Isoflavones in processed soybean products from Ecuador

Abstract

Soy products produced in Ecuador, with a local developed and cultivated soybean variety (INIAP 306), were analysed for isoflavone content and profile. The products presented high total isoflavone contents, varying from 53 to 106 mg/100 g (wet basis, expressed as aglycones), the lowest content being for okara and the highest for the low fat soybean flour obtained by extrusion cooking of the seeds at the field moisture. Soy nuts showed the same content of isoflavones than the seeds, but with lower amounts of malonylglycosides and higher of the deesterified beta-glycosides. The malonylglycosides were the predominant form of the isoflavones in the flours, and the beta-glycosides in soymilk and textured soy protein. Genistein derivatives were the compounds present in the highest proportions in all the products analysed.