Carbohydrates and Protein

One tablespoon of mustard seed contains only 3.9 grams of total carbohydrates, with 1.6 grams of total fiber. That is 6.6 percent of your daily recommended dietary fiber intake, and it means that mustard seed offers a very high ratio of carbohydrates to fiber. Fiber is an important part of your diet to keep your digestion functioning properly. The mustard seed also contains 2.8 grams of protein, which is about 5.6 percent of your daily protein requirement.