Assessment of variation in methods to determine reported iron content of nutrition labels of commercial dark chocolate bars

Objective To assess variation in methods used by industry for determining iron content in dark chocolate bars to provide information for nutrition labeling. Methods Ten brands of dark chocolate bars (70–85% cocoa solids) were purchased from vendors on the US Pacific Coast (San Francisco, California to Victoria, BC). Reported values for iron content (%DV), controlled for serving size, were assessed. Producers were contacted to confirm specific analytical methods or other data utilized for product nutrition labels. Results For the chocolate bars assessed, reported iron content ranged from 4–39 %DV (Mode = 10, SD = 11.7). Label values for iron content were obtained by the following methods: 2 producers used USDA Nutrient Laboratories databases, 4 used analytical testing, 1 was exempt from labeling, 3 did not provide test methods. Conclusion Iron, a class II nutrient, is required by FDA to be listed as a percentage of the 18mg daily value (%DV). There is a high level of variability in how dark chocolate producers obtain data for product nutrition labels. This highlights a need for standardized methods to determine iron content for labeling dark chocolate bars. As a result of this analysis, we plan to perform and compare several accepted methods for determining the iron content in dark chocolate bars. Data will be compared to nutrition labels to assess any true variation of iron content in dark chocolate bars. Grant Funding Source : Center for Student Research Bastyr University