time and sucrose concentration on the accuracy of measurement results were analyzed. The detection conditions were optimized as follows： temperature 25℃, reaction time 25 min, the dosage of 10% trichloroacetic acid was 10 m L/50 m L. In addition, the concentration of sucrose in the juice also has an effect on the determination of dextran content. It is found that when sucrose concentration is 8%, the measured dextran content is the closest to the true value. Determination of dextran in mixed juice, clear juice and syrup by turbidimetric method with optimized detection conditions, recovery rate and relative standard deviation（RSD） were 97.28%~101.54% and 2.65%~3.98% respectively, which indicated that the optimized turbidity method could accurately measure the dextran content in sugar juice.