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

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. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study conducted a comprehensive analysis of the polyphenol profiles in strawberry, raspberry, blueberry, and blackberry decoctions, revealing a greater variety of polyphenols in the extractable fraction of the decoction by-products. Ellagic acid and hydroxybenzoic acid were identified as the major polyphenols in the berry decoction by-products, with various proanthocyanidins also present. The results demonstrate that while berry decoctions are rich in polyphenols, the decoction by-products are even more abundant in a diverse range of polyphenols.