n-Alkanes and n-Alkenes in Virgin Olive Oil from Calabria (South Italy): The Effects of Cultivar and Harvest Date

The Cuticular Hydrocarbons of Dasineura Oleae Show Differences Between Sex, Adult Age and Mating Status

In insects, cuticular lipids prevent water loss and act as semiochemicals. Because of their ecological function, the profile change across the insects' sex and development offers insight into insect biology and possible tools for pest management. Here, the first work on cecidomyiid cuticular extracts is proposed considering Dasineura oleae (Diptera: Cecidomyiidae) males and females at different adult ages (0-12 h, 12-24 h, 24-36 h) and distinct sexual conditions (virgin and mated). A set of 49 compounds were recorded (12 alkanes, 1 monomethyl alkane, 11 fatty acids, 4 esters, 1 aldehyde, 1 allylbenzene, 1 amine, 1 flavonoid, 1 ketone, 1 phenol, 1 steradiene, 1 sterol, 1 terpene, 1 triterpene and 11 unknown compounds), and 18 of them showed significant differences between groups. Among alkanes, hexacosane (nC26) exhibited a decreasing trend from the youngest to the oldest females, while pentacosane (nC25) and nonacosane (nC29) showed a decreasing trend from 0 to 12 h to 12-24 h virgin females. In addition, nonadecane (nC19) was significantly more abundant in the youngest males compared to older males and females. The alkanes nC25, nC26 and nC29 have been reported to be age-related also in other dipterans, while nC19 has been described as gender-specific chemical cue for platygastrid parasitoids. Further behavioural trials and analyses are required to assign the specific ecological roles to the characterized compounds. Our results may contribute to develop new low-impact control strategies relying on the manipulation of D. oleae's chemical communication (e.g. disruption of mating or species recognition). HIGHLIGHTS: • Cuticular hydrocarbons are often involved in dipteran intraspecific communication. • We explored the cuticular profile of D. oleae at different age, sex, mating condition. • Five alkanes and one mono-methyl alkane showed differences among groups. • Linoleic acid is the most abundant compound in virgins, absent in mated insects. • Eleven compounds disappear in mated insects, but were present in all virgins.

Endogenous n-Alkanes in Vegetable Oils: Validation of a Rapid Offline SPE-GC-FID Method, Comparison with Online LC-GC-FID and Potential for Olive Oil Quality Control

The potential of endogenous n-alkane profiling for the assessment of extra virgin olive oils (EVOO) adulteration (blends with cheaper vegetable oils) has been studied by relatively few authors. Analytical methods used for this purpose often involve tedious and solvent-intensive sample preparation prior to analytical determination, making them unattractive. A rapid and solvent-sparing offline solid phase extraction (SPE) gas chromatography (GC) flame ionization detection (FID) method for the determination of endogenous n-alkanes in vegetable oils was, therefore, optimized and validated. The optimized method demonstrated good performance characteristics in terms of linearity (R² > 0.999), recovery (on average 94%), and repeatability (residual standard deviation, RSD < 11.9%). The results were comparable to those obtained with online high-performance liquid chromatography (HPLC)-GC- FID ( RSD < 5.1%). As an example of an application to prove the potentiality of endogenous n-alkanes in revealing frauds, the data set obtained from 16 EVOO, 9 avocado oils (AVO), and 13 sunflower oils (SFO), purchased from the market, was subjected to statistical analysis and principal component analysis. Two powerful indices, namely (n-C₂₉ + n-C₃₁)/(n-C₂₅ + n-C₂₆) and n-C₂₉/n-C₂₅, were found to reveal the addition of 2% SFO in EVOO and 5% AVO in EVOO, respectively. Further studies are needed to confirm the validity of these promising indices.

Zeolites and Biochar Modulate Olive Fruit and Oil Polyphenolic Profile

Soil degradation processes and climate change threaten the sustainability of Mediterranean rainfed olive orchards, with repercussions on crop yield and quality of olives, olive oil and olive by-products. Using soil amendments can enhance soil fertility for sustained environmental quality and plant performance. For two years, we evaluated, under rainfed conditions, the effects of a fertilizer compound (FC) and its combination with zeolites (ZL) and biochar (BC) amendments on soil moisture, yield, fruit and oil polyphenols and quality indices. The polyphenolic composition was strongly influenced by treatments, although no effects were observed on crop yield. ZL improved soil moisture (average increase of 26.3% compared to FC), fruit fatty acid composition (increase of 12.4% in oleic/linoleic ratio in 2018) and oil quality, BC enhanced the concentrations of polyphenols with high nutritional value (average annual increase of 25.6, 84.8 and 11.6% for 3,4-dihydroxyphenylglycol, oleuropein and rutin, respectively). In contrast, olive oil from FC fruits showed the poorest quality, with oxidation and hydrolytic breakdown signals. The applied soil amendments appear to be a promising sustainable strategy to implement in olive rainfed orchards.

Study of vegetable oils and their blends using infrared reflectance spectroscopy and refractometry

The present study aims to perform a comparative analysis of vegetable oils and their two-component blends using infrared spectroscopy and refractometry. The study was conducted in Almaty (Kazakhstan) in 2020. Three samples of 44 vegetable oils and their blends made from two components were examined. Fractometry and infrared spectroscopy were used to investigate the properties of blended vegetable oils. To this end, the fatty acid fraction (in percentage), iodine number, and index of refraction (IOR) were calculated. Afterward, the spectrograms obtained for the blends were analyzed. It was found that the difference between the intensities of weak bands and the band expansion of 722 cm^-1 indicates greater expressiveness. When low-intensity bands (1653 cm^-1) become more distinct due to vibrations of double carbon bonds (C-bonds), the level of unsaturated fatty acids in the blend increases as well.

