A tactical matter
by Laurie Gorton
Add it, and they will buy. It, of course, is chocolate. What other bakery ingredient can boast such marketing power? Chocolate certainly has enormous appeal to consumers, but getting it to work with automated processing lines can be tricky. Among the baker’s many ingredients, chocolate is one of the most technically challenging. Even chocolate drops and the more forgiving chocolate-flavored compound coatings benefit from informed selection, proper handling and careful bakery processing.
VARIED. “There is not one magic form of chocolate that fits all bakery applications,” stated Mark Adrianssens, director, R&D, Americas, Barry Callebaut USA, Pennsauken, NJ. What’s more, important distinctions exist in formulation, flavor and use.
“It is important for bakers and snack manufacturers to know the differences between real chocolate and compound coatings, also known as confectioner’s coatings or imitation chocolate,” stressed Daniel Barreda, quality manager, R&D, Puratos Chocolate USA, Cherry Hill, NJ. Another name for the latter is summer coatings, so-called because of their ability to stand up to the heat and humidity present during warmer months.
Dark chocolate combines chocolate liquor (or cocoa mass), sugar and cocoa butter. Milk chocolate adds milk fats and proteins. White chocolate omits the chocolate liquor. Chocolate typically contains 25 to 35% fat. Chocolate couverture is a high-quality format that contains extra cocoa butter to a total of 32 to 39% and provides sheen and snap to the finished item. Compound coatings use cocoa-butter equivalents based on vegetable oils.
In the US, the content of chocolate is regulated by the Food and Drug Administration’s federal Standards of Identity (21 CFR 163), which state that the only fat permitted is cocoa butter. Recent changes in the European Union, however, allow use of some vegetable fat in chocolate, up to 5% of total weight.
Compound coatings can be flavored and colored as desired, but the only flavor permitted in chocolate is vanilla or vanillin, with a blanket ban on added colors. “The main flavor component of chocolate chips comes from cocoa powder and chocolate liquor,” said Brian Reifsteck, director, sweet and cereal, chocolate, compounds, fillings and variegates, Kerry Ingredients and Flavours, Americas Region, Beloit, WI. “With a compound coating, other flavors are permitted, for example, orange.”
Inclusions (chips, chunks, drops and formed pieces) can be made of either chocolate or compound coating. They contain 30% or less fat and, if produced from confectionery coating, can be colored and flavored.
“Chips used as inclusions come in a large variety of sizes from 800 to 10,000 count per lb. We have different chunk sizes as well,” said Dan Kazmierczak, technical service manager, Blommer Chocolate Co., Chicago, IL.
MATCHED. Suppliers offer chocolate and cocoa in forms intended for specific use, according to Thalia Hohenthal, senior scientist, R&D, Guittard Chocolate, Burlingame, CA. “The formulator needs to understand these differentiations and specify according to application,” she added.
The choice depends on the characteristics sought for the finished products. “What fits the application?” Mr. Adrianssens asked. “Will it be a filling, or will it be used to enrobe or bottom? Will it be for a cake, cookie or cereal bar? Does it require a hard snap or a soft texture?” Choice also depends on process, and he said that baking time and type of oven as well as cooling system have different effects.
High-end items generally call for chocolate with high cocoa content, a more European style, while compound coatings would suit so-called “fudge coated” value products, according to Mr. Kazmierczak. Additionally, all companies offer a line of economic chocolates that would be suitable for use in baking applications.
Flavor and its strength depend on the chocolate liquor component, the source of the cocoa beans and how they are handled and roasted. Companies such as Guittard select cocoa beans for high-intensity flavor, according to Ms. Hohenthal.
“You have to decide what the finished product characteristics should be, then pick the chocolate, coating or inclusion to match,” Mr. Reifsteck said.
For example, if a shiny appearance and a distinct snap are desired, then particle size becomes important, the smaller the better. For this application, Ms. Hohenthal recommended using pure chocolate with a particle size ranging from 0.0004 to 0.0008 in. (10 to 20 microns). “Larger particle sizes, 0.0008 to 0.0015 in. (20 to 40 microns), work best for products with a more crumbly nature,” she said.
