Formulating and processing healthful chocolate products
March 29, 2011
by Rebeca López-García, Ph.D.
In a study published in the Journal of Agricultural and Food Chemistry, researchers from Purdue University and Kraft Foods concluded that although the antioxidant content of chocolate is the most important factor in delivering the benefits, formulation is also important since net absorption of antioxidants is directly related to the food matrix. In this study, the highest blood levels of flavan-3-ol were obtained following consumption of a chocolate beverage in a high-sugar matrix. Thus, it is important to consider the matrix to facilitate rapid appearance of flavan-3-ols in the blood or design formulations to maintain lower flavan-3-ol concentration for an extended period of time.
A study published in the Journal of Food Science by the Hershey Co., Hershey, PA, in collaboration with Brunswick Laboratories also found that leavening agents play an important role. A chocolate cake that uses baking powder rather than baking soda better preserves the flavonol content and the antioxidant activity.
Mark Adriaenssens, director of R&D North America at Barry Callebaut, Pennsauken, NJ, specified that it is important to match the right product with the application. Factors that affect the choice of ingredient include the type of product desired (chocolate vs. compound), application (inclusion vs. coating), processing conditions (baking time and temperature) and cost. He also explained that healthy components in cocoa and chocolate can be affected by high processing temperatures and other conditions. Some chocolate ingredients are stable in the baking process. However, for chocolates containing probiotics, special handling is necessary to maintain the active levels of the beneficial organisms.
Rose Potts, corporate manager sensory and product guidance, Blommer Chocolate Co., Chicago, IL, also recommended adding ingredients as late as possible in the process to minimize heat damage.
Josh Rahn of Cargill Cocoa & Chocolate, Lititz, PA, noted that to maintain control over chocolate, it is important to understand the product and processing conditions, including the melting points. When baked goods exit the cooling tunnel at low temperatures into warm, humid plant conditions, condensation can develop on the product’s surface. To avoid this, temperatures must be elevated in the final stage of the cooling tunnels to bring the product closer to the ambient temperatures. However, if preservation of bioactive compounds is expected, then this temperature range must be taken into account or consider the addition of coatings with high polyphenol content after the process.
Neil Widlak, director of product services and development, ADM Cocoa, Milwaukee, WI, pointed out that generally, cooling a baked product to 70°F is sufficient to minimize belt smearing; however, slower solidifying particulates such as milk chocolate-based and compound fat inclusions will increase the potential for smearing, having a drop point under 95°F. Dextrose can be added to the inclusion formula to reduce post-baking smearing. Sufficient cooling of the product must also occur before packaging to avoid condensation and protect the product’s quality as well as its safety, since bacterial growth may occur if a source of nutrients (chocolate) combines with available water (condensation).
Mr. Widlak recommended a 3-stage cooling tunnel to provide optimum cooling conditions for coating to obtain the desired level and appearance of the coating. Re-circulated coatings must be heated prior to blending back into coating supply or proper crystal development may be compromised. Again, if a coating is added to increase the health promoting benefits of chocolate, then a processor must work with the supplier to find the ideal balance to preserve the antioxidant activity while obtaining an appealing product with excellent quality, appearance and shelf life.
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