Identification of important fine flavor components in two genotypes of the chocolate tree

FSMI 2013

Vortrag von D. Kadow, 19.02.2013

Daniel Kadow 1*, Joerg Bohlmann 2, Wilberth Phillips 3 and Reinhard Lieberei 1

1 University of Hamburg, Biocenter Klein Flottbek, Ohnhorststr. 18, 22609 Hamburg, Germany
2 University of British Columbia, Michael Smith Laboratories, 321 - 2185 East Mall, Vancouver B.C., Canada V6T 1Z4
3 Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), 7170 Cartago, Turrialba 30501, Costa Rica

Cocoa seeds (Theobroma cacao L.) are the key raw material in chocolate manufacturing. Depending on the variety traders separate them into bulk and fine or flavour cocoa. The latter is characterized by the presence of special aroma notes (e.g. fruity and floral). Fine cocoa is of higher value than bulk cocoa. In contrast to chocolate aroma that derives from seed endogenous components (storage proteins and carbohydrates) fine aroma has been linked to the fruit pulp surrounding the seeds. Apparently, the respective components permeate into the seed tissue during the post harvest treatment that the seeds undergo in the countries of origin. However, detailed information on the molecular background of fine flavour is lacking.
In the present study we analyzed fruit pulp and seeds of two fine or flavour cocoas (SCA 6 and EET 62) with defined organoleptic properties and a bulk cocoa (CCN 51) using GCMS.
β-myrcene, β-trans-ocimene, β-cis-ocimene and β-linalool were characteristic for the SCA 6 volatile composition. Regarding EET 62 2-heptanol, 2-heptanol acetate, 2-heptanone and 2-nonanone were typical. We conclude that these molecules are important components of SCA 6 and EET 62 fine aroma. Accordingly, fine aroma components apparently derive from different metabolic pathways depending on the genotype. Thus, these traits may be integrated into breeding concepts.