Comparative volatiles, amino acids, and phenolic compounds and characteristics of roasted germinated wheat (Triticum aestivum L.) during beverage preparation
Thinzar Aung, Bo Ram Kim, Sung‐Mi Kim, Eui‐Cheol Shin, Mi Jeong Kim
Abstract
The aim of this study was to explore the volatile compound contents and antioxidant potential of wheat beverage at various stages of preparation. Samples of raw wheat (RW), germinated wheat (GW), steamed germinated wheat (SGW), and roasted-steamed germinated wheat (RSGW) were collected, their physicochemical and structural characteristics were analyzed, and their bioactive components, amino acids, volatile profiles, phenolics, and antioxidant potentials were determined by spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), High Performance Liquid Chromatography, and electronic nose. RSGW had the highest level of bioactive components (2.46 mg/g GABA, 0.72 mg CE/g total flavonoid content, 4.66 μM TE/g 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and 10.20 mM TE/g Trolox equivalent antioxidant capacity). Also, the highest level of phenolic acids, gallic, p-coumaric, ferulic, syringic, and caffeic acids, were detected in RSGW. The FT-IR spectra revealed similar band positions for all samples. A principal component analysis clearly discriminated each preparation stage and established that SGW and GW had the highest amino acid contents while RSGW had the greatest bioavailability and highest abundance of volatiles and phenolic compounds.