Occurrence of n-Alkanes in Vegetable Oils and Their Analytical Determination

Investigation of bioactive compounds and their correlation with the antioxidant capacity in different functional vinegars

There are complex and diverse substances in traditional vinegars, some of which have been identified as biologically active factors, but the variety of functional compounds is currently restricted. In this study, it was aimed to determine the bioactive compounds in 10 typical functional vinegars. The findings shown that total flavonoids (0.21-7.19 mg rutin equivalent/mL), total phenolics (0.36-3.20 mg gallic acid equivalent/mL), and antioxidant activities (DPPH: 3.17-47.63 mmol trolox equivalent/L, ABTS: 6.85-178.29 mmol trolox equivalent/L) varied among different functional vinegars. In addition, the concentrations of the polysaccharides (1.17-44.87 mg glucose equivalent/mL) and total saponins (0.67-12.46 mg oleanic acid equivalent/mL) were determined, which might play key role for the function of tested vinegars. A total of 8 organic acids, 7 polyphenol compounds and 124 volatile compounds were measured and tentatively identified. The protocatechuic acid (4.81-485.72 mg/L), chlorogenic acid (2.69-7.52 mg/L), and epicatechin (1.18-97.42 mg/L) were important polyphenol compounds in the functional vinegars. Redundancy analysis indicated that tartaric acid, oxalic acid and chlorogenic acid were significantly positively correlated with antioxidant capacity. Various physiologically active ingredients including cyclo (Pro-Leu), cyclo (Phe-Pro), cyclo (Phe-Val), cyclo (Pro-Val), 1-monopalmitin and 1-eicosanol were firstly detected in functional vinegars. Principle component analysis revealed that volatiles profile of bergamot Monascus aromatic vinegar and Hengshun honey vinegar exhibited distinctive differences from other eight vinegar samples. Moreover, the partial least squares regression analysis demonstrated that 11 volatile compounds were positively correlated with the antioxidant activity of vinegars, which suggested these compounds might be important functional substances in tested vinegars. This study explored several new functionally active compounds in different functional vinegars, which could widen the knowledge of bioactive factor in vinegars and provide new ideas for further development of functional vinegar beverages.

Optimization of sample clean-up for the determination of small amounts of MOSH and MOAH in edible oils - method DGF C-VI 22 (20)

Methods for determining MOSH and MOAH in edible oils showed major problems with interlaboratory comparability of analytical results, especially in the lower concentration range below 10 mg/kg. However, a method with improved sensitivity and reproducibility is urgently needed to obtain a valid data basis for minimization efforts. To cope this problem a new method was created in 2020. The method was established as the standard method DGF C-VI 22 (20) of the German Society for Fat Science e.V. (DGF). For the development of this method different sample epoxidation approaches have been performed, evaluated and improved. Additionally, a saponification, a decision tree for sample preparation, an upstream clean-up column and a system suitability test were introduced. The focus was on reliability and interlaboratory comparability over all edible oil matrices up to a LOQ of 1 mg/kg. The optimized method was validated in terms of trueness and precision in a collaborative trail with 11 laboratories. The achieved recovery rates of 89-105% MOSH and 70-105% MOAH met the JRC requirements. Method and validation results were obtained with HorRat values between 1.3 and 1.8 for MOSH and MOAH.

Determination of extractable pollutants from microplastics to vegetables: Accumulation and incorporation into the food chain

The presence and impacts of microplastics (MPs) are being extensively researched and reviewed, especially in the marine environment. However, mobility, transportation routes, and accumulation of leaching compounds such as additives in plastic waste including MPs are scarcely studied. Information regarding ecotoxicity and leachability of compounds related to MPs contamination in the environment is limited. Current work presents the levels of leachates from plastic materials in edible-root and non-edible root vegetables. Samples were analyzed by static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) and the presence of 93 putative compounds was accurately monitored in the samples by the usage of Mass Spectrometry-Data Independent Analysis software. The application of chemometrics to the SHS-GC-MS dataset allowed differentiation between the levels of plastic related compounds in edible root and non-edible root vegetables, the former showing a higher content of plastic leachates. For SHS sampling, 3 g of the sample were incubated at 130 °C for 35 min in the HS vial and toluene and naphthalene were added as internal standards for quantification purposes. The developed SHS-GC-MS methodology is straightforward, reliable, and robust and allowed the quantification of sixteen plastic associated compounds in the samples studied in a range from 0.14 to 28800 ng g-1 corresponding to 2,4-di-tert-butylphenol and p,α-dimethylstyrene, respectively. Several of the quantified compounds pointed out to potential contamination of polystyrene and/or polyvinyl chloride MPs.

Toxicity and chemical composition of commercial road palliatives versus oil and gas produced waters

Across the United States, road palliatives are applied to roads for maintenance operations that improve road safety. In the winter, solid rock salts and brine solutions are used to reduce the accumulation of snow and ice, while in the summer, dust suppressants are used to minimize fugitive dust emissions. Many of these products are chloride-based salts that have been linked to freshwater salinization, toxicity to aquatic organisms, and damage to infrastructure. To minimize these impacts, organic products have been gaining attention, though their widespread adoption has been limited due to their higher cost. In some states, using produced water from conventionally drilled oil and gas wells (OGPWs) on roads is permitted as a cost-effective alternative to commercial products, despite its typically elevated concentrations of heavy metals, radioactivity, and organic micropollutants. In this study, 17 road palliatives used for winter and summer road maintenance were collected and their chemical composition and potential human toxicity were characterized. Results from this study demonstrated that liquid brine solutions had elevated levels of trace metals (Zn, Cu, Sr, Li) that could pose risks to human and environmental health. The radium activity of liquid calcium chloride products was comparable to the activity of OGPWs and could be a significant source of radium to the environment. The organic fractions of evaluated OGPWs and chloride-based products posed little risk to human health. However, organic-based dust suppressants regulated toxicity pathways related to xenobiotic metabolism, lipid metabolism, endocrine disruption, and oxidative stress, indicating their use could lead to environmental harm and health risks to operators handing these products and residents living near treated roads.

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.

Degradation of biogas in a simulated landfill cover soil at laboratory scale: Compositional changes of main components and volatile organic compounds

A laboratory experiment lasting 28 days was run to simulate a typical landfill system and to investigate the compositional changes affecting the main components (CH₄, CO₂, and H₂) and nonmethane volatile organic compounds from biogas generated by anaerobic digestion of food waste and passing through a soil column. Gas samples were periodically collected from both the digester headspace and the soil column at increasing distances from the biogas source. CH₄ and H₂ were efficiently degraded along the soil column. The isotopic values of δ¹³C measured in CH₄ and CO₂ from the soil column were relatively enriched in ¹³C compared to the biogas. Aromatics and alkanes were the most abundant groups in the biogas samples. Among these compounds, alkylated benzenes and long-chain C₃₊ alkanes were significantly degraded within the soil column, whereas benzene and short-chain alkanes were recalcitrant. Terpene and O-substituted compounds were relatively stable under oxidising conditions. Cyclic, alkene, S-substituted, and halogenated compounds, which exhibited minor amounts in the digester headspace, were virtually absent in the soil column. These results pointed out how many recalcitrant potentially toxic and polluting compounds tend to be relatively enriched along the soil column, claiming action to minimise diffuse landfill gas (LFG) emissions. The proposed experimental approach represents a reliable tool for investigating the attenuation capacities of landfill cover soils for LFG components and developing optimised covers by adopting proper soil treatments and operating conditions to improve their degradation efficiencies.

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.

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.

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

n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet.