Influence of genotype and environment on coffee quality

•Key biochemical components of coffee seeds are described.•Genetic and environmental regulation of coffee metabolism and quality is reviewed.•Higher Arabica quality is controlled by genetic differences in coffee metabolism.•Shade improves coffee quality by regulating accumulation of key compounds.•Genomic analysis of environmental impact on coffee quality is illustrated.

BackgroundCoffee is one of the most valuable commodities exported worldwide. Greater understanding of the molecular basis of coffee quality is required to meet the increasing demands of consumers. Genotype and environment (G and E) have been shown to influence coffee quality. Analysis of coffee metabolism, the genes governing the accumulation of key components and the influence of environment on their expression during seed development supports the identification of the molecular determinants of coffee quality.Scope and approachThe metabolism of important biochemical components of the coffee bean: caffeine, trigonelline, chlorogenic acids sucrose and lipids in coffee was reviewed. Analysis focused on how coffee metabolism was regulated by G and E throughout seed development and evaluation of transcriptome studies as an effective tool for use in understanding this system.Key findings and conclusionsAn overview of metabolism of the key components of coffee identified critical metabolic steps regulating the final concentration of metabolites that determine coffee quality. Coffee metabolism is influenced by both G and E and explains the higher quality of Arabica when compared to Robusta as well as the improvement of coffee quality by shade. Interaction of G and E (G × E) also contributes to quality. However, coffee metabolism is still not fully understood and there is scope for further studies to explain the contributions of G, E and G X E.