Effects of Different Carbohydrase Complexes on Dietary Fiber Composition, Techno-Functional Properties, and Structural Characteristics of Apple Pomace

Abstract Apple pomace (AP), a fiber-rich by-product of juice processing, holds potential as a functional ingredient. However, its highly insoluble nature limits its applicability in food formulations. This study compared the effectiveness of two enzymatic complexes, a carbohydrolytic enzyme complex (CHEC) or a cellulolytic enzyme complex (CEC), in reducing the AP insoluble profile. Structural changes were analyzed using Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray diffraction, and particle size. Techno-functional properties, including solubility, water retention capacity (WRC), oil retention capacity (ORC), and swelling capacity (SWC), were also evaluated. Both enzymes significantly ( p < 0.05) reduced the lignin and hemicellulose contents, while increasing soluble DF components such as soluble uronic acid and neutral sugars. CEC decreased cellulose content by 20%, whereas CHEC did not affect it. While CHEC treatment reduced WRC by 20%, it yielded the highest solubility. CEC enhanced SWC and solubility by 45% and 59%, respectively, compared to untreated AP. FT-IR and DSC results demonstrated that both enzymatic treatments disrupted the hydrogen bonding of cellulose and hemicellulose, as well as the pectic β-glycosidic linkages, thereby reducing particle size and enhancing techno-functional properties. Consequently, CHEC and CEC emerge as viable strategies to enhance AP functionality through DF modification. CHEC is particularly efficient, requiring lower enzyme concentrations, milder processing conditions, and shorter hydrolysis times. These findings highlight enzymatic modification as a promising approach for valorizing AP as a functional ingredient.