Kinetics of degradation of saponins in soybean flour (Glycine max.) during food processing

Saponin glycosides present in a wide variety of plants have the ability to haemolyse red blood cells. They are known to be relatively heat stable. The present study aims at the development of a kinetic model for degradation of saponins in soybean flour (Glycine max.) subjected to a defined set of processing conditions. This study was carried out at isothermal conditions over a temperature range of 80–130 °C, and also under nonisothermal conditions in three different cooking methods viz., open pan, pressure cooking and cooking in a recently developed and patented fuel efficient ‘EcoCooker’. The degradation of saponins was adequately modeled by the Arrhenius equation. Using the time–temperature data of the nonisothermal heat process and isothermal kinetic rate parameters, a mathematical model has been developed to predict the degradation of saponins in any nonisothermal heating process of known time–temperature profiles.