Synergistic Effect of Enzyme‐Assisted Fermentation on Phytochemical Content, Volatile Profile, and Antioxidant, Antidiabetic, and <scp>ACE</scp> Inhibitory Properties of Sea Buckthorn‐Based Cereal Beverages

Today, plant-based beverages are increasingly being recognized for their health-promoting properties. Here, we investigate how the innovative use of enzyme-assisted fermentation enhances the phytochemical content, bioactivity, and aroma profile of sea buckthorn-based cereal beverages (SBCB). Enzyme-assisted fermentation significantly increased phytochemical content compared to the untreated sample. Specifically, F3% (fermented, 3% enzyme-treated SBCB) boosted total phenolic and flavonol contents by 124.94% and 147.24%, while F5% (fermented, 5% enzyme-treated SBCB) raised total flavonoid and proanthocyanidin contents by 177.74% and 58.32%. Notably, F5% showed the most pronounced improvements in antioxidant, antidiabetic, and ACE inhibitory effects. Analysis from the Mantle test showed that low pH and enzyme activity contributed to increased phytochemical content and enhanced bioactivity, while the aroma analysis revealed higher levels of alcohols and acids (e.g., 3-methyl butan-1-ol, acetic acid) alongside reduced ester content in the enzyme-treated fermented samples. Together, our findings demonstrate enzyme-assisted fermentation as an innovative strategy for developing fruit-based cereal beverages with superior functional properties.