Profiling, quantification and classification of cocoa beans based on chemometric analysis of carbohydrates using hydrophilic interaction liquid chromatography coupled to mass spectrometry

Fifty-six cocoa bean samples from different origins and status of fermentation were analyzed by a validated hydrophilic interaction liquid chromatography-electrospray ionization-time of flight-mass spectrometry (HILI-CESI-TOF-MS) method. The profile of the low molecular weight carbohydrate (LMWC) was analyzed by high resolution and tandem mass spectrometry, which allowed the identification of mono-, di-, tri- and tetrasaccharides, sugar alcohols and iminosugars. This study provides, for the first time in a large set of samples, a comprehensive absolute quantitative data set for the carbohydrates identified in cocoa beans (fructose, glucose, mannitol, myo-inositol, sucrose, melibiose, raffinose and stachyose). Differences in the content of carbohydrates were observed between unfermented (range of 0.9-4.9 g/g DM) and fermented (range 0.1-0.5 g/g DM) cocoa beans. The use of multivariate statistical tools allowed the identification of biomarkers suitable for cocoa bean classification according to the status of fermentation, procedure of fermentation employed and number of days of fermentation.