Anti-fouling tight ultrafiltration membrane for gastrodin purification

The issues of flux decline and irreversible membrane fouling must be considered in membrane separation . In this paper, the culture medium, bacterial cells, and proteins were removed using a one-step tight ultrafiltration (UF) membrane separation process. Although the membrane resistance of the tight UF membranes increased owing to their smaller pore size, the stable flux of the 6 nm membrane during fermentation broth filtration of gastrodin was 28.0% higher than that of loose UF membranes, and the flux recovery ratio reached 97.3%. During purification, a higher filtration flux was obtained by retaining the operating pressure within the range of 2–3 bar and the operating temperature range of 50–60 °C. The average flux of a 6 nm 19-channel membrane reached 56 L·m −2 ·h −1 , and the total yield of gastrodin reached 96.2%. This study provides a basis for the large-scale application of tight UF membrane in food industry.