Conching

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 

Efforts have been made to shorten this time-, energy- and space-consuming final refinement in conche pots. Processes have heen developed that are based on the separate pre-refinement of cocoa nibs or cocoa mass. The spray-film technique uses a cocoa mass with its natural water content or, in the case of highly acidic cocoa varieties, with the continuous addition of 0.5-2% of water. In a turbulent film with direct heat transfer, the cocoa mass is continuously dehumidified, deacidified, degassed, and roasted in counterfiow with hot air (up to 130 °C). For the final refinement, apart from the time-tested conche pots, newly developed intensive refiners can be used. They reduce the conching time to 8 hours. The development of continuously operated conche pots is also being expedited. 

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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. ... 

Conching temperatures range from 55—85°C for sweet chocolate and from 45—55°C for milk chocolate. Higher temperatures are used for milk chocolate if caramel or butterscotch flavors are desired (24). 

Conching time varies from a few hours to many days and many chocolates receive no conching. Nonconched chocolate is usually reserved for inexpensive candies, cookies, and ice cream. In most operations, high quaUty chocolate receives extensive conching for as long as 120 hours. 

Flavors, emulsifiers, or cocoa butter are often added during conching. The flavoring materials most commonly added in the United States are vanillin, a vanillalike artificial flavor, and natural vanilla (25) (see Flavors AND SPiCEs). Cocoa butter is added to adjust viscosity for subsequent processing. 

Several chemical changes occur during conching including a rise in pH and a decline in moisture as volatile acids (acetic) and water are driven off. These chemical changes have a mellowing effect on the chocolate (26). 

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). 

Conversely, for an unreactive XH, or one present in small conch, or for a highly aq medium, the reverse of reaction (8) prevails over reaction (16), and the rate of nitration now depends on both the nature and concn of XH, ie, it is first-order in XH. The comments made above about H2S04 or N03 additives are also applicable to this situation... 

Determination of the nature of the sulfate content was attempted by following the conch of this impurity in two ways (1) during the course of laboratory simulated industrial stabilization procedures, and (2) from successive dissolutions of unstabilized NC samples in various solvents and subsequent repptn from non-solvents. This approach was based on the premise that free occluded sulfuric acid would be released from the fibers by the soln-pptn treatment, whereas chemically combined sulfate would remain unaffected. The fuli details of the various expts can be found in Ref 5 some typical results are shown in Table 3 for four samples of NC of different nitrogen content... 

Table 1. U, Th data for active straw stalactite and drip water from Conch Bar Cave, Middle Caicos...

Figure 7. vs. l/[Th] of dripwaters from Conch Bar Caves, Middle Caicos, British West... 

Concentration standards, 75 750-751 Concentrators, sulfuric acid, 23 787 Concentric annular reactors, 23 544 Concentric cylinder viscometer, 27 733 Concentric hemispherical analyzer (CHA), 24 103-104, 105 energy resolution of, 24 106 Conching, milk chocolate, 6 363-364 Concomitant polymorphism, 8 69 CONCORD program, 6 10 76 752 Concrete(s)... 

On the other hand, association with more palatable seaweeds may have a negative impact on the chemically defended partner. For example, Halimeda specimens from Conch Reef, Florida Keys, with more than 50% of their thalli covered by Dictyota grow significantly slower than unepiphytized thalli (Beach et al. 2003). This study also verified that epiphytic Dictyota negatively affects metabolic rates of Halimeda tuna in part by shading their thalli, but probably also by chemical means, because the exposure to Dictyota-conditioned water elevated respiration rates in a manner similar to when H. tuna is naturally epiphytized by Dictyota. 

Terrestrial (land) snails Marine snails Whelks Conches Bivalves Clams Oysters Mussels Scallops Cockles Cephalopods Squids Octopuses Cuttlefishes... 

Boettcher, A.A. and Targett, N.M., Induction of metamorphosis in queen conch, Strombus gigas Linnaeus, larvae by cues associated with red algae from their nursery grounds, J. Exp. Mar. Biol. Ecol., 196, 29, 1996. 

Boettcher, A. A. and Targett, N.M., Role of chemical inducers in larval metamorphis of queen conch, Strombus gigas, Linaeus relationship to other marine invertebrate systems, Biol. Bull., 194, 132, 1998. 

Liquefaction of the rolled product with more cocoa butter and lecithin occurs at 60°C (Fig. 14.28, right). This works mainly with pre-treated raw materials, such as crumb powder, where the flavor has already been formed and the moisture content has already decreased to less than 1%, providing a free-flowing mixture that allows for easy for pouring. This process saves several days of batch conching. 

There are seven living classes of molluscs,23 including the worm-like Aplacophora, the chitons of the Polyplacophora, the limpet-like creatures of the Monoplacophora and the Gastropods which includes the abalone, marine snails, slugs, nudibranchs and conch. The next three are comprised of the Cephalopods (cuttlefish, squid and octopus), the Bivalves (clams, oysters) and the Scaphopoda (Tusk shells). Figure 6.5 shows that the most prolific order within Mollusca is the Aplysiomorpha (Anaspidea) with 507 articles and 384 structures published since 1951. There have been a total of 1684 publications and 1225 chemical structures reported from the order Mollusca. One of the most well-known structure classes from molluscs are the dolastatins, which are from the Anaspidea order. 

Groupe des Conches Minces and Department of Engineering Physics, cole Polytechnique, CP. 6079, Succursale A, Montreal, Quebec H3C 3A7, Canada... 

Chemical bonding as a means of solidihcation is very widely observed in nature. Formation of sedimentary rocks, such as carbonate rocks, is an excellent example. Carbonate rocks are formed by the reaction of calcium oxide with the carbon dioxide from the sea water [14]. Sea organisms also use this process and construct seashells. The organisms that flourish in calcium-saturated solutions of sea water change the alkalinity of the solutions slightly and precipitate calcium carbonate, which is used to form protective shelters such as shells and conches. 

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