The Flavor of Milk Chocolate Changes Caused by Processing Marlene Stauffer Blommer Chocolate Company he purpose of this paper is to discuss Formulations using a single bean vari- Tand demonstrate flavor differences ety versus a blend of beans may make dra- among milk chocolates that are formulated matic flavor differences in a chocolate for- with a constant recipe, altering only the mula. To date, much of the understanding processing parameters. A product devel- of chocolate flavor has been based on gas opment team worked together to develop chromatographic and mass spectral data a protocol.The ground rules were set.The of the volatile aroma fraction of dried first step was to establish the formula, then and/or roasted cocoa beans and the result- determine processing techniques, focus on ing formulated chocolate. More than 400 what processing techniques to alter, ana- compounds have been found in cocoa fol- lyze the product and finally to evaluate the lowing fermentation, drying, roasting and Stauffer is the sensory effects of the process changes. conching. Some flavor elements in choco- director of quality The goal was to maintain the formula in late are highly volatile compounds con- assurance and new Figure 1 throughout the test process. tributing sour notes; moderately volatile product develop- Certain assumptions that would affect compounds contributing roasted or flow- ment at Blommer flavor were made prior to any samples actu- ery notes; and low volatile compounds con- Chocolate. She has ally being manufactured. Roasting, the type tributing milky or caramel notes. The been with Blommer and amount of raw materials, the refining ensemble of all these flavor components since 1982. process and the conching process are all produces a unique chocolate flavor. Spe- variables that play a part in determining cific beans are chosen for their known con- the final flavor outcome. tribution to chocolate flavor. For our test, we have chosen to keep the roasting para- ROASTING meters constant using a low roast West Roasting parameters could alter the flavor African-type chocolate liquor and to focus by the selection of bean type, degree of on the chocolate manufacturing process. roast (whether it is a low, medium or high roast chocolate liquor) and also the amount MILK COMPONENT of chocolate liquor in the formula. Milk as a raw material in a milk chocolate Marlene Stauffer 54th PMCA Production Conference, 2000 145 The Flavor of Milk Chocolate Functional formulation is critical. Functional perfor- Deodorized cocoa butter was chosen for performance, mance, sensory properties, cost and stor- the test samples so that the flavor of the sensory properties, age life are all factors determining the value cocoa butter would not interfere with the of milk in a formulation. chocolate intensity of the samples and to cost and storage The type of milk selected is also a fac- reduce the variability in flavor which can life are all factors tor. Whole milk powder is the most com- sometimes be found in prime press cocoa determining the mon milk ingredient in a milk chocolate. butter of similar blends. value of milk in a Roller-dried whole milk is often used for its formulation. high free-fat usage and more yellow color. FLAVORINGS Spray-dried whole milk is more readily Flavorings are added to further enhance available; however, the process used will or modify already existing notes in a choco- determine the amount of free fat available late.The most common flavor additive used to the chocolate manufacturer. It is typi- in chocolate is vanilla, either in the form cally more white than a roller-dried prod- of natural vanilla or the now more com- uct.The amount of fat in a whole milk pow- monly used artificial vanillin. Salt is the sec- der may also vary from 26 to 28.5 percent. ond most common additive. These addi- A combination of nonfat dry milk and tions are not used to mask the chocolate anhydrous milkfat is sometimes used in flavor, but to intensify it.Vanilla and vanillin chocolate formulations for a more buttery help to add creamy notes, whereas salt flavor and a high free-fat system. This will accents clean, crisp notes and helps to obviously alter the rheological properties of reduce bitterness. a particular chocolate formulation and is Vanillin, the most common additive to sometimes used when cost is an issue. milk chocolate, was the flavoring added to Milk crumb is also another common the test samples manufactured. milk product used to manufacture special formula milk chocolates. The milk crumb REFINING helps provide caramel flavors. Maillard Various types of refining equipment exist in browning reactions occur between free the chocolate industry today. Two-stage amino groups and reducing sugars. These refining consisting of a prerefiner and five- reactions result in brown colors and roll refining is the most common system caramel flavors.The degree of carameliza- and was used for the manufacturing of the tion can be precisely controlled in crumb test samples. Controls of this equipment manufacture. set the stage for preconditioning a choco- For this project, roller-dried whole milk late mass to achieve an optimal conching powder with a fat content of 28.5 percent process. It is important to envelope the par- was chosen as the milk component. ticles with fat so that undesirable absorp- tion of water during refining does not occur. COCOA BUTTER If refining is poorly adjusted, it will be Chocolate manufacturers have a number impossible to make up for this during the of requirements with respect to the quality conching cycle. of cocoa butter. Prime press cocoa butter The refining process has certain para- Formula from a blend of chocolate liquors might be meters that can be changed that might alter Sugar . 