Target and Suspect HRMS Metabolomics for the Determination of Functional Ingredients in 13 Varieties of Olive Leaves and Drupes from Greece

Abstract

The huge interest in the health-related properties of foods to improve health has brought about the development of sensitive analytical methods for the characterization of natural products with functional ingredients. Greek olive leaves and drupes constitute a valuable source of biophenols with functional properties. A novel ultra-high-performance liquid chromatography–quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to identify biophenols through target and suspect screening in Greek olive leaves and drupes of the varieties: Koroneiki, Throumbolia, Konservolia, Koutsourelia, Kalamon, Petrolia, Amigdalolia, Megaritiki, Mastoeidis, Agouromanakolia, Agrilia, Adramitiani and Kolovi. The method’s performance was evaluated using the target compounds: oleuropein, tyrosol and hydroxytyrosol. The analytes demonstrated satisfactory recovery efficiency for both leaves (85.9–90.5%) and drupes (89.7–92.5%). Limits of detection (LODs) were relatively low over the range 0.038 (oleuropein)–0.046 (hydroxytyrosol) and 0.037 (oleuropein)–0.048 (hydroxytyrosol) for leaves and drupes, respectively For leaves, the precision limit ranged between 4.7 and 5.8% for intra-day and between 5.8 and 6.5% for inter-day experiments, and for drupes, it ranged between 3.8 and 5.2% for intra-day and between 5.1 and 6.2% for inter-day experiments, establishing the good precision of the method. The regression coefficient (r2) was above 0.99 in all cases. Furthermore, the preparation of herbal tea from olive leaves is suggested after investigating the optimum infusion time of dried leaves in boiling water. Overall, 10 target and 36 suspect compounds were determined in leaves, while seven targets and thirty-three suspects were identified in drupes, respectively.

Bioactive Compounds in Waste By-Products from Olive Oil Production: Applications and Structural Characterization by Mass Spectrometry Techniques

“…Michel et al used the same analytical approach for an extended investigation on olive leaves metabolites, with 86 compounds identified, including coumarin, described for the first time in O. europaea [108]. The presence of functional compounds in different Greek varieties of olive leaves and drupes was assessed by Kritikou et al using reversed-phase LC coupled to high resolution mass spectrometry [109].…”

Biophenolic Profile Modulations in Olive Tissues as Affected by Manganese Nutrition

“…According to the literature, the pharmacological properties of biophenols include antioxidant [ 6 ], anti-inflammatory [ 7 , 8 ], antimicrobial [ 9 ], antiviral [ 10 ] and anti-carcinogenic activities [ 11 ], as well as beneficial cardiovascular effects [ 12 ]. These effects are attributed strictly to the presence of a range of compounds primarily dominated by phenolic acids (ferulic, vanillic, and caffeic acid), phenolic alcohols (tyrosol and hydroxytyrosol), flavonoids (luteolin-7- O -glucoside, apigenin-7- O -glucoside, rutin, luteolin-4′- O -glucoside, apigenin, and luteolin), hydroxycinnamic acid derivatives (verbascoside), and secoiridoids (oleuropein) [ 3 , 11 , 13 , 14 , 15 ]. In addition to leaves, pruning generates a significant amount of olive stems, an underestimated source of biophenols [ 16 ].…”

HPLC-HRMS Global Metabolomics Approach for the Diagnosis of “Olive Quick Decline Syndrome” Markers in Olive Trees Leaves

“…To date, there are no literature reports of the use of a HPLC-HRMS untargeted method to discover the early infection markers for Xylella fastidiosa -related OQDS. However, several untargeted metabolomics approaches were developed for the characterization and valorization of different Olea europaea cultivars and origins [ 22 , 23 ] and their oils [ 24 , 25 ].…”