Influence of hydrothermal process on bioactive compounds extraction from green coffee bean

Abstract

Abstract This study reconnoiters the influence of subcritical water hydrolysis (SCWH) to recover bioactive substances rich soluble coffee extract (CE) from five types of raw coffee beans obtained from different geographical origins. The SCWH was conducted at a temperature of 180–220 °C and pressure of 30–60 bar. The extracts were evaluated for total phenolic content (TPC), total flavonoids content (TFC), individual phenolic acid content. Moreover, the extracts were evaluated for their antioxidant, antimicrobial and antihypertensive activity. The TPC and TFC ranged from 120.4 to 144.4 mg GAE/g and 15 to 43 mg/g catechin equivalent respectively. Chlorogenic acid found to be the dominant phenolic acid in all tested samples. The extracts showed high antioxidant and antimicrobial activity. Furthermore, the CE showed good in vitro antihypertensive activity with IC 50 values ranged from 1.989 to 2.562 mg/mL of lyophilized CE. CE from Coffea canephora showed better bio-functionality than that of Coffea arabica in all tested assays. Industrial relevance Recently, natural antioxidants and antimicrobial agents getting momentum in replacing their synthetic counterparts as the later have speculations to create health complications. Phenolic compounds from natural resource have a potential to replace synthetic preservative. However, extraction techniques to recover the phenolics from their sample matrix have significant impact on the yield, quality and economic feasibility in industrial application. In this study, we have showed a novel approach to extract bioactive compounds from raw coffee bean using subcritical water hydrolysis. The outcomes of the study demonstrated that, SCWH can be employed as green and an efficient extraction technique for production of soluble CE that might have a potential application in food and related industries.