Particle size is a function of the refining process at the chocolate manufacturer and also affects viscosity. “The rheology of the coating is vital to achieve the right flowability to cover the product,” Mr. Adrianssens said.
Viscosity determines how thickly (or thinly) the chocolate or coating can be applied, and viscosity depends mostly on fat content. “Thin or light applications require low viscosity,” Ms. Hohenthal said, observing that as the amount of fat increases, viscosity decreases. Chips, because of their relatively low fat content, maintain their piece integrity during baking.
The shortening used in basecakes and centers of enrobed items should be compatible with the coatings. “If not, the fat could bloom during the product’s shelf life,” said Michelle Girard, R&D project manager and baking specialist, Barry Callebaut Canada, St. Hyacinthe, QB. “The formulator must consider the whole product. If a fractionated palm kernel fat is present in the basecake, then the coating or chip will also need to be made with a compatible fat.”
“Never mix coatings, unless you know they are compatible,” advised Neil Widlak, director of product services and development, ADM Cocoa, Decatur, IL. “While coatings with different base fats may mix together, they may not crystallize well together.” The result will be loss of gloss, grainy texture and development of fat bloom.
Fat and carbohydrate contents are also important in high-sugar items, if sugar bloom is to be avoided, according to Mr. Reifsteck. “The formulator must take care to balance water activity to avoid moisture getting into the chocolate, which affects sugar crystalization.”
The amount of dextrose in an inclusion will affect conveying of those items. Mr. Kazmierczak explained that dextrose eases movement from one belt to the next. “You may want higher amounts of dextrose if you have multiple transfer points in your process.” Dextrose reduces post-baking smearing, added Mr. Widlak.
Source chocolate as you would any other ingredient, advised Eric Schmoyer, project manager, Barry Callebaut USA. “Take into consideration the existing references and special requirements such as kosher certification or any other criteria specific to the application,” he said.
HANDLED. Chocolate, compound coatings and inclusions are already finished goods when they arrive at the bakery and must be handled as such. “They should not be intermixed with raw agricultural products in storage,” Ms. Hohenthal said. “Chocolate can be recontaminated if not properly stored.”
Several experts emphasized the sensitive nature of chocolate. It should be stored at 60 to 70°F and at a relative humidity (RH) no higher than 50%. “Putting it in a cooler, at 40°F, is not proper storage,” Ms. Hohenthal emphasized. When such cold materials enter the warm, moist plant, moisture will condense on them, drawing out the sugar and setting up the coatings for sugar and fat bloom problems later on.
“Bakers and snack manufacturers must understand best practices when handling chocolate.” Mr. Barreda said. “The most critical control points are during transport, storage and application of the product.” In addition to cautioning about proper temperature and RH, he also advised that the storage area should be well ventilated and free from strong odors and direct light.
Temperature control must be maintained throughout the process, with special attention paid to melting and use tanks. “You have more leeway with compound coatings than chocolate, but you still need to strain out any crumbs entrained during the enrobing process,” Mr. Kazmierczak advised.
Chocolate melts at body temperature, and this sensitivity affects its performance in bakery processes.
“When using real chocolate, you may also need to temper it in-house and take measures to maintain that temper throughout the manufacturing process,” Mr. Reifsteck said. “If the temperature is not in the right range for tempering, unstable fat crystals will form, and the fat will bloom out later. Compound coatings are a little more forgiving since they do not require tempering, but in either case, you need to be cognizant of temperatures so that the viscosity works to your advantage.”
Milk chocolate inclusions tend to be more susceptibel to breakage and smearing than other chocolate- or compound coating-based inclusions because of their 2 to 4% butterfat content, according to Mr. Widlak. Dextrose can reduce the potential for smearing.
Compound coatings do not require tempering, but Mr. Adrianssens explained that cooling is important to getting the right texture for the finished product.
