Singular Olive Oils from a Recently Discovered Spanish North-Western Cultivar: An Exhaustive 3-Year Study of Their Chemical Composition and In-Vitro Antidiabetic Potential

Abstract

In this work, the quality and physicochemical parameters, phenolic composition, and antidiabetic potential of olive oils obtained from olives belonging to centenarian olive trees of the so-called ‘Mansa de Figueiredo’ cultivar were evaluated during three consecutive crop seasons (2017–2019). The oils produced during the three crop years were classified as extra virgin based on the quality-related indices, sensory analysis, and the genuineness-related parameters. In addition, LC-ESI-TOF MS was used to get a comprehensive characterisation of the phenolic fraction while LC-ESI-IT MS was applied for quantitation purposes. The content of phenolic compounds (ranging from 1837 to 2434 mg/kg) was significantly affected by the harvest year due to the environmental conditions and ripening index. Furthermore, although significant differences in the inhibitory effects against the α-glucosidase enzyme for the EVOOs extracted throughout the three successive years were detected, all the studied EVOOs exhibited a stronger inhibitor effect than that found for acarbose.

Combining Zeolites with Early-Maturing Annual Legume Cover Crops in Rainfed Orchards: Effects on Yield, Fatty Acid Composition and Polyphenolic Profile of Olives and Olive Oil

“…Regarding fruit fat composition ( Table 7 ), the most abundant FAME of olive oil was oleic acid (C18:1), ranging between 74.5% to 77.4%, followed by palmitic acid (C16:0), between 12.7% up to 14.7%, and linoleic acid (C18:2), from 5.0% to 8.4%. The obtained values accounted for 95.8% to 98.2% of the total fatty acid composition, being in accordance with those found in the literature [ 8 , 45 , 54 ]. At the same time, all percentages of fatty acids fell within the recommended ranges for EVOO set by EU Regulation (Commission Implementing Regulation, 2019/1604) [ 55 ].…”

“…In fact, in the olive oil samples from 2018, higher concentrations of hydroxytyrosol, hydroxytyrosol acetate, oleuropein aglycone, caffeic acid, 3,4-DHPEA-EDA, verbascoside, oleuropein, rutin and apigenin were found, whereas in the olive oil samples from the 2019 harvest, superior levels of DHPG, tyrosol, luteolin-7-glucoside and apigenin-7- O -glucoside were observed. Changes in the phenolic composition between crop seasons have also been verified by other researchers [ 43 , 44 , 45 ].…”