2, black beans belong to the grain, its shelf life is longer, usually about 2 years, stored for a shorter period of time, the nutritional value of black beans, which is rich in vitamin E, dietary fiber, not only can play a certain role in eliminating free radicals in the body antioxidant, but also to promote digestion, to avoid constipation.

3, but put ten years of black beans are usually more serious loss of nutrients, and it is likely to be moldy and can not be eaten. Therefore, the storage of twenty years of black beans is not recommended to eat, so as not to stimulate the intestinal tract, causing diarrhea and vomiting and other symptoms.