Differentiation of cocoa nibs from distinct origins using comprehensive two-dimensional gas chromatography and multivariate analysis

Author(s)

Oliveira, Luciana F. ; Braga, Soraia C. G. N. ; Augusto, Fabio ; Hashimoto, Juliana C. ; Efraim, Priscilla ; Poppi, Ronei J.

• Document type: Journal article
• Source: Food Research International; v. 90, p. 133-138, DEC 2016.
• Web of Science Citations: 13

Abstract

Headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography was used for identification of volatiles compounds responsible for differentiation between cocoa nibs from Brazil and Ivory Coast. The unfolded GC x GC with Flame Ionization Detector (FID) chromatograms were first aligned using the correlation optimization warping (COW) algorithm and normalized. After that, Fisher ratio was calculated for each variable, and a threshold value was chosen-to select the variables that best promote a separation of nibs samples from different sources in a principal component analysis (PCA) model. To identify the relevant compounds for the separation, representative samples of each source were analyzed in the same conditions by GC x GC with detection by quadrupole mass spectrometry. Finally, the average peak volumes for each key compound obtained for both classes were compared using a Student t-test and it was possible to identify 15 volatile compounds responsible for differentiation between cocoa nibs from Brazil and Ivory Coast. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 12/14695-8 - Utilization of chemometric methods in comprehensive two-dimensional gas chromatography for evaluate cocoa, its derivatives and carob
• Grantee: Luciana Fontes de Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate