Lipid characteristics and phenolics of native grape seed oils grown in Turkey

Free tocopherols and tocotrienols in 82 plant species' oil: Chemotaxonomic relation as demonstrated by PCA and HCA

The tocopherol (T) and tocotrienol (T3) profile were investigated in the present study for four hundred and eighteen plant oil samples, including thirty-one families, eighty-two species, and five cross-species. Fifteen species were dominated by tocotrienols, while sixty-seven - by tocopherols. The mean proportion of γ-T was almost half of the total tocochromanol content (49.3%) in the investigated samples, while α-T constituted to one quarter (25.0%), and the remaining other tocochromanols were present as minor constituents. A strong relationship between the taxonomic plant origin and the presence of the characteristic tocochromanol profile in oils obtained from those plants was noted. This is the first study to demonstrate that not only monocotyledonous, but also dicotyledons families can be rich in tocotrienols. The usefulness of statistical tools - principal component analysis (PCA) and hierarchical cluster analysis (HCA) for plant sample discrimination based on their tocochromanol profile was also shown.

The effects of plant growth substances on the oil content and fatty acid composition of Ricinus communis L.: an in vitro study

BACKGROUND

Ricinus communis L. (castor bean) is valued for its oil and the performance of oil is closely related to its fatty acid composition. Thus, producing oil in vitro with favored fatty acid profiles is a promising research area and may also offer industrial opportunities.

MATERIAL AND METHOD

In line with this, the total amount of oil and the fatty acid composition of the samples, which were endosperm and calli obtained by treatment of various doses of plant growth regulators were determined.

RESULTS

Results showed that the type and amount of the plant growth regulator used in the media affect the fatty acid composition. In detail, the biggest change was shown by Indole-3-Acetic Acid (IAA), in general, using the plant growth regulators at 5 mg L-1, instead of 20 mg L-1, was found to have induced larger differentiations. The effect of a natural plant growth regulator (IAA) on fatty acid profiles was bigger than the synthetic ones (NAA, 1-Naphthaleneacetic acid, and 2,4 D, 2,4-Dichlorophenoxyacetic acid). The media containing 5 mg L-1 of NAA, 20 mg L-1 of NAA, 20 mg L-1 of 2,4 D, or 5 mg L-1 of 2,4 D gave similar results.

Characterization of the chemical and nutritive quality of coldpressed grape seed oils produced in the Republic of Serbia from different red and white grape varieties

Six cold-pressed oil samples obtained from the seeds of different grape varieties grown in a Fruška Gora vineyard in the Republic of Serbia were examined for chemical and nutritive quality, as well as antiradical capacity. All the tested samples were of good quality, but the results showed noticeable differences in seed oil properties for red and white grape varieties. The highest content in total tocols, 575.23 ± 4.46 mg/kg, was found in the red grape seed oil of the Merlot variety, but the vitamin E activity of white grape seed oils was significantly higher. Regarding single phenols, the most prevalent fraction in all the oil samples was ursolic acid, up to 336.3 ± 4.8 μg/g in the grape seed oil of the Hamburg variety. The highest content in the total phenolic compounds, 54.92 ± 0.93 μg GAE/g, was detected in the oil of red grape seeds. Although significant differences existed between samples, EC50 values were the lowest for the red grape seed oils, varying from 29.84 ± 1.07 to 65.34 ± 0.32 mg oil/mg DPPH, indicating that these oils had the highest antiradical capacity.

In Vitro Digestion of Grape Seed Oil Inhibits Phospholipid-Regulating Effects of Oxidized Lipids

The intake of dietary lipids is known to affect the composition of phospholipids in gastrointestinal cells, thereby influencing passive lipid absorption. However, dietary lipids rich in polyunsaturated fatty acids, such as vegetable oils, are prone to oxidation. Studies investigating the phospholipid-regulating effect of oxidized lipids are lacking. We aimed at identifying the effects of oxidized lipids from moderately (18.8 ± 0.39 meq O₂/kg oil) and highly (28.2 ± 0.39 meq O₂/kg oil) oxidized and in vitro digested cold-pressed grape seed oils on phospholipids in human gastric tumor cells (HGT-1). The oils were analyzed for their antioxidant constituents as well as their oxidized triacylglycerol profile by LC-MS/MS before and after a simulated digestion. The HGT-1 cells were treated with polar oil fractions containing epoxidized and hydroperoxidized triacylglycerols for up to six hours. Oxidized triacylglycerols from grape seed oil were shown to decrease during the in vitro digestion up to 40% in moderately and highly oxidized oil. The incubation of HGT-1 cells with oxidized lipids from non-digested oils induced the formation of cellular phospholipids consisting of unsaturated fatty acids, such as phosphocholines PC (18:1/22:6), PC (18:2/0:0), phosphoserine PS (42:8) and phosphoinositol PI (20:4/0:0), by about 40%–60%, whereas the incubation with the in vitro digested oils did not affect the phospholipid metabolism. Hence, the gastric conditions inhibited the phospholipid-regulating effect of oxidized triacylglycerols (oxTAGs), with potential implications in lipid absorption.

