Abstract:
The kinetics of colour (measured as Hunter 'a' value) degradation in tomato puree (Lycopersicon esculentum L.) has been studied over a temperature range of 50-120 A degrees C (isothermal condition), and also during normal open pan cooking, pressure cooking and cooking in a newly developed and patented fuel-efficient 'EcoCooker' (non-isothermal condition). The degradation of colour as measured by Hunter 'a' value was found to follow first order kinetics. The temperature dependence of degradation was adequately modelled by Arrhenius equation. A mathematical model has been developed using the isothermal parameters obtained to predict correctly the losses of red colour from the time-temperature data of non-isothermal heating/processing method. The results obtained indicate a colour degradation of similar magnitude in all the three modes of cooking used in the study.
