a b s t r a c t
Tangential filtration technique was used to separate and quantify three different fractions of nitrogenous
compounds depending on their molecular size, during cocoa fermentation. On every phenotype and origin
analyzed, protein profile of non-fermented samples was similar. During fermentation course, proteins
get degraded with a concomitant increase in amino acids content. Peptides between 3 and 10 kDa were
observed at low levels. A strong correlation between amino acids and ammonia nitrogen, a fermentation
marker was found. Attention was drawn on each fraction, and enabled to point out other phenomenon
occurring during fermentation. The migration of some nitrogenous compounds towards the bean shell
during fermentation was demonstrated. Acetone treatment of cocoa powder prior to SDS–PAGE led to
losses of nitrogenous compounds. This result gives clues on the tanning phenomenon carried out by
polyphenols on nitrogenous compounds, phenomenon which increases during fermentation.