Abstract
Rutin and its decomposed materials, isoquercitrin and quercetin, belong to flavonoids obtained from many plant extracts. Flavonoids are a large family of secondary plant metabolites, and their biosyntheses, origins, properties, physiological and antioxidant activities have been studied for a long time. In recent years, they have attracted attention, since they exhibit a wide range of biological effects, including anti-inflammatory, anti-allergic, anti-carcinogenic, anti-hypertensive, and preventing platelet aggregation. Each of three rutin related compound is also valuable for food additive, as antioxidant in its ability of inhibiting oxidation. Antioxidants have a protective function against oxidative damage, which causes the decrease in the flavor and nutritive value of oil and fat in foodstuffs. As a consequence, various antioxidants have often been incorporated to prevent lipid peroxidation. Recently, the interests in naturally occurring antioxidants have increased considerably. However, determination of the greater part of naturally occurring food additives in foodstuffs have not been established up to now. The purpose of this study is to develop an analytical method for simultaneous determination of above three compounds in foodstuffs, using high-performance liquid chromatography with (1) electrochemical (ECD) and (2) ultraviolet detection (UV). Good separations of each compound were obtained at optimized conditions of both HPLC systems. Test solutions for salad oil, margarine and crude confectionery were prepared. Recoveries of these compounds from above foodstuffs added were (1) 79.6〜98.0% and (2) 80.1〜98.1%, respectively. ECD was 10 to 25-fold more sensitive than UV. Well resolved, interference free chromatograms were obtained for each analysis. The results of sample solutions for salad oil are shown in figure (upper; 100μg/g of each was added, lower; no added). This method should be useful as a routine analysis of rutin related compounds in foodstuffs. [figure]
