Genistein and Daidzein Content of Soybean, Tofu Waste, and “Oncom Merah”.

Abstract

Isoflavone (genistein and daidzein) can be found in Leguminosae, especially in soybean. Soybean can be processed into tofu and get around to tofu waste, which can be processed finally to “oncom merah”. Soybean, tofu waste, and “oncom merah” had been analysed in this research for genistein and daidzein contents. Soybean, tofu waste, and “oncom merah” were hydrolysed using 4 N HCl and ethanol, followed by partition using ethyl acetate. Components purification by flash chromatography and its contents were determined by high performance liquid chromatography. Genistein and daidzein contents of soybean were 128.69 mg/100g and 134.46 mg/100g, respectively. Tofu waste contained 65.93 mg/100g genistein and 63.68 mg/100g daidzein. Furthermore, genistein and daidzein contents of “oncom merah” were 32.41 mg/100g and 27.70 mg/100g. Soybean contained genistein and daidzein two times higher than tofu waste and four times higher than “oncom merah”.