Citrus Fiber Derived From Huyou Processing Waste and Its Application in the Lower Glycemic Index Bread

The expanding production of Changshan Huyou (Huyou) products has resulted in large quantities of by-products, particularly peel residues, posing challenges for environmental sustainability and resource utilization. Current uses of Huyou peel residues focus mainly on the extraction of pectin and flavonoids, yet substantial precipitates remain unutilized. Meanwhile, the growing demand for health-conscious diets has increased interest in high-fiber bread due to its benefits for glycemic control and gut health. This study employs a low-temperature acid extraction method to recover the precipitate-Huyou fiber-after pectin extraction, thereby improving the utilization of peel residues. Compared with commercial citrus fiber, Huyou fiber demonstrates comparable thermal stability and viscosity at higher concentrations (3%). Incorporating moderate amounts (<5%) of Huyou fiber into bread formulations enhances dough cohesiveness and elasticity and lowers the gelatinization temperature of dough compared with the control (without added fiber), increases slowly digestible and resistant starch contents, and significantly reduces the estimated glycemic index (eGI) (from 78.3 ± 0.8 to 68.6 ± 1.0, p < 0.05). These findings support the high-value utilization of Huyou peel residues and underscore the potential of Huyou fiber as a functional ingredient for developing low-GI bakery products. PRACTICAL APPLICATIONS: This research converts abundant Huyou peel waste into functional fiber. Compared to common citrus fiber, Huyou fiber holds up better during baking (superior heat stability) and helps create a softer texture (higher viscosity). Adding a small amount (<5%) to bread maintains good texture while significantly lowering its blood sugar impact. This offers bakers a way to turn waste into value and provides consumers with more nutritious baked goods.