Chocolate refining

Codex has also defined the various types of cocoa butter ia commercial trade (10). Press cocoa butter is defined as fat obtained by pressure from cocoa nib or chocolate Hquor. In the United States, this is often referred to as prime pure cocoa butter. ExpeUer cocoa butter is defined as the fat prepared by the expeUer process. In this process, cocoa butter is obtained direcdy from whole beans by pressing ia a cage press. ExpeUer butter usuaUy has a stronger flavor and darker color than prime cocoa butter and is filtered with carbon or otherwise treated prior to use. Solvent extracted cocoa butter is cocoa butter obtained from beans, nibs, Hquor, cake, or fines by solvent extraction (qv), usuaUy with hexane. Refined cocoa butter is any of the above cocoa butters that has been treated to remove impurities or undesirable odors and flavors. 

Refining. The next stage in chocolate processing is a fine grinding in which a coarse paste from the mixer is passed between steel rollers and converted to a drier powdery mass. Refining breaks up crystalline sugar, fibrous cocoa matter, and milk soflds. 

The name conche derives from the seasheU shape of the first really effective conching machine, which consisted of a tank with curved ends and a granite bed on which the chocolate paste from the refiners was slowly pushed back and forth by a granite roUer. This longitudinal conche, the development of which is commonly attributed to Rodolph Lindt of Switzerland in 1879, is stiU used and many experts consider it best for developing subtle flavors. 

Several other kinds of conches also are used today. The popular rotary conche can handle chocolate paste in a dry stage direct from the refiners (23). The recently developed continuous conche actually Hquifies and conches in several stages and can produce up to 3600 kg of chocolate per hour in a floor area of only 34 m. ... 

Control of the polymorphic forms in cocoa butter is further compHcated by the presence of other fats such as milk fat. The fat in a chocolate can be likened to the mortar between the bricks in a mason s wall. The soHd particles in a weU-conched chocolate bed down better than the soHds in a coarsely refined and poorly mixed one (30). 

Refined cocoa butter - [CHOCOLATE AND COCOA] (Vol 6) - [CHOCOLATE AND COCOA] (Vol 6)... 

The quantitative determination of sterenes has been used to detect added CBEs or refining in cocoa butter and to establish the presence of CBAs in retail chocolates (Crews et al., 1997). The high quantity of triterpene alcohols in shea butters means that dehydration products of these sterols are formed in detectable levels when shea is bleached. These triterpene sterenes, which have not be characterized, can be detected in the stearin fraction used in CBEs (Crews etal., 1999). 

While free fat remains a controversial concept in liquid dairy products, it undoubtedly has an important role in whole milk powder (WMP) for certain applications (e.g., chocolate manufacture) high-free fat WMP is favored. Keogh et al, (2003) reported that the particle size in chocolate mixes after refining and the viscosity of the molten chocolate decreases as the free fat content of the WMP increased such changes have significant implications for the mouthfeel and smoothness of chocolate. For more information on the role of fat in milk powder, see Chapter 13... 

The chocolate paste, having 28% fat content, is further worked through five-roll refiners or machines which work on different principles. The objective of this operation is to reduce the size of the majority of the solid particles to under 20 micron. 

The fine ground chocolate powder or paste is conveyed into refining equipment where the rest of the cocoa butter, emulsifying agent (lecithin) and the flavourings are added. 

MCT oils are usually made by esterification of distilled C8 and Cio fatty acids, derived from the acid-oil byproducts of lauric oil refining or from high pressure splitting of lauric oils. Another route is the direct molecular distillation of lauric oils. The C8 to Ci0-depleted oils are then even richer sources of lauric and myristic acids for the oleochemical and soap industries. Examples of MCT oils used in dietetic chocolate spread are shown in Table 6.39. 

The cocoa bean (Theobroma cacao) is the source of two important ingredients of chocolate cocoa powder and a solid fat called cocoa butter.To evaluate the oxidative behavior of cocoa butter, the autoxidation of refined and unrefined butter samples is accelerated (oxidized at day light at room temperature and at 90 C). The quantity of certain aldehydes formed during the oxidation of cocoa butter is examined by gas chromatography. The oxidation stability of butter is evaluated over a 12 week period. ... 

Refining is a size reduction process. This is carried out in a mill fitted with multiple, water cooled rollers [3-5], Chocolate is usually refined to a particle size of 50-114 pm of which less than 10% are smaller than 5 pm and not more than 20% are larger than 22 pm. It is the distribution of particle sizes that determines the eating quality of the resulting chocolate [8]. 

The refining step is performed by single or multiple refining rollers which disintegrate the chocolate paste into a smooth-textured mass made up of much finer particles. The rollers are hollow and can be adjusted to the desired temperature by water cooling. The refined end-product has a particle size of less than 30 to 40 pm. Its fat content should be 23-28%. 

The refined chocolate mass is dry and powdery at room temperature and has a harsh, sour flavor. It is ripened before further processing by keeping it in warm chambers at 45-50 °C for about 24 h. Ripening imparts a doughy consistency to the chocolate and it may be used for the production of baking or other commercial chocolates. An additional conching... 

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