On Saturday, November 6, 2021, the Coffee, Tea, and Cocoa Processing Technology course of the UGM TPHP Department held a guest lecture on the topic “Alkalization of Cocoa Nibs, Mass, and Cake Processes”. The guest lecture was delivered by Drs. Purwo Susanto, who is the author of the book Cocoa and Chocolate Production Technology. The guest lecture, which took place from 09.00-11.00 WIB, was conducted through the Zoom platform and moderated by Dr. Ir. Supriyadi, M.Sc., lecturer of TPHP UGM.
Alkalization is the process of adding alkali to cocoa nibs, mass, and cake to raise pH, give color, and improve product solubility. Alkaline materials that can be used are Potassium bicarbonate, Potassium carbonate, Ammonium bicarbonate, etc.
Alkalizer is an important tool in making cocoa powder because it can produce various colors. The use of an alkalizer is most widely applied to nibs alkalization because it can make cocoa powder brown, red, to darker colors.
The alkalization process on cocoa nibs was originally intended to make cocoa and chocolate together because the process is the same, making the process flow simpler. The changes that occur after alkalization include: better solubility of cocoa powder due to the formation of ester bond compounds and hydrolysis of cocoa bean cell walls by the alkaline solution; during fermentation, the color of cocoa beans will change from slaty to purple and then brown; the acidity of cocoa is reduced from 60% to 30% and glycosylated flavanols are formed which causes the bitter taste to disappear and the glycation reaction reduces astringency.
Alkalization of cocoa liquor is done with an alkaline solution that has a lower water content than that of cocoa nibs. There are two processes for cocoa liquor alkalization: batch process where the alkaline solution is added to the tank and heated and stirred for 8 hours and flash process where the alkaline solution is added to the mass flow continuously but this process is not applicable for red cocoa color.
Cocoa cake alkalization is usually done with the addition of Ammonium bicarbonate, Potassium bicarbonate, and Iron oxide or Iron tartrate. The advantage of cake alkalization is that it produces better cocoa butter, while the disadvantages are that the taste is not as good as nibs alkalization and it requires a lot of energy to crush the cake. The color of the alkalized cake is light brown to dark black.
Video of the Guest Lecture on Coffee, Tea, and Cocoa Processing Technology can be accessed through the following link
[embedyt] https://www.youtube.com/watch?v=olJ_NoCFtrk[/embedyt]
