A new spiral press filter to purify tomato juice: A central composite strategy for experimental design and optimization

Abstract

We investigated and optimized the simultaneous effects of pressure and fluid temperature on the tomato juice filtration process. For this purpose, we manufactured a new spiral press filter. This filter is innovative in that it has a fixed spiral cylinder, while the fluid travels along the spiral path using hydraulic force. This design has the advantages of both press filters and spiral press filters. The turbidity of filtered tomato juice decreased from 1632NTU to 643NTU. The optimum conditions for the tomato juice filtration process were found to be 6 bar fluid pressure and 45 °C fluid temperature. These conditions resulted in a desirability index of 0.99, which is a very good value. The optimum values of the response variables, including permeate flux, total energy consumption, lycopene content, and vitamin C content of filtered tomato juice were 503.15 × 10−6 m3 m2 s−1, 0.033 kWh, 2.44 mg 100 g−1, and 13.40 mg 100 g−1, respectively.