Chocolate Adds Flavor to Chemistry Course
What causes chocolate to appear chalky after it’s refrigerated? Why is Brazilian cocoa better in ice cream than Ghanaian cocoa? Does Hershey contain more antioxidants than Dove? In a unique upper-division course centered on chocolate, CSUSM students are not simply satisfying a sweet tooth, they're learning about chemistry.Chemistry 316, titled Chocolate: A Chemical Investigation, is an general education course that introduces the principles of chemistry to primarily non science majors using chocolate as the prevailing theme. Tackling fundamental topics from the molecular structures of atoms to covalent and ionic bonding, chocolate enables chemistry concepts to be more easily digestible.“The course is not dumbed down by using chocolate,” explained Professor Jackie Trischman. “In fact I am able to teach the principles of chemistry at a higher level and dig deeper into scientific concepts.”Take the concept of polarity, for example. In chemistry, polarity describes how electrons are shared between atoms. Applying that concept to chocolate, polarity refers to the balance of ingredients, such as which fats are present and how much mixes best with milk, cocoa solids and sugars.In the case of pH and its effect on solubility, students learn about the differences between non-alkalized and alkalized chocolate. Alkalized chocolates have been treated with potassium carbonate to provide a smooth texture, allowing the chocolate crumb to mix well with the other ingredients. Common in Dove products, alkalized chocolate might taste a little soapy to some palates at first bite but that flavor quickly dissipates as the silky creaminess of the chocolate overpowers the taste buds, an experience that can be explained through understanding the chemical processes that are taking place.The course also reveals that not all chocolate is created equally. For instance, cacao beans grown farthest from the equator, like those in Brazil, are often best used in frozen products because the cocoa butter in the bean has a lower melting point than cacao grown in Malaysia or Ghana, which have higher melting points in the fat of the cocoa bean and are commonly used in candy bars.Trischman first introduced the course at CSUSM in 2011 after being inspired by a seminar talk at an American Chemical Society conference. Previously, Trischman tried other unique ways of teaching complex chemistry concepts, even juggling in front of the class to demonstrate molecular interactions and using illustrations of cleaning gasoline spills to describe how atoms bond, but she found that despite her best efforts, students continued to struggle with the subject matter. By focusing on chocolate, Trischman has found a way to make fundamental principles of chemistry practical.“I have had students in this course who were originally intimidated by science and through this approach of using chocolate, they are not only getting it, but they are able to understand and apply chemistry concepts to broader topics.”Chocolate: A Chemical Investigation was offered as an online class for the first time this summer and will likely be taught again on campus by Trischman in spring 2014.