This work reports the results of some preliminary studies aimed at analyzing key factors involved in separation with colloidal gas aphron (CGA) both of standard phenolic compounds (i.e. gallic acid), as well as complex phenolic mixtures (i.e. extract of grape pomace). In particular, during the experiment several batch tests were carried out by using a flotation column of 4.2 mm internal diameter and 50.6 cm height. The analyzed parameters are: the volumetric CGA/sample ratio (varied in 1-24 range), pH (varied in 3-8 range), type (CTAB and Tween 20) and concentration (varied in 1-10 mM range) of the surfactant. The results were evaluated in terms of percent recovery, quality of phenolic compounds in aphron phase and separation factor. The results show the effectiveness of CGA in the separation of phenolic compounds from plant extracts. However, the authors argue that further studies are needed to improve the selectivity of extraction and optimize operating parameters. Through the use of surfactants for food use, the proposed system is an interesting technology able to obtain, economically, natural bioactive ingredients.
G. Spigno et al., Convegno GRICU 2012, Montesilvano (PE), 16-19 September 2012, pag.75-78