Composite malt with dark‐purple rice malt improves the phenolic profile and antioxidant activity of malt extract

Abstract

SummaryThis research presents a modification of bioactive compounds of malt extract produced from Riceberry rice malt (RRM)–barley malt composite for malt‐based beverage. Malt extract was produced by varying RRM at 20% w/w, 40% w/w, 60% w/w, 80% w/w, and 100% w/w and were analysed for total polyphenol content (TPC), phenolic acids constituent, and antioxidant activity. The 100% RRM extract was rich in TPC relative to 100% w/w barley malt extract. The composite malt extract containing 40% w/w–80% w/w RRM had enough TPC in the filtered malt extract (236–524 mg L−1) and boiled hopped malt extract (216–485 mg L−1) and were directly proportional to the antioxidant activity in the extract. Barley malt fraction in the malt extracts had a positive response on ferulic acid and sinapic acid, whereas RRM inclusion in malt extract increased p‐coumaric acid, vanillic acid, rutin, and methyl coumarate concentration. Therefore, the cereal malt composite could provide strong oxidative stability to the malt extract and derived products.