Does unsaponifiable fraction of grape seed oil attenuate nitric oxide production, oxidant and cytotoxicity activities

Triterpenoids, tocopherols, and phytosterols presented in unsaponifiable fraction of grape seed oil have several beneficial effects comprising antioxidant, anti-inflammatory, and antitumor capacities. In this study, the unsaponifiable fraction of three Tunisian grape seed varieties (Vitis vinifera L.), namely Merlot, Carignan, and Syrah, was investigated. The identified compounds were two triterpenic compounds (β-amyrin, lanosterol), six phytosterols (campesterol, ∆⁷ -avenasterol, stigmasterol, β-sitosterol, β-sitostanol, cholesterol), and three tocopherols (α, β, and γ tocopherols). The unsaponifiable fraction had significant protection against oxidative damage by modulating NO production and antioxidant activity. Statistical analysis showed the presence of three clusters of varieties associated to specific composition patterns. These results clearly demonstrated that unsaponifiable fraction profiles of grape species could be considered as a complementary data to the existing taxonomic evidence and classification purposes. PRACTICAL APPLICATIONS: Recently, much attention has been focused to substitute artificial antioxidant by others originating from natural products as plant matrices. The unsaponifiable fraction of grape seed oils is an interesting source of bioactive components like phytosterols, tocopherols, triterpenoids, and other various components. These components are known for their antitumor, anti-inflammatory and antioxidant capacities.

Phenolics from Winemaking By-Products Better Decrease VLDL-Cholesterol and Triacylglycerol Levels than Those of Red Wine in Wistar Rats

Winemaking by-products account for more than 30% of the grape production, but this inexpensive feedstock has not yet been fully exploited. Accordingly, we evaluated the potential biological activity of winemaking by-products produced with Syrah grapes in comparison with those of the wine produced using the same grape cultivar. Winemaking by-products showed higher contents of total anthocyanins, flavonols, stilbenes, and flavanols than red wine as evaluated by HPLC-DAD-FD (on a dry weight basis). In contrast, red wine was a better source of phenolic acids. However, the contribution of phenolic acids was minor for both samples. Furthermore, equivalent concentration of winemaking by-products (100 mg/kg/d) showed greater biological activity by than that of red wine by decreasing the levels of VLDL-cholesterol and triacylglycerols in Wistar rats. Therefore, this study supports the use of winemaking by-products as an economical source of bioactive phenolics with potential use in the food and nutraceutical industries.

Characterisation of seed oils from different grape cultivars grown in China

To explore the potential of the large amount of grape pomace in wineries of China, oils of three Eurasian grape cultivars (Chardonnay, Merlot and Carbernet Sauvignon) and two Chinese traditional grape cultivars (Vitis amurensis and Vitis davidii), were characterised. The results showed seed oil properties differ for various grape varities. Grape seed oils were demonstrated to be good sources of polyunsaturated fatty acid (PUFA) (63.88-77.12 %), sterols (227.99-338.83 mg/100 g oil) and tocotrienols (320.08-679.24 mg/kg oil). Seed oil of V. amurensis exhibited the highest values of polyunsaturated fatty acid, total tocotrienols, total tocols and DPPH· scavenging capacity. Seed oil of Carbernet Sauvignon had the highest contents of squalene, total sterols, total tocopherols and total phenolics. Principal component analysis five grape cultivars differentiated on the basis of bioactive components content and antioxidant properties.

Muscadine grape seed oil as a novel source of tocotrienols to reduce adipogenesis and adipocyte inflammation

Tocotrienols are unsaturated forms of vitamin E previously shown to reduce adipogenesis and adipose inflammation. In this study, muscadine grape seed oil (MGSO) was identified as a novel source of tocotrienols containing significant amounts of α- and γ-tocotrienol (T3) with minor seasonal changes. The aim of this study was to assess the anti-adipogenic and anti-inflammatory potential of MGSO by using primary human adipose-derived stem cells (hASCs). Differentiating hASCs were treated with MGSO and compared with rice bran and olive oil. Accumulation of triglyceride was significantly lower in MGSO-treated hASCs than rice bran and olive oils. A tocotrienol rich fraction (TRF) from MGSO was prepared by solid phase extraction and eluted with 15% 1,4-dioxane in hexane. The MGSO-derived TRF treatment significantly reduced mRNA and protein expression that are crucial to adipogenesis (e.g., PPARγ and aP2) in hASCs. Furthermore, TRF from MGSO markedly reduced LPS-induced proinflammatory gene expression in human adipocytes and cytokine secretion to the medium (IL-6 and IL-8). Collectively, our work suggests that MGSO is a stable and reliable natural source of T3 and MGSO may constitute a new dietary strategy to attenuate obesity and its associated adipose inflammation.