Effect of membrane filtration on the flavor of virgin olive oil

Cross-flow microfiltration (MF) and ultrafiltration (UF) with different commercial membranes were applied to virgin olive oil (VOO) in order to remove some compounds that are responsible for oil unplea- sant flavor without altering the oil composition. Experimental tests were carried out using a Spanish VOO from Andalusia, which had the typical eucalyptus aroma. Several classical analytical parameters (acidity, peroxide number, UV absorbance) were determined. Moreover, the contents of total chlorophyll and minor polar compounds were detected. The effect of filtration on oil aroma was evaluated by detecting carbonyl compounds and by a panel of trained tasters. The UF Carbosep M1 membrane was the most suitable for softening the oil organoleptic features. Carbosep UF M1 and MF M14 membranes also induced a reduction of the content of total chlorophyll, which certainly slowed down the oil oxidation processes. It should be considered, however, that the observed decrease in the content of phenolic com- pounds with Carbosep M1 might have an adverse affect on the oil’s stability to oxidation, but the observed decrease in total chlorophyll content should oppose it.