Chocolate version 2.0

Exploiting the flavour potential of cocoa (Theobroma cacao L.) genetic resources- An update

N.A. Ali, G.S.H. Baccus-Taylor, D.A. Sukha and P. Umaharan, 2015.

Edited by Dr. Marissa Moses and Dr. Lambert Motilal (Cocoa Research Centre, The UWI St. Augustine Campus) of a Paper presented at the International Fine Cocoa Innovation Centre Conference & Symposium, Trinidad and Tobago, March 23-24, 2015.

Micro fermentation toolkits: exploiting the flavour potential of the bean.

A leading communications giant announces that there is soon to be a cellular upgrade. Overnight, the tech world is whipped into an excited frenzy and by the next day, persons eagerly jostle for position in front the nearest electronic store to make their purchase. Current research at the Cocoa Research Centre (CRC) is poised to do the same for the chocolate industry, as new niche and ultra niche markets are being crafted to delight the taste buds of chocolate aficionados, and anyone clamouring to have a unique taste experience of their favourite confectionery.

Flavour is indeed a multifaceted characteristic for any food product and chocolate is no exception. According to work done at the CRC, the flavour profile of cocoa depends on the complex interplay between genotype, environment and postharvest processing, such as the fermentation step (Figure 1). It is during the fermentation process that the true flavour of the bean is brought forward as fermentation removes undesirable flavours (bitterness and astringency) and improves desirable flavours (e.g. fruity, floral, nutty, caramel). Therefore, improved fermentation manipulation can potentially exploit the inherent diversity in bean chemical characteristics, towards optimising the expression of intrinsic flavour potential.

In 2012, a project entitled Leveraging the International Cocoa Gene Bank to Improve Competitiveness of the Cocoa Sector in the Caribbean Using Modern Genomics was initiated by the CRC with support from The University of the West Indies-Trinidad and Tobago Research and Development Impact Fund. Objectives of the study include determining fermentation requirements and distinctive flavour attributes for six of the identified genetic clusters (Amelonado, Contamana, Iquitos, Marañon, Nacional and Nanay) and two hybrids (Trinitario and Refractario). The intention of this ongoing study is not to generate fixed recipes for fermenting the groups but rather to provide information about the potential of each group in terms of flavour. These will be presented in the form of simplified models for dissemination.

In the experiment, sensory assessment of sampled beans after 4, 6 and 8 days of fermentation (5 replicates per sample), for 13 flavour attributes were conducted. Scores for cocoa, fruity and floral flavour, for the 8 genetic clusters reveal trends which may help us to decide on optimum endpoints for fermentation. For example, the Marañon genetic group had highest average cocoa and fruity scores on Day 4, but highest floral score on Day 8 (Figure 2). This suggests that different end points maybe obtained at different fermentation times.

Figure 1: Fermentation of beans in wooden box

Figure 1: Fermentation of beans in wooden box

 

Figure 2. Evolution of flavour attributes of interest in Marañon with fermentation time

Figure 2. Evolution of flavour attributes of interest in Marañon with fermentation time

The flavour attributes of each of the genetic groups are currently being retested over a four year period. It is hoped that this research translates into the production of micro fermentation toolkits which cocoa processors can use to make products with a wider spectrum of flavour attributes; showcasing and celebrating the diversity of the cocoa bean.


To learn more about this topic we recommend:

  1. Motamayor, J.C., Lachenaud, P., e Mota, J.W.D.S., Loor, R., Kuhn, D.N., Brown, J.S. and Schnell, R.J. (2008). “Geographic and genetic population differentiation of the Amazonian chocolate tree (Theobroma cacao L).”PLoS One, 3(10), p.e3311.
  2. Sukha, D.A., Butler, D.R., Comissiong, E.A. and Umaharan, P. (2014). “The impact of Processing Location and Growing Environment on flavor in cocoa (Theobroma cacao L.) – implications for “Terroir” and Certification – Processing Location study.” In:III International Conference on Postharvest and Quality Management of Horticultural Products of Interest for Tropical Regions. Port of Spain, Trinidad and Tobago: Acta Horticulturae. (International Society for Horticultural Science) 1047, 255-262.
  3. Sukha, D.A., Butler, D.R., Umaharan, P. and Boult, E. (2008). “The use of an optimised organoleptic assessment protocol to describe and quantify different flavour attributes of cocoa liquors made from Ghana and Trinitario beans.”European Food Research and Technology, 226(3), pp.405-413.