Analysis of volatile compounds of five varieties of Maya cocoa during fermentation and drying processes by Venn diagram and PCA

Abstract

Fermented cocoa beans can be described as a complex matrix that integrates the chemical history of beans, their processing, and environmental factors. This study presents an analysis that aims to identify volatile compounds of five varieties of fine-aroma cocoa types. The cocoa types studied were Carmelo, Rojo Samuel, Lagarto, Arcoiris, Regalo de Dios, that grow in the Maya lands of Chiapas, Mexico. Profile of volatile compounds was obtained from each cacao type during fermentation and drying process. This profile of volatile compounds also was compared with beans unfermented, using a statistical analysis of Venn diagram and a multivariate Analysis of Principal Components (PCA). One hundred nine different compounds were identified by SPME-HS GC-MS, these compounds mainly related to desirable aromatic notes generated by esters, aldehydes, ketones, and alcohols. The differences in chemical composition of the volatile compounds were associated mainly with the process and not to cocoa varieties. Fermented dry cocoa beans showed a higher content of esters, aldehydes, pyrazines, alcohols, some acids, and furans where Lagarto (CL), Rojo Samuel (CR), and Regalo de Dios (TRD) cocoas type showed a more interesting aromatic profile. On the other hand, as expected dry unfermented cocoas presented a few numbers of aroma compounds, in the five cacao types, where alcohols, ketones and hydrocarbons predominated.

Keywords: 2-Heptanone (PubChem CID: 8051); 2-Methylbutanal (PubChem CID: 7284); 2-Nonanone (PubChem CID: 13187); Acetophenone (PubChem CID: 7410); Benzeneacetaldehyde (PubChem CID: 998); Benzonitrile (PubChem CID: 7505); Cocoa beans; Criollo and Trinitario; Fermented and unfermented; Furfural (PubChem CID: 7362); Isobutyl benzoate (PubChem CID: 61048); Trimethylpyrazine (PubChem CID: 26808); Volatile profile, aromatic quality; β-Myrcene (PubChem CID: 31253).