Detection of Nitro-Conjugated Linoleic Acid and Nitro-oleic Acid in Virgin Olive Oil under Gastric Conditions: Relationship to Cultivar, Fruit Ripening, and Polyphenol Content

Abstract

Nitro-fatty acids (NO 2 -FAs) are being formed in virgin olive oil (VOO), exhibiting pleiotropic anti-inflammatory responses. We analyzed the fatty acid profile, polyphenols, pigments, and NO 2 -FA levels in two contrasting olive cultivars, Arbequina and Coratina, under two ripening conditions. During in vitro gastric conditions, the extent of nitro-conjugated linoleic acid and nitrooleic acid in Coratina VOO was higher at the intermediate stage. In contrast, Arbequina VOO did not present changes on NO 2 -FA formation. The presence of polyphenols in Arbequina VOO promoted fatty acid nitration, while their absence switched nitration to lipid oxidation processes. In Coratina, the absence of polyphenolic compounds did not affect the NO 2 -FA levels. This is because Coratina contains greater levels of other bioactive constituents such as pigments that could protect VOO from oxidation. Based on these results, we set the conditions where the composition of VOO promotes the formation of NO 2 -FA to enhance its health beneficial properties.

Cercospora leaf spot of olive in Uruguay

“…During autumn, the low to moderate temperatures (10-20°C) accompanied by humid and rainy periods, probably gave favourable conditions for CLS development (Giménez and Castaño, 2013;Ávila et al, 2020). In addition, in Uruguay olive fruits are usually harvested early, between maturity indices of 1 and 2.5, which prioritizes oil quality over yields (Sánchez et al, 2022) and restricts CLS symptom development.…”