Virgin Olive Oil Extracts Reduce Oxidative Stress and Modulate Cholesterol Metabolism: Comparison between Oils Obtained with Traditional and Innovative Processes.

Carmen Lammi,Carlo Franchini,Carlotta Bollati,Lorenzo Cecchi,Filomena Corbo,Maria Lisa Clodoveo,Nadia Mulinacci,Maria Bellumori,Anna Arnoldi,Martina Bartolomei

doi:10.3390/antiox9090798

Abstract

This study was aimed at demonstrating the substantial equivalence of two extra virgin olive oil samples extracted from the same batch of Coratina olives with (OMU) or without (OMN) using ultrasound technology, by performing chemical, biochemical, and cellular investigations. The volatile organic compounds compositions and phenolic profiles were very similar, showing that, while increasing the extraction yields, the innovative process does not change these features. The antioxidant and hypocholesterolemic activities of the extra virgin olive oil (EVOO) phenol extracts were also preserved, since OMU and OMN had equivalent abilities to scavenge the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals in vitro and to protect HepG2 cells from oxidative stress induced by H2O2, reducing intracellular reactive oxygen species (ROS) and lipid peroxidation levels. In addition, by inhibiting 3-hydroxy-3-methylglutarylcoenzyme a reductase, both samples modulated the low-density lipoprotein receptor (LDLR) pathway leading to increased LDLR protein levels and activity.

Highlights

New lifestyles, higher incomes, and consumer awareness are creating consumer demand for high-quality, diverse, and innovative food products
The positive attributes are mainly associated to the volatile organic compounds (VOCs) originated from the lipoxygenase (LOX) pathway, whereas other classes of VOCs are associated to the main sensory defects [19,20,33,34]
These results indicate that the new ultrasound process does not impair the molecular mechanism through which extra virgin olive oil (EVOO) extracts promote hypocholesterolemic effect through the modulation of Hydroxy-3-Methylglutaryl Coenzyme a Reductase (HMGCoAR) activity, an enzyme that is crucial in cholesterol biosynthesis and is the well-known target of statins [45,54]

Summary

Introduction

Higher incomes, and consumer awareness are creating consumer demand for high-quality, diverse, and innovative food products. European research programs supporting new technologies and innovative products are continuously introduced in the food market. Our interdisciplinary research team is applying an innovative and sustainable process method to produce high-quality, cost-effective, and resource-efficient extra virgin olive oil (EVOO), employing an emerging technology based on the simultaneous treatment of olive paste both with ultrasound and heat-exchange [3,4,5]. Due to the mechanical effects of the sound waves within the olive paste, it is possible to eliminate the malaxation, the only batch phase in the continuous extraction process. When the negative pressure values are below the water vapor pressure in the olive paste, it undergoes a phase change from liquid to gas, forming cavities containing steam and giving rise to the phenomenon of cavitation. If implosion occurs near the cell wall of the olive fruit, it generates a liquid microjet that breaks the wall, freeing oil and minor compounds [16]

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Conclusion