2.11.00. TOBACCO PRO- CESS FOOD AND BEVERAGE APPLICATION NOTE 2.10.04 DUTCH PROCESS COCOA POWDER PRODUCTION www.vaisala.com POTASSIUM CARBONATE K2CO3, SODIUM CARBONATE Na2CO3, AMMONIUM BICARBONATE NH4HCO3 Typical end products Dutched cocoa powder for making chocolate and other chocolate- brown or red color, and even improved solubility in flavored foodstuffs such as confectionery, desserts and drinks. liquids compared to the natural ones. Chemical curve: Potassium Carbonate R.I. per % b.w. at Ref. Temp. of 20˚C Dutched cocoa powders are more commonly used in Europe. In America, most cocoa powder brands available in the supermarket are of natural type. However, Dutched cocoa powders are widely used in the making of american style chocolate sandwich cookies, since cookies preparared with these acquire an attractive, rich chocolate color. Application The Dutching process, also known as Alkalizing or Alkalization, simply consists of reacting cacao material with an alkalizing agent, typically in the form Introduction of an aqueous solution. Cocoa powder is the most important ingredient in the Dutching can be done to cocoa bean kernels, or preparation of chocolate and other chocolate-flavored nibs, cocoa liquor or even directly to cocoa powder. sweet and confectionery, bakery products, ice creams Cocoa beans are harvested and fermented for some and drinks. Cocoa powder is produced by processing days to change the flavor, aroma and color of the the beans from cacao plants. bean to brown. After fermentation, the cacao beans are cleaned and usually broken in pieces known as There are two types of cocoa powder. Natural cocoa nibs before the manufacture of chocolate or cacao powder is brown in color, and naturally acidic (with a products. The nibs can also be treated with steam or pH between 5 and 6). Dutch process cocoa powder roasted before alkalization. or Dutched cocoa powder is made from cacao beans that have been washed with an alkaline solution to For Dutching, the particle size of the cacao material is neutralize their acidity to a pH of 7. Dutching produces further reduced, for example in a grinder. The ground a variety of cocoa powders for specific applications. cacao material is then mixed with an aqueous alkali Dutched cocoa powders have a softer flavor, deeper solution at a temperature around 90 °C (200 °F). 102 Food and Beverage | Confectionery and Sweets Processing FOOD AND BEVERAGE APPLICATION NOTE 2.10.04 DUTCH PROCESS COCOA POWDER PRODUCTION www.vaisala.com The alkali agent used can be potassium hydroxide, Once cooking is completed, the dutched cacao potassium carbonate, sodium hydroxide, sodium material is removed from the cooker. Then the nibs carbonate, sodium bicarbonate, ammonium are roasted, if not previously done so, cooled to room bicarbonate, ammonium hydroxide, or mixtures of temperature and milled to form a chocolate liquor and these. The alkali and its concentration are specific pressed to remove fat and create a presscake. Some of the desired properties and end use for the cocoa producers remove the fat already before dutching powder being produced. For instance, potassium to minimize the amount of soap produced from the compounds are used to obtain a dark red product. reaction of fat (or fatty acids) in the cacao material Some countries may have regulations on the level of and the alkali. alkali used for dutching, so it is of outmost importance to monitor and control the preparation of the alkalizing The cocoa presscake is pulverized, dried and screened solution. The total amount of alkali concentration to obtain a final dutched cocoa powder product. ranges from 1-20 % based on the weight of the cacao material. Instrumentation and installation The reaction happens in a closed jacketed vessel. The type and concentration of the alkali used for After addition of the alkali solution, the temperature dutching are critical parameters to obtain the desired is raised to about 120 °C (250 °F). The total cooking dutched cocoa powder. The Vaisala K-PATENTS® time depends on many factors including the alkali Process Refractometer can be installed directly in concentration, the cacao material being treated, and the alkali preparation tank to measure in real time the temperature employed, but usually it is about 10- the concentration as the aqueous alkali solution 30 hours. The process conditions differ for each final is prepared. The refractometer can be installed product. For example, for reddish colored cocoas, air in a recirculating line, or directly in the vessel. A is usually introduced into the mixer during reaction, for refractometer flush mounted option is available for black cocoas, the introduction of air is minimized. The vessels with stirrers. cooking can be done under atmospheric conditions, under pressure or under vacuum to facilitate the The accurate measurement by the refractometer following drying step. ensures that dutching takes place at the correct alkalizing levels, in order to comply with regulations and to obtain the correct dutched cocoa powder product which is suitable for the desired end application. Instrumentation Description Sanitary Compact Refractometer PR-43-AC for hygienic installations in small pipe line sizes of 2.5 inch and smaller. The PR-43-AC refractometer is installed in the pipe bend. It is angle mounted on the outer corner of the pipe bend directly, or by a flow cell using a 3A Sanitary clamp, I-clamp or Varinline® connection. Sanitary Probe Refractometer PR-43-AP for hygienic installations in large pipes, tanks, cookers, crystallizers and kettles and for higher temperatures up to 150°C (300 °F). The PR-43-AP refractometer is installed in the pipe line or vessel through a 2.5 inch or 4 inch Sanitary clamp, I-clamp, APV Tank bottom flange or Varinline® connection. Sanitary Flush Mounted Refractometer PR-43-AP-T for hygienic flush mounting installations in cookers, cooling crystallizers and other vessels that have scrapers or mixers. Installation through an APV Tank bottom flange. User Interface Selectable multichannel MI, compact CI or a web-based WI user interface options allow the user to select the most preferred way to access and use the refractometer measurement and diagnostics data. Measurement range Refractive Index (nD) 1.3200 – 1.5300, corresponding to 0-100 % b.w. Food and Beverage | Confectionery and Sweets Processing.