Γ-tocopherol Content Research Articles

The potential of lysine to extend the shelf life of soybean oil evidenced by 1H Nuclear Magnetic Resonance

The effect of 1% and 2% proportions of L-lysine on the oxidation process of soybean oil, performed at 70 °C under stirring conditions, has been studied by 1H Nuclear Magnetic Resonance. This technique allows one to monitor the generation and further evolution of a wide variety of oxidation products (hydroperoxides, epoxides, aldehydes, keto-dienes and hydroxy-derivatives), providing a comprehensive view of the oxidation process. The addition of lysine considerably delays the degradation of the oil acyl groups and the generation of both primary and secondary oxidation compounds, while preserving the oil content of γ-tocopherol for longer, especially at the highest enrichment level. A diminution in the maximum concentration reached by some types of secondary oxidation products is also observed in the lysine-enriched samples. This is particularly noticeable for aldehydes, whose concentration is markedly reduced, above all that of the toxic oxygenated α,β-unsaturated ones, probably due to their reaction with lysine. Therefore, the ability of lysine to extend the shelf life of soybean oil is proved in this work, as well as its feasibility as a potential antioxidant for use in lipidic foods. These findings could also contribute to a better understanding of the antioxidant effect of proteins.

Maize Cd-tolerant ZmVTE4 encoding γ-tocopherol-methyl-transferase alleviated Cd-toxicity through its product α-tocopherol

Cadmium (Cd) is a widespread non-essential toxic heavy metal and usually arouses oxidative stress which impairs plant growth. The key lipophilic antioxidant α-tocopherol is synthesized from γ-tocopherol by γ- tocopherol-methyl-transferase (γ-TMT encoded by VTE4) in response to a variety of abiotic stresses.The main purpose of this study was to characterize the Cd-tolerant maize ZmVTE4 which was obtained through high-throughput survival screening in the presence of Cd. Further heterologous expression of a ZmVTE4 enhanced Cd tolerance in yeast as well in tobacco. Moreover, Cd treatment induced the increment of tocopherols in maize leaves. Similarly, transient overexpressing ZmVTE4 increased the content of γ-tocopherol and α-tocopherol thus enhancing the Cd tolerance in tobacco leaves. Visualized fluorescence indicated that ZmVTE4 was localized in chloroplasts, where tocopherols were synthesized. These results collectively implicated that ZmVTE4-mediated α-tocopherol generation facilitated plant tolerance to Cd.

Influence of Carbonic Maceration Pre-treatment on Functional Quality of Dried Tomato Quarters

As a novel pre-treatment, carbonic maceration (CM) was investigated in this study to figure out its effect on functional quality of conventionally dried tomato quarters (60 °C, 1.3 m/s air velocity). Carotenoids, tocopherols, total flavonoid, total phenolic and DPPH radical scavenging potential were determined for dried tomato samples (directly dried as a control and CM treated samples). Lycopene and β-carotene contents of CM treated tomato quarters were high compared to control samples (only conventionally dried). β-, γ-Tocopherol contents in dried tomato were raised with CM pre-treatment, as α-tocopherol decreased. Total flavonoid was found to be more than 2.5 times higher for CM treated samples compared to that in fresh tomato. CM displayed a promoter effect on total phenolic content and antioxidant activity of hydrophilic extracts, whereas there was no difference between those values determined for lipophilic extracts from control and pre-treated samples. CM has a potential as a pre-treatment before conventional drying of tomato to improve its nutritional contents and functional potential.

