To create a new mapping, you just need to find the nutritional item in the database that is the closest match the ingredient, and drag and drop the item from the nutritional database to the ingredient row that needs a mapping. Once you do this, the correct nutritional values will be available to calculate the nutritional information for the ingredient. While most ingredients will have mappings, occasionally you’ll find that the nutritional database doesn’t have a good match. When this happens, the nutritional information for the recipe has to be calculated without the ingredient. The USDA does update the database often, though, so at some point all of the ingredients could be available for your calculations.