HPTLC fingerprint profile analysis of cocoa proanthocyanidins depending on origin and genotype.

Cocoa beans are rich in bioactive phytochemicals such as alkaloids, anthocyanins, as well as monomeric and oligomeric flavan-3-ols. A high performance thin layer chromatography (HPTLC) method was developed for a fast analysis of a fingerprint of bioactive compounds present in cocoa beans depending on genotype and origin. Evaluation was performed using HPTLC followed by densitometry. The best separation for a fingerprint consisting of eight phenolic compounds as markers was achieved on silica gel 60 F HPTLC plates with a solvent mixture of ethyl formate, formic acid, water, toluene 30/4/3/1.5 (v/v/v/v). Staining with Fast Blue Salt B enabled visualization and quantitative evaluation. Compounds of interest were confirmed by eluting zones using a TLC-MS interface. LODs were ≤ 100ng/zone for all compounds. The fingerprints obtained are useful for quality control of cocoa beans allowing their differentiation according to cocoa or chocolate sorts, varieties, and origins.