title: Effect of shading on yield, sugar content, phenolic acids and antioxidant property of coffee beans (Coffea Arabica L. cv. Catimor) harvested from north-eastern Thailand.
abstract: BACKGROUND
  Environmental conditions, including shading, generally influence the physical and chemical qualities of coffee beans. The present study assessed the changes in some phenolic compounds, antioxidant activity and agronomic characters of coffee beans (Coffea arabica L. cv. Catimor) as affected by different shading conditions including full sun, three artificial shading conditions using a saran covering (50% shade, 60% shade, and 70% shade) and lychee shade.
  
  
  RESULTS
  Bean weight and bean size increased significantly (P < 0.05) when the shade level was progressively increased. The coffee beans grown under lychee shade exhibited superior bean yield, 1000-bean weight, total phenolic content and antioxidant activity compared to all other beans. Chlorogenic acid was the most predominant phenolic acid in all samples studied, being the highest in the beans grown under lychee shade, followed by 60% shade, 70% shade, 50% shade and full sun, respectively. In contrast, bean grown under full sun had the highest amount of vanillic acid and caffeic acid.
  
  
  CONCLUSIONS
  Antioxidant activity was highly positively associated with chlorogenic acid content. The content of total sugar (fructose, glucose and sucrose) was found highest in coffee beans grown in 60% shade, with fructose the predominant sugar. Under climatic conditions similar to this experiment, it is advisable that growers provide shade to the coffee crop to reduce heat from direct sunlight and promote yield as well as obtain good quality coffee beans.
authors.affiliation: Department of Horticulture Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Chanyarin
authors.initials: C
authors.lastname: Somporn
authors.forename: Amnouy
authors.initials: A
authors.lastname: Kamtuo
authors.forename: Piyada
authors.initials: P
authors.lastname: Theerakulpisut
authors.forename: Sirithon
authors.initials: S
authors.lastname: Siriamornpun
mesh_terms: D000383:Agriculture / Q000379:methods; D000975:Antioxidants / Q000494:pharmacology*; D018533:Biomass; D001713:Biphenyl Compounds / Q000378:metabolism; D002109:Caffeic Acids / Q000032:analysis / Q000494:pharmacology; D002726:Chlorogenic Acid / Q000032:analysis / Q000494:pharmacology; D040503:Coffea / Q000737:chemistry* / Q000254:growth & development; D003624:Darkness; D019422:Dietary Sucrose / Q000032:analysis*; D032125:Litchi; D010636:Phenols / Q000032:analysis / Q000494:pharmacology*; D010851:Picrates / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry* / Q000254:growth & development; D013785:Thailand; D014641:Vanillic Acid / Q000032:analysis / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002109:Caffeic Acids; D019422:Dietary Sucrose; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D002726:Chlorogenic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D014641:Vanillic Acid; C040048:caffeic acid