Sensory Attributes of Coffee under Different Shade Regimes and Levels of Management

Despite coffee bean physical and beverage quality attributes being inherent factors, the environment, which includes crop management factors, can play a major role in determining their expression. This study was conducted to evaluate the effect of management and shade levels on beverage quality of coffee. The study was carried out at the Kenya Agricultural and Livestock Research Organization, Coffee Research Institute (KALRO-CRI) farm in Bungoma County, Kenya. The coffee management levels were categorized depending on field operations and application of inputs. The different shade levels were based on the distances from the trunk of shade tree and shading levels were estimated by measuring the Photosynthetic Photon Flux Density (PPFD) in µmol m-2 s-1 using a Line Quantum Sensor. The sensory characteristics fragrance/aroma, flavor, aftertaste, acidity, body, balance and overall were assessed by a panel of seven trained judges. The beverage quality, except for acidity and balance, were largely unaffected by management or shade levels, however trends showed that most of the variables, on average, had higher scores in shade than in full sun. Shade was positively correlated with all sensory variables while management was negatively correlated with all. This suggested that use of shade, under low management, could offset the limited application of external inputs to some extent. Keywords: Coffea arabica, shade, management levels and quality

Volatile Organic Compounds in Brewed Kenyan Arabica Coffee Genotypes by Solid Phase Extraction Gas Chromatography Mass Spectrometry

Besides its stimulatory effect, coffee is appreciated and/or consumed for its pleasing aroma, which is a key quality index. The objective of this study was to characterize the volatile organic compounds in brewed Kenyan Arabica coffee genotypes. Solid phase Extraction (SPE) technique was used for the extraction of the organic compounds in the brewed coffee, while characterization of the compounds was done by gas chromatography mass spectrometry (GC-MS). Various volatile organic compounds were identified and classified into alcohols, aldehydes, carboxylic acids, furans, ketones, pyrazines and pyrroles. Differences were observed in the chromatographic profiles of the eluents from the seven coffee genotypes evaluated. Compounds such as 2, 6-dimethylpyrazine,5-methyl-1H-pyrole-2-carboxyaldehyde,2-furanmethanolacetate, 4-Ethylcatechol, Methoxy-4-vinylphenol, 2,6-Dihydroxyacetophenone and Ionone, were found to be present in all the coffee genotypes. This study demonstrated the presence of appreciable levels of volatile organic compounds in the coffee brew of the genotypes studied with variations in the types and concentrations being observed among the genotypes. Keywords: Kenya, Coffee genotypes, Solid Phase Extraction (SPE), Gas Chromatography Mass Spectrometry (GC-MS) Volatile organic compounds

Coffee Leaf Rust (Hemileia vastatrix) in Kenya—A Review

Coffee is one of the most important cash crops and beverages in the world. Production of coffee is limited by many factors, which include insect pests and diseases, among others. One of the most devastating coffee diseases in many coffee-producing countries is Coffee Leaf Rust caused by the fungus Hemileia vastatrix. Kenya is a coffee-producing country and has conducted studies to understand and manage the disease. Management strategies for the disease include the development and use of fungicide spray programs, cultural control practices, breeding resistant coffee varieties, and biological control agents. This paper reviews the status of the disease and management options applied in Kenya