In Vitro Investigation on Phenolic Compound and Antioxidant Activities from Methanolic Extracts of Black Soybean Seed

Abstract

Indonesia always imports soybean annually to meet a demand for food industries, namely tempe, tofu and soy sauce. For example, Indonesia imported 2.26 million ton soybean in 2015 which is equivalent to US$ 1.03 million (Kompas 2016). A significant decrease of national soybean production is caused by unfavorable price of soybean seed. Under such undesirable condition for growing soybean, farmers shift to grow other crops, such as corn and horticultural crops. An increase of soybean price to meet the benefit of the farmers and consumers would drive the farmers' motivation to grow soybean in a larger area. In such circumtances, it is expected to increase the National soybean production. Japanese government subsidizes soybean price to farmers as much as 11,310 yen/60 kg soybean (Yusman 2017) in order to motivate farmers growing soybean. However, this strategy seems to be unlikely to happen in Indonesia. It seems to be possible to increase the domestic soybean price through better awareness and understanding of the Indonesian people that soybean seeds generated by a conventional breeding is safer and better to be consumed. In addition to high protein content, soybean produces secondary metabolites playing a role as antioxidant (