A quanti-qualitative study of a phenolic extract as a natural antioxidant in the frying processes

•The phenolic extract (PE) performance as natural additive in continuos frying was studied.•The PE protects the α-tocopherol against oxidation.•The PE hampers the formation of negative volatiles compounds.•The PE gives higher content of French fries phenols for four frying cycles.•The PE can be used in place of synthetic antioxidants. The aim of this work was to evaluate the effects of a phenolic extract from olive mill waste water on the stabilization of refined olive oil and on French fry quality during the frying process. Frozen, pre-fried potatoes were fried at 180 °C for 8 min in refined olive oil enriched by different concentrations of a phenolic extract, while oil enriched by a common synthetic antioxidant (butylated hydroxytoluene) was used for comparison. The whole frying process took six hours. The phenolic extract has revealed as a very promising oil stabilizing agent during frying, playing an important role (dose-dependent) in preserving the antioxidants both in oil and in food, in reducing the formation of unwanted compounds (acrolein and hexanal), and in contrasting the acrylamide production. These results clearly show that the phenolic extract can be used as a source of natural antioxidants to replace (or avoid) synthetic additives in foods or beverages.