Evaluation of Industrial Sour Cherry Liquor Wastes as an Ecofriendly Source of Added Value Chemical Compounds and Energy

There has been a growing interest in the recovery and valorization of chemical products from biomass wastes. In the present study pomace from sour cherry liquor was analyzed in order to evaluate its potential for valorization. Two different samples of liquor pomace and two different extraction methods were screened through determination of their phenolic content (HPLC/PDA) and antioxidant activity (FRAP and DPPH assay). Results obtained showed that skins (pomace without kernel) presented a higher extraction yield, polyphenolic content and antioxidant activity than pomace with kernel (skin+kernel). Decoction at 100 °C allowed a higher recovery of phenolic compounds, but, maceration with water at 25 °C was considered a more sustainable process. HPLC analyses allowed the identification and quantification of phenolic compounds such as cyanidin-3-O-glucoside, (+)catechin and (−)epicatechin and some phenolic acids. The analyzed by-products might be a promising source of natural polyphenolic compounds, which can act as a new eco-friendly antioxidant ingredient, with potential to be incorporated in nutraceutical formulations or applied in food or cosmetic industries. The residues remaining after extraction have a high calorific value and fat content, suggesting its valorization as a source of energy or through the extraction of value-added oil.