Development of a protein-enriched oat beverage: Enhancing antioxidant activity, functional properties and stability with soy protein hydrolysates

Oat beverages are popular as dairy alternatives, but their low protein content limit their functionality. Soybean protein hydrolysates, derived from enzymatic hydrolysis, could improve both the nutritional and functional properties of these beverages. This study aimed to develop a protein-enriched oat beverage with enhanced functional and physical properties by incorporating soybean protein hydrolysates. Soybean protein hydrolysates were prepared from defatted soybean cake isolates. Oat beverages were enriched to 3 % protein concentration using either protein isolates or hydrolysates. The chemical composition, physical properties, antioxidant activity (ABTS and ORAC assay) and volatile profile (PTR-MS) of the prepared beverages were investigated. Hydrolysate-enriched beverages exhibited higher antioxidant activity (2848 ± 121 μmol TE/g) and phenolic content (1334 ± 25 μmol GAE/g) than isolate-enriched beverages. They also showed improved physical stability, with reduced sedimentation. The volatile profile of the hydrolysate beverage was similar to the control. Soybean protein hydrolysates were effective for enhancing the nutritional and functional quality of oat-based beverages with potential for wider application in plant-based formulations.