Enzymatic clarification of carrot juice by using response surface methodology

Abstract

Carrot juice was treated with pectinase at various enzyme concentrations (0.01% to 0.1%), process temperatures (350C to 550C) and incubation time (40 to 120 min).  The effect of these enzyme treatments on filterability, clarity, turbidity and viscosity of the juice were studied by employing a second order central composite design.  The coefficient of determination (R2) values for filterability, clarity, turbidity and viscosity were greater than 0.85.  Statistical analysis showed that filterability, clarity, viscosity and turbidity were significantly correlated to enzyme concentration, incubation temperature and incubation time.  Enzyme concentration was the most important factor affecting the characteristics of the carrot juice as it exerted a highly significant influence on all the dependent variables.  An increase in process time and/or concentration of enzyme treatment was associated with an increase in filterability and clarity, and decrease in turbidity and viscosity.  Based on response surface and contour plots, the optimum conditions for clarifying carrot juice were 0.092% enzyme concentration, incubation temperature of 54.20C and incubation time of 119 min.

Keywords: carrot juice, enzyme clarification, response surface methodology