Biochemical and Structural Characterization of Rice and Oat Bran Hydrolysates and Their Functional Implications in Food Systems
Abstract
Cereal bran, a by-product of grain milling, is a nutrient-rich material with significant potential for use in functional food applications. This paper examined the biochemical structure, antioxidant properties, and functionality of rice and oat bran hydrolysates obtained via hydrothermal treatment. Proximal analysis revealed significant compositional differences between raw brans and their hydrolysates, indicating increased nutrient extractability after hydrolysis. Antioxidant activity was evaluated using DPPH (% inhibition), FRAP (µmol Fe²⁺/g), ABTS (mmol TE/g), total phenolic content (mg GAE/g), and total flavonoid content (mg RE/g). Oat bran hydrolysates showed higher antioxidant activity in DPPH, FRAP, and ABTS assays. Rice bran hydrolysates exhibited slightly higher total phenolic content, while oat bran hydrolysates showed superior antioxidant activity. The difference was explained by the differences in phenolic composition and synergistic interactions with β-glucan in oat bran. FTIR and SEM analyses were used to confirm structural changes, which showed that functional groups and the microstructure changed after incorporation of hydrolysates. Bread systems' functional analysis revealed that hydrolysates had a considerable impact on texture, color, and sensory characteristics. Rice bran hydrolysates raised firmness and flavor and oat bran hydrolysates raised structural balance and acceptability. These results indicate the promise of rice and oat bran hydrolysates as value-added functional ingredients to enhance the creation of nutritionally enriched and structurally enhanced food items.