Effect of temperature on viscosity of kokum, karonda, mango pulp and cashew apple syrup

Abstract

The viscosity of the food products (kokum, karonda, mango pulp and cashew apple syrup) was determined at temperatures 20ºC, 30ºC, 40ºC, 50ºC and 60ºC and at different spindle speed such as 0.07, 0.09, 0.1, 1.1 and 17 r min^-1 for mango pulp and 17, 140, 150, 160, 180 and 200 r min^-1 for kokum, karonda and cashew apple syrup using Brookfield viscometer.  The kokum, karonda, mango pulp and cashew apple syrup showed shear thinning behavior and pseudo-plastic in nature (n<1).  The viscosity of kokum, karonda, mango pulp and cashew apple syrup decreased with increasing temperature.  For the kokum syrup it decreased from 52.25 to 2.69 mPas, for karonda syrup it was decreased from 43.15 to 7.38 mPas, for cashew apple syrup it decreased from 64.06 to 3.17 mPas and for mango pulp it decreased from 19,581 to 1,669 mPas with increase in temperature from 20ºC to 60ºC.  All the syrups showed the flow behavior index (n) less than 1 indicating pseudoplastic nature.  TSS of kokum syrup, karonda syrup, cashew apple syrup and mango pulp decreased from 16.7 to   15.7 ºBrix, 18.87 to 17.85 ºBrix, 15.5 to 14.65 ºBrix and 26.8 to 25.73 ºBrix respectively with increase in temperature range between 20ºC to 60ºC.

Keywords: kokum, karonda, mango pulp, cashew apple syrup, rheology, viscosity