## 3 Results  
### IDF, SDF, and RS Content in Enzymatically Treated Apple Pomace  
The saccharide composition of enzymatically treated AP is presented in Figure 1. Low-molecular-weight carbohydrates, such as RS, composed a major part of the fraction of AP carbohydrates, while the DF content was significantly lower. [PERSON] et al. [36] also reported a high sugar content with glucose (21.7%) and fructose (24.3%) as the primary reducing sugar in AP. According to the literature, the DF content in AP can range from 26.8 to 82.0%, and it depends on various factors, such as the plant variety, fruit maturity, and processing conditions [37].  
The enzymatic hydrolysis significantly (\(p\leq 0.05\)) increased the RS content and decreased the TDF in all treated AP samples. The highest RS content was obtained after a 5 h hydrolysis with Viscozyme and Pectinex (1.38 and 1.4 times higher than the control, respectively). AP hydrolysis with the cellulolytic enzyme Celluclast increased the SDF content by approximately 20%; however, the duration of hydrolysis did not have a significant impact (\(p\leq 0.05\)) on the SDF content. [PERSON] et al. [38] also reported that cellulase increased the amount of SDF in AP after hydrolysis. Enzymatic hydrolysis with Pectinex and Viscozyme, which are composed of different carbohydrate mixtures, had a negative impact on IDF and SDF by reducing their content. It is known that pectin in the cell walls of apple is like protopectin, which is associated with cellulose and hemicellulose and reduces the effect of enzymes [39]. The synergistic effect of enzymes such as pectinases, cellulases, and \(\beta\)-glucosidase facilitates the breakdown of the pectin and lignin network and the access of the enzymes to the cellulose [40; 41]. Note that in this study, the pectin of AP could be hydrolysed by pectinases from Viscozyme and Pectinex by increasing cellulase access to cellulose. While SDF could be hydrolysed to smaller fragments, i.e., oligosaccharides and mono- and disaccharides that are soluble in ethanol and are not identified as SDF, according to the AACC 32-07.01 and AOAC 991.43 methods, this may lead to an underestimation of the actual hydrolysis products and their potential benefits. [PERSON] et al. [42] found a similar decrease in the TDF content of date fruit fibre after hydrolysis with Viscozyme. The obtained result indicates that AP, after enzymatic hydrolysis with Viscozyme and Pectinex, could be used as a value-added ingredient for fermentation or for sweet products as a natural sweetener, while AP hydrolysed with Celluclast could be used as an SDF source. However, AP is composed of a complex array of carbohydrates, and while enzymatic  
Figure 1: Saccharide composition of enzymatically hydrolysed AP. Data values are expressed as means with the standard deviation (\(n=3\)). a–f means with different superscripts are significantly different (\(p<0.05\)). IDF—insoluble dietary fibre; SDF—soluble dietary fibre; RS—reducing sugar.  
hydrolysis using carbohydrate preparations such as Viscozyme, Pectinex, and Celluclast can be effective, its efficiency is limited by the accessibility of the substrate. The structural complexity of the cell wall and the interactions between its components may hinder enzymatic action, thus affecting the overall hydrolysis process and limiting the potential yield of functional ingredients.