Equations for the Calculation of Viscosity of Fruit Juice and Syrup

K. KOLAROV, K. DINKOV, N. MENKOV and D. ZHELYAZKOV
Higher Institute of Food Industry, BG-4000 Plovdiv, Bulgaria

Abstract

KOLAROV, K., K. DINKOV, N. MENKOV and D. ZHELYAZKOV, 2001. Equations for the calculation of viscosity of fruit juice and syrup. Bulg. J. Agric. Sci., 7: 451-453

Experimental data were used for two juice groups: fruit juices (apple, grape, sour cherry) and berry juices (raspberry, strawberry). The mathematical models were determined on the basis of arithmetical mean values of viscosity under varying input operating factors: temperature range from 20 to 80 °C and dry matter concentration of 10 to 50%. A generalised model of the temperature effect on viscosity was obtained for the two juice groups (fruit and berry juices). Empirical models of the dependence of the a and b generalised model coefficients on the dry matter concentration were determined. The generalised mathematical models presented describe the experimental results with sufficient accuracy and are suitable for application in engineering practice.

Key words: fruit juice and syrup, viscosity, regression models, concentration, temperature