Separation processes based on colloidal gas aphrons for the recovery of phenolic compounds

This work presents the results of experimentations carried out to determine the main factors affecting the colloidal gas aphrons (CGA) separation of both standard (gallic acid) and real (a red grape marc extract) phenolic compounds and to gain a better insight into the separation mechanism. Batch mode trials were performed in a flotation column set-up (i.d. 4.2 cm, H 50.6 cm) investigating the influence of different parameters: volumetric (CGA/sample) ratio; pH; surfactant type and concentration. Results were evaluated in terms of recovery yield and quality of phenolic compounds in the aphron phase, and of separation factor. Data showed the potential of CGA to separate polyphenolic compounds from real plant extracts. Further research is in progress for optimisation of working parameters and employment of food-grade surfactants is in progress to develop low-cost purification processes for the production of bioactive ingredients.