Rhamnolipid assisted recovery of lycopene from the tomato-based processing wastewater using foam fractionation

The feasibility of foam fractionation for recovering lycopene from the tomato-based processing wastewater was investigated by using tomato proteins as the collectors. Rhamnolipid would be used as the foam stabilizer to improve the interfacial adsorption of protein-lycopene complex. Under the optimal conditions of rhamnolipid concentration 1.5 g/L, temperature 50 degrees C, pH 7.0, volumetric gas flow rate 150 mL/min and loading liquid volume 500 mL, the enrichment ratio and the recovery percentage of lycopene were 4.42 and 83.43%, respectively. Meanwhile, the recovery percentage of rhamnolipid reached 94.52% in the foamate. Moreover, rhamnolipid in the supernatant of the foamate could be reused to recover lycopene from tomato-based processing wastewater for three times with a constant recovery percentage of lycopene. This work has provided a new insight into the recovery of a non-surface-active material from its aqueous solution and is expected to facilitate the research on the resourceful treatment of food wastewaters. (C) 2015 Elsevier Ltd. All rights reserved.