Eat two chocolate bars and call me in the morning is hardly customary advice from a doctor. Chocolate has long been a favored treat, even a guilty pleasure, but continuing research into the possible health benefits of cocoa has many in the baking industry looking at chocolate in a new way.
The key behind chocolate’s possible health benefits lies in compounds called polyphenolic flavonoids, which are known to feature antioxidant properties, among other benefits.
Polyphenols are a family of plant-derived chemical compounds with carbon-ring structures, notes David Mark, Ph.D., president of dmark consulting LLC, Maynard, Mass., and consultant to Hershey’s and other food and dietary supplement companies. Polyphenolic flavonoids fall within this family and can be found not only in cocoa, but in dark colored fruits, some vegetables and whole grains. They are widely spread throughout our diet, but some of the richest sources are found in bitter and astringent foods, such as red wine or Concord grape juice, cocoa, tea, pomegranate, raspberries and blueberries. The most evident benefit of these compounds are their heart health benefits, Mark notes.
“Human and animal studies show the compounds are absorbed into the blood stream and tissues, which promotes arterial relaxation. As people age, their arteries become stiffer and more prone to reduced blood flow, and blood pressure becomes elevated. If arteries can be made to relax more, that will lower blood pressure and also reduce the risk of acute heart attacks,” he adds. While the latter hasn’t been proven, what has been shown is that these compounds help relax arteries. “[Polyphenolic compounds] also make platelets less sticky, which is another component of acute heart attacks and artery clogging. Making platelets less sticky and causing arteries to relax are heart health benefits and evidence continues to build that these [effects] are true,” Mark says.
But the benefits of polyphenols goes beyond heart health. Diets high in cocoa powder also have been shown to raise HDL cholesterol and lower LDL [bad] cholesterol, says Ron Schade, R&D manager, Barry Callebaut USA, Chicago. In the case of diabetics, eating foods with a higher polyphenolic content can have a positive effect on glucose metabolism, resulting in a lower net increase in blood sugar levels. Chocolate has even been shown to ease a persistent cough. “The theobromine found naturally in cocoa acts on the sensory nerve endings of the vagus, which can ease the feeling of a need to cough,” he notes.
In addition, chocolate may help with memory function. “There is also some interesting animal work that shows that polyphenolic compounds can reverse the decline of mental function, such as memory, balance, coordination and strength,” Mark says. Some studies show that people who drink red wine, another source of polyphenolic compounds, may be less at risk for Alzheimer’s disease.
Still, it is important to balance the benefits with the potentially high fat and sugar content in some cocoa and chocolate products, Schade notes.
Get the most out of cocoa
“The key is the amount of cocoa in the serving,” Mark says. “Therefore, a higher percentage is going to have a greater impact per serving. The amount in a milk chocolate bar is too small to be useful. The high cocoa chocolate bars are more likely to have [healthful] effects than normal-size servings,” he notes.
Still, gorging on 78 percent cocoa bars each week won’t do much good as far as health benefits go. “The molecules are absorbed and do not stay long within the body; we’re talking about maybe two to six hours. Two servings a day of phenol-rich foods is going to be useful to get some of these health benefits,” Mark says. “It really has to be something that becomes part of a daily diet. A 40-gram dark chocolate bar would count as one serving,” he adds.
Most cocoa beans arrive at the processor already fermented. The fermentation process creates the sweet cocoa flavor consumers love, but it also destroys many of the polyphenols.
Today, most of the world’s cocoa is fermented. More than 70 percent of cocoa comes from West Africa, notes Steve Laning, director of technical services North America, ADM Cocoa. The long fermentation process results in “wonderful color and flavor development in the bean, but fermentation also depletes some of these polyphenols. In fact, it is some of these polyphenols that are being transformed during
fermentation into other compounds that actually contribute to color and flavor development,” he notes. The largest source of unfermented beans is Southeast Asia, including almost all the crop from Indonesia, he adds.
“Unfermented or underfermented cocoa beans in chocolate manufacturing is one way of achieving a higher polyphenol level in the finished product,” Schade says. An unfermented bean, however, does not develop the same chocolate flavor, but instead gives the cocoa powder an undesirable, unfermented flavor. Still, bakers can substitute part of the fermented cocoa powder with unfermented beans to acheive a higher level of polyphenols in the finished product without negatively impacting the flavor, Schade notes.
Dark chocolate is picking up some momentum because the antioxidants are more concentrated in dark chocolate than in milk chocolate. “It also gives formulators an opportunity to show off chocolate in a different way. Maybe what triggered it was antioxidants, but now consumers are getting more experience with what dark chocolate can do for certain products and how it can be very enjoyable but maybe in a different way than the milk chocolate they’ve been enjoying for a long time,” Laning says. “If [bakers] use higher levels of cocoa solids in the finished product, there is more likely to be more polyphenols present, which is one reason why dark chocolate is getting more interest.”
Some companies are working on bars and other cocoa products that include higher polyphenolic content. Patents keep many companies from following suit, but more advancements in this area may be around the corner.
Production process
The polyphenolic compounds, and thus the healthful benefits of cocoa, can be destroyed or lessened during production. “The destruction of these is either by exposure to oxygen or very high temperatures,” Mark says. “Baking temperatures may be mild enough that these compounds are preserved. Frying temperatures or long exposure to oxygen during fermentation may also diminish the amount of these compounds. There is a lot of exploration right now in the chocolate industry as to what preserves these polyphenolic compounds and what does not,” Mark adds.
Phenolic compounds are stable enough to withstand baking and won’t lose their value when incorporated into baked products, Mark notes.
According to what Mark learned at the 2007 Institute of Food Technologists (IFT) meeting, “hot chocolate drinks, chocolate icing and to some degree, brownies, preserved the polyphenol content and antioxidant activity of cocoa. Chocolate cake baking resulted in significant loss, especially if the presence of baking soda as an ingredient resulted in a pH in excess of 7.5. Dutch cocoa has been treated with an alkali to neutralize its acids (and hence raises the pH to >7.0), and by this process loses much of its antioxidant activity.”
Chocolate’s future
Consumers in the United States appear to be taking more of a global view on chocolate, similar to that of Europeans, notes Schade. “In America, we’ve always thought of chocolate as a really indulgent product, where the European market looks at is as a stable food stuff. In some countries, they eat it everyday,” he says.
Mark predicts more growth in the high cocoa content of bars marketed with health statements. Regulatory agencies will look very closely at the content of chocolate products before condoning healthful statements to ensure products high in saturated fat do not boast a health claim in a contradictory manner.
Still, word about chocolate’s healthful possibilities may have Americans feeling less guilty about reaching for that indulgent cocoa treat.
“Chocolate has this amazing combination of these apparently healthful properties, along with its well respected indulgent flavor,” Laning says. “People are starting to really appreciate the different types of chocolate and the different types of flavors that can be enjoyed via chocolate, and at the same time, we’re realizing through science that eating it may not be something that makes us as guilty as it once did because of the potential health benefits.”
Even the saturated fat in chocolate may not be as unhealthful as thought when compared with other saturated fats. “The cocoa butter in chocolate, even though it is largely a saturated fat, is a fat that has a lot of stearic fatty acid, which is a unique saturated fat in that it doesn’t raise blood cholesterol levels,” Laning adds. “Cocoa butter has unique nutritional properties and it too is being revisited and better understood. When you combine that with the polyphenols and chocolate’s wonderful taste, I think chocolate has a very bright future. Not only do we have reasons to keep enjoying it, but we have reasons to enjoy it in more and more ways.”