Influence of Jet-Cooking Prowashonupana Barley Flour on Phenolic Composition, Antioxidant Activities, and Viscoelastic Properties

The objective was to study the influence of jet-cooked Prowashonupana barley flour on total phenolic contents, antioxidant activities, water-holding capacities, and viscoelastic properties. Barley flour was jet-cooked without or with pH adjustment at 7, 9, or 11. Generally, the free phenolic content and antioxidant activity decreased after jet-cooking, while the bound phenolic content and antioxidant significantly increased regardless of pH. Detectable levels of gallic acid, caffeic acid, ferulic acid, and p-coumaroyl-pentose in the jet-cooked barley flour hydrolysates along with vitexin were found among 21 phenolics by LC-ESI-Q-TOF-MS analysis. Jet-cooking at an elevated pH resulted in increased pasting viscosities. The oil content was decreased after jet-cooking and continued to decrease with increased pH values. Jet cooking dramatically increased water holding capacity from 179% for unprocessed flour to 643% for jet-cooked flour without pH adjustment, and water-holding capacity was greatly increased to 914% by jet-cooking at pH 11. The combination of jet-cooking and pH adjustment had tremendous influence on water-holding and pasting properties. This increase in functionality should contribute to food applications such as bakery and frozen products because of the release of the bound phenolic content, antioxidant activities, and improved water-holding and pasting abilities.