Cucurbita maxima Pumpkin Seed Oil: from the Chemical Properties to the Different Extracting Techniques

Pumpkin seed oils are rich in bioactive compounds such as tocopherols, sterols, β-carotene, and lutein that have, along with some fatty acids, high nutritional value factors. In addition, it has so far been proven that these compounds have a positive effect on human health. The present study mainly aimed at evaluating the chemical composition and the bioactive compounds of pumpkin (Cucurbita maxima) seed oil of the ‘Béjaoui’ Tunisian cultivar using both cold pressing and solvent extraction methods. The seed oils contained substantial amounts of unsaturated fatty acids, particularly oleic and linoleic acids, with values ranging respectively from 28.19% for cold pressed pumpkin seed oil to 30.56% for pumpkin seed oil extracted by pentane and from 43.86% for pumpkin seed oil extracted by pentane to 46.67% for cold pressed pumpkin seed oil of the total amount of fatty acids. Investigations of different seed oils revealed that extraction techniques had significant effects on the antioxidant activity and the γ-tocopherol. Cold pressed pumpkin seed oil revealed the highest γ-tocopherol content (599.33 mg kg-1) and the highest oxidative stability (3.84 h). However, the chloroform/methanol extracted pumpkin seed oil, which is rich in total phenolics (54.41 mg Gallic Acid Equivalent kg-1), was a more effective scavenger of DPPH radicals (250 µmoles Trolox kg-1) than the poor phenolic pumpkin seed oils extracted by hexane and pentane (110 µmoles Trolox kg-1 vs 100 µmoles Trolox kg-1). Based on its unique seed oil features, cold press extracted pumpkin seed may add great value to product innovation in the industrial, nutritional, cosmetic, and pharmaceutical fields.

Effect of the Harvest Time on Oil Yield, Fatty Acid, Tocopherol and Sterol Contents of Developing Almond and Walnut Kernels.

Oil content and bioactive properties of almond and walnut kernels were investigated in developing almond and walnut kernels at 10 days intervals. The oil contents of almond and walnuts after the first harvest (1.H) stage changed between 46.2% and 55.0% to 39.1% and 70.5%, respectively (p<0.05). Oleic acid contents of almond and walnut oils ranged from 71.98% (1.H) to 78.68% (5.H) and 10.51% (1.H) to 16.78% (2.H) depending on harvest (H) times, respectively (p<0.05). In addition, linolenic acid contents of walnut and almond oils were found between 62.35% and 67.78%, and 12.02% and 17.65%, respectively. The almond kernel oil after the first harvest stage contained 1.045, 1.058, 1.018, 0.995 and 0.819 mg/kg ɑ-tocopherol, respectively. γ-Tocopherol contents of walnut oil changed between 1.364 (3.H) and 2.954 mg/kg (1.H). The β-sitosterol contents of both almond and walnut oils were found between 1956.6 (5.H) and 2557.7 (1.H), and 1192.1 (3.H) and 4426.4 mg/kg (1.H). The study exhibited the presence of high percentage of oleic and linoleic for almond and walnut, respectively, and γ-tocopherol and β-sitosterol.

Stabilities of tocopherols and phenolic compounds in virgin olive oil during thermal oxidation.

The effects of thermal oxidation at 60°C on tocopherols (α, β, γ) and phenolic compounds (hydroxytyrosol and tyrosol) of olive oil were studied. Tocopherols were determined by HPLC and phenolic compounds by HPLC and GC-MS. Peroxide value of olive oil increased with treatment time until it reached to 56.6meq/kg. α-Tocopherol, β-tocopherol and γ-tocopherol contents of olive oil decreased with treatment time. α-Tocopherol in olive oil was decomposed after 63days of treatment. β-Tocopherol in olive oil was depleted after 33days of treatment. The reduction in γ-tocopherol of olive oil was 75% after 63days of treatment. The degradation of hydroxytyrosol in olive oil was 91% after 63days of treatment. Tyrosol was more stable than hydroxytyrosol in olive oil. Inverse correlations of peroxide value with hydroxytyrosol, α-Tocopherol, β-tocopherol and γ-tocopherol were observed.

Seed Carotenoid and Tocochromanol Composition of Wild Fabaceae Species Is Shaped by Phylogeny and Ecological Factors.

