The Effect of Heat Processing on Chemical Composition and Antioxidative Activity of Tea Made from Barley Sprouts and Wheat Sprouts.

Abstract

Barley sprouts and wheat sprouts have received much interest as functional foods in many countries. In this study, the effects of heat processing and extraction temperature on the bioactive components and antioxidative properties were examined in barley and wheat sprout teas. Both barley and wheat sprout teas were processed with two different methods (steaming or pan-roasting). Crude protein was increased, and moisture content was the lowest, in the roasted barley and wheat sprout teas. Total phenolics content and flavonoid contents were significantly higher in the roasted teas than in the steamed teas. Vitamin C content was the highest after an extraction temperature of 55 °C (24.05 mg/mL) in the roasted wheat sprout tea. Both roasted barley and wheat sprout teas exhibited the most antioxidative effects in vitro, demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and nitrite-scavenging activities. Therefore, the roasting method can be considered an appropriate technique for the production of barley and wheat sprout teas. PRACTICAL APPLICATION: Barley and wheat sprouts have received much attention in recent years as functional food materials in many countries and can be consumed as a form of tea. Heat processing methods such as steaming and roasting were applied and compared to increase the bioactive components and antioxidative activity in barley and wheat sprout teas. We found that roasting showed higher bioactive components and antioxidative activity than steaming in both barley and wheat sprout teas. In addition, wheat sprouts tea showed better bioactive components and antioxidative activity compared with the barley sprout tea.