Valorization of artichoke outer petals by using ultrasound‐assisted extraction and natural deep eutectic solvents (NADES) for the recovery of phenolic compounds

Abstract

BACKGROUNDIn the present study, natural deep eutectic solvents (NADES) as a novel green tool were used for the recovery of bioactive compounds with respect to the valorization of artichoke outer petals. NADES coupled with ultrasound‐assisted extraction was applied by varying the type of hydrogen bond acceptors (choline chloride or betain) and hydrogen bond donors (sucrose, lactic acid, citric acid, oxalic acid and glycerol) in the NADES mixtures. Thereafter, extraction efficacy was assessed in terms of total phenolic content, antioxidant capacity and individual phenolic composition and their levels by comparing the results obtained by NADES with those for a reference methanolic extract.RESULTSBased on the results of the present study, the use of choline chloride and lactic acid mixtures was superior for obtaining extracts with high levels of phenolic compounds (12.96 g GAE kg−1 DW) and high antioxidant potential (60.68 g TE kg−1 DW). In addition, gallic acid, syringic acid, chlorogenic acid, ferulic acid, sinapic acid, luteolin, apigenin, rutin and quercetin were detected in all extracts by chromatographic evaluation. As major phenolic compounds, chlorogenic acid and ferulic acid were found to be maximum in lactic acid‐based NADES mixtures.CONCLUSIONThe present study reveals the potential treatment of various plants, wastes or by‐products with NADES combined with an ultrasonication method for the extraction of bioactive compounds with enhanced recovery and selectivity, with the aim of incorporating them into various food and pharmaceutical formulations. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Globe Artichoke (Cynara scolymus L.) By-Products in Food Applications: Functional and Biological Properties

“…Bracts and stems are good source of inulin (70%) with high DP (32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42), which has a greater stimulation action on the growth of different Bifidobacteria and Lactobacilli than the commercial FOS. In particular, an increase in OD 600 (from 0.1 to 0.5-1.5, depending on the strain) was observed after 48 h of incubation at 37 • C under anaerobic conditions, indicating a proliferation of Bifidobacteria and Lactobacilli [21].…”

“…In fact, a thermal treatment before the extraction process or enzymatic hydrolysis can increase fiber recovery from stems. This fiber is mainly characterized by 70% inulin, with a low amount of low-DM (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33) pectin; it exhibits high or low viscosity, depending on whether a high or low shear rate is applied, as pseudoplastic material. The high amount of inulin, together with the presence of low-DM pectin and calcium (40 mg/g pectin), contribute to form rigid gels.…”

“…This allowed for overcoming the limitations of traditional technologies and reducing the reagent cost deriving from the by-products' re-use, also being time saving [31,32]. Regarding ABPs, the use of green solvents (water, methanol, ethanol, and natural deep eutectic solvents-NADES) [33] and the applications of heat treatment [13,32,34], microwaves (microwave-assisted extractions-MAE) [35], pressure (pressurized-liquid extraction-PLE or pressurized-hot water extraction-PHWE) [36][37][38], or ultrasounds (ultrasound-assisted extraction-UAE) [39][40][41], often combined, were explored, obtaining more rapid, efficient, and selective extraction processes potentially scalable at industrial level [24,32].…”