Steam pressure treatment of defective Coffea canephora beans improves the volatile profile and sensory acceptance of roasted coffee blends

Abstract

Between 15 and 20% of Brazilian coffee production corresponds to defective beans (PVA), which decreases the quality of the coffee brew. Steam treatment has been reported as an alternative to improve the volatile profile and cup quality of coffee. The aim of this study was to propose a steam treatment of defective Coffea canephora beans to improve the volatile profile of the roasted coffee. The sensory impacts of adding steamed coffee (SC) in Coffea arabica blends were evaluated. The steam treatments studied modified the volatile profile of roasted SCs, increasing the contents of acetoin, benzyl alcohol, maltol, 2,6-dimethylpyrazine, 2-furfurylthiol, and 5-methylfurfural and decreasing the contents of 4-ethylguaiacol, isovaleric acid, methional, 2,3-diethyl-5-methylpyrazine, and 3-methoxy-3-methylpyrazine. Among the evaluated parameters, the best condition to maximized the content of the volatiles with a potential positive impact and minimize those with a potential negative impact was 5bar/16min (SC 5). The thresholds of consumer rejection and of detection indicate that up to 30% SC 5 can be added to a high cup quality Coffea arabica coffee without perception or rejection of the coffee brew. A blend of 30% of SC 5 and 70% of Coffea arabica was well accepted.

Keywords: 2,3-Pentanedione (PubChem CID: 11747); 2-Furfurylthiol (PubChem CID: 7363); 3-Methylbutanal (PubChem CID: 11552); Acetic acid (PubChem CID: 176); Acetoin (PubChem CID: 179); Black; Coffee brew; Dimethyldisulfide (PubChem CID: 12232); Furfuryl acetate (PubChem CID: 12170); Immature; PVA beans; Phenylethyl alcohol (PubChem CID: 6054); Pyridine (PubChem CID: 1049); Roasted and ground coffee; Sour; Vanillin (PubChem CID: 1183).