Chocolate materials

Copper(II) ions in aqueous solution are readily obtained from any copper-containing material. The reactions with (a) alkali (p. 430), (b) concentrated ammonia (p 413) and (c) hydrogen sulphide (p. 413) provide satisfactory tests for aqueous copper(II) ions. A further test is to add a hexacyanoferrate(II) (usually as the potassium salt) when a chocolate-brown precipitate of copper(II) hexacyanoferrate(II) is obtained ... 

A flavor is tried at several different levels and in different mediums until the most characteristic one is selected. This is important because the character of a material is known to change quaUty with concentration and environment. For example, anethole, ben2aldehyde, and citral taste different with and without acid. Gamma-decalactone has different characters at different levels of use. -/ fZ-Butyl phenylacetate with acid is strawberry or fmity without acid it is creamy milk chocolate. 2,5-Dimethyl-4-hydroxy-3-(2Fi)-furanone with acid is strawberry without acid it is caramel or meat. 

Bot nic l nd Animal Extracts. Tinctures and fluid and soHd extracts of items such as vanilla, coffee, cocoa, and Hcorice are produced by treating the raw materials with a solvent. Vanilla is by far the most widely used extract and is often found in chocolate products, baked goods, beverages, and frozen desserts (49,52). 

A small quantity of flexible packaging material, usually oriented polypropylene, shrink polypropylene, or polyethylene, is used to overwrap paperboard cartons. The film is wrapped around the carton and sealed by heating. Products such as boxed chocolates, candies, and cookies are overwrapped, sometimes by a printed film. 

The food flavor industry is the largest user of vanillin, an indispensable ingredient in chocolate, candy, bakery products, and ice cream. Commercial vanilla extracts are made by macerating one part of vanilla beans with ten parts of 40—50% alcohol. Although vanillin is the primary active ingredient of vanilla beans, the full flavor of vanilla extract is the result of the presence of not only vanillin but also other ingredients, especially Httle-known resinous materials which contribute greatly to the quaUty of the flavor. 

Cocoa powder (cocoa) is prepared by pulverizing the remaining material after part of the fat (cocoa butter) is removed from chocolate Hquor. The U.S. chocolate standards define three types of cocoas based on their fat content. These are breakfast, or high fat cocoa, containing not less than 22% fat cocoa, or medium fat cocoa, containing less than 22% fat but more than 10% and low fat cocoa, containing less than 10% fat. 

Lecithin (qv), a natural phosphoHpid possessing both hydrophilic and hydrophobic properties, is the most common emulsifier in the chocolate industry (5). The hydrophilic groups of the lecithin molecules attach themselves to the water, sugar, and cocoa soflds present in chocolate. The hydrophobic groups attach themselves to the cocoa butter and other fats such as milk fat. This reduces both the surface tension, between cocoa butter and the other materials present, and the viscosity. Less cocoa butter is then needed to adjust the final viscosity of the chocolate. 

Many confections are coated in a thin layer of chocolate. The latter is a mixture of chocolate, cocoa butter and other fats, blended to form a suitable coating material. This layer melts at a temperature generally in the range 27-34°C. The manufacturer wishes to coat the confection in a thin, continuous layer, and then harden this layer so that the product can be wrapped and packed with the least delay on the production line. 

The cacao plant, Theobroma cacao, is the source of chocolate which is well known and highly prized in international commerce. The cacao pods contain beans which are fermented and pressed to provide a brown liquid which is the raw material for chocolate. The press cake is ground and sold as cocoa and it also provides a brown colorant. The pods, beans, shells, husks and stems have also been suggested as colorants. They contain a very complex mixture of acyl acids, leucoanthocyanins, flavonoid polymers, tannins, and catechin-type polymers.33... 

A variety of xanthines including caffeine, theobromine, and theophylline have been found from food materials including.coffee, chocolate, and tea (419-420). Theophylline determination in sera has been much studied. The technique allows the determination of theophylline at serum levels of 1.5-20 mg/liter theophylline with sample sizes ranging from 50 to 10 /xl (42 -425). Hill (426) assayed theophylline using 50 /xl of serum and an analysis time of 8 min with good interbatch precision and accuracy. Alternative methods which allow the determination of as little as 0.1 mg/ml (427) or 20 ng theophylline in 10 ml serum have been described (428). 

The kukersites mined from the Estonia deposit have a light chocolate-brown colour in dry condition (10YR 6/4, i.e., light yellowish brown Munsell Color Company 1994), with a conchoidal fracture oblique to the lamination. The density is less than 2.1 g/cm3, but varies depending on the content of clastic material and carbonate minerals versus organic matter. 

The use of polyamide is advantageous because it separates natural from synthetic coloring material, removes sugars, acids, and flavoring materials, and concentrates dilute solutions of colors (156,167). However, the use of polyamide is not applicable to chocolate brown FB, chocolate brown HT, or indigotine, because the two chocolate browns are not completely eluted from the column and indigotine decomposes during extraction (157). 

Although cocoa as a drink is now rather unfashionable, it provides the raw material for the manufacture of chocolate and is commercially very important. Cocoa (or cacao) is derived from the roasted seeds of Theobroma cacao (Sterculiaceae), a tree widely cultivated in South America and West Africa. The fruits develop on the trunk of the tree, and the seeds from them are separated, allowed to ferment, and are then roasted to develop the characteristic chocolate flavour. The kernels are then separated from the husks, ground up, and processed in various ways to give chocolate, cocoa, and cocoa butter. 

One o-f the world s most popular -flavors, chocolate, is a product o-f both -fermentation and roasting. Early studies by Rohan (44-47) pointed out the importance o-f liberating the precusor materials (amino acid) so that roasting will generate chocolate aroma. 

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