Integration of GWAS, metabolomics, and sensorial analyses to reveal novel metabolic pathways involved in cocoa fruity aroma.
The biosynthesis of aroma compounds in cocoa beans is complex and its study involves many disciplines. This scientific publication uses molecular genetics to characterize the many genes involved in the biosynthetic pathways of the "fruity" type aroma compounds, which are very characteristic of the Nacional cocoa variety grown in Ecuador. These new elements can be used in the framework of selection programs for aromatic cocoa varieties, which are more profitable for small cocoa producers.
Kelly Colonges, Juan-Carlos Jimenez, Alejandra Saltos, Edward Seguine, Rey Gastón, Loor Solorzano, Olivier Fouet, Xavier Argout, Sophie Assemat, Fabrice Davrieux, Emile Cros, Claire Lanaud, Renaud Boulanger
Abstract
Nacional is a variety of cocoa tree known for its "Arriba" aroma characterized mainly by fruity, floral, and spicy aromatic notes. In this study, the genetic basis of the fruity aroma of modern Nacional cocoa was investigated. GWAS studies have been conducted on biochemical and sensorial fruity traits and allowed to identify a large number of association zones. These areas are linked to both the volatile compounds known to provide fruity flavours and present in the beans before and after roasting, and to the fruity notes detected by sensorial analysis. Five main metabolic pathways were identified as involved in the fruity traits of the Nacional population: the protein degradation pathway, the sugar degradation pathway, the fatty acid degradation pathway, the monoterpene pathway, and the L-phenylalanine pathway. Candidate genes involved in the biosynthetic pathways of volatile compounds identified in association areas were detected for a large number of associations.
Published: 19/05/2022