Cocoa butter, adulteration, detection

With its development, HPLC was found to be useful in many authenticity determinations, either for the same or different components to those detected by GC. Triglycerides were the most immediate application. With the exception of milk fat, now that the major components of commercial fats can be completely separated by HPLC, the patterns of components can be analysed to detect adulteration. Cocoa butter adulteration with palm fractions can be detected by the presence of excess monounsaturated and diunsaturated components from the palm fraction, while more sophisticated products may be detected by measuring dipalmitoyl-monooleoyl glycerol (POP), palmitoyl-oleoyl-stearoyl glycerol (POS) and distearoyl-monooleoyl glycerol (SOS) components. In other oils, apart from the pattern of components, the presence of any significant level of... 

Much of the sterol component of shea butter is present as esters of cinnamic acid, which are less readily saponified than esters with glycerol (Peers, 1977) published data for this fat might therefore underestimate the hue value. Surprisingly measurement of cinnamic acid has not been used to test for the presence of shea butter in mixtures. Triterpene alcohols similar to those found in shea also occur in sal fat. Homberg and Bielefeld (1982) showed the presence of triterpene alcohols in illipe and sal fats and in commercial CBEs, and their analysis was proposed as a qualitative measure to detect cocoa butter adulteration. 

When the composition of the cocoa butter glycerides is expressed in terms of carbon number, as determined by GLC, a straight-line relationship between the C50 and C54 triglycerides is observed and this can be used to detect adulterated cocoa butters (Padley and Timms, 1980 Fincke, 1980). 

Detection of adulterations and contaminations. TLC on normal silica plates has been used to detect adulteration of cocoa butter by kokum butter. Deotale, Patil and Adinarayaniah (1990) have found that kokum butter (a cocoa butter substitute) appeared as a bluish green spot under UV light and... 

Plant lipids contain 0.15-0.9% sterols, with sitosterol as the main component (Table 3.52). In order to identify blends of fats (oils), the data on the predominant steroids are usually expressed as a quotient. For example, the ratio of stigmas-terol/campesterol is determined in order to detect adulteration of cocoa butter. As seen from Table 3.53, this ratio is significantly lower in a number of cocoa butter substitutes than in pure cocoa butter. The phytosterol fraction (e. g. sito- and campesterol) has to be determined in order to detect the presence of plant fats in animal fats. 

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