Integrated membrane separation processes aiming to concentrate and purify lycopene from watermelon juice

- Microfiltration and diafiltration processes concentrate lycopene almost 5.6 times.
- Sugars content decreased 51%, 26% and 100% for glucose, fructose and sucrose,
- Permeate flux throughout reverse osmosis does not rapidly decline over time.
- Final extract presented a lycopene content almost 18 higher than the fresh juice.
- The final extract presented a dark red color (L * = 37.09).

The increasingly consumer demand for ingredients obtained from natural sources and sustainable processes represents for the industry the challenge to place on the market innovative products with high added value. Watermelon is known for its high lycopene content, the red pigment with recognized antioxidant properties. This work investigated the integration of microfiltration, diafiltration and reverse osmosis processes to obtain a low sugar lycopene-rich extract from watermelon juice. Permeate flux, lycopene and sugars content, the antioxidant capacity and color parameters were used to evaluate the performance of the integrated membrane processes. Average permeate fluxes of microfiltration/diafiltration and reverse osmosis processes were 69.6 and 19.1 kg h− 1 m− 2, respectively. An increase up to 17 and 11 times in lycopene content and antioxidant capacity as well as a decrease in sugars concentration were achieved. The final product showed a dark red color, as highlighted by the brightness value (L *) of 37.06.Industrial relevanceWatermelon juice concentration can be an alternative to produce lycopene-rich products, especially colorants and antioxidants. Membrane processes are a good alternative to the conventional thermal concentration once they operate at milder temperature conditions avoiding the undesirable losses of heat-sensitive compounds as well as sensorial characteristics as color and flavor. The integration of microfiltration, diafiltration and reverse osmosis can be useful to obtain a lycopene-rich extract from watermelon juice, with low sugar content.