The influence of three different types and dosage of alkaline on the inherent properties in cocoa powder

Alkalization modifies the color and flavor of the cocoa products. The aim of the present survey was to determine how different types and dosage of alkaline relate to the color quality, total polyphenol amount and alkylpyrazine content of cocoa powder. Cameroon cacao beans were used to produce cocoa nibs. The nibs were alkalized with the solutions of NaOH, K 2 CO 3 , and NH 4 HCO 3 at their different concentrations and combinations. The browning index (OD 460 /OD 525 ) and alkylpyrazine content were changed significantly ( p ≤ 0.01) with changing the type and the concentration of the alkali solution. The browning index, moisture, ash, and acid-insoluble ash content increased as the concentration of the alkali increased. In general, the not-alkaline products had more polyphenol and ratio of tetramethylpyrazine to trimethylpyrazine than the alkalized ones. Besides, the polyphenol and alkylpyrazine amounts decreased as the concentration of the alkali increased ( p ≤ 0.01). At the same concentration, alkalization with a NaOH solution produced a higher polyphenol and alkylpyrazine content, but lower OD 460 /OD 525 value than that with a K 2 CO 3 solution. The samples with a high concentration of alkaline solution had the lowest ratio of monomer anthocyanins to yellow and brown polymers content (F 1 /F 3 ) value.