Beverage quality and biochemical attributes of arabusta coffee (C. arabica L. x C. canephora Pierre) and their parental genotypes

Arabica coffee (Coffea arabica L.) is known for the production of high quality beverage while Robusta coffee (Coffea canephora Pierre) has been characterized as a neutral, weak flavored and occasionally with strong acid and pronounced bitterness. Viable and reasonably fertile interspecific hybrids can easily be obtained from crosses between the allotetraploid C. arabica L. and induced autotetraploid forms of C. canephora P. This study was carried out to determine beverage quality characteristics and biochemical components of 15 coffee genotypes, nine of them being interspecific Arabusta F1 hybrids. Beverage quality was determined by a panel of six judges using the prescribed sensory evaluation procedures, while caffeine, oil, trigonelline, total chlorogenic acids (CGA) and sucrose were analyzed in green coffee samples using recommended methodologies. The results indicated significant (p<0.05) variations among the genotypes for all the sensory attributes. The total score, which is a reflection of the broad coffee quality performance showed that SL34 and SL28 (which served as reference in sensory quality), were not significantly different from Arabusta hybrids SL34 x UT8, SL28 x UT8, N39 x UT8, SL34 x UT6, CaturraxUT6 and SL28 x UT6. The quality of some Arabusta hybrids was found to be similar to that of pure Arabica genotypes. Similarly, biochemical variables revealed significant (p<0.05) variations for caffeine, oil and sucrose, among genotypes except for CGA and trigonelline which were not significantly different. There were positive significant correlations between all the sensory characteristics. Sucrose showed significant (P<0.05) correlations with fragrance flavour, aftertaste and overall. Trigonelline showed a significant negative correlation with body and caffeine. All the Arabusta hybrids scored specialty grade (80 points and above for total score) and therefore future studies on their performance in many locations with more variable climatic conditions is recommended.   Key words: Coffee, Arabusta, F1 interspecific hybrids, sensory variables, biochemical components.