Thermal properties and volatile compounds profile of commercial dark-chocolates from different genotypes of cocoa beans (Theobroma cacao L.) from Latin America

S J Calva-Estrada; M Utrilla-Vázquez; A Vallejo-Cardona; D B Roblero-Pérez; E Lugo-Cervantes

doi:10.1016/j.foodres.2020.109594

Thermal properties and volatile compounds profile of commercial dark-chocolates from different genotypes of cocoa beans (Theobroma cacao L.) from Latin America

Food Res Int. 2020 Oct:136:109594. doi: 10.1016/j.foodres.2020.109594. Epub 2020 Jul 25.

Authors

S J Calva-Estrada¹, M Utrilla-Vázquez¹, A Vallejo-Cardona², D B Roblero-Pérez¹, E Lugo-Cervantes³

Affiliations

¹ Unidad de Tecnología Alimentaria, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco (CIATEJ) A.C., Camino Arenero 1227, El Bajío, C.P. 45019 Zapopan, Jalisco, Mexico.
² Unidad de Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C., Av. Normalistas 800, Colinas de la Normal, C.P. 44270 Guadalajara, Jalisco, Mexico.
³ Unidad de Tecnología Alimentaria, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco (CIATEJ) A.C., Camino Arenero 1227, El Bajío, C.P. 45019 Zapopan, Jalisco, Mexico. Electronic address: elugo@ciatej.mx.

PMID: 32846619
DOI: 10.1016/j.foodres.2020.109594

Abstract

There is a growing interest in the identification of chemometric markers that allow the distinction and authentication of dark-chocolates according to their cocoa geographical origin and/or genotype. However, samples derived from Latin American cocoa, including specimens from North and South America, have not been studied in this context. An exploration of the melting behavior, fat composition, bioactive content, and volatile profile of commercial darkchocolates was conducted to identify possible patterns related to the genotype and/or origin of cocoa from Latin America. The melting properties were evaluated by DSC and related to fat content and fatty acids profile. Total polyphenol, anthocyanin, methylxanthine, and catechin content were analyzed. Finally, the volatile compounds were extracted and identified by HS-SPME/GC-MS and were analyzed through Principal Component Analysis (PCA) and the Hierarchical Cluster Analysis Heatmap (HCA Heatmap). The fatty acids profile showed a relationship with the melting properties of dark chocolate. The samples exhibited two glass-transition temperatures (T_g) at ≈19 °C and ≈25.5 °C, possibly related to traces of unstable polymorphic forms of monounsaturated triacylglycerides. The analysis of bioactive compounds demonstrated great variability among samples independent of the cocoa origin, genotype, and content. The PCA and HCA Heatmaps allowed discriminating against the chocolates in relation to the cocoa origin and genotype. Compounds like tetramethylpyrazine, trimethylpyrazine, benzaldehyde, and furfural could be considered as dark-chocolate aroma markers derived from Latin American cocoas (North American region). The 2-phenylethyl alcohol, 2-methylpropanoic acid, 2,3-butanediol, 2-nonanone, and limonene for derived from South America. And the 2-phenylethyl acetate, 3-methyl-butanal, and cinnamaldehyde could allow to distinguishing between regional genotypes.

Keywords: 2,3-Butanediol (PubChem CID 262); 2-Methylpropanoic acid (PubChem CID 6590); 2-Nonanone (PubChem CID 13187); 2-Phenylethyl acetate (PubChem CID 7654); 2-Phenylethyl alcohol (PubChem CID 6054); 3-Methyl-butanal (PubChem CID 11552); Benzaldehyde (PubChem CID 240); Chemometrics; Differential scanning calorimetry; Furfural (PubChem CID 7362); Hierarchical cluster analysis heatmap; Polymorphism; Principal component analysis; Tetramethylpyrazine (PubChem CID 14296); Trimethylpyrazine (PubChem CID 26808).

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cacao*
Chocolate*
Genotype
Latin America
South America