Carotenoids distribution and function in seeds have been very scarcely studied, notwithstanding their pivotal roles in plants that include photosynthesis and phytohormone synthesis, pigmentation, membrane stabilization and antioxidant activity. Their relationship with tocochromanols, whose critical role in maintaining seed viability has already been evidenced, and with chlorophylls, whose retention in mature seed is thought to have negative effects on storability, remain also unexplored. Here, we aimed at elucidating seed carotenoids relationship with tocochromanols and chlorophylls with regard to phylogenetic and ecological traits and at understanding their changes during germination. The composition and distribution of carotenoids were investigated in seeds of a wide range of wild species across the Fabaceae (the second-most economically important family after the Poaceae). Photosynthetic pigments and tocochromanols were analyzed by HPLC in mature dry seeds of 50 species representative of 5 subfamilies within the Fabaceae (including taxa that represent all continents, biomes and life forms within the family) and at key timepoints during seedling establishment in three species representative of distinct clades. Total-carotenoids content positively correlated with tocopherols in the basal subfamilies Detarioideae, Cercidoideae, and Dialioideae, and with chlorophylls in the Papilionoideae. Papilionoideae lacked tocotrienols and had the highest total-carotenoids, chlorophyll and γ-tocopherol contents. Interestingly, lutein epoxide was present in 72% of the species including several herbs from different subfamilies. Overall, species original from temperate biomes presented higher carotenoids and lower tocochromanols levels than those from tropical biomes. Also shrub species showed higher carotenoids content than herbs and trees. During germination, total content of photosynthetic pigments increased in parallel to changes in relative abundance of carotenoids: zeaxanthin and anteraxanthin decreased and β-carotene augmented. Notably, the highest contents of nutritionally valuable carotenoids were found in Papilionoideae subfamily to which all pulses of socio-economic importance belong. The major differences in carotenoids and tocochromanols composition across the Fabaceae are apparently related to phylogeny in conjunction with ecological traits such as biome and growth form.

Acorn (Quercus spp.) as a novel source of oleic acid and tocopherols for livestock and humans: discrimination of selected species from Mediterranean forest.

The aim of the present work was to characterization and compare acorns from selected Quercus spp. from the Mediterranean forest in Spain, namely, Portuguese oak (QF, Quercus faginea Lam.), Cork oak (QS, Quercus suber L.), Pyrenean oak (QP, Quercus pyrenaica Wild), Kermes oak (QC, Quercus coccifera L.), Holm oak (QB, Quercus ilex L. subsp. ballota [Desf.]). All physicochemical attributes varied significantly between species. Fat contents ranged from 1.30 to 4.70g 100g-1 fresh matter. The most abundant fatty acids were oleic (62.44, 56.25, 57.46, 48.02, 65.83%), followed by linoleic (16.42, 20.73, 21.30, 25.38, 14.17%) and palmitic (11.69, 14.27, 12.17, 16.22, 12.28) acids in QF, QS, QP, QC and QB species, respectively. The tocopherol content was high in the range of 31.83-45.25mgkg-1, and γ-tocopherol constituted 67-78% of total tocopherols. Only an effect of the location on γ-tocopherol content in QB was observed. The present results show the potential of different species of acorn to be used as agricultural and food resources and that geographical location plays a secondary role.

Comparisons of proximate compositions, fatty acids profile and micronutrients between fiber and oil flaxseeds (Linum usitatissimum L.)

Hydrophobic orbitides or cyclolinopeptides (CLs) are specialty micronutrients and of great abundance in flax (Linum usitatissimum L.) seed oils, and show many potential health benefits. The aim of this study was to evaluate the differences in proximate compositions, fatty acids profile and micronutrients including orbitides as well as tocopherol in flaxseeds or their oils from 13 Chinese cultivated oil and fiber flax samples. A total of 14 types of orbitides in 13 oils were identified and quantified by HPLC-ESI-QTOF-MS/MS, concentrations of which varied from 273±3 to 434±7μg/g of oil. The contents of proximate compositions, orbitides, γ-tocopherol and fatty acid profiles among 13 cultivars were significantly discriminatory. Only oil flax Dingya23 showed significantly higher oil content, with ALA level 55% greater than fiber flax, and the mean proportions of ALA and γ-tocopherol in oils from oil flax were similar to those in oils from fiber flax. In addition, the fiber flax showed higher mean levels of crude protein and total orbitides than oil flax. These results indicated that except for Dingya23, oil flax did not present clear germplasm superiority of components over fiber flax.

