Rheological characteristics as a function of particle size at 25°C and the effects of pre-treatment and temperature on colour degradation kinetics of green chilli puree were investigated. Green chilli puree behaved as a shear-thinning fluid and the power law described well the shear stress–shear rate behaviour. The consistency index ( K ) decreased while the flow behaviour index ( n ) increased as the particle size of the puree decreased. The results indicated that colour degradation during thermal processing of chilli puree followed a first-order reaction kinetics. The combination L × a × b closely described the colour degradation behaviour. Dependence of the rate constant during thermal processing of chilli puree obeyed the Arrhenius relationship. The activation energy values for water-blanched and lye-treated chilli puree were 11.4 and 16.0 kJ/g mol, respectively. Lye treatment resulted in retarding the colour degradation rate.
