Berry by-products obtained from a decoction process are a rich source of low- and high-molecular weight extractable and non-extractable polyphenols

[Display omitted] •Berry decoctions were rich in several anthocyanins and hydroxycinnamic acids.•A wide variety of extractable polyphenols were identified in the berry by-products.•Ellagic acid was the major polyphenol found after acid hydrolysis of by-products.•Hydroxybenzoic acid was bound to the matrix by glycosidic and ether/ester bonds.•Procyanidins, prodelphinidins, and propelargonidins were found in the by-products. In this study, we carried out an exhaustive characterization of the polyphenol profile of strawberry, raspberry, blueberry, and blackberry decoctions; as well as the extractable (EPP) and hydrolysable (HPP) polyphenolic and proanthocyanidin profile of the residues obtained during berries decoctions (decoction by-products) by UPLC-ESI-Q-ToF MS. A greater variety of polyphenols was identified in the EPP fraction of the berry decoction by-products as compared to the decoctions, which were rich in several ellagitannins, flavonols, hydroxybenzoic acids, and anthocyanins. Ellagic acid was identified as the major polyphenol after acid hydrolysis in all berry decoction by-products, followed by hydroxybenzoic acid, which was found bound to the matrix by glycosidic, ether and ester bonds. Regarding proanthocyanidins, procyanidin, prodelphinidin, and propelargonidin dimers were identified in the strawberry, raspberry, and blackberry decoction by-products by MALDI-ToF MS. The results obtained from this study demonstrates that berries decoctions are rich in polyphenols; however, berry decoction by-products were richer in polyphenols with a great variety of extractable and non-extractable polyphenols.