Characterisation of the phenolic compounds retained in different organic and inorganic filter aids used for filtration of extra virgin olive oil

The aim of this work was to identify and quantify some of the phenolic compounds retained by different filters used for the filtration of two varieties of extra virgin olive oil (Arbequina and Picual). This was performed by HPLC–ESI–TOF and Folin–Ciocalteau spectrophotometric technique. A significant loss in the phenolic concentration with all the tested filter aids was observed. This suggests that the organic filter aids present a higher performance than traditional industrial filters on a laboratory scale, although they show more retentive power regarding the phenolic concentration.