High-dose testosterone enanthate supplementation boosts oxidative stress, but exerts little effect on the antioxidant barrier in sedentary adolescent male rat liver.

Anabolic-androgenic steroids abuse is on the rise among adolescent boys and young men, mostly in those seeking a 'shortcut' to an improved body image. This approach is associated with the risk of severe adverse health effects, some of which involve the liver and are linked to hepatic oxidative stress. Testosterone and its esters is a cornerstone of most anabolic-androgenic steroid stacking protocols. We assessed and compared several hepatotoxicity and liver oxidative stress indices, as well as the contents of some components of the hepatic antioxidant barrier between sedentary adolescent male rats given a 6-week course of weekly im testosterone enanthate (TE, 8 or 80mg/kgBW/week) or vehicle (sesame oil) injections. Blood and livers for the assessments were harvested seven days after the last injection. TE supplementation dose-dependently elevated blood testosterone and significantly increased the liver content of thiobarbituric acid-reactive substances. Only the high-dose TE supplementation significantly slowed down body weight gain, reduced the liver weight/body weight ratio, increased liver heat shock protein 70/72 content and elevated blood enzyme markers of liver stress. There was no significant difference in reduced glutathione and α- or γ-tocopherol content between the TE-treated and control rats. Of the antioxidant enzymes studied (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase), only the dismutase activity was significantly while moderately elevated and only by the high-dose TE supplementation. (Sub)chronic supplementation of sedentary adolescent male rats with high TE doses does not exert a lasting major effect on the liver antioxidant barrier and redox homeostasis.

Physicochemical characteristics of the cold-pressed oil obtained from seeds of Fagus sylvatica L.

A physicochemical characteristic of the cold-pressed oil obtained from seeds of common beech (Fagus sylvatica L.) has been presented. This plant may be considered as unconventional oilseeds crops because of relatively high content of fat (27.25%). The analyzed beech seeds oil has been classified as oleic-linoleic acids oil with more than 76% percentage share of those species. Beech seeds oil contains 4.2% of gamma-linolenic acid (GLA). Unique characteristic is the high content of γ-tocopherol (75.4mg/100g) and δ-tocopherol (34.05mg/100g). γ-Tocopherol is effective scavengers of reactive nitrogen species and prevents DNA bases nitration, what makes beech seeds oil interesting raw material in the production of cosmetics. Additionally the content of carotenoids, very effective photooxidation inhibitors, is at high level in comparison with other cold-pressed oils. It was demonstrated that PCA analysis may help to determine the authenticity of oil obtained from beech seeds.

Chemical Profile and Antioxidant Activity of the Oil from Peony Seeds (Paeonia suffruticosa Andr.).

Peony seed oil (PSO) is a novel vegetable oil developed from the seeds of Paeonia suffruticosa Andr. The present study aimed to make an overall investigation on the chemical profile and antioxidant activities of PSO for reasonable development and utilization of this new resource food. Chemical analysis revealed that PSO was characterized by an uncommon high portion of α-linolenic acid (>38%), fairly low ratio of n-6 to n-3 polyunsaturated fatty acids (0.69), and much higher content of γ-tocopherol than various conventional seed oils. In vitro assay indicated that PSO is a more potent scavenger of free radicals than extra virgin olive oil. Moderate intake of PSO exhibited obvious protection against various oxidative damages such as tetrachloromethane-induced acute liver injury in mice and diet-induced hyperlipidemia in rats. The changes in the key indicators of oxidative injury and fatty acid composition in the liver caused by PSO administration were measured, and the results demonstrated that antioxidant properties of PSO are closely related to their characteristic chemical composition. Consequently, the present study provided new evidence for the health implications of PSO, which deserves further development for medical and nutritional use against oxidative damages that are associated with various diseases.

