Cocoa butter quality

Alternative vegetable fat formulations intended legitimately to replace a small proportion of the cocoa butter in chocolate are difficult to distinguish from 

Consumer demands for more specialized chocolate products have led to some newer authenticity issues. There is a growing demand for organically farmed food products, which might be difficult to monitor in a food where the ingredients are grown at considerable distance from the site of product manufacture. Also, Theobroma cacao is prone to insect attack and disease and the benefits from the use of chemical agents are high. 

Many consumers also wish to be made aware of any genetic modification to the crop. Genetic modification might be beneficial for cocoa butter production as the characteristics of the butter could be modified in the growing bean, and also resistance to pests and diseases might be introduced to the plant. Analytical methods are required to detect such modification, in both the raw materials and the processed product. 

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There are two aspects to cocoa butter authenticity. First, the butter as sold to the trade for chocolate production may be of an inferior quality and/or identity to that claimed by the producer. In this situation the consumer will also be misled as a matter of consequence. Second, part of the cocoa butter component of chocolate may be replaced by non-cocoa fats in contravention of legislation or labelling. Whilst this is in the strictest terms an adulteration of the chocolate product the issue has long been discussed in terms of cocoa butter authenticity and will be given due attention in this chapter. 

Pino, J., Nunez de Villavicencio, M. and Roncal, E. (1993) Pattern recognition of GC profiles for classification of cocoa butter of Ghanaian and Cuban varieties. J. Food Quality, 16, 125-132. 

Shukla, V.K.S. (1995) Cocoa butter properties and quality. Lipid Technol., May, 54—57. 

Table 7 lists the oxazoles and thiazoles identified in the sample of cocoa butter. They were present only in roasted cocoa butter. The sensory characteristics of these compounds shown in Table 7 indicated that oxazoles and thiazoles possessed interesting green, fatty, sweet, and nutty sensory qualities and were high-impact flavor... 

Double Fractionation. Double fractionation is carried out for the production of palm olein with higher iodine value of above 60 or for the production of palm-midfraction (PMF), which contains a high proportion of oleodipalmitin used for production of palm-based cocoa butter equivalent (60, 61). Usually the first olein obtained is recycled back to the plant for further cooling, crystallization, and filtration. The second stearin otained is termed palmmidfraction. Special and skillful control of the crystallization of both stages is critical in achieving the desired quality of the products. 

There is a good correlation between the triacylglycerol composition and solid fat content of these cocoa butters. Malaysian, Sri Lankan, and Indian cocoa butters are the hardest, and Brazilian is the softest, whereas others lie in between. The quality of the Brazilian cocoa butter can be unproved by mixing it with Malaysian cocoa butter, which will result in higher solid fat content at various temperatures. 

At International Food Science Center, we have measured diacylglycerols levels varying between 1.5% and 2.8%. Higher diacylglycerol levels affect the crystallization of cocoa butters remarkably, and thus all efforts should be made to reduce these levels in good quality cocoa butters. 

This stearin is extremely hard and can be used effectively to improve the quality of soft cocoa. Attempts have been made to improve the quality of Brazilian cocoa butter by fractionation. 

Diamond, graphite, fullerenes and nanotubes are polymorphic forms (denoted as allotropes for elements) of carbon all exhibiting very different properties. Cocoa butter can crystallize in at least five different ways, the various crystal structures affecting the perception of the epicurean quality of the prepared chocolate, although all forms are chemically identical. 

Ccxjoa butter is the triglyceride which derives from cocoa beans it is composed of a large amount of palmitic acid on the glyceral backbone. Because of the high saturation, cocoa butter is a solid and exhibits a rather sharp melting point at about body temperature which incidentally, is partially responsible for the pleasant texture of high quality chocolates. 

V.K.S. Shukla. Cocoa butter properties and quality, Lipid Technology, 1995, 7, 54-57. F.B Padley, Lipid Technologies and Applications (ed. F.D. Gunstone and F.B. Padley) Marcel Dekker, New York (1997), pp.391-432. P.J. Lawler and P.S. Dimick, Food Lipids Chemistry, Nutrition, and Biotechnology, (ed. C.C. Akoh and D.B. Min) Marcel Dekker, New York (1998) pp.229-250. 

Janssen K., Matissek R. Fatty acid tryptamides as shell indicator for cocoa products and as quality parameters for cocoa butter. European... 

Many researchers have studied the effect of lipid composition and polymorphism on macroscopic rheological properties but have not sufficiently considered the importance of the microstmcture of the network. Depending on the source and the refining process, the chemical composition of cocoa butter may vary (Dimick, 1999). This has been shown to influence crystallization rates and hardness characteristics. Within the microstmctural level, the polymorphic form of cocoa butter has been shown to affect the shape and size of the crystals (Vaeck, 1960). In terms of final product quality the polymorphic form of the crystals will determine melting characteristics. However, lipid composition and polymorphism alone cannot be used to predict the macroscopic properties of a fat crystal network. 

The major fatty acids present in cocoa butter triglycerides are palmitic acid (P), oleic acid (O), and stearic acid (S). Cocoa butter is composed mainly of symmetrical triglycerides (>75%) with oleic acid in the sn-2 position (POP, POS, SOS) and with trace amounts of asymmetrical triglycerides (PPO, PSO, and SSO) (Shukla, 1995 van Malssen et al., 1996). This natural fat is relatively simple insofar as it is composed of a small number of TAG components and melts over a narrow temperature range, which is important in terms of textural quality (Shukla, 1995). The typical composition of cocoa butter is shown in Table 1. 

Solvent fractionation of palm oil from acetone has been used extensively for manufacture of high quality palm midfractions (PMFs) for confectionery use, particularly in cocoa butter equivalents or extenders (CBEs) [43]. Acetone frac-... 

The best conditions were found at 480 bar and 100°C. A residual butter content below one per cent can be reached in 1,5 hours. The extraction temperature is limited at about 100°C. At higher temperature the content of free fatty acids increases, because it seems that a part of the triglycerides is splitted to fatty acids. The aroma losses are low and the defatted cocoa powder is of high quality. 

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