Concentration of camu-camu juice by the coupling of reverse osmosis and osmotic evaporation processes

The objective of this work was to evaluate the technical feasibility of coupling two membrane separation processes, reverse osmosis (RO) and osmotic evaporation (OE), in order to concentrate clarified camu-camu juice, focusing on the vitamin C, phenolic compounds and antioxidant activity of the final product. The juice was firstly pre-concentrated by RO, reaching 285 g kg−1 of soluble solids. During this step, the juice's osmotic pressure showed to be the main factor controlling mass transfer. The juice was then concentrated by OE, reaching 530 g kg−1 of soluble solids. Vitamin C, total phenolics and antioxidant activity levels of 94.6 g ascorbic acid kg−1, 105.2 g galic acid kg−1 and 762 mmol Trolox kg−1, respectively, were achieved in the final product. The use of integrated membrane processes proved to be an interesting alternative to the concentration of thermosensitive juices, reaching concentration levels up to 7 times for camu-camu juice's bioactive compounds.