Pressurized Liquid Extraction Combined with Enzymatic-Assisted Extraction to Obtain Bioactive Non-Extractable Polyphenols from Sweet Cherry (Prunus avium L.) Pomace

Abstract

Sweet cherry generates large amounts of by-products within which pomace can be a source of bioactive phenolic compounds. Commonly, phenolic compounds have been obtained by conventional extraction methodologies. However, a significant fraction, called non-extractable polyphenols (NEPs), stays held in the conventional extraction residues. Therefore, in the present work, the release of NEPs from cherry pomace using pressurized liquid extraction (PLE) combined with enzyme-assisted extraction (EAE) using PromodTM enzyme is investigated for the first time. In order to study the influence of temperature, time, and pH on the NEPs extraction, a response surface methodology was carried out. PLE-EAE extracts displayed higher TPC (75 ± 8 mg GAE/100 g sample) as well as, PA content, and antioxidant capacity than the extracts obtained by PLE (with a TPC value of 14 ± 1 mg GAE/100 g sample) under the same extraction conditions, and those obtained by conventional methods (TPC of 8.30 ± 0.05 mg GAE/100 g sample). Thus, PLE-EAE treatment was more selective and sustainable to release NEPs from sweet cherry pomace compared with PLE without EAE treatment. Besides, size-exclusion chromatography profiles showed that PLE-EAE allowed obtaining NEPs with higher molecular weight (>8000 Da) than PLE alone.

Oligomeric Proanthocyanidins: An Updated Review of Their Natural Sources, Synthesis, and Potentials

“…Another extraction method, supercritical carbon dioxide extraction, can get proanthocyanidins with high purity and does not require toxic solvents, such as methanol, chloroform, and acetone [59]. Enzyme extraction can yield components with high biological activity and can also yield the non-extractable polyphenols (NEPs) that are difficult to extract by traditional extract methods, such as pressurized liquid extraction (PLE), combined with enzyme-assisted extraction (EAE) can provide more proanthocyanidins with high antioxidant capacity than those extracted by traditional methods [60]. In addition, microwave-assisted extraction [61,62] and ultrasound-assisted extraction can increase the purity of extracts [63].…”

Sustainable Valorization of Industrial Cherry Pomace: A Novel Cascade Approach Using Pulsed Electric Fields and Ultrasound Assisted-Extraction

“…Rich in lignin, cellulose, dietary fiber, and phenolic compounds such as neochlorogenic acid, chlorogenic acid, 4-p-coumaroylquinic acid, and rutin, cherry pomace also serves as a valuable source of anthocyanins like cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside [11,12]. These compounds contribute to various biological activities, including antioxidant, anti-inflammatory, anticancer, α-glucosidase inhibiting, and antihypertensive properties [13][14][15][16].…”