title: Influence of growing altitude, shade and harvest period on quality and biochemical composition of Ethiopian specialty coffee.
abstract: BACKGROUND
  Coffee quality is a key characteristic for the international market, comprising cup quality and chemical bean constituents. In Ethiopia, using total specialty cup scores, coffees are grouped into Q1 (specialty 1) ≥ 85 and Q2 (80-84.75). This classification results in market segmentation and higher prices. Although different studies have evaluated the effects of altitude and shade on bean quality, optimum shade levels along different altitudinal ranges are not clearly indicated. Information on effects of harvest periods on coffee quality is also scanty. The present study examined the influences of these factors and their interactions on Ethiopian coffee quality RESULTS: Coffee from high altitude with open or medium shade and early to middle harvest periods had a superior bean quality. These growing conditions also favoured the production of beans with lower caffeine. An increasing altitude, from mid to high, at approximately 400 m, decreased caffeine content by 10%. At high altitude, dense shade decreased Q1 coffee by 50%. Compared to late harvesting, early harvesting increased the percentage from 27% to 73%. At mid altitude, > 80% is Q2 coffee.
  
  
  CONCLUSIONS
  Changes of quality scores driven by altitude, shade and harvest period are small, although they may induce dramatic switches in the fraction Q1 versus Q2 coffee. The latter affects both farmers' profits and competitiveness in international markets. © 2016 Society of Chemical Industry.
authors: College of Agriculture and Veterinary Medicine, Jimma University, PO Box 307, Jimma, Ethiopia.|Isotope Bioscience Laboratory - ISOFYS, Ghent University, Gent, Belgium, Coupure Links 653, 9000, Gent, Belgium.
authors: Kassaye
authors: K
authors: Tolessa
authors: Isotope Bioscience Laboratory - ISOFYS, Ghent University, Gent, Belgium, Coupure Links 653, 9000, Gent, Belgium.
authors: Jolien
authors: J
authors: D'heer
authors: Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Belgium, Salisburylaan 133, 9820, Merelbeke, Belgium.
authors: Luc
authors: L
authors: Duchateau
authors: Isotope Bioscience Laboratory - ISOFYS, Ghent University, Gent, Belgium, Coupure Links 653, 9000, Gent, Belgium.
authors: Pascal
authors: P
authors: Boeckx
mesh_terms: D000531:Altitude; D002110:Caffeine / Q000032:analysis; D040503:Coffea / Q000737:chemistry / Q000254:growth & development*; D003069:Coffee / Q000737:chemistry; D005002:Ethiopia; D011786:Quality Control; D012639:Seeds / Q000737:chemistry* / Q000254:growth & development; D013997:Time Factors
chemical_list: D003069:Coffee; D002110:Caffeine
keywords: Arabica coffee; altitude; caffeine; chlorogenic acid; cup quality; shade