Optimization of Processing Parameters for Clarification of Blended Carrot-orange Juice and Improvement of its Carotene Content

Abstract

The aim of this work was to optimize the processing parameters for the clarification of blended carrot-orange juice using Response Surface Methodology (RSM) and to improve the carotene content. The blended carrot-orange juice was treated with Pectinex Ultra SP-L enzyme at different concentrations (0.04- 0.12%), pH (2.5-5), reaction temperature (40-60oC) and time (70-110 min). The effect of these independent variables on clarity, turbidity, and viscosity of the carrot-orange juice was evaluated (coefficient of determination (R2) greater than 0.9). From the RSM analysis, the optimum processing conditions were found as; 0.06% (w/v) enzyme concentration, 3.6 pH, 49oC temperature, 91 min reaction time. The estimated carotene content in raw juice was higher (＞5 mg/mL) than that of clear juice (＜5 mg/mL) following enzymatic clarification. None the less, the combination of blended carrot-orange juice with 2-Hydroxypropyl-$-Cyclodextrin prior to clarification improved carotene content by threefold compared to clear juice. Hence, the clear carrot-orange juice favorably improves the nutritional content and consumer acceptance.