Utilization of Grape Pomace as A Value-added Phenolic Component for Oat Milk Production

Grape pomace (GP), a wine industry byproduct rich in dietary fiber and polyphenols, was aimed to enhance the nutritional, phytochemical, and sensory qualities of oat milk. Oat milk, a sustainable dairy alternative rich in β-glucan and minerals, but its low phenolic and antioxidant content limits its functional potentiality. This work incorporated GP extract into oat milk to improve its bioactive profile, stability, and consumer appeal, meeting the demand for plant-based functional beverages. The study assessed the effects of GP fortification on phenolic composition, antioxidant activity, and acceptability. Oat milk exhibited stable emulsion properties at pH 6.77 ± 0.12 and titratable acidity 0.43 ± 0.21%. GP supplementation significantly increased bioactive potential: total phenolic content rose from 35.08 ± 2.30 to 101.43 ± 25 mg GAE/g DW, total flavonoids from 69.56 ± 1.5 to 180.11 ± 18 mg QE/g DW, and antioxidant activity to 48 ± 8 mM Trolox/g DW. Anthocyanin content also increased, highlighting GP's role in enhancing phenolic delivery. Sensory evaluation showed that 0.2% GP-fortified oat milk achieved the highest acceptability in flavor, color, aroma, mouthfeel, and overall preference. Higher GP levels (0.3-0.5%) intensified flavor and color but reduced consumer acceptance. Overall, GP fortification, particularly at 0.2%, improves oat milk's nutritional and functional properties as a value-added ingredient for functional beverages within a circular economy.