Rheological behaviour of enzyme clarified sapota (Achras sapota L.) juice at different temperatures (10 to 85°C) and total soluble solid content (10.2 to 55.6°brix) corresponding to a water activity (a w ) (0.986 to 0.865) was studied using controlled stress rheometer by coaxial cylinders attachment. The rheological parameter shear stress (Pa) was measured upto a shear rate of 1,000 s . The investigation showed that the enzyme clarified sapota juice and its concentrates behaved like a Newtonian liquid and the viscosity (η) values were in the range 4.340 to 56.418 mPa s depending upon temperature and concentration studied. The temperature dependency of viscosity of enzyme clarified sapota juice was described by Arrhenius equation (r >0.94) and activation energy (E a ) for viscous flow was in the range 5.218 to 25.439 KJ/mol depending upon concentration. The effect of total soluble solid content on flow activation energy was described by exponential relationship (r > 0.95, rmse% <13.5, p <0.01) and that of water activity was described by power law relation (r >0.99, rmse% <5.80, p <0.01). The effect of total soluble solid content on viscosity of enzyme clarified sapota juice followed second order exponential type relationship (r >0.99, rmse%<3.53) at the temperature used. The effect of water activity on viscosity of enzyme clarified sapota juice followed power law equation (r >0.98, rmse%< 4.38). A single equation representing combined effect of temperature and total soluble solid content/water activity on viscosity of enzyme clarified sapota was established.

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