Determination of purple corn husk anthocyanins

Abstract

Components of the purple corn husk anthocyanin complex as a rich inedible source for the preparation of natural dyes were analyzed by reversed-phase HPLC with spectrophotometric and mass-spectrometric detection. The wide speciation of anthocyanins was found and its main components were identified as malonylation products of cyanidin-3-glucoside, 3″,5″-dimalonate (31.0%), 5″-monomalonate (32.2%), and 3″-monomalonate (7.3%), with low concentrations of similar pelargonidin and peonidin derivatives. The total accumulation level of anthocyanins in the samples under study exceeded 3.5 g per 100 g of an air-dry material. The results of the study of anthocyanin complexes of other purple corn parts are presented for comparison. Based on the studies performed, supplements to differential spectrophotometric and chromatographic methods for the determination of anthocyanins were proposed, which gave reproducible data for two alternative methods of their determination.