Extraction and optimization of guava juice by using response surface methodology

Raw guava juice is turbid, viscous and gray in color. This study was initiated to optimize the enzymatic clarification process of guava juice using response surface methodology. Guava juice was treated with pectinase at various enzyme concentrations (0.01-0.2%), temperatures (30-50°C) and time (30-150 min) of treatment. The effect of enzyme treatments on percentage yield, clarity, turbidity, titrable acidity and viscosity of the juice were studied by employing a second order central composite design. Based on response surface and contour plots, the optimum conditions for clarifying guava juice obtained were: 0.11% enzyme concentration, incubation temperature of 41.30°C and incubation time of 115.98 min with percent yield (80.03%), clarity (1.34 Abs), turbidity (1.07 Abs), titrable acidity (0.525%), viscosity (2.4 cps) and desirability of 0.942. Statistical analysis showed that percentage yield, clarity, viscosity and turbidity were significantly (p<0.05) correlated to enzyme concentration, incubation temperature and incubation time. © 2012 Academic Journals Inc.