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Processes 2019, 7(3), 126;

Water–Organic Solvent Extraction of Phenolic Antioxidants from Brewers’ Spent Grain

Department of Chemical Engineering, Materials and Environment, Sapienza University, 00185 Rome, Italy
Author to whom correspondence should be addressed.
Received: 7 January 2019 / Revised: 15 February 2019 / Accepted: 18 February 2019 / Published: 1 March 2019
(This article belongs to the Special Issue Green Separation and Extraction Processes)
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Brewers’ spent grain (BSG) is the most abundant by-product of the brewing process. BSG is currently disposed of or used as a supplement for animal feed, although it contains significant amounts of bioactive compounds of great interest to the pharmaceutical, cosmetic and food sectors. In this study we investigate the feasibility of using a simple solvent extraction procedure to recover phenolic antioxidants from BSG. Acetone–water and ethanol–water mixtures were used as extraction solvents. Phenolic extracts obtained by treatment of BSG with the two solvent systems were characterized in terms of total phenolics and antioxidant activity. For both systems, the extraction yield was maximum at 60% (v/v) organic solvent concentration. At all solvent compositions, mixtures containing acetone provided higher extraction yields. As suggested by the strong correlation between the antioxidant activity of BSG extracts and their phenolic content, the antioxidant capacity of the extracts can be mainly attributed to polyphenols. Overall, the obtained results strongly support the exploitation of BSG as a source of phenolic antioxidants and the possibility of recovering them by a mild and green extraction process. View Full-Text
Keywords: brewers’ spent grain; phenolic compounds; solvent extraction; waste valorization brewers’ spent grain; phenolic compounds; solvent extraction; waste valorization

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Zuorro, A.; Iannone, A.; Lavecchia, R. Water–Organic Solvent Extraction of Phenolic Antioxidants from Brewers’ Spent Grain. Processes 2019, 7, 126.

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