Analysis of anthocyanins in dietary supplements containing blueberry extract

Abstract

An extraction and analytical method was developed for determination of the content and profiles of anthocyanins in commercial dietary supplements containing blueberry extract. Dietary supplements were refluxed with hydrochloric acid-methanol solution, and spectrophotometric assay was performed to evaluate the total anthocyanidin content in extracted solutions as delphinidin, which is one of the anthocyanidins in blueberry extract. Twenty compounds (15 anthocyanins and 5 anthocyanidins) in extracted solutions were separated by HPLC analysis with gradient elution using formic acid and methanol-acetonitrile as the mobile phase, and each peak was confirmed by LC/MS analysis. The proposed method was applied to 25 kinds of commercial dietary supplements, and one supplement whose profile was different from that of the fresh bilberry extract was found.