RESUMO
Anthocyanins are naturally occuring phytochemicals and the main components of the coloring of plants, flowers and fruits. They are known to elicit antioxidative, anti-inflammatory and cancer preventive activity. In this study, we investigated anthocyanins in black / yellow soybean seedcoats using different methods of detection - thin layer chromatography (TLC), capillary zone electrophoresis (CZE) and HPLC analysis. The anthocyanins in soybean seedcoats were extracted by five independent methods of extraction and the aglycons (anthocyanidins) of the corresponding anthocyanins were prepared by acid mediated hydrolysis. The anthocyanin / anthocyanidin in black soybean seedcoat showed characteristic TLC mobility, CZE electrophoretic retention and HPLC migration time while little of anthocyanins were detected from yellow soybean seedcoat. The extracted anthocyanins showed pH dependent retention time in CZE and spectral change in UV-Vis spectrum. HPLC analysis of the hydrolyzed extract of black soybean seedcoat identified the presence of four anthocyanidins. The major anthocyanin in black soybean seedcoat was cyanin (cyanidin-3-O-glucoside), with the relative order of anthocyanidin in cyanidin > delphinidin > petunidin > pelargonidin.