Scientific research

Samples (54) of dried fermented cocoa beans from different world regions were analysed for levels of organic acids, pH and titratable acidity. The effects of the organic acids on the flavour characteristics of cocoa were examined by sensory evaluation of chocolate made from samples of cocoa beans. Concentrations (g/kg) of acids ranged from 1.3 to 11.8 for acetic, 1-6 to 9-9 for citric, 0.6 to 11.1 for lactic and 2.1 to 6.5 for oxalic. pH values ranged from 4.6 to 5.8, while titratable acidity ranged from 0.08 to 0.31 equivalents of sodium hydroxide per kg sample. Cocoas from South East Asia and the South Pacific tended to be more acidic than West African beans in terms of both chemical and sensory characteristics. Lactic and acetic acids were found to be in greater concentrations in cocoas from the former regions and were considered to be largely responsible for higher acid flavour scores. In contrast, citric and oxalic acids were generally lower in these beans. Flavour assessments of cocoas with and without added organic acids indicated that oxalic acid played an important role in chocolate flavour. These results suggest that a reduction in the levels of acetic and lactic acids only, may not be sufficient to produce a desirable flavour balance.