Quantitative Measurement of the Chemical Composition of Fatty Acid of Cocoa Butter and the Isotopic Content of Glycerol Contained in Cocoa Butter by the NMR ~(13)C from the INEPT Sequence and Characterization of the Geographical Origin of the Cocoa

摘要

The determination of the chemical composition of cocoa butter and the isotopic contents of the carbons (C-2, C-l and C-3) of the glycerol contained in the cocoa butter were measured by the NMR-~(13)C from the INEPT sequence. This technique has already been applied to triglycerides of animal origin. Thus, cocoa butter is made up of nearly 66 saturated fatty acid composed mainly of stearic acid and palmitic acid. Monounsaturated fatty acids represented by oleic acid have an average content of 31 and polyunsaturated fatty acids represent less than 4. Likewise, the isotopic contents of the glycerol of the triglycerides of cocoa butter in ~(13)C of the carbons C-2, C-l and C-3 were measured directly and values vary from-llo to-19o for the C-2 and from-39o to-41o for all C-l and C-3 because of the symmetry of glycerol.