Originated in Japan, Black soybean pods may be green, yellow or brown at harvest. Plus, each one of them contains jet black and mostly round beans. They also have an excellent buttery texture, and offer a nutty and richer, sweeter flavor than yellow soybeans. Nutrition-wise, Black soybeans are rich in nutritional content containing dietary fiber, iron, calcium, B vitamins, zinc, lecithin, phosphorous, magnesium. Furthermore, soybeans such as the Black soybean are the only legume which contains all nine essential amino acids. It is worth noting that the body assembles individual amino acids into complete proteins which it uses to repair damaged tissues, such as muscle fibers.