Analysis of avenanthramides in oat products and estimation of avenanthramide intake in humans

Abstract

Avenanthramides are phenolic compounds found only in oats, and are of interest due to suggested bioactivities, including anti-inflammatory effects and induction of apoptosis. The objective of this work was to optimise a high performance liquid chromatography (HPLC) method for analysis of avenanthramides in food, and analyse the avenanthramide content in 45 oat fractions and products. The optimised HPLC method was based on triplicate extraction of 100 mg sample with 1 ml 80% ethanol in phosphate buffer (pH 2.8) and used gallacetophenone as an internal standard. Avenalumic acid-derived avenanthramide homologues 2f_d and 2p_d were also present, making up to 20% of the total avenanthramides detected in oats. The amounts of avenanthramides detected in oat products was 2-82 µg/g. It was estimated that mean avenanthramide intake among oat consumers ranges from 0.3 to 2.1 mg/day, considerably lower than the amount used in studies that have investigated biological effects of avenanthramides in humans.

Keywords: Antioxidants; Avenanthramides; HPLC; LC–MS/MS; Oats; Phenolic compounds; Whole grains.