“QB/T4093-2010液体糖”旋光法测定蔗糖时还原糖的影响研究

Study of the Effect of Reducing Sugar on Measuring Sucrose Proportion by Polarimetric Method in QB/T 4093-2010 “Liquid Sugar”

广州市华侨糖厂生产的液体糖含少量还原糖,按照QB/T4093中全蔗糖浆的方法,总糖分常不达标,特别是蔗糖转化糖浆,总糖分值全都小于99.5%。本文通过在精制糖中添加葡萄糖等还原糖,测定比较其中的(旋光)蔗糖分,研究还原糖对蔗糖分测定的影响。结果表明,在测定液体糖总糖分时,其中的果糖、葡萄糖等还原糖,会对采用一次旋光法测定蔗糖分产生影响。葡萄糖使蔗糖分的测定值比实际值大,F42、F55果葡糖浆比实际值小,且都随着它们含量的增加而增大。对于蔗糖转化糖,其影响旋光法蔗糖分的测定值的校正关系式为y=0.393x-0.100。通过蔗糖水解验证试验,考虑转化糖影响,经此关系式校正后,所得的总糖分可达到≥99.5%的要求,解决了QB/T4093检测方法和该厂液体糖产品"不合格"等问题。

The content of total sugar of the liquid sugar produced by our factory often could not reach the standard when we used the method that used in the pure sucrose syrup in the QB/T4093 to measure it in the past days, especially in the case of the sucrose invert syrup, the content of total sugar of which were all less than 99.5%, and considered to be unqualified. This article researched the effect of reducing sugar on the measuring sucrose proportion by measuring and comparing the （polarimetry） sucrose proportion of the refined sugar in which had added the glucose and other reducing sugars. The results showed that the reducing sugar like fructose and glucose in the liquid sugar could affect the measuring of the sucrose proportion using once polarimetric method when measuring the content of total sugar in the liquid sugar. The glucose made the result larger than the actual value, and the F42, F55 fructose made the result less, both of the effect increased with the increase of the content of these reducing sugars. For the sucrose invert syrup, the calibration relationship of effect is y= 0.393x-0.100, which made the content of total sugar meet the requirement of being more than 99.5% by using the sucrose hydrolysis to test and verify. It solved the problems like QB/T 4093 method and the ＂unqualified＂ products in our factory.