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Candy R&D
Trends and Applications in Ingredient Technology

By, Jessie Ray Sectzer

Consider them akin to the hot wax seals affixed to critical and/or highly personal pieces of mail sent by royalty, aristocrats, poets and lovers ages ago. Yes, similar to the hot wax seals, confectionery coatings preserve the precious contents until they're ready for consumption.

As John Urbanski, vice prresident of technical sales and services for Wilbur Chocolate Co., Lititz, Pa., points out, the most obvious products using coatings are boxed candy centers and candy bars, The coatings perform a variety of tasks, which include providing structural support, keeping moisture and oxygen out to enhance the shelf life of the center, adding a sensory complement to the center (i.e., a strong semi-sweet chocolate over a sweet mint center, and setting a moisture migration barrier).

"Coatings may be applied in layers where a precoat is employed to provide a functional benefit and a second coat is used for its sensory attributes," he says. For example, nutmeats often receive a precoating to slow oil migration and reduce fat bloom.

Coatings can also functionally exist among sugar-free products. According to Ubranski, the proliferation of sugar-free candy products in the past couple years has led to a dramatic increase in sugar-free coatings. "As consumer demand for improved offerings in this area grow, manufacturers are seeking ways to improve the sensory properties of sugar-free coatings," he says.

Wilbus is reviewing its sugar-free line and investigating alternative sweetening systems to deliver more of a "real chocolate" profile in the next generation of sugar-free products.

The company is also actively pursuing opportunities in the nutritional bar markets where the standard practice has been very limited to using conventional chocolate and compound coatings, "We believe that by incorporating protein, fiber, vitamins and/or minerals into the coatings and inclusions such as chips we can effectively mask some of the less desirable organoleptic properties of these materials," he explains.

"We have also found that we can give finished product formulators more flexibility in their bar and center recipes to alleviate some of the compounding problems they face (water activity issues, mineral reactivity, etc.)," Urbanski says.

Tim Surin, industry marketing manager, Loders Croklaan, Channahon, Ill., uses coatings specifically to substitute for chocolate in confectionery products that are used primarily to give finished products the desirable characteristics of taste, appearance and texture.

"Coatings are hard to the touch but melt rapidly in the mouth, delivering the expected 'chocolaty' taste," he says. "Products can be enrobed with a coating or mold, or the substitute chocolate coating can be used for a bar application. Regardless of the application, the primary value that coatings provide is a cost-effective replacement for chocolate in the formulation."

The choice of coating type depends completely on the manufacturers' objectives for the product. Mouth-feel, taste, texture, appearance, distribution and labeling requirements must be addressed before a coating is developed.

Surin explains that the latest issue that the industry faces involves trans fatty acid labeling. Today, it's not whether the USDA will require manufacturers to list the amount of trans fatty acids in the product, but when and how.

Most coating fats (as well as all fats) are hydrogenated or partially hydrogenated to increase the stability of the oil. "When you hydrogenate oil, trans fatty acids are created and will have to be listed," he says. Recent medical studies pinpoint trans fatty acids as contributing factors in the development of coronary heart disease.

"The issues with trans labeling will force manufactures to find ways to reduce the amount of tans fatty acids in the end product," Surin says. "Depending on the final decision, it could have a significant impact on the confectionery industry and coatings in particular.

"One method for lowering trans fatty acids in a product is via the use of cocoa butter equivalents (CBE)," he says. "We have a complete line of CBEs that we continue to develop and optimize to ensure that the customer is getting the solution that best meets their needs without any sacrifice in mouth-feel, taste, or texture."

Not all developments regarding coatings, however, have their roots in regulatory compliance.

"Coatings can be used to polish, seal or sub-coat products as well as to keep confections from sticking together," says Pam Gesford, manager, technical services, food and confectionery, Colorcon, West Point, Pa. "But coatings can also be used to adhere colorants, flavors or other additives to the surface of confections."

Colorcon offers Opadry Type F products or complete film coating systems to add color and flavor on the outside of panned confections. The company also carries a wide range of coating varieties, such as those that are solvent-based like shellac confectioner's glaze, oil-based like gummi polish, aqueous liquids that can be based on gum or dextrin for sub-coating and sealing, or complete film coating systems based on a variety of edible film formers (gums, dextrins, etc.).

Colorcon's new pearl pigments require very thin applications to show up as pearls, providing a perfect complement for coatings, "Pigmented confectioner's glaze or complete film coating systems can be used to apply these pigments — Colorcon's Opaglos and Opadry products," Gesford says.

John M. Krochta, professor at the University of California, Davis, department of food science and technology, in Edible Films and Coatings Lab, has been working on two types of new coatings that have relevance to confectionery. One development involves an oxygen-barrier coating for nuts that inhibits oxidative rancidity.

“Confections that include nuts are often limited in shelf life due to the oxidative rancidity that develops in a fairly short time in the nuts,” he explains.

Krochta and his team have also developed whey protein (WP)-based films that can be formed as thin coatings on nuts. These film coatings have oxygen-barrier properties as good as the best synthetic polymer films.

“We have demonstrated that we can form the coatings on peanuts and the rate of rancidity development is significantly reduced,” he says. “Over time, our early oxygen-barrier coating formulations showed some tendency to crack and flake off the nuts. So, at present, we are working on improving the adhesion of the WP coatings to the nuts and improving creating durability related to handling experienced during packaging, transportation and marketing.”

“The advantage of such oxygen-barrier coatings on nuts is that the flexible packaging required for achieving a targeted shelf life can be simplified, with resulting cost savings and improvement in recycle-ability of the package,” Krochta explains. “Furthermore, the oxygen-barrier coating continues to provide protections after the package is opened (in the case where the entire food product is not consumed immediately). Finally, the coating can carry anti-oxidants to enhance the oxygen-barrier properties. The coating can also carry flavors and colors.”

Krochta is presently working with the confectionery industry to help bring the concept of WP-based oxygen-barrier coatings to commercialization. The professor and his team have submitted a patent application on this concept and are looking for additional industrial partners to appropriately target and enhance our oxygen-barrier coating commercialization-focused research.

“We have developed WP-based gloss coatings that can be formed on chocolate-covered almonds and other confections," he says. “The coatings have gloss comparable to shellac coatings. Additionally, a consumer study showed that WP coatings were comparable to shellac coatings," Krochta says.

Reprinted with permission from the May 2002, issue of Candy Industry®
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