Forward Osmosis Membrane Concentration Process of Anthocyanins from Pomegranate Fruit

Abstract

The production of concentrated pomegranate juice was investigated by using forward osmosis membrane concentration process. Suspended solids were completely removed in the clarification step, while soluble solids and organic acids were concentrated using forward osmosis membrane process. The processes was performed at ambient temperature (25 ± 2 °C) and non pressure driven process to produce a concentrated extract to a total soluble solids (TSS) content of 60ï‚° Brix from an initial concentration of 4 ï‚°Brix (15 times increase). The antioxidant activity of pomegranate aril juice, attributed to a great extent to total phenols and anthocyanins content, was efficiently preserved during the concentration step independently on the achieved level of total soluble solids. Non-enzymatic browning index and degradation constant for thermally concentrated sample were found to be approximately two (0.78–0.35) and eight (63.0×10−3 to 8.0×10−3 day−1) times, respectively, as compared to the concentrate produced by forward osmosis. An integrated membrane process scheme for the production of concentrated pomegranate juice with potential applications for food, pharmaceutical and cosmetic sectors was proposed.

Keywords: forward osmosis, pomegranate, membrane process, anthocyanins pigment