Physicochemical Stability and Functional Quality of Hydrolyzed Collagen-Fortified Hibiscus sabdariffa Beverages: Effects of Collagen Concentration, Pasteurization, and Storage

Abstract Hydrolyzed collagen has been proposed as a stabilizer of anthocyanins in functional beverages; however, its effectiveness under practical processing and storage conditions remains unclear. This study evaluated the effects of collagen fortification, pasteurization, and storage on the quality of Hibiscus sabdariffa beverages. Collagen fortification (0–5%) significantly influenced physicochemical, color, sensory, bioactive, and antioxidant properties, whereas anthocyanin content exhibited a non-linear response. The beverage containing 3% collagen achieved the highest overall acceptability (7.14/9). Pasteurization at 90 °C for 10 min reduced total plate counts from 80 to 3 CFU/mL while causing only minor changes in bioactive compounds. During six months of storage, microbial and physical stability were maintained. Total phenolic content and DPPH antioxidant activity remained comparatively stable, whereas ABTS activity decreased after three months. In contrast, anthocyanins declined rapidly and followed first-order degradation kinetics with a half-life of 0.68 months. Anthocyanin degradation was primary factor limiting long-term beverage quality.