EXTRACTION AND FRACTIONATION OF COCOA PROTEINS AS APPLIED TO SEVERAL VARIETIES OF COCOA BEANS

Protein was extracted from cocoa [Theobroma cacao] beans with a buffer solution and separated on Sephadex LH20. After dialysis and freeze dehydration protein preparations were characterized according to solubility in different aqueous media and electrophoretic behavior on disc gels. Compared to pigmented varieties, extracts from nonpigmented beans yielded only half as much protein off the Sephadex column, and nondialyzable solids were less pure with respect to protein (60% vs. 30% protein). Electrophoresis of pigmented varieties gave 8 protein bands which were more intense and numerous than for nonpigmented types. Differences reflect protein-polyphenol interactions important to quality characteristics of chocolate, and methods used are suggested as adjuncts in breeding programs related to optimization of desirable quality characteristics.