Extra virgin olive oil and its co-products: technologies for facing new sector challenges
It has been widely demonstrated that a heterogenic group of bioactive components including mono-unsaturated and polyunsaturated fatty acids, natural antioxidants and volatile compounds is responsible for the biological, health-promoting and sensorial properties of extra virgin olive oil (EVOO). Phenolic and volatile compounds represent the most important contributors to EVOO quality. The first group are considered the principal bioactive compounds of EVOO (secoiridoid derivatives, in particular), showing high antioxidant activity and developing an important role in preventing and/or reducing several human diseases. Moreover, the phenols are the compounds of impact for the characteristic notes of EVOO bitterness and pungency. Aldehydes, alcohols and esters are produced enzymatically by the lipoxygenase pathway during the oil mechanical extraction process (OMEP). They represent the most important key odorants responsible for the positive aroma notes found in high-quality EVOOs. The concentration of those compounds in EVOO depends on several agronomic and technological factors. Besides technological factors, crushing and malaxation operative conditions are the critical points in the OMEP, affecting the hydrophilic phenol and volatile content of EVOO. Current scientific research is focused on the improvement of EVOO yield and quality, with particular attention on optimization of the working efficiency of the extraction plant, aimed at reducing malaxation time. Several technological solutions can be adopted as alternative thermal conditioning systems during the preparation of the olive paste. Much effort has been made in the valorization of olive oil co-products (pomaces and olive-vegetation waters (OVW)), providing economic advantages for the olive oil sector and minimizing their polluting load. The best way of valorizing OVW is considered to be recovery of the phenolic fraction, for its use as an active ingredient in foods, on which it also exerts antioxidant and antimicrobial activity, while stoned pomaces are added to animal feed, improving the quality and oxidative stability of milk, cheese and meat.
Servili, M., Taticchi, A., Esposto, S., Urbani, S., Veneziani, G., Sordini, B., Di Maio, I. and Selvaggini, R. (2018). Extra virgin olive oil and its co-products: technologies for facing new sector challenges. Acta Hortic. 1199, 449-458
phenolic and volatile compounds, technological strategies, valorization of olive oil co-products