New Strategies in the Cultivation of Olive Trees and Repercussions on the Nutritional Value of the Extra Virgin Olive Oil

Abstract

The health advantages of extra-virgin olive oil (EVOO) are ascribed mainly to the antioxidant ability of the phenolic compounds. Secoiridoids, hydroxytyrosol, tyrosol, phenolic acid, and flavones, are the main nutraceutical substances of EVOO. Applications of beneficial microbes and/or their metabolites impact the plant metabolome. In this study the effects of application of selected Trichoderma strains or their effectors (secondary metabolites) on the phenolic compounds content and antioxidant potential of the EVOOs have been evaluated. For this purpose, Trichoderma virens (strain GV41) and Trichoderma harzianum (strain T22), well-known biocontrol agents, and two their metabolites harzianic acid (HA) and 6-pentyl-α-pyrone (6PP) were been used to treat plants of Olea europaea var. Leccino and var. Carolea. Then the nutraceutical potential of EVOO was evaluated. Total phenolic content was estimated by Folin–Ciocalteau’s assay, metabolic profile by High-Resolution Mass spectroscopy (HRMS-Orbitrap), and antioxidant activity by DPPH and ABTS assays. Our results showed that in the cultivation of the olive tree, T22 and its metabolites improve the nutraceutical value of the EVOOs modulating the phenolic profile and improving antioxidants activity.

An Environmentally Friendly Practice Used in Olive Cultivation Capable of Increasing Commercial Interest in Waste Products from Oil Processing

“…The industry requires phenolic compounds to produce functional foods, supplements, food additives, and the formulation of cosmetics and drugs [5,33,34]. Trichoderma species promote the production of phytochemicals, including phenolic compounds [23,26], whose production varies according to the strain used [35]. Previous studies have discussed that the Trichoderma can enhance phenols in EVOO and olive leaves [1,35].…”

“…Trichoderma species promote the production of phytochemicals, including phenolic compounds [23,26], whose production varies according to the strain used [35]. Previous studies have discussed that the Trichoderma can enhance phenols in EVOO and olive leaves [1,35]. In this work, we tested the ability of the Trichoderma to increase the concentration of phenolic compounds in the olive pomace and the olive vegetation water.…”

Endophytic Fungi of Olive Tree

“…As soon as interactions between endophytes and plants have been disclosed, it has been argued that they can be exploited for the development of innovative applications in sustainable but still highly productive cultivation systems ( [17], and literature therein), similarly to the better known other groups of microbes. As a result of the rising demand for organic agricultural products, perspectives for the application of these microorganisms as potential biopesticides and biofertilizers have become more consistent in the olive sector too [18], along with an incremental interest for the search and identification of species-specific endophytes [19]. Tables 1 and 2 list records concerning occurrence of endophytic fungi in olive tree as inferred from examination of the available literature and GenBank accessions.…”

“…Strains of Trichoderma , mainly reported from Portugal and ascribed to at least four species, have already been experimentally evaluated on olive tree, with reference to both kinds of beneficial effects, particularly for the biocontrol of V. dahliae and N. solani [ 18 , 69 , 70 , 71 ]. The typical soil fungus Penicillium restrictum has been reported as an antagonist and mycoparasite of several plant pathogens [ 72 ], but other Penicillium spp.…”

An Innovative Olive Pâté with Nutraceutical Properties

“…Olives contain polyphenols [ 31 , 32 ], biomolecules with antioxidant activity able to decrease the risk of cancer, cardiovascular diseases, and inflammation [ 33 , 34 , 35 , 36 ]. Polyphenols are amphiphilic molecules, some of which are more soluble in water, others in oil; therefore, some classes are more concentrated in the extra virgin olive oil, others in the vegetation water fraction.…”