Cocoa content

Caf,Tb,Tp,3MeX,X,dyp, OHEtTp Analysis cocoa content in milk-powder products uBondapak C18 300x4 Me0H-H20-AcOH(19 80 1) 207... 

In this example, 11 dark chocolates from the French market were analysed (Table 6.1). As can be seen, this selection includes chocolates made with various cocoa contents. Some products are from major brands, as well as from private labels, and two products are fair trade and organic chocolates. 

Product name Cocoa content (%) Short name... 

Figure 6.3 FP sensory map (i.e. score plot from the GPA consensus) with 95% confidence ellipses for each product. Two-digit numbers in product names represent the cocoa content.

A more complex flavor development occurs in the production of chocolate. The chocolate beans are first fermented to develop fewer complex flavor precursors upon roasting, these give the chocolate aroma. The beans from unfermented cocoa do not develop the chocolate notes (84—88) (see Chocolate and cocoa). The flavor development process with vanilla beans also allows for the formation of flavor precursors. The green vanilla beans, which have Htfle aroma or flavor, are scalded, removed, and allowed to perspire, which lowers the moisture content and retards the enzymatic activity. This process results in the formation of the vanilla aroma and flavor, and the dark-colored beans that after drying are the product of commerce. 

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. 

Cocoa Powder Manufacture. When chocolate Hquor is exposed to pressures of 34—41 MPa (5000—6000 psig) in a hydrauHc press, and part of the fat (cocoa butter) is removed, cocoa cake (compressed powder) is produced. The original pot presses used in cocoa production had a series of pots mounted vertically one above the other. These have been supplanted by horizontal presses that have four to twenty-four pots mounted in a horizontal frame. The newer presses are capable of complete automation, and by careflil selection of pressure, temperature, and time of pressing, cocoa cake of a specified fat content can be produced. 

The amount of lecithin required falls within a narrow range of about 0.2—0.6% (27). It can have a substantial effect on the amount of cocoa butter used, reducing the final fat content of chocolate by as much as 5%. Because cocoa butter is usually the most costly ingredient in the formulation of chocolate, the savings to a large manufacturer can be substantial. 

Table 10. Amino Acid Content of Cocoa and Chocolate Products,. mg/g ...

Table 12. Vitamin Content of Various Samples of Cocoa Beans and Chocolate Products, Whole Weight Basis, mg/100 g...

The endo-action of the K. marxianus PG was demonstrated by a extremely rapid attack on plant tissue. This activity appears to be at least equivalent to that of several commercial preparations used for separating plant cells for protoplast preparation (RMC, unpublished data). Most of the endo-PGs produced by plant pathogens and saprophytes have so far been reported to possess macerating activity. PG secreted by K. marxianus CCT 3172 also had a strong activity in reducing the viscosity of cocoa pulp. Cocoa pulp generally contains 1 - 1.5% (w/w) of pectin consisting of 68% esterification and 11.6% methoxyl content [18]. 

Franzke, C.L., Grunert, K.S., and Griehl, H., Estimation and contents of theobromine and theophylline in mate, cola and cocoa. Zeitschrift fuer Lebensmitteluntersuchung und Forschung, 139,85,1969... 

Leszczynska, T., Nitrate and nitrite content of tea, coffee and cocoa, Bromatol. Chem. Toksykol., 27(4), 327, 1994. (Polish) (CA122 263903s)... 

Although low levels of methylxanthines have been detected in the leaves and flowers of T. cacao, the primary storage location is within the seed or bean.16 The cocoa bean is the major natural source of the methylxanthine theobromine, but contains only small amounts of caffeine. Theophylline has been detected in cacao beans, but at such low concentrations that its presence generally is ignored. Together, theobromine and caffeine account for up to 99% of the alkaloid content of T. cacao beans. Alkaloid content is affected by genetic makeup, maturity of beans at harvest, and fermentation process. Analytical methodology also is partially responsible for some of the disparity in methylxanthine values since many early methods were unable to separate theobromine and caffeine. 

