Chemical environment of an acidic Hibiscus sabdariffa beverage and its role in early amylolytic interactions in a starch-based food system.

Amylolytic enzymes operate in aqueous food matrices whose soluble composition can shape the chemical context of early starch hydrolysis. This study evaluated how the chemical environment of an acidic Hibiscus sabdariffa beverage relates to α-amylase and α-glucosidase readouts in a beverage-starch food system. A comparative design integrated HPLC-DAD-ESI-MS compositional profiling, physicochemical descriptors, docking-based spatial analysis, in vitro enzyme inhibition assays, and an acute randomized crossover postprandial evaluation. The beverage contained 769.86 mg 100 mL-1 quantified bioactives and was dominated by organic acids, with lower-abundance flavonoids and anthocyanins, whereas the placebo contained 1.56 mg 100 mL-1 quantified bioactives. The complete beverage-derived fraction inhibited α-glucosidase by 96.05% compared with 35.25% for the placebo and inhibited α-amylase by 92.64% compared with 22.19%. Docking mapped predicted ligand-enzyme contacts involving organic acids, hydroxycinnamic acid derivatives, flavonoid glycosides, and anthocyanins. In healthy adults (n = 13), consuming the beverage 5 min before white bread decreased 30 min glucose from 131.00 to 116.38 mg dL-1 and lowered glucose Cmax by 17.6 mg dL-1 vs. white bread. The post-load sequence showed weaker early separation than the pre-load sequence. These findings describe an acid-dominated, polyphenol-containing matrix associated with comparative amylolytic inhibition and short-term sequence-associated postprandial changes under the tested conditions.