50% Milk . 19% used to further enhance chocolate flavor the flavor. Refining will determine the size Cocoa Butter . 16% or a deodorized cocoa butter could be used reduction of a chocolate mass as it is being Chocolate Liquor . 15% to give a more mild chocolate flavor. The manufactured. Whether a product is fine, Soya Lecithin . 0.3% choice depends on the intensity of the fla- medium or coarse ground will determine Vanillin . 0.01% vor desired in the end product as well as the palette’s flavor perception.The particles Figure 1 the melting and solidification properties. will be coated with fat, which is the flavor 146 54th PMCA Production Conference, 2000 The Flavor of Milk Chocolate carrier. When these particles enter the ufacturing and the conche temperature. The function of the mouth, the melt, sweetness and mouthfeel With greater conching intensity, derivatives conche is to all will influence how the product tastes.A have been found indicating sugar break- remove unwanted product with a high fineness (coarse) will down. The most prominent in the process flavors but at the also appear darker in color compared to a is the caramelization of lactose, which same time retain low fineness (fine) chocolate. A low fine- would be a source for the malty and ness product will have more surface area, intensely caramel notes. the more desirable requiring a greater amount of fat to coat A goal in conching is also to obtain the ones. each particle, and will sometimes give a optimum viscosity (flow properties) at the sticky mouthfeel due to the energy lowest practical fat content. Key elements required to smooth the particles across the in this goal would be moisture reduction, tongue. A coarse product will have more input of energy, control of superfines and free fat due to less cocoa butter needed to amount of free fat available. coat the solid particles. This will create a There are several different types of more free-flowing (thinner) viscosity conches in the industry today—from dry requiring less energy to coat the tongue conching to wet conching to continuous and giving a different flavor perception. conching.Test samples were manufactured from a wet-conching pilot system. CONCHING It is well known that adjustments to conch- PARAMETERS ing parameters can modify chocolate fla- The parameters we chose to focus on to vor. Conching can be manipulated by time, examine the flavor profile of the exact same temperature, moisture content and shear. paste formula follow: Introducing energy to the product mass in • Conching time the form of shearing and increased tem- • Conching temperature perature over a period of time will create • Particle size certain flavor developments. The function These parameters were chosen based on the of the conche is to remove unwanted fla- above previous assumptions. We felt these vors but at the same time retain the more particular sample types would demonstrate desirable ones. The amount of conching is differences by process and by examples. important. Typically, conched chocolate is considered more mellow and blended as PROCEDURES compared to unconched chocolate. The paste was manufactured using granu- Acidity and bitterness are reduced dur- lated sugar, roller-dried whole milk pow- ing conching. Ziegleder states that 30–40 der, deodorized cocoa butter, low roast percent of highly volatile elements are West African-type chocolate liquor, soya removed through the conching process and lecithin (an emulsifier) and vanillin. The Schneider feels that reduction of acid in a raw materials remained constant through- chocolate mass can succeed much easier out the test process. in a dry substance rather than in a pasty The products were mixed in a Hobart substance.Temperature adjustment will aid mixer, measuring each ingredient very pre- in the degree of caramelization based on cisely, then sent through the refining the Maillard browning reaction, where the process and into a high shear Frisse pilot basic reaction is between free amino groups conche. Time, temperature and amperage and reducing sugars.The Maillard reaction were monitored throughout the cycle.The may well depend heavily upon the recipe; product was then standardized to the the prior treatment of raw materials such as agreed-upon formula and analyzed.