Experimental optimization of nanofiltration with a novel two-stage periodic washing mechanism for bioactive compound concentration in tomato serum.

This study optimized nanofiltration incorporating periodic washing in two successive stages for tomato serum concentration and evaluation of Lycopene content and Vitamin C content. Response surface methodology and desirability optimization identified 120.9 s and 22.3 °C as the selected conditions. The confirmation experiment yielded 3.87 × 10-7 m3 m-2 s-1 for Permeate flux, 0.309 kWh per standardized batch concentration run for Energy consumed, 8.14 mg 100 g-1 for Lycopene content, and 46.41 mg 100 g-1 for Vitamin C content. Concentration factors were 3.36 for lycopene and 3.51 for vitamin C. The overall liquid mass balance closed at 100%, and apparent rejection values for the integrated process were 98.3% and 96.4%, respectively. In five replicate controls without periodic washing at 7 bar and 22.3 °C, complete cessation of flow occurred after a mean of 4.3 min; periodic washing allowed processing to continue to 14°Brix.