Nitro-fatty acids formation in Virgin Olive Oil during gastric digestion and its relationship to cultivar and fruit ripening

Abstract

19Virgin olive oil (VOO) represents the main source of unsaturated lipids in the 20 Mediterranean diet associated with low mortality. Health benefits of VOO rely on 21 its composition, mainly fatty acids and minor components such as polyphenols. 22 In addition, VOO contains nitro-fatty acids (NO 2 -FA), novel signaling mediators 23 exhibiting pleiotropic anti-inflammatory responses. Previous work from our group 24 reported the presence of nitro-oleic acid (NO 2 -OA), nitro-linoleic acid (NO 2 -LA) 25 and nitro-conjugated linoleic acid (NO 2 -cLA) in extra virgin olive oil under gastric 26 conditions. Herein, we analyzed the fatty acid profile, phenol, pigment and NO 2 - 27FA formation in two contrasting Uruguayan olive cultivars, Arbequina and 28 Coratina at two ripening conditions. We demonstrate that VOO fatty acid nitration 29 is dependent on olive cultivar as well as fruit ripening. Under gastric nitration 30 conditions, the presence of polyphenols in Arbequina VOO promoted fatty acid 31 nitration. In contrast, the absence of polyphenols favor lipid oxidation, decreasing 32 fatty acid nitration. In Coratina, where the content of polyphenolic compounds is 33 higher than in Arbequina, their absence did not affect the formation of NO 2 -FA. 34Coratina contains other bioactive constituents such as pigments that could play 35 an important role in protection of VOO from lipid oxidation. Overall, we postulate 36 that unsaponifiable constituents of VOO, e.g. polyphenols and pigments, 37 contribute to the formation of NO 2 -FA in gastric conditions, thus potentiating their 38 health beneficial 39 3 40 42 component in diets of high nutraceutical value. According to IOC data [1], the total 43 world consumption of olive oil increased by 55% between 1990 and 2000 and an 44 additional 25% between 2000 and 2010, remaining constant until 2018. This 45 represents an incremental difference of 80% in the last 28 years. This increase 46 responds to the knowledge generated about the health benefits of olive oils, 47which are attributed to its composition and the physical extraction process 48 distinguished as a natural fruit juice [2,3,4,5,6,7,8,9,10,11]. The saponifiable 49 fraction represents 98% of the oil weight being oleic acid (18:1, OA) the fatty acid 50 in greater proportion between 55 and 83%. Linoleic acid (18:2, LA) can reach 51 20% and linolenic acid (18:3, LnA) up to 1%. The main saturated fatty acid is 52 palmitic acid (16:0, PA) with percentages between 7.5 and 20%, followed by 53 stearic acid (18:0, SA) from 0.5 to 5% [1]. The unsaponifiable fraction, which 54 represents approximately 2% of the total weight, includes chlorophylls, volatile 55 compounds, carotenoids and phenols, the latter being the main antioxidant 56 components in VOO. These compounds also define sensory quality, bitterness, 57 spiciness, aromas and are associated with human health benefits 58 [3,7,8,12,13,14,15,16]. Moreover, VOO contains a high monounsaturated fatty 59 acids (MUFA)/ polyunsaturated fatty acids (PUFA) ratio that confers...

An overview of food lipids toward food lipidomics

“…They are produced with high stereospecificity by a variety of enzymes, predominantly the LOX, cyclooxygenase (COX), and cytochrome P450 families (Hajeyah et al., 2020; Mosblech et al., 2009). Nitro FAs are formed by the reaction of FAs with reactive nitrogen species and are generated in humans through the electrophilic addition of nitric oxide and related species to UFAs in the gastric system, although they are also endogenously present in plants, such as olives (Fazzari et al., 2014; Sánchez‐Calvo et al., 2019; Winkler & Hertweck, 2007). Oxidized FA can be found free (e.g., oxylipins) or esterified to complex lipids, leading to the formation of oxidized triglycerides or oxidized PLs.…”