Generally speaking, the less time chocolate, coatings and inclusions spend on the plant floor awaiting use, the better they perform. Also, inclusions should be added at the correct time in the process to protect their piece integrity. For example, when making muffins, put the chips into the dough after all other ingredients are incorporated and mix only for a short time.
CONTROLLED. One of the best ways to assure quality results when taking a chocolate application from the bench to the line is to budget for and spend enough time in scale-up activities. “In taking products to the plant, processing operations can present pitfalls such as the mechanical sheer encountered in pumping,” Mr. Reifsteck observed. It can affect chocolate’s viscosity.
“Scale-up offers the ability to test and learn,” he continued. “You may need to adjust the formula, take the viscosity up or down, change the fat system, adjust the proportion of chocolate liquor or cocoa powder — any number of things can happen.”
The scale-up exercise allows product developers to anticipate and solve problems, “especially with expensive ingredients such as chocolate,” Mr. Reifsteck said. “You need to do your homework ahead of time.”
Probably the most critical aspect of chocolate use in high-volume processing is cooling. The fat system determines the cooling needs of the product in both dwell time and temperature profile. “To maintain the product’s quality, it is important to cool it properly after baking and before enrobing and to let the chocolate set 24 to 48 hours so the fat crystallizes properly before shipment,” Ms. Girard said.
“With pure chocolate, the cooling curve in the tunnel should be 17°C (62°F) at the front end, 12°C (54°F) in the middle zones and 18°C (65°F) in the final zone,” she said. “You don’t want to shock products.” If cooled too quickly, the fat system adopts an unstable crystal from. Baked foods enrobed with compound coatings should also be cooled under controlled temperatures.
Chances of temperature shock can also occur as products leave the cooling tunnel. “Moisture condensing on the coating’s surface will lead to sugar bloom during shelf life,” Mr. Adrianssens said. “You need to treat these materials correctly.”
Instruments that monitor the color and temper of chocolate materials can help keep it in control. Mr. Kazmierczak suggested that use of data loggers and “the good old-fashioned thermometer” will enable formulators and line staff to watch trends. “Conditions too cool or too hot will create problems of their own,” he observed.
Proper temperature and humidity also assure quality through distribution of the finished baked foods. “Make sure the parameters of storage of finished products are the same as those for the reference product retained for QA purposes,” Mr. Schmoyer said.
What does it mean to “temper” chocolate? By melting and cooling chocolate under gentle agitation in a controlled process, the processor assures the formation of stable fat crystals. It becomes tempered. Cocoa butter is most stable in the b (beta) form. Its a (alpha) and b’ (beta prime) crystalline forms melt at lower temperatures and are, thus, less stable, leading to problems during storage, distribution and shelf life.
“If the baker tempers chocolate in-plant, then a temper meter should be used to control this process,” said Mark Adrianssens, director, R&D, Americas, Barry Callebaut USA, Pennsauken, NJ, who also recommended use of color meters to monitor baking performance.
“Good temper means high gloss and sharp snap to the finished product,” said Thomas Allen, sales, TRICOR Systems, Elgin, IL. “Metering assures the needed consistency.”
Available in at-line and on-line configurations, a temper meter analyzes samples of chocolate and calculates the sample’s time-temperature slope. Data is recorded, and trends are displayed. Typically, a 0° slope indicates good temper.
A skilled chocolate technician can accurately perform the manual method for taking chocolate’s temper, but fewer and fewer such individuals are available today. “And the manual technique is subject to human variability as well as ambient humidity and temperature conditions,” Mr. Allen said. “The machine does the test the same way every time and reports results based on a mathematical algorithm that TRICOR instruments have successfully used for 30 years.”
At start-up, the temper of chocolate should be taken every 10 minutes until the line stabilizes. “After that, intervals of 30 to 60 minutes are suitable, depending on the consistency of operation of the company’s other equipment on the line,” Mr. Allen said.
“What temper meters give is guidance,” noted Dan Kazmierczak, technical service manager, Blommer Chocolate Co., Chicago, IL. “You need to train the operator to use the instrument correctly and interpret its results in terms of the performance you want from your chocolate ingredients.”