Oleocanthal Quantification Using 1H NMR Spectroscopy and Polyphenols HPLC Analysis of Olive Oil from the Bianchera/Belica Cultivar

Abstract

The cultivar Bianchera is an autochthonous variety from the eastern part of northern Italy, but it is also cultivated in the Slovenian and Croatian peninsula of Istria where it is named Belica (Slovenia) and Bjelica (Croatia). The properties of oleocanthal, a natural anti-inflammatory ibuprofen-like compound found in commercial monocultivar extra virgin olive oils, were determined by means of both quantitative 1H NMR (qNMR) and HPLC analyses, where qNMR was identified as a rapid and reliable method for determining the oleocanthal content. The total phenolic content (TPC) was determined by means of the Folin–Ciocalteau method and the major phenols present in the olive oils were also quantified by means of HPLC analyses. All these analyses confirmed that the cultivar Bianchera was very rich in polyphenols and satisfied the health claim provided by the EU Commission Regulation on the polyphenols content of olive oils and their beneficial effects on human health.

The Tower of Babel of Pharma-Food Study on Extra Virgin Olive Oil Polyphenols

“…For these reasons, high-resolution mass spectrometry (HRMS, such as TOF, Q-TOF, Orbitrap, and FTICR), which provides excellent mass accuracy and measurements of the correct isotopic pattern, especially when combined with tandem mass spectrometry experiments, appears as the best choice to achieve definitive characterization and identification of EVOO polyphenols [41][42][43]. In many cases where mass spectral data are insufficient to establish a definitive structure for these complex phenolic compounds, nuclear magnetic resonance spectroscopy (NMR) is a powerful complementary technique for the structural assignment [44,45]. Further attempts have been used in recent years with a special coupling technique, LC-NMR [46][47][48].…”

Impact of fresh olive leaves addition during the extraction of Arbequina virgin olive oils on the phenolic and volatile profiles

“…The two dialdehydic forms, oleocanthal and oleacein, are formed by hydrolysis of the methyl ester followed by decarboxylation. The hydrolysis and decarboxylation reactions can occur either enzymatically or chemically due to the acidic aqueous conditions of the extraction (Starec, Calabretti, Berti & Forzato, 2021). Recently, two methylesterase enzymes (elenolic acid methylesterase 1 & 2) have been identified, being responsible for the conversion of the monoaldehydic aglycones forms (from the β-glucosidase action on oleuropein and ligstroside) into oleacein and oleocanthal (Volk et al, 2019).…”

Nuclear magnetic resonance analysis of extra virgin olive oil: classification through secoiridoids

“…Additionally, according to cited literature, 5 the same compound in chloroform has H‐8 at 6.61 ppm (q, 7.1 Hz) and H‐10 at 2.04 ppm (d). Moreover, the H‐6′ proton at 6.60 ppm (dd) and the H‐5′ at 6.70 ppm (d, 7.9). Moreover, according to cited literature, 11,38 the dialdehydic form of ligstroside lacking a carboxymethyl group (oleocanthal, 12 ) has its H‐8 proton resonating at 6.65 ppm (q, 7.0) (and its H‐3 proton at 9.54 ppm (s, br)). Additionally, the H‐2′ proton of oleuropein aglycon ( 7 ) resonates at 6.65 ppm (d, 1.8) (and its H‐3 at 9.5 ppm). According to cited literature, 39 the H‐8 proton of oleocanthalic acid ( 18 ). Finally, at the C,A region of Fig. 2, oleokoronal ( 10 ) is expected to resonate at the above region (whereas ligstrodial protons are not expected in this region).…”

“…Moreover, the H-6 0 proton at 6.60 ppm (dd) and the H-5 0 at 6.70 ppm (d, 7.9). (ii) Moreover, according to cited literature, 11,38 the dialdehydic form of ligstroside lacking a carboxymethyl group (oleocanthal, 12) has its H-8 proton resonating at 6.65 ppm (q, 7.0) (and its H-3 proton at 9.54 ppm (s, br)). (iii) Additionally, the H-2 0 proton of oleuropein aglycon (7) resonates at 6.65 ppm (d, 1.8) (and its H-3 at 9.5 ppm).…”