Physical Quality Analysis of Roasted Arabica Coffee Beans Subjected to Different Harvesting and Postharvest Processing Methods in Eastern Ethiopia

Abstract

Improper pre and postharvest processing practices are among the factors that has been directly or indirectly affecting the physical quality of green and roasted coffee beans. Thus, comprehensive information on the effect of harvesting and postharvest processing methods and their interaction on physical roast coffee bean quality are very crucial. From this point of view, this study was conducted to evaluate the effect of harvesting and postharvest processing methods on the physical quality characteristics of roasted coffee beans. The coffee samples were prepared from one Hararghe coffee genotype (H-622/98) at Mechara Agricultural Research Center. The experiment was designed as a factorial combination of two harvesting (selective and strip harvesting) and six postharvest processing methods (dry processed dried on bare, cemented and plastic sheet ground floor, and dry, wet and semi-washed processed dried on raised mesh wire) in CRD with three replications. The results indicated that the main of effect of harvesting and postharvest processing methods was highly significantly influenced all physical roast quality attributes whereas their combined effects was highly significantly affected roast volume change and bulk density of roasted bean. Selective harvesting was better than strip harvesting in producing low roast weight loss and volume change. Selective harvesting coupled with dry processing and drying on raised mesh wire was best in producing roast coffee beans with lowest (55%) roast volume change and highest (0.41 g/ml) bulk density of roasted bean. Variation on roast physical properties of Arabica coffee due to different harvesting and postharvest processing methods was profound for coffee quality. The result can be used to improve cup quality of Arabica coffee directing at different harvesting and postharvest processing methods.

Keywords: roast coffee beans; physical quality; weight loss; volume change; bulk density