Stability assessment of lycopene microemulsion prepared using tomato industrial waste against various processing conditions

BACKGROUNDGreen separation techniques are growing at a greater rate than solvent extraction as a result of the constant consumer drive to go natural'. Considering the increasing evidence of the health benefits of lycopene and massive tomato industrial waste, in the present study, lycopene was extracted from tomato industrial waste using microemulsion technique and its mean droplet size and size distribution was determined. Moreover, the effects of pasteurization, sterilization, freeze-thaw cycles and ultraviolet (UV) irradiation on the thermodynamic stability, turbidity and lycopene concentration of the lycopene microemulsion were monitored. RESULTSFreeze-thaw cycles, pasteurization and short exposure to UV irradiation showed no or negligible influence on lycopene content and turbidity of the microemulsion. However, long exposure to UV (260 min) reduced the lycopene content and turbidity by 34% and 10%, respectively. HHST (higher-heat shorter-time) and sterilization also reduced lycopene content (25%) and increased turbidity (32%). CONCLUSIONThe lycopene microemulsion showed satisfactory stability over a process where its monodispersity and nanosize could be of potential advantage to the food and related industries. Regarding the carcinogenicity of synthetic colourants, potential applications of the lycopene microemulsion include in soft drinks and minced meat, which would result in a better colour and well-documented health-promoting qualities. (c) 2017 Society of Chemical Industry