Bioactive Compounds and Antioxidant Activity from Spent Coffee Grounds as a Powerful Approach for Its Valorization

Abstract

Coffee is one of the world’s most popular beverages, and its consumption generates copious amounts of waste. The most relevant by-product of the coffee industry is the spent coffee grounds, with 6 million tons being produced worldwide per year. Although generally treated as waste, spent coffee grounds are a rich source of several bioactive compounds with applications in diverse industrial fields. The present work aimed at the analysis of spent coffee grounds from different geographical origins (Guatemala, Colombia, Brazil, Timor, and Ethiopia) for the identification of bioactive compounds with industrial interest. For this purpose, the identification and quantification of the bioactive compounds responsible for the antioxidant activity attributed to the spent coffee grounds were attempted using miniaturized solid-phase extraction (µ-SPEed), combined with ultrahigh-performance liquid chromatography with photodiode array detection (UHPLC-PDA). After validation of the µ-SPEed/UHPLC-PDA method, this allowed us to conclude that caffeine and 5-caffeoylquinic acid (5-CQA) are the most abundant bioactive compounds in all samples studied. The total phenolic content (TPC) and antioxidant activity are highest in Brazilian samples. The results obtained show that spent coffee grounds are a rich source of bioactive compounds, supporting its bioprospection based on the circular economy concept closing the loop of the coffee value chain, toward the valorization of coffee by-products.

Spent Coffee Grounds—A Coffee By-Product Abundant in Bioactive Compounds with Antioxidant Properties

“…Our results associated with the caffeine content, CQA content, and BI in the SCG extract are in accordance with those reported in the literature [27][28][29].…”

Valorization of spent coffee ground and coffee silverskin as a source of nutrients and bioactive compounds

“…Most abundant phenolic compounds are mainly found in coffee beans and consequently in coffee by-products are the chlorogenic acids (CGAs) (Esquivel & Jiménez, 2012). These CGAs are water-soluble Andrade et al, 2022;Angeloni, Nzekoue, et al, 2020;López-Barrera et al, 2016;Ramón-Gonçalves et al, 2019;Torres-Valenzuela et al, 2019;Zengin et al, 2020Angeloni, Nzekoue, et al, 2020Castaldo et al, 2020;Mesías et al, 2014;Nzekoue et al, 2020aNzekoue et al, , 2020bZengin et al, 2020 2 Quinine Andrade et al, 2022;Angeloni, Nzekoue, et al, 2020;García-Roldán et al, 2023;Ho et al, 2020;López-Barrera et al, 2016;Ramón-Gonçalves et al, 2019;Zengin et al, 2020Angeloni, Nzekoue, et al, 2020Bresciani et al, 2014;…”

Brewer’s Spent Grain, Coffee Grounds, Burdock, and Willow–Four Examples of Biowaste and Biomass Valorization through Advanced Green Extraction Technologies

“…Besides lignin, cellulose, hemicellulose, and other polysaccharides [ 39 ], the recovery of the lipid fraction is of primary interest for this type of raw material. Compounds such as triacylglycerols (TAGs), diacylglycerols (1,2 DAGs), diterpene alcohol esters, fatty acids, sterols, caffeine cafestol, and kahweol [ 40 , 41 , 42 , 43 ] have an impact on human health and have been studied regarding their relation to anticarcinogenic [ 43 ] and antioxidant effects [ 44 , 45 ].…”