Optimized Roasting Conditions of Germinated Wheat for a Novel Cereal Beverage and Its Sensory Properties

Abstract

The objective of this study was to investigate the possibility of using germinated wheat as a nutritionally improved novel cereal beverage. To enhance the health-related functionality of a germinated wheat beverage (GWB), the roasting time and temperature of germinated wheat were optimized using a central composite design and response surface methodology. The optimum roasting conditions were determined as roasting temperature of 180 °C and roasting time of 44.56 min, resulting in maximum total flavonoid content (0.74 mg CE/g), total phenolic content (1.95 mg GE/g), 2,2-diphnyl-1-picrylhydrazyl (DPPH) radical scavenging activity (5.10 μM TE/g), Trolox equivalent antioxidant capacity (9.45 mM TE/g), and γ-aminobutyric acid content (2.25 mg/g). The germinated wheat roasted with optimum conditions was prepared in two types of GWB (hot and cold), and the sensory characteristics were tested by consumers (n = 102). The cold GWB showed relatively high preferences compared to hot GWB in appearance, odor, taste, and overall acceptabilities. In the intensity results of the sensory properties of GWB, the cold GWB tended to have stronger browning, grain odor, and nutty taste than the hot GWB. Conclusively, this study showed that optimizing the roasting conditions of germinated wheat could achieve desirable sensory properties and consumer acceptance while improving the health-related functionality of GWB.

Keywords

• germinated wheat beverage
• gamma-aminobutyric acid
• total phenolic content
• total flavonoid content
• antioxidant capacity
• response surface methodology