Effects of Extruded Sugar Beet Pulp By-Product on Bioactive Composition, Antioxidant Activity, and Quality of Classic and High-Protein Gluten-Free Pasta.

This study investigated pure extruded sugar beet pulp (ESBP), a by-product containing 58.0% dietary fiber, 6.2% protein, and 18.0% sugars as a novel functional ingredient for conventional and high-protein (HP) gluten-free pasta. The analysis of cooking quality showed that cooking losses increased with enrichment, reaching a 2.9-fold increase in the HP_15% variant. In terms of texture, ESBP addition increased cutting work to 9.65 N·s in HP_15%, suggesting improved matrix cohesion while maintaining stable instrumental firmness. Enrichment also caused noticeable darkening; in the conventional system, lightness (L*) decreased from 70.8 to 56.2 after cooking at the 15% addition level. Although 15% ESBP resulted in the greatest bioactive enrichment, including a 72% increase in phenolic content and significantly enhanced ABTS antioxidant activity, HPLC-DAD analysis confirmed that the phenolic profile was dominated by hydroxybenzoic acids, particularly gallic and 4-hydroxybenzoic acids, whose contents increased by up to 48% and 44%, respectively. Consumer acceptance testing revealed that ESBP levels above 10% markedly reduced acceptability, including a 35% lower overall acceptability score in the HP system, due to a pronounced earthy aroma and excessive cooking losses. The results indicate that ESBP functionality is highly matrix-dependent and that a 10% substitution level represents the optimal compromise between improved bioactive properties and acceptable technological and sensory quality. These findings highlight the potential of pure ESBP for the development of specialized foods with high nutritional and health-promoting value, while future research should focus on the gastrointestinal bioaccessibility of phenolic compounds and overcoming the technological limitations associated with their use.