Published November 30, 2023 | Version v1
Publication Open

Decoding the fine flavour properties of dark chocolates

  • 1. Zurich University of Applied Sciences (ZHAW), Wädenswil, Switzerland
  • 2. Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM), Freising, Germany


The demand of consumers for high quality chocolate, organic cocoa and bean-to-bar products is increasing. This led to a higher share of fine or flavour cocoa and a higher production of bean-to-bar chocolates that are made of cocoa beans of defined variety and origin. These chocolates differentiate themselves from the mass market products by their unique flavour properties. The diversity of cocoa flavours is well described on a sensory level. On the molecular level, the flavour of cocoa and chocolate has generally been well studied and different types of off-flavours have already been elucidated on the molecular level. However, the molecular background of specific fine flavour attributes such as fruity, floral, and cocoa-like is still not fully understood.

Therefore, the aim of this investigation was to decode specific fine flavour properties of dark chocolates. For this reason, chocolates made from reference liquors of the Cocoa of Excellence Programme were analysed for their molecular composition. The liquors were very distinct in certain flavour attributes and referenced with flavour properties such as fruity, floral, or cocoa-like. After the screening for odour-active molecules by means of aroma extract dilution analysis (AEDA), selected flavour compounds were quantified in the chocolates with the overall aim to decode the fine flavour properties on the molecular level. 

In summary, acidic and fruity flavour notes were associated with high dose over threshold factors (DoT factors) of acetic acid and fruity smelling esters with the main contribution of ethyl 2-methylbutanaote, ethyl 3-methylbutanoate, and 3-methylbutyl acetate. Cocoa-like and roasty flavour notes were associated with high DoT factors of 2-methylbutanal, 3-methylbutanal, 4-hydroxy-2,5-dimethylfuran-3(2H)-one, and dimethyltrisulfane. The floral and astringent flavour properties were linked to high DoT factors of (−)-epicatechin, procyanidin B2, procyanidin C1, and 2-phenylethan-1-ol. The acquired knowledge of the molecular background of specific cocoa fine flavour attributes provides a basis for future quality assessment of cocoa and chocolate and the development of standardised training samples for sensory evaluation of cocoa products. 

Keywords: molecular flavour compositions, stable isotopically substituted odorants, dark chocolates, sensory references, fine flavour properties