Chocolate quality

Schwan RF, Wheals AE (2004) The microbiology of cocoa fermentation and its role in chocolate quality. Crit Rev Food Sci Nutr 44 205-211... 

In contrast, a less extensive but still convincing database has identified important clinical differences in efficacy for antidepressants used to treat patients with atypical or comorbid depression. Individuals with atypical depression (distinct quality of mood, hyperphagia, hypersomnia, psychomotor retardation, rejection sensitivity, and such unusual atypical features as chocolate craving] have superior responses to monoamine oxidase inhibitors (MAOIs], selective serotonin reuptake inhibitors (SSRIs), and perhaps venlafaxine, and most do not respond well to tricyclic antidepressants (TCAs] (Davidson et al. 1982 Liebowitz et al. 1988 Quitkin et al. 1988, 1991). Despite these data, TCAs unfortunately have been the first choice for most atypical patients until SSRIs were introduced. 

Some people prefer dark chocolate. Others go for the gooey chocolate-covered cherries. Many don t care for coconut in their sweets. And most people are happy with any mixture of any kind. Different kinds of candies have different prices, depending on the ingredients. When you combine different candies in packages, the quality or price of each type is multiplied by the quantity or weight to determine the price of the mixture. 

One feature of desires experienced as compulsive is their power to capture one s attention. It is in this sense that we speak of a musical rhythm, or a literary plot, as compelling. This quality is generally desirable in a tune or drama but can be quite unwanted in other contexts. Desires can be more or less compelling in this sense. One measure of the strength of desires is their capacity to claim one s consciousness, direct one s fantasies, break one s concentration on other things. One finds it difficult to keep one s mind on one s work because one keeps thinking of one s lover, or of the chocolate cake in the pantry, or of the cigarettes at the market. The objects of these desires tend to demand or dominate one s attention, despite oneself. 

VIGNETTE IV RHEOLOGY IN MANUFACTURING AND QUALITY CONTROL Rheology of Chocolate... 

Dr. Joe Vinson of the University of Scranton believes that there is something to the chocolate effect, and he came to Belmont to tell us about his intriguing research. Vinson has determined the total polyphenol content of various chocolates and has also found a way of measuring how effective these mixtures are in preventing the oxidation of human ldl in a test tube. In other words, he has calculated a phenol antioxidant index, which takes into account both the quantity and the quality of these desirable substances. At the symposium Vinson reported that cocoa powder and dark chocolate are the best, followed by milk chocolate. Instant cocoa mixes trail the field. Then Vinson delivered the kicker chocolate has more, and better, polyphenols than fruits or vegetables and more than red wine. A forty-gram bar of dark chocolate has as many polyphenols as a cup of that widely promoted antioxidant cocktail we call tea. But there is still the matter of chocolate s fat content. Researchers tell us, though, that at least half of it is stearic acid, which does not raise blood cholesterol. 

Nisin has been applied successfully to prepare sterile beverage-quality chocolate milk. The antibiotic serves as a sterilization aid because it inhibits outgrowth of heat-damaged spores and so permits use of less drastic heat treatments for sterilization (Heinemann et al. 1964). 

Heinemann, B., Stumbo, C. R. and Scurlock, A. 1964. Use of nisin in preparing beverage-quality sterile chocolate-flavored milk. J. Dairy Sci. 47, 8-12. 

Vanillin is added, in powder form during the manufacturing process of chocolate, in average amounts of 20 g per 100 kg of the finished product. However, this amount varies according to the quality of the chocolate being made. 

Obsidian from the Alca source is of excellent quality. The glassy matrix is very uniform and easy to use for tool manufacture. Large nodules measuring up to 20-30 cm length are widely available at the main deposit. Smaller nodules are common in neaiby streams. Alca obsidian comes in a range of colors from black, chocolate-brown, to a rare aqua blue (45). 

Pure chocolate is a mixture of torrefied, powdered cacao with sugar (saccharose) sometimes excess of fat is added and sometimes a small quantity of various essences or spices. Starch chocolate contains, in addition, one of a number of starches or flours (of rice, oats, chestnut, or of oily seeds such as walnut, arachis, etc.). Chocolate of lower quality sometimes contains powder cacao husks, and occasionally other sugars than saccharose (glucose) are added other adulterants are dextrin, gum and gelatine. Milk chocolate is prepared with cacao, sugar and milk powder or extract. 

There is no evidence that any of the manufacturers of cocoa and chocolate have adapted any part of the Maillard technology to their manufacturing processes. There are at least two reasons for this. First, the standard processes, as applied to beans of good quality, produce excellent products. Second, while the work just reviewed has given us a rather clear outline as to how chocolate aroma is developed in the roasting of fermented beans, the research work has not yet been done, or reported, that would serve as a basis for improving the industrial processing of cacao beans. 

The quality of the phenol antioxidants was assessed by Vinson et al. (1999) using the IC50 for LDL + VLDL (very low density lipoprotein) oxidation, with smaller values indicating a higher quality. Quality of the antioxidants was due to free-radical scavenging activity and not chelation as the concentration of polyphenols for 50% inhibition was < 1 xM and cupric ion 25 xM in the oxidation medium. There was less percent variation within the groups for this parameter than for the total polyphenol content. The quality order was dark chocolate > cocoa > milk chocolate. The dark chocolate and cocoa were significantly different from the milk chocolate (p < 0.05), but not... 

Vinson, J.A., Proch, A., and Zubik, L., Phenol antioxidant quantity and quality in foods cocoa, dark chocolate, and milk chocolate, J. Agric. Food Chem., 47, 4821 4824, 1999. 

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 little-known resinous materials which contribute greatly to the quality of the flavor. 

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. 

Particle size is an important property with respect to the sensory quality of chocolate, and in chocolate manufacture. It can be measured using laser light diffraction spectrophotometry (see Section 22.2.11.2), and by a variety of other means such as micrometry, microscopy, wet sieve fractionation, sedimentation and Coulter counting (Minifie, 1999). 

Kleinert, J. 1976. Rheology of chocolate. In Rheology and texture in food quality, ed. J.M deMan et al. Westport, CT AVI Publishing Co. 

From the snap, gloss and texture of chocolate to the shelf life of frozen foods, crystalline microstructure plays a very important role in the texture, appearance, shelf life and overall quality of many foods. The total amount of crystaUine phase in a food, as well as the size distribution and shape of the crystals within the food, can affect the physical properties of the product. Furthermore, some mataials in food can crystallize in different polymorphic forms so that control of polymorphic transformations may also be necessary. 

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