Preliminary study of cocoa powder's polyphenol extraction by food grade solvent

Abstract

Cocoa contains polyphenol substances, namely flavan-3-ols, i.e. catechin, epicatechin, and proanthocyanidin. Its polyphenol antioxidant activity is larger than that of other sources, like green tea, apple, etc. Polyphenol of cocoa can be extracted from cocoa powder which is defatted partially by mechanical pressing (mechanical defatting) before, so that there is little of cocoa fat which still presence in cocoa powder by approximately 11% (w/w). However, the fat has characteristic as interference of polyphenol extraction. Generally, the non-food grade non-polar solvent are used to take the fat before extracting polyphenol, i.e. hexane, petroleum ether, and etc. By the research, it was studied about directly extraction of partially defatted cocoa powder's polyphenol by food grade solvent without defatting process previously. The chosen solvent comprised water, acidified water (citric buffer), 50% ethanol, and 80% ethanol. Besides it, the study was also focused on extraction temperature that varied in room temperature (22°C) and 50°C. The parameter evaluated in this study were total phenolic content (TPC) and antioxidant activity expressed as antiradical power (ARP). The results showed the directly extraction of polyphenol consists of steps, i.e. extraction, centrifugation, first filtering, chilling, and second filtering. The highest of total phenolic content (TPC) was obtained from extraction conducted by 50% ethanol at temperature of 50°C and the highest antiradical power was obtained from extraction conducted by 50% ethanol at temperature of 22°C.