Functional, Biochemical, and Phenolic Responses of Commercial Canada Western Red Spring Wheat Samples to Controlled Germination

Pre-harvest sprouting is a major challenge in wheat production because premature germination activates hydrolytic enzymes that reduce grain functionality and processing quality. The aim of this study was to link the phenolic composition of mature grain to the magnitude of germination-induced biochemical and functional responses by using controlled germination. Forty-one wheat samples were analyzed as native and germinated whole-wheat flours following 24 h of germination at 21 °C and 80% relative humidity. Kernel morphology, germination percentage, Falling Number (FN), α-amylase activity, reducing sugars, lactic acid solvent retention capacity (SRC), total phenolic content (TPC), and eleven individual phenolic acids were assessed using linear mixed-effects models, correlation analysis, and principal component analysis. Controlled germination markedly altered wheat quality, reducing FN from approximately 330–450 s to 60–200 s while increasing α-amylase activity from 0.20–0.35 to 0.30–0.95 CU g−1 and increasing reducing sugar concentration. Germination also increased TPC from approximately 4031–6128 to 5182–7188 µg g−1 dry matter. Significant increases were observed in several phenolic acids, including ferulic, p-coumaric, and sinapic acids. Correlation analysis showed a strong negative association between germination and FN (r = −0.934, p < 0.001) and positive associations with reducing sugars, p-coumaric acid, and ferulic acid. Principal component analysis clearly separated native and germinated samples in multivariate space. Overall, 24 h controlled germination simultaneously enhanced phenolic composition and modified biochemical and functional properties relevant to wheat processing.