Upcycling defatted rice bran into alginate based noodles via hydrocolloid assisted development and assessment of...

Upcycling defatted rice bran (DRB), a nutrient rich byproduct of rice milling, offers a sustainable way to add value and reduce waste. Despite its nutritional potential, its coarse texture, low stability, and poor compatibility with food systems limit its direct application. This study aimed to valorize DRB by formulating functional noodles using alginate-based encapsulation and to investigate the effects of different hydrocolloids including gelatin, carrageenan, and agar on noodle structure, texture, in vitro digestion, and phenolic release. Sodium alginate was used at 1.8 % (w/v), DRB at concentrations ranging from 1 to 5 % (w/v), and hydrocolloids at 0.25-1.0 % (w/v). Response Surface Methodology identified the optimal formulation as 1.0 % (w/v) DRB combined with 1.0 % (w/v) hydrocolloid. Gelatin significantly improved tensile strength and encapsulation efficiency, carrageenan softened the texture, and agar provided balanced textural properties. FT-IR revealed stronger hydrogen bonding in gelatin-based noodles, while X-ray diffraction (XRD) indicated increased crystallinity. LC-MS-MS analysis confirmed greater retention of phenolic acids, particularly ferulic and sinapic acids, in gelatin formulations following thermal processing. In vitro digestion showed that gelatin-based noodles released the most phenolics and proteins with superior antioxidant activity, suggesting improved bioavailability. Although DRB incorporation increased glucose release in all formulations, the gelatin DRB combination yielded the lowest glucose release, likely due to the gel matrix formed by gelatin acting as a diffusion barrier. The findings suggest that alginate-based noodles can be sustainably developed using DRB, with gelatin enhancing structural integrity and bioactive stability, supporting a novel approach to functional food innovation.