The aim of this study was to investigate the potential antioxidant effect of olive byproduct extracts during food in vitro digestion. For this purpose, French fries were fried in sunflower oil enriched or not with 100 ppm of olive leaves extract and olive mill wastewater extract. Potato samples corresponding to 5 th and 10th cycles of frying were submitted to in vitro gastrointestinal digestion. Lipids of fried potatoes before and after digestion were extracted and analyzed using Proton Nuclear Magnetic Resonance (1H NMR), paying special attention to potential differences on lipolysis degree, lipid composition and oxidative status.
No significant differences were observed on the extent of lipolysis among samples. As for main acyl groups composition, a higher degradation of linoleic chains (C18:2ꞷ6) was observed in the lipid digests of potatoes fried in non-enriched sunflower oil, in comparison with those corresponding to enriched oils (especially in potato digests of the 5th frying cycle). These results are in agreement with differences observed on primary and secondary oxidation products. During digestion the generation of cis,transhydroperoxy-octadecadienoates and of alkanals was higher in the lipid digests of potatoes fried in non-enriched sunflower oil, than in those fried in enriched oils. These findings suggest that extracts of olive leaves and olive mill wastewater added to frying oils could have a potential antioxidant effect in food lipids during digestion.
Acknowledgments: PID2021-123521OB-I00/ MCIN,AEI/ 10.13039/ 501100011033/ ERDF,UE and EJ-GV IT1490-22