Olive Fruit Ripening Degree and Water Content Relationships with Phenolic Acids and Alcohols, Secoiridoids, Flavonoids and Pigments in Fruit and Oil.

Olive drupe traits (i.e., ripening index and pericarp water content) and minor components (i.e., phenols and pigments in both fruit and oil) are important for human health and are affected by agronomic background. The aim of this study was to investigate the relationship between fruit traits, phenols, and pigments in samples derived from different soil and water management practices. Chromatographic (UHPLC-MS/MS) and spectroscopic (1HNMR and near UV-Vis spectroscopy) techniques were employed for the characterization of olive fruits and oils. The use of various techniques allowed the identification of interesting trace compounds. We observed that most of the fruit phenols (a total of 29 compounds) were correlated with the degree of ripening: most of the phenolic acids (and their derivatives), phenolic alcohols, and secoiridoids were negatively correlated, whereas the majority of the studied flavonoids were positively correlated. The relationship between the ripening index and fruit phenolic compounds appears to be dependent on the metabolic pathway that controls the synthesis of each individual compound. Conversely, the secoiridoids and pigments in olive oil showed a negative correlation with pulp moisture, probably because of the influence of the water content on the extractability and transfer in the oil phase of these minor components.

Revealing adulterated olive oils by triacylglycerol screening methods: Beyond the official method.

Official control methods to detect olive oil (OO) adulteration fail to provide satisfactory consumer protection. Thus, faster and more sensitive screening tools are needed to increase their effectiveness. Here, the official method for adulterant detection in OO was compared with three untargeted screening methods based on triacylglycerol analysis using high-throughput (FIA-HESI-HRMS; HT-GC-MS; HPLC-RID) and pattern recognition techniques (PLS-DA). They were assayed on a set of genuine and adulterated samples with a high natural variability (n = 143). The sensitivity of the official method was 1 for high linoleic (HL) blends at ≥2 % but only 0.39 for high oleic (HO) blends at ≥5 %, while specificity was 0.96. The sensitivity of the screening methods in external validation was 0.90-0.99 for the detection of HL and 0.82-0.88 for HO blends. Among them, HT-GC-MS offered the highest sensitivity (0.94) and specificity (0.76), proving to be the most suitable screening tool for OO authentication.

Cations and Phenolic Compounds Concentrations in Fruits of Fig Plants Exposed to Moderate Levels of Salinity.

Fig trees are often grown in areas affected by salinity problems. We investigated changes in the concentrations of 15 phenolic compounds and mineral elements (Mg, Ca, K, Zn, Cu, Mn, Mo, Fe, Na) in fruits of fig plants (Ficus carica L. cv. Dottato) subjected to irrigation with saline water (100 mM of NaCl) for 28 days. We used UHPLC-MS/MS techniques to determine chlorogenic acid, tiliroside, catechin, epicatechin (ECTC), p-coumaric acid, trans-ferulic acid, phloridzin, phloretine, quercetagetin 7-O-glucoside, rutin, quercetin 3-O-glucoside, kaempferol 3-O-rutinoside, kaempferol 7-O-glucoside, kaempferol 3-O-glucoside, and quercetin. There was a steep gradient of Na+ concentrations between the root and the canopy of salinized plants, but leaf Na+ was similar in control and salt-treated plants. Quercetin, ECTC, and chlorogenic acid were the most abundant phenolic compounds in fig fruits. Salinity increased total phenols by 5.6%, but this increase was significant only for ECTC. Salt stress significantly increased Zn and Mg concentration in the fruit. Leaf levels of K, Mg, Ca, and Mn were similar in control and salinized plants. Moderate salt stress appears to improve fig fruit quality because of its positive effect on nutrients and antioxidant compounds such as epicatechin.

Near UV-Vis and NMR Spectroscopic Methods for Rapid Screening of Antioxidant Molecules in Extra-Virgin Olive Oil.

Several spectroscopic techniques have been optimized to check extra-virgin olive oil quality and authenticity, as well as to detect eventual adulterations. These methods are usually complementary and can give information about different olive oil chemical components with bioactive and antioxidant properties. In the present work, a well-characterized set of extra-virgin olive oil (cultivar Frantoio) samples from a specific area of Tuscany (Italy) were investigated by combining near UV-Vis absorption spectroscopy, 1H and 13C nuclear magnetic resonance (NMR) to identify and quantify different chemical components, such as pigments, secoiridoids and squalene, related to the nutritional and quality properties of olive oils. Moreover, the pigmentation index of olives, organoleptic and sensory properties, total phenolic compound contents and the lipidic fractions of olive oils were investigated. The results obtained are, finally, compared and discussed in order to correlate several properties of both olives and olive oils with specific features of the cultivation area.