3种测定广式酱油中总糖含量的方法比较

Comparison of Three Methods for the Determination of Total Sugar Content in Cantonese Soy Sauce

摘要:

该研究通过比较直接滴定法、苯酚硫酸法、蒽酮硫酸法3种方法测定广式酱油总糖含量的差异，并对这3种方法进行方法学验证，以期筛选出一种适合广式酱油总糖含量测定的方法。结果显示，直接滴定法、苯酚硫酸法和蒽酮硫酸法分别在0.50~8.00、0.00~0.08和0.00~0.08 mg/mL范围内线性关系良好。直接滴定法、苯酚硫酸法和蒽酮硫酸法的精密度试验的RSD值分别为1.07%、0.05%、0.05%，重现性试验的RSD值分别为0.88%、3.93%、3.24%，直接滴定法在24 h内显色稳定，苯酚硫酸法和蒽酮硫酸法在1 h内显色稳定。而在加标回收率试验中，蒽酮硫酸法的平均加标回收率较高，为168.04%，RSD值为2.97%，直接滴定法的平均加标回收率为104.67%，RSD值为2.07%，苯酚硫酸法的平均加标回收率为103.85%，但其RSD值为8.04%，蒽酮硫酸法测定酱油总糖含量的准确度低于其他两种方法。因此，直接滴定法和苯酚硫酸法的精密度、重现性、稳定性良好，理论上均具有可行性，蒽酮硫酸法不适合用于广式酱油总糖含量的测定。酱油中总糖含量是反映酱油品质的基本指标之一，筛选出适合酱油总糖含量的检测方法，对实际酱油生产监控和产品加工过程的品质控制都有重要意义，同时也为酱油总糖含量测定方法标准的制定提供一定的实验参考。

Abstract:

In this study, the differences in the total sugar content of Cantonese soy sauce determined by three methods, the direct titration method, phenol-sulfuric method and anthrone-sulfuric acid method were compared, and the three methods were verified by the methodological approach, in order to screen out a suitable method for the determination of the total sugar content in the Cantonese soy sauce. The results showed that the direct titration method, phenol-sulfuric acid method and anthrone-sulfuric acid method had good linearity in the concentration range of 0.50~8.00 mg/mL, 0.00~0.08 mg/mL and 0.00~0.08 mg/mL, respectively, with their RSD values of the precision test being 1.07%, 0.05% and 0.05%, respectively, and their RSD values of the reproducibility test being 0.88%, 3.93% and 3.24%, respectively. The color developed was stable within 24 h for the direct titration, and within 1 h for both the phenol-sulfuric acid and anthrone-sulfuric acid methods. In the spike-recovery experiments, the anthrone-sulfuric acid method led to an average recovery of 168.04% with an RSD value of 2.97%, whilst the direct titration method resulted in an average recovery of 104.67% with an RSD value of 2.07%. The phenol-sulfuric acid method showed an average recovery of 103.85% but had a higher RSD value of 8.04%. The accuracy of the anthrone-sulfuric acid method was lower than the other two methods. Therefore, the direct titration method and the phenol-sulfuric acid method have good precision, reproducibility and stability, thus, both are theoretically feasible. The anthrone-sulfuric acid method is not suitable for the determination of total sugar content in Cantonese soy sauce. The total sugar content in soy sauce is one of the basic indicators to reflect the quality of soy sauce. Selecting a suitable detection method for the total sugar content in soy sauce is of great significance for the actual soy sauce production monitoring and product quality control during processing, and also provides a certain experimental reference for the development of the determination method standard for the total sugar content in soy sauce.