An investigation into green coffee press cake as a renewable source of bioactive compounds

Abstract

The residual biomass of coffee, obtained after the oil extraction from coffee beans, called coffee beans residual press cake, has been attracted interest as a source of compounds with antioxidant capacity. This study investigated the effects of ethanolic and methanol-acetone extracts of green coffee beans (GCB) and its residual press cake (GCC) on the phenolic composition and antioxidant capacity. Antioxidant capacity was assayed through five different methods (total phenolic compounds, •DPPH, ABTS, FRAP and b-carotene bleaching assay), and the phenolic profile of the samples through High Performance Liquid Cromatography. GCB and GCC enclosed chlorogenic (55.16 and 64.96 mg g À1 , respectively) and caffeic (25.07 and 44.37 mg g À1 , respectively) acids as the major components, and the cake presented higher antioxidant capacity than the actual green bean. Antioxidant capacity was higher for GCC extracted with methanol and acetone. This study on the evaluation of the effects of the type of solvent on the bioactive compounds from GCB and GCC showed that this by-product can be a source of new value-added products, such as phenolic antioxidant adjuncts for food or pharmaceutic processing.

Extraction and Chemical Characterization of Functional Phenols and Proteins from Coffee (Coffea arabica) By-Products

“…CGBs and their press cake (remaining after the extraction of the oil) have in fact been studied for the recovery of bioactive compounds, specifically polyphenols with antioxidant activity. In this case, the antioxidant capacity of the by-product was even higher than that of the green beans [ 7 ].…”

Effect of Ecofriendly Bio-Based Solvents on Oil Extraction From Green Coffee Bean and Its Industrial Press Cake

“…The green coffee oil expression operation, carried out with the aid of a screw press or expeller, is not efficient enough to completely remove oil from matrices with low oil content (< 20%) (Koubaa et al, 2016), such as green coffee beans (Farah, 2012). Besides leaving a residual oil in the meal (or press cake), a great amount of bioactive compounds may also be found in this residue, because most of the phenolic compounds are of hydrophilic nature (Oliveira et al, 2019a;2019b). According to Affonso et al (2016), coffee bean press cake is a residual biomass from the coffee bean oil extraction process, claimed to be rich in bioactive compounds of interest for human health, the food industry, and cosmetics.…”

Sustainable utilization of cold‐pressed green coffee oil and its by‐products for high‐value materials

“…As the demand for GCO has increased in the cosmetic industry, the residual press‐cake became of interest because of its antioxidant potential. Higher amounts of phenolic compounds were extracted from cake using ethanol 70% for 3 hr, then using ethanol 99% for 60 min (67.9 and 34.9 mg GAE/g, respectively) (Oliveira et al, 2019; Resende Oliveira et al, 2019). In the present study, phenolic content in cake samples ranged from 37.5 to 55.8 (mg GAE/g) extracted with ethanol 50%, interesting that defective beans showed the highest value ( p < .05) (Table 1).…”

“…These compounds have a number of beneficial health properties related to their potent antioxidant activity as well as hepatoprotective, hypoglycemic, and antiviral activities (Gawlik‐Dziki et al, 2014; Guy et al, 2009). Therefore, the press‐cake from cold‐pressed GCO has gained interest, especially with the confirmation of its high antioxidant activity (Castro et al, 2018; Resende Oliveira et al, 2019). However, there are no scientific reports on GCO pressing conditions from either regular or defective unroasted beans, as well as about the residue formed by the precipitation of finer materials from the raw oil called sediment.…”