J Food Sci Technol DOI 10.1007/s13197-013-1222-5
ORIGINAL ARTICLE
Rheological behaviour of enzyme clarified sapota (Achras sapota L) juice at different concentration and temperatures Pranjal S. Deshmukh & S. S. Manjunatha & P. S. Raju
Revised: 3 October 2013 / Accepted: 21 November 2013 # Association of Food Scientists & Technologists (India) 2013
Abstract 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 (aw) (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−1. 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 (Ea) 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%
ORIGINAL ARTICLE
Rheological behaviour of enzyme clarified sapota (Achras sapota L) juice at different concentration and temperatures Pranjal S. Deshmukh & S. S. Manjunatha & P. S. Raju
Revised: 3 October 2013 / Accepted: 21 November 2013 # Association of Food Scientists & Technologists (India) 2013
Abstract 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 (aw) (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−1. 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 (Ea) 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%
