Mathematical Modelling the Drying Kinetics of Beetroot Strips during Convective Drying at Different Temperatures

  • S. S. Manjunatha DRDO-Defence Food Research Laboratory, Mysore-570 011, India
  • P. S. Raju DRDO-Defence Food Research Laboratory, Mysore-570 011, India
Keywords: Beetroot strips, Beta vulgaris L., Convective drying, Drying models, Arrhenius equation, Effective moisture diffusivity, Activation energy


The thin layer drying of beetroot strips was evaluated at drying temperatures from 60 °C to 90 °C using convective dryer at inlet air velocity of 1.0 m/s. The different drying models were tested to evaluate the drying characteristics of beetroot strips. The investigations showed that Page’s and modified Page’s equations were satisfactorily describing the drying behaviour of beetroot strips during convective drying with appreciable high correlation coefficient (0.9971<r<0.9990) with low error values. The effective moisture diffusivity was increased from 3.563 x 10-10 m2/s to 8.038 x 10-10 m2/s with increase in drying temperature. The temperature dependency of effective moisture diffusivity was described by Arrhenius equation and activation energy for moisture diffusivity was 30.08 KJ/mol. The drying kinetic coefficients were significantly (p<0.05) affected by drying air temperature. The exponents of models were decreased linearly with drying air temperature during drying of beetroot strips. The equilibrium moisture content was markedly affected by drying air temperature and it decreased linearly with drying air temperature. The results were very useful in standardisation and optimisation of drying process of beetroot strips in large scale commercial production.

Author Biographies

S. S. Manjunatha, DRDO-Defence Food Research Laboratory, Mysore-570 011, India

Mr S.S. Manjunatha obtained MSc (Physics) from Mysore University, and presently working as Scientist D in DRDO-Defence Food Research Laboratory, Mysore. He has developed various quick cooking dehydrated vegetable curry mixes, spray dried fruit juice mixes, He is working in the areas of food engineering, processing engineering, Food texture and Food rheology. He also was working on mathematical modelling of food processes.

P. S. Raju, DRDO-Defence Food Research Laboratory, Mysore-570 011, India

Dr P.S. Raju obtained his in PhD in Botany. Presently working as Fellow in DRDO-Defence Food Research Laboratory, Mysore


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How to Cite
Manjunatha, S., & Raju, P. (2019). Mathematical Modelling the Drying Kinetics of Beetroot Strips during Convective Drying at Different Temperatures. Defence Life Science Journal, 4(2), 140-149.
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