Asamoa and Wurziger tabulated the caffeine content of a variety of cocoa beans.22 The mean concentration (percentage in fat-free samples) in Amelonado and Amazonas beans, respectively, after 5 d of fermentation at various stages of maturity were green beans 0.06,0.19 yellow 0.09,0.18 orange 0.08, 0.23 and black 0.10, 0.22. These results confirmed significant differences between the two varieties and also the low caffeine content of Forastero-type beans. The caffeine content of 16 other samples of various... 

Chocolate liquor is the solid or semiplastic food prepared by finely grinding the nib of the cacao bean. It is commonly called baking chocolate, unsweetened chocolate, or bitter chocolate and, in Europe, is frequently referred to as chocolate mass or cocoa paste. Chocolate liquor is essentially the starting point from which all chocolate products are produced. Table 5 lists the theobromine and caffeine content of 22 various chocolate liquor samples determined by high pressure liquid chromatography (HPLC). The liquors averaged 1.22% theobromine and 0.214% caffeine.27- 28 The ratio of theobromine to caffeine ranged from 2.5 1 to 23.0 1. 

According to Schutz, it is well known that cocoa contains about 2.5% by weight of theobromine and caffeine.29 Although the presence of theophylline has been demonstrated, its concentration is so low that it is generally ignored. In a summary of the literature values for 27 commercial cocoa powders and cocoa masses, Hadorn found that the mean total alkaloid content was 3.36 0.48%.23 Theobromine and caffeine content of several cocoa powders is shown in Table 6. HPLC analyses by DeVries et... 

Cocoa butter is the fat obtained from subjecting chocolate liquor to pressure. Since the alkaloids are sparingly soluble in fat, only trace amounts of theobromine and caffeine in cocoa butter have been reported. The theobromine and caffeine content of four cocoa butter samples averaged 0.008% and 0.038%, respectively.33... 

Most chocolate is consumed in the form of chocolate confectionery. Sweet chocolate is produced from chocolate liquor with the addition of sugar and cocoa butter. Sometimes called dark chocolate, sweet chocolate must contain at least 15% chocolate liquor, but may contain as much as 50%. Semisweet or bittersweet chocolate consists of a minimum of 35% chocolate liquor. The chocolate liquor content results in sweet and semisweet chocolate containing the highest amount of theobromine and caffeine per serving of any type of chocolate confectionery (Table 9). Within brands of sweet chocolate, there is wide variation in the methylxanthine... 

Consumption of sweet chocolate in the U.S. is low. The majority of chocolate consumed is milk chocolate produced from chocolate liquor, sugar, cocoa butter, and milk solids. Because most milk chocolate produced in the U.S. contains 10 to 12% chocolate liquor, differences in methylxanthine content among commercial milk chocolate are due more to the varieties and blends of cocoa bean (Table 9). Based on analytical data from seven brands of commercial milk chocolate, a typical 40-g milk chocolate bar contains approximately 65 mg theobromine and less than 10 mg caffeine.28 Milk chocolate bars containing other ingredients, such as peanuts, almonds, and confectionery fillings, obviously contain less methylxanthines. In a survey of 49 marketed chocolate and confectionery products, theobromine concentrations ranged from 0.001 to 2.598% and caffeine content from 0.001 to 0.247%.33... 

The theobromine content of chocolate foods prepared from home recipes using common chocolate sources — cocoa, semisweet baking choco-... 

This chapter has compiled and evaluated information on the methylxanthine composition of cocoa and various chocolate foods and beverages, as well as the consumption pattern for these commodities. Cacao is the major natural source of the xanthine base theobromine. Small amounts of caffeine are present in the bean along with trace amounts of theophylline. Numerous factors, including varietal type and fermentation process, influence the methylxanthine content of beans. 

Chocolate liquor is a semifinished product commonly called "baking" or unsweetened chocolate. The average theobromine and caffeine content of liquors has been reported at 1.2% and 0.21%, respectively. Cocoa powder, which is prepared after partial removal of the cocoa butter, contains about 1.9 to 2.7% theobromine and 0.16 to 0.26% caffeine. Milk chocolate averages 0.168% theobromine and 0.022% caffeine, thus providing about 65 mg of theobromine and less than 10 mg of caffeine in a 40-g serving. The methylxanthine content of chocolate foods has received only slight attention in the literature, yet is necessary in order to obtain an accurate assessment of the total amount of theobromine and caffeine that is ingested via the diet. 

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