아마인 및 아마인유의 유지자원으로서의 특성

The objective of this research was to find out the potential value of flaxseed as a dietary supplement as well as an edible oil resource. The characteristics of yellow flaxseed oil and brown flaxseed oil were compared to check which oil is better in the aspects of cooking purpose and of nutritional value. The quality of flaxseed oil was evaluated based on the composition of fatty acid, the content of phenolic compounds and the anti-oxidant activity. The total phenolics of yellow flaxseed oil and brown flaxseed oil were 10.78±0.46 and 29.88±3.25 mg/100 g, respectively. Their γ-tocopherol contents were 20.59 and 17.94 mg/100 g, respectively. Contents of linolenic acid were 56.60 and 31.38% and oleic acid were 18.24 and 39.16 %, respectively. Yellow flaxseed oil showed higher ratio of unsaturated fatty acid than brown flaxseed oil. However, brown flaxseed oil showed higher electron-donating abilities than brown flaxseed oil, which might be due to its higher content of phenolic compounds. In conclusion, flaxseed has a great potential as a good edible oil resource due to its high content of unsaturated fatty acid and anti-oxidant activity.

Roles of MPBQ-MT in Promoting α/γ-Tocopherol Production and Photosynthesis under High Light in Lettuce.

2-methyl-6-phytyl-1, 4-benzoquinol methyltransferase (MPBQ-MT) is a vital enzyme catalyzing a key methylation step in both α/γ-tocopherol and plastoquinone biosynthetic pathway. In this study, the gene encoding MPBQ-MT was isolated from lettuce (Lactuca sativa) by rapid amplification of cDNA ends (RACE), named LsMT. Overexpression of LsMT in lettuce brought about a significant increase of α- and γ-tocopherol contents with a reduction of phylloquinone (vitamin K1) content, suggesting a competition for a common substrate phytyl diphosphate (PDP) between the two biosynthetic pathways. Besides, overexpression of LsMT significantly increased plastoquinone (PQ) level. The increase of tocopherol and plastoquinone levels by LsMT overexpression conduced to the improvement of plants’ tolerance and photosynthesis under high light stress, by directing excessive light energy toward photosynthetic production rather than toward generation of more photooxidative damage. These findings suggest that the role and function of MPBQ-MT can be further explored for enhancing vitamin E value, strengthening photosynthesis and phototolerance under high light in plants.

Physicochemical properties and oxidative stabilities of mealworm (Tenebrio molitor) oils under different roasting conditions.

Physicochemical properties and oxidative stabilities of mealworm (Tenebrio molitor) oils under different roasting conditions were investigated. Oils were extracted using n-hexane from mealworms roasted at 200°C for 0, 5, 10, and 15 min and physicochemical properties and oxidative stabilities of oils were analyzed. Roasting increased the color intensity and the oleic acid and δ-tocopherol contents, but decreased linoleic acid, and α- and γ-tocopherol contents. An improvement in oxidative stability was observed in roasted mealworm oils, demonstrated by induction time and peroxide values. Mealworm oil contained abundant essential fatty acids and exhibited a superior oxidative stability.

