Study On Rapid Determination Of Total Sugar In Red Wine

According to the Commodity Inspection Law of the People’s Repblic of China and Food Safety Law of the People’s Republic of China, imported wine that enter into domestic market shall comply with the wine requirements of our mandatory national standard GB 15037-2006, otherwise will be returned or destroyed. Standard physical and chemicalindicator requirements specified that the total sugar content of the dry red wine should be lessthan 4.0 g.L-1. The testing method in national standard GB15037-2006 is Fehling reagent method, in which the operating process is complicated, and has many influence factors. One inspection personnel that mastering this method very well can only test 5samples per day. If there are hundreds of samples, this testing method seriously restrict the testing periodic time, which will cause a series problems such as delaying of custom clearance, increasing of storage cost, lagging of shelving time,and so on. There is an increasing concern about reducing sugar analyzer, and it has been successfully applicated in many fields of the total sugar determination, however, the determination of total sugar in wine can be affected by pigment, and accurate and reliable results can’t be obtained by using the reducing sugar analyzer according to the procedures described in national standard.This paper investigated the physical and chemical properties of activated carbon and its adsorption abilities, and choose a suitable activated carbon sample for pigment adsorption test in wine. The factors such as the added time, added amount, absorption time of activated carbon that affected the pigment absorption and total sugar determination in wine were also analyzed. The results show that no matter under what conditions, the effect ofpigment adsorption as well as the absorption of sugar is enhanced with the increasing amount of activated carbon added. In addition, the longer of the absorption time, the more sugar can be absorbed, which cause the results a little to the low side. For import and export commodity inspection and supervision institutions, the low determination resultof total sugar will directly lead to wrong administrative actions because they maytreat the unqualified wine as qualified wine. Therefore, using activated carbon to absorb the pigment in wine to reduce the effect of pigment in total sugar determination by reducing sugar analyzer is inappropriate.This paper attempts to resolve the problem from the optimal instrument conditions. The sugar concentration of the test solution and the injection volume of the instrument influence on the test results were also investigated. This problem was solved finally, a method using automatic reducing sugar analyzer to determine the total sugar in wine was established. Method validation test results show that this method is reliable and repeatable. This method can be used as an alternative method to GB/T 15038-2006 to determine the total sugar in dry red wine.