Sensory and Organoleptic Cup Attributes of Robusta Coffee (Coffea canephora Pierre ex A. Froehner)

Abstract

Coffea canephora organoleptic cup attributes are the most important factors that define its price in world markets. Determining the components that contribute to the diversity of organoleptic characters will help in the improvement of these qualities in order to obtain favourable markets. Two hundred and six genotypes from twenty one districts and two research institutes were analyzed by a three member expert panel from Uganda Coffee Development Authority using a 10 point descriptive scale and protocols from, The Coffee Quality Institute of America (CQIA). The results revealed that the evaluators’ organoleptic cup trait ratings were significantly different (p< 0.05) for all attributes, reflecting a diversity of cup interests. Four multivariate groups that were significantly different for fragrance, aroma and flavour were formed offering diverse cup tests to different markets. A variety of fine and commercial flavours were detected in ripe cherry and green roasted beans. Cup balance contributed the highest regression coefficient (R²=0.90) to overall assessment while fragrance/aroma had the least (R²=0.22). The above average rating of 75% for cup balance, flavour, mouth feel, aftertaste, fragrance and aroma revealed that Ugandan Robusta coffees were of high quality with a mild taste. The higher cup acidity among land races,‘nganda’ and ‘erecta’ genotypes revealed that genotypes with high sugars and cup acidity could be selected for from local germ-plasm. Coffee types and environmental factors such as soil texture, altitude and location influenced the content and level of organoleptic cup attributes. A diversity of flavours that exist among Uganda Robusta coffee and has so far remained unexploited, would provide new marketing channels, enhance quality and earn the country the much desired foreign exchange capital.