Soybean sprouts are made from soybeans. Soybean sprouts not only retain the nutritional characteristics of soybeans, but also give birth to many new nutrients. It was found that the protein and fat content of soybean remained basically unchanged after 3 ~ 4 days of germination, but the substances in soybean that were not easily absorbed and easily flatulence (such as raffinose) decreased sharply or even disappeared completely. In the process of germination, various components beneficial to human body appear or increase continuously. The contents of vitamin C and amino acids are the highest in bean sprouts germinated for 3 ~ 4 days, and the length of bean sprouts is 3 ~ 4 cm. But if we continue to grow, the nutrients will be gradually lost. Popular medical advice: when purchasing bean sprouts, try to choose bean sprouts that germinate for 3 ~ 4 days and are 3 ~ 4 cm long. When cooking bean sprouts, put some vinegar first, so that the bean sprouts cooked are crisp, refreshing and nutritious.