Upcycled Defatted Rice Bran in Alginate-Based Noodles Enhances Postprandial Satiety and Antioxidant Capacity in Humans

• DRB-enriched noodles increased GLP-1 and PYY secretion versus alginate alone. • Antioxidant capacity (FRAP, TEAC, thiol) was significantly enhanced by DRB. • Postprandial glucose remained stable across all noodle formulations. • DRB-enriched noodles increased postprandial fullness and reduced hunger ratings. • Gelatin provided structural support but no added impact on satiety or physiology. Defatted rice bran (DRB), a nutrient-rich by-product of rice milling, is an abundant source of fiber and bioactive compounds but has limited direct food applications due to unfavorable sensory attributes. Encapsulation within alginate-based noodles may enhance its stability, functionality, and consumer acceptability. This randomized, controlled, three-period crossover trial investigated the acute effects of DRB-enriched alginate noodles, with or without gelatin, on postprandial satiety, antioxidant responses, and glucose homeostasis in 21 healthy young adults. Participants consumed 240 g of noodles with 150 mL broth in three formulations: alginate only (A), alginate with 5% DRB (AD), and alginate with 5% DRB plus 1% gelatin as a structural enhancer (ADG), with a one-week washout between interventions. Blood samples and appetite ratings were collected at baseline and up to 180 minutes postprandially. Both DRB-containing formulations significantly increased glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) secretion compared with A, which was accompanied by a marked suppression of hunger and desire to eat, and higher fullness ratings. Plasma antioxidant capacity, assessed by FRAP, TEAC, and thiol assays, was also significantly elevated in AD and ADG relative to A ( p < 0.05), while postprandial plasma glucose responses remained stable across treatments. No differences were detected between AD and ADG, indicating that gelatin primarily enhanced noodle structure without altering physiological outcomes. These findings extend recent evidence that upcycling DRB through alginate encapsulation acutely improves satiety hormone responses, appetite regulation, and systemic antioxidant defense without affecting glycemia, supporting its application in the development of sustainable, health-promoting staple foods.