Composition of methylxanthines, polyphenols, key odorant volatiles and minerals in 22 cocoa beans obtained from different geographic origins

Twenty-two cocoa bean samples were collected from different geographic origins of Indonesia. The composition of methylxanthines, polyphenols, key odorant volatiles, and minerals in the samples were quantified to better understand the quality variation of the beans. The results revealed great diversity in chemical composition of these beans. Unfermented cocoa beans were rich in methylxanthines and polyphenols but had low amounts of key odorant volatiles. Fermented samples shared similar characteristics (less bioactive compounds and abundant key odorant volatiles) regardless of their geographic origins. The origins of the samples could not be determined using the results of bioactive compounds and key odorant volatiles probably due to the influence of post-harvest processing. Separation of samples based on their fermentation degree (under-fermented and fermented samples) during principal component analysis (PCA) improved the accuracy of the determination of geographic origins. The origin of cocoa beans could be delineated by PCA using mineral composition data of the fermented samples.

Automated summary

This study analyzed 22 cocoa bean samples from different geographic origins of Indonesia, revealing great diversity in their chemical composition. Unfermented cocoa beans were rich in methylxanthines and polyphenols but had low amounts of key odorant volatiles, while fermented samples shared similar characteristics with abundant key odorant volatiles. Mineral composition data of fermented samples could be used to delineate the origin of cocoa beans through PCA.