Cocoa deodorization

Stearic acid is the most common of the long-chain fatty acids. It is found in many foods, such as beef fat and cocoa butter. It is widely used as a lubricant in soaps, cosmetics, food packaging, deodorant sticks, and toothpastes. It is also a commonly used softener in rubber. 

It is not known how long vanilla has been used as a spice, but it dates back at least 1,000 years. The first known cultivators of vanilla were the Totonac people in the Veracruz region of Mexico, who regarded vanilla as a sacred plant and used it as a deodorant. The use of vanilla was acquired by the Aztecs after their invasion and interaction with the Totonacs. The Aztecs called vanilla tlibcochitl, which translates as black flower, a reference to the dark brown-black color of the dried pods after curing. Aztec royalty used vanilla to sweeten the bitter taste of their cocoa drink xocolatl and for medicinal purposes. The Spanish explorer Hernando Cortez... 

The flavour of cocoa butter is determined by both the geographical origin of the beans and the deodorization conditions. Deodorization reduces the levels of free fatty acids but also some antioxidant compounds such as tocopherols. Deodorized butters are therefore often blended with expressed cocoa butter for better stability of the product. 

Press cocoa butter is the fat that is obtained by pressure from cocoa nib or cocoa mass (liquor) and treated only by filtering, centrifugation, degumming and deodorization by normal methods. 

Kamm el al. (2001) analysed intact steryl esters in the presence of silylated sterols by online transfer from HPLC to a 15 m low-polarity high temperature GC column. Steryl esters were quantified against a cholesteryl laurate internal standard and identified by offline thin layer chromatography-gas chromatography-mass spectrometry. When esters of sitosterol, stigmasterol and campesterol with the major cocoa butter acids were measured in cocoa butters from South America, Asia and Africa, no differences were apparent between cocoa butters of different geographical origin, or between deodorized and non-deodorized butters. 

Tocopherols and tocotrienols are precursors of vitamin E and are important antioxidants in oils. Their reactivity means that they are not stable to many oil processing procedures, including deodorization, which reduces levels by up to 15%. Levels of tocopherols in cocoa butter are usually about 100-300 mg/kg, with the y-isomer (IV) being the major component (about 90%), but they can be entirely absent (Lipp et al., 2001) (Figure 3.3). Tocotrienols have a similar structure with unsaturation of alternate bonds along the alkyl chain. Only y-tocotrienol is found in cocoa butter and this at low levels (< 5 mg/kg). Palm oil is notably high in tocopherols and tocotrienols, of which a-tocopherol and a-tocotrienol make up 20% to 30% each with most of the remainder as y-tocotrienol. 

Pyrolysis of food samples provides a large number of products, which, after detection by MS and analysis by advanced statistical treatment, can be used to compare different samples. The method is very rapid and does not require chromatographic separation or MS identification of the pyrolysis products. Pyrolysis MS, coupled with multivariate data analysis procedures, has been used to discriminate between cocoa butters of three different continental areas (Radovic et al., 1998). The technique could in some cases separate deodorized from non-deodorized cocoa butters and also show those that have had alkali treatment. The presence of non-cocoa fats did not affect the assay. 

Kohiyama et al. (1992) reported mean levels of nickel, iron and copper of 0.03, 0.30 and 0.04 mg/kg, respectively, in 10 samples of cocoa butter. Baxter et al. (2001) found comparable results from the determination of 23 elements in 42 cocoa butters and 22 CBA fats, mostly of known geographical origin and processing history, by the sensitive multi-element technique of inductively coupled MS. No distinction could be made between the cocoa butters based on geographical origin or deodorization, and the very low levels of most elements in the CBA fats meant that their presence in mixtures with cocoa butter could not be detected. 

The deodorization of cocoa butter is necessary to reduce free fatty acid content and to give a product that satisfies the present day requirement of a neutral bland flavor. Deodorization is a suitable method for partially eliminating chlorinated insecticides from cocoa butter. The normal deodorization temperatures are in the range 160-180°C. The oxidative stability of various cocoa butters listed in Table 4 shows extremely high values, and these are unaffected during the deodorization process. Stability against oxidation depends on natural antioxidants present in cocoa butters. The tocopherol composition in Table 5 shows a predominance of... 

Supercritical fractionation of a liquid lipid feed material is usually carried out in a packed column. Standard columns are not available commercially and have to be custom built either in-house or by manufacturers of extraction units. Lab-scale and pilot-scale supercritical columns, 0.6-13.6 m high with internal diameters of 14.3-68 mm are available in research labs around the world and have been used for the processing of deodorizer distillates (56, 57, 86-90), vegetable and fish oils (91-105), cocoa butter, and milkfat (106-109). A schematic diagram of a typical SCCO2 fractionation column (2.8 m, 2.54 cm o.d.), which was designed and built... 

Timms (21) has heat of fusion to 17.7-22.3 kcal/kg for milkfat, 24-31 kcal/kg for fully hardened milkfat, 26-29 kcal/kg for cocoa butter in the p polymorph, 22.6 kcal/kg for refined, bleached, and deodorized (RBD) palm oil, 29.7 kcal/kg for RBD palm kernel oil, 26.0 kcal/kg for RBD coconut oil, 31.6 kcal/kg for fully hardened palm kernel oil, and 31.2 kcal/kg for fully hardened coconut oil. The heat of fusion is an empirical physical property dependent on the thermal history or tempering of the oil. 

The tocopherols present in non-deodorized and deodorized cocoa butters are given in Table 3.24. These, together with phenolic and other unidentified antioxidants, ensure that cocoa butter is very stable to autoxidation. 

The odorants of cocoa powder are listed in Table 21.24. A model (cf. 5.2.7) made by using the 24 aroma substances on the basis of deodorized cocoa powder reproduced the aroma of cocoa very closely. 

It must be stressed that this state diagram is specific to the cocoa butter used in this study. This particular cocoa butter has been degummed, deodorized, and bleached and therefore lacks phospholipids and other minor components, which most likely slows down its crystallization. In addition, the absence of phospholipids may also slow down polymorphic transformations. 

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