**1. Introduction**

Agricultural by-products form a large part of waste, with approximately 88 metric tons per year generated in Europe alone [1]. However, these by-products are considered to be potential sources of various high added-value, bioactive compounds (dietary fibers, pigments, essential minerals, fatty acids, antioxidant polyphenolic compounds, etc.) [2]. Berry pomace (or press cake) obtained after juice pressing usually contains skin, stems, and seed parts [1]. Various fruit and berry products are substantially composed of structural polysaccharides and their related oligosaccharides and these compounds are commonly described as insoluble (IDF) and soluble (SDF) dietary fibers [3]. The dietary fiber in berry pomace is usually composed of pectin, lignin, cellulose, hemicellulose, and inulin [1]. These types of compounds have a potentially significant impact on human health [3], such as a decrease in the risk of hypertension, obesity, diabetes, coronary heart disease, stroke, and certain gastrointestinal disorders [1]. The Food and Drug Administration recommendation for the use of dietary fiber in the diet is approximately 25–35 g per day, and 6 g of it should be SDF. Furthermore, some studies show that 10 g of extra dietary fiber in a diet could help decrease the risk of death caused by coronary heart disease by up to 35% [1,4].

**Citation:** Jagelaviciute, J.; Basinskiene, L.; Cizeikiene, D.; Syrpas, M. Technological Properties and Composition of Enzymatically Modified Cranberry Pomace. *Foods* **2022**, *11*, 2321. https://doi.org/ 10.3390/foods11152321

Academic Editors: Marco Poiana, Francesco Caponio and Antonio Piga

Received: 14 July 2022 Accepted: 1 August 2022 Published: 3 August 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Polyphenols and cell-wall polysaccharides can also positively modulate the profile of the gu<sup>t</sup> microbiota, which may have implications in the prevention against metabolic diseases [5]. Other studies indicate that SDF can be used as a prebiotic [1]. Islam et al. [6] reported that the incorporation of cranberry pomace in the food not only improved the short-term iron and cholesterol levels in the blood serum of broilers, but also increased the levels of beneficial bacterial genera and decreased the undesirable ones. Other studies indicated that the fractions of cranberry oligosaccharide and the xyloglucan and purified cranberry xyloglucan compounds have shown a distinct lack of antimicrobial properties or cytotoxic effects in numerous bacterial and human cell lines [3]. The oligosaccharides extracted from cranberries even shown the ability to modify the biofilm formation of some *E. coli* strains [7]. Liu et al. [8] reported that cranberry oligosaccharides can be used as a carbon source for *Lactobacillus*, however the oligosaccharide metabolization is strain specific. The supplementation of fermented meat with cranberry pomace significantly inactivates *Salmonella* and increases the growth of lactic acid bacteria [9].

An increase in the level of dietary fiber in food products usually negatively influences the products' texture and color, depending on the properties and level of fiber. However, some studies indicated that enzymatic treatment is practical and a potential modification method to obtain functional food materials with better technological properties from agriculture by-products [10,11]. For example, the enzymatically treated tomato peels have higher contents of lycopene and dietary fiber [10]. The enzymatic treatment can effectively increase the release of antioxidants and phenolic compounds and the fiber composition. However, this is not the case for all of the fruit and berry matrixes; in some cases, enzymatic treatment can reduce the fiber content and increase the free monosaccharides [11]. The treatment of fruit fiber with enzymes of different activities has resulted in structural changes that have altered the technological properties, such as the water-holding and swelling capacities [12].

In this study, cranberry pomace was enzymatically treated with several commercially available enzymes to modify their technological properties and the composition of the dietary fiber. The technological properties were determined, such as water-holding, oilholding, swelling, emulsion capacities, dietary fiber composition, and prebiotic potential. Most previously published studies indicated cranberry by-products as a good source for isolating bioactive compounds. However, there is a lack of information regarding the effect of enzymatic treatments on cranberry pomace properties. This study provides experimental support for the whole cranberry pomace as a source of dietary fiber and for developing functional and innovative food products.
