谷物食品总黄酮比色法定量的问题及选用原则

The Problem and Selection of the Colorimetric Quantification of Flavonoids of Cereal Foods

越来越多的研究证明:谷物中富含多种酚类化合物,其中黄酮类是一个重要的酚类组成部分,具有多种生物活性,准确测定总黄酮含量对于食品营养价值判定、功能食品开发等十分重要。用分光光度计比色分析是黄酮定量最常用的方法,其中较多使用的有NaNO_2-Al^(3+)-NaOH法、AlCl_3法和2,4-二硝基苯肼法,然而不同的谷物黄酮种类不同,增加了方法选用和准确定量的难度。本文综述了不同谷物类黄酮的组成与含量,并根据常见比色方法的原理及各方法下类黄酮的吸收情况,指出一些近年来谷物食品总黄酮测定中存在的可能误用,并提出方法的选择原则和对应的合理方法,以便增加食品总黄酮定量的准确性,也可为果蔬及功能食品产业提供参考。

More and more studies have shown that cereals were rich in a variety of phenolic compounds and the flavonoids with plenty of biological activities occupied an important part. Thus, accurate quantification of total flavonoid contents was very important for the judgement of food nutritional value and the development of functional food. Spec- trophotometric analysis was the most commonly adopted method for quantification of flavonoids, among which NaNO2-AP＋- NaOH method, aluminum chloride method and 2,4-dinitrophenylhydrazine method were frequently used. But flavonoids varied in different cereal food, which increased the difficulty of method selecting and accurate quantification. Therefore, this paper summarizes the statistics of flavonoid composition and contents distribution among different types of grains. Ac- cording to the absorption of flavonoids under different determination methods, it points out the possible misuse and meanwhile suggests the most appropriate proposal, which will be helpful to enhance the accuracy of flavonoids determina- tion and as a reference in fruit and vegetable and functional food industry.