Optimizing of Tomato Juice Clarification Process by Immobilized Commercial Pectinase Using Response Surface Methodology

The pectinase enzyme has a great importance in the food industry. It is capable of decomposing Pectin significantly, which is the substantial element of turbidity of the juices. As a result, it plays an important role in clarification also ability to maintain organoleptic properties and quality of nutrients. The usage of enzymes in the industry is costly and some measures should be taken to allow the enzyme to be used several times without altering its efficiency. In this research the commercial pectinase enzyme was immobilized on calcium alginate beads. Free and immobilized enzymes activities in different temperatures and pH were determined. Then storage stability and reusability of enzyme were investigated. For optimized clarification of tomato juice by immobilized enzyme, the response surface methodology was used. Three factors including temperature (30-45°C), time (15-45 min) and enzyme concentration (2-6%) in 3 levels were used to evaluate the effect of parameters on turbidity of tomato juice as a model system, the importance of interacting the effects of factors also determined. Optimization has been conducted to achieve the lowest turbidity of tomato juice at the lowest used enzyme. Optimized conditions achieved by concentration of immobilized enzyme 2%, temperature 45◦C and time 45min, and with yield of clarification 27/09 times for tomato juice. Results showed that the best temperature and pH for free and immobilized enzymes were 45°C and 3, respectively.