Nutraceuticals: Focus on Anti-Inflammatory, Anti-Cancer, Antioxidant Properties in Gastrointestinal Tract

In recent years, nutraceuticals have gained great popularity, owing to their physiological and potential health effects, such as anti-inflammatory, anti-cancer, antioxidant, and prebiotic effects, and their regulation of lipid metabolism. Since the Mediterranean diet is a nutritionally recommended dietary pattern including high-level consumption of nutraceuticals, this review aimed to summarize the main results obtained by our in vitro and in vivo studies on the effects of the major constituents of the Mediterranean diet (i.e., extra virgin olive oil compounds, polyunsaturated fatty acids, and fruit components). Based on experimental studies, the therapeutic purpose of nutraceuticals depends on their bioavailability, solubility, toxicity, and delivery system. This review provides more in-depth knowledge on the effects linked to nutraceuticals administration on human health, focusing the gastrointestinal tract and suggesting specific dietary components for personalized adjuvant therapies.

Characteristics of Some Wild Olive Phenotypes (Oleaster) Selected from the Western Mountains of Syria

This study presents the evaluation of some technological and production specifications of 20 selected wild olive (oleaster) phenotypes from Hama Province, western–central Syria. The analyses of oil quantity showed that the olive oil (OO) extracted ranged from 10.43 to 29.3%. The fatty acid composition determined by gas chromatography (m/m%, methyl esters), conforming to commercial standards, showed the percentages of palmitic (ranged 13.2–15.06%), stearic (2.27–4.2%), arachidic (0.42–0.7%), palmitoleic (0.73–1.25%), oleic (64.29–73.17%), linoleic (8.96–16.45%), and linolenic (0.23–1.6%). Our results suggest that, despite being in a harsh environment and lacking agricultural service, two wild olive phenotypes (WA4, WA6) are interesting since their fruits showed high-quality properties (fruit weight 2.16, 3.24 g; flesh 75.83, 86.2, respectively), high content of OO% (29.27, 29.01, respectively), and better fatty acid composition (oleic % 68.45, 66.74, respectively). This enables them to be a very promising introductory feature in olive genetic improvement processes. Thus, both phenotypes were adopted tentatively as inputs, the first for oil purposes and the second for dual purposes (oil and table olives). It will be important to further evaluate these promising phenotypes in terms of their OO minor compounds, as well as their ability to resist biotic and abiotic stresses.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components—such as oleic acid, hydroxytyrosol, and oleuropein—in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

Influence of Olive Oil and Its Components on Breast Cancer: Molecular Mechanisms

Breast cancer is the most frequent malignant neoplasia and a leading cause of mortality in women worldwide. The Mediterranean diet has been proposed as a healthy dietary pattern with protective effects in several chronic diseases, including breast cancer. This diet is characterized by the consumption of abundant plant foods and olive oil as the principal source of fat, which is considered one of the main components with potential antioxidant, anti-inflammatory and anticancer effects. Extra-virgin olive oil (EVOO) has several bioactive compounds, mainly including monounsaturated fatty acids, triterpenes and polyphenols, such as phenolic alcohols (e.g., hydroxytyrosol), secoiridoids (e.g., oleuropein and oleocanthal), lignans (e.g., pinoresinol) or flavonoids (e.g., luteolin). While epidemiological evidence is still limited, experimental in vivo and in vitro data have shown a protective effect of this oil and its compounds on mammary carcinogenesis. Such effects account through complex and multiple mechanisms, including changes in epigenetics, transcriptome and protein expression that modulate several signaling pathways. Molecular targets of EVOO compounds have a role in the acquisition of cancer hallmarks. Although further research is needed to elucidate their beneficial effects on human prevention and progression of the disease, evidence points to EVOO in the context of the Mediterranean diet as a heathy choice, while EVOO components may be promising adjuvants in anticancer strategies.

Controlled Release of Flavor Substances from Sesame-Oil-Based Oleogels Prepared Using Biological Waxes or Monoglycerides

The flavor substances in sesame oil (SO) are volatile and unstable, which causes a decrease in the flavor characteristics and quality of SO during storage. In this study, the effect of gelation on the release of flavor substances in SO was investigated by preparing biological waxes and monoglycerides oleogels. The results showed that the release of flavor substances in SO in an open environment is in accordance with the Weibull equation kinetics. The oleogels were found to retard the release of volatiles with high saturated vapor pressures and low hydrophobic constants in SO. The release rate constant k value of 2-methylpyazine in BW oleogel is 0.0022, showing the best retention effect. In contrast, the addition of gelling agents had no significant retention effect on the release of volatiles with low saturated vapor pressures or high hydrophobic constants in SO, and even promoted the release of these compounds to some extent. This may be due to the hydrophilic structural domains formed by the self-assembly of gelling agents, which reduces the hydrophobicity of SO. This work provides a novel approach for retaining volatile compounds in flavored vegetable oils. As a new type of flavor delivery system, oleogels can realize the controlled release of volatile compounds.