Sweet Tooth Science - Chocolate Antioxidants
Food scientists at the University of British Columbia have developed a faster and cheaper way to quantify antioxidant levels in chocolate. It’s a method they plan to use in new research to help uncover when antioxidant levels rise and fall during the manufacturing process, from raw cocoa beans to chocolate bars.
“Our method predicts the antioxidant levels in chocolate in under a minute, compared to the industry standard that can take several hours or even days,” said Xiaonan Lu, an assistant professor in food, nutrition and health in the faculty of land and food systems, who developed the method alongside PhD student Yaxi Hu. “It’s not a substitute for the traditional method used at the moment, but it does show a strong correlation for being just as reliable.”
The UBC method uses infrared spectroscopy, a technology that can be used to illuminate infrared light onto chocolate samples. The infrared spectra record the chemical composition of each sample, including the amount of polyphenols, micronutrients with high antioxidant properties. The traditional method relies on biochemical tests to read absorbance values and can be quite time consuming and expensive.
“Testing for antioxidant levels can give chocolatiers guidance on which cocoa beans to select, or how to improve their processing parameters,” said Hu.
Chocolate is made from cocoa beans and is manufactured through several processing stages, including drying, roasting and fermentation of the beans. The UBC food scientists have started to use their method to measure cocoa bean samples from around the world in each stage to determine when antioxidant levels are at their highest and lowest.
“If we identify drying as the step that significantly lowers the bean’s antioxidant properties, for example, we will want to develop a strategy to reduce the drying time, or drying temperature,” Lu said.
Story from the University of British Columbia. Please note: The content above may have been edited to ensure it is in keeping with Technology Networks’ style and length guidelines.
Hu, Y., Pan, Z. J., Liao, W., Li, J., Gruget, P., Kitts, D. D., & Lu, X. (2016). Determination of antioxidant capacity and phenolic content of chocolate by attenuated total reflectance-fourier transformed-infrared spectroscopy. Food Chemistry, 202, 254–261. doi:10.1016/j.foodchem.2016.01.130