Biodiversity of Tunisian virgin olive oils: varietal origin classification according to their minor compounds

The analysis of minor compounds (minor fatty acids, squalene, phenols and tocopherols) of eight autochthonous Tunisian varieties of virgin olive oils (VOOs) (Chemchali, Chemlali Sfax, Chemlali Zarzis, Chetoui, Oueslati, Sayali, Zalmati and Zarrazi) allows for the varietal origin authentication. The compositions of minor ω9 and ω7 fatty acids, especially 16:1 and 18:1 isomers, are important criteria for distinction among eight varieties of VOOs. The squalene content was ranged between 1.39 and 5.37 g/kg. Total phenol and the sum of α-, β- and γ-tocopherol contents were, respectively, ranged between 81–691 and 147–585 mg/kg. This minor fraction is not only highly dependent on the variety, but also the maturity index. Chemchali, Zarrazi and Sayali are characterized by having high content in total phenols, whereas Chemlali Sfax, Chemlali Zarzis and Zalmati are rich in total tocopherols. The intervarietal variation in the studied minor compounds was confirmed by chemometric treatment through PCAs. The potential of using the minor compounds in the authentication of the Tunisian olive oil varietal origin was tested through PLS-DA performed for the two most representative varieties (Chemlali Sfax and Chetoui). The obtained percentages of correct classification (superior to 97 %) proved the potential of the used method in varietal origin authentication.

Changes in the Bioactive Compounds Content of Soybean as a Function of Grain Moisture Content and Temperature during Long-Term Storage.

Soybean is a rich source of bioactive compounds, such as phenolic acids, flavonoids, isoflavones, carotenoids, and tocopherols. The amount of bioactive compounds in freshly harvested soybeans and their derived products has been determined; however, when they are used in the food industry, soybeans are generally stored prior to being processed. This study aimed to evaluate the effects of soybean moisture content (12%, 15%, and 18%) and storage temperature (11, 18, 25, and 32 °C) on the free phenolic, total flavonoid, vanillic acid, total carotenoid, and δ- and γ-tocopherol content of soybeans stored for 12 mo. Moreover, the ABTS and DPPH radical scavenging activities of phenolic extracts were determined. There was an increase in free phenolics and total flavonoids in the stored grains compared with the grains on the 1st d of storage. Vanillic acid showed a decrease in soybeans stored at 15% and 18% moisture content and 25 or 32 °C, which indicated some degradation into other metabolites. Total carotenoid content decreased as a function of storage temperature and showed some temperature-dependent degradation. The δ- and γ-tocopherol content also tended to decrease in grains stored at 15% or 18% moisture content or 25 or 32 °C, regardless of the moisture content studied.

Effect of short-term storage on walnut fruit quality

Two Hungarian and two introduced walnut cultivars were examined as fresh samples and under storage. Some important compositional data were determined in order to evaluate the differences between the cultivars and the changes after storage. The cultivars’ oil contents were the same, but there was some difference in fatty acid composition; ‘Alsószentiváni 117’ had a higher mono-unsaturated fatty acid content than the others. Considering the oxidative stability, ‘Alsószentiváni 117’ contained good properties in all stages (induction time equals or higher than 10 h). Lower antioxidant capacity was measured in ‘Chandler’ samples compared to the others. ‘Alsószentiváni 117’ has higher α- and γ-tocopherol contents than the other cultivars studied. Two different drying methods were also compared in case of the Hungarian cultivars. The changes in compositional data showed no tendencies. We found that Hungarian cultivars were at least as valuable as the introduced ones.

Fatty acid composition and tocopherol content of the kernel oil from apricot varieties (Hasanbey, Hacihaliloglu, Kabaasi and Soganci) collected at different harvest times

The oil content of ‘Hasanbey’ apricot kernels (Prunus armeniaca L.) was created from harvest-1 (14.6.2011) (35.80 %; v/w) and harvest-4 (6.7.2011) (49.00 %; v/w). In addition, the oil content of ‘Kabaasi’ apricot kernels is created from 28.0 to 49.2 % (v/w) between the same harvests. The oleic acid of ‘Hasanbey’ nut oil is created from 42.94 to 59.13 % (v/w) from harvest-1 to harvest-4. The linoleic acid concentration in the same variety ranged from 44.99 to 31.71 % (v/w) depending on harvest times. In addition, ‘Hacihaliloglu’ apricot nut oil contained 45.74 % (harvest-1) to 66.79 % (harvest-4) oleic acid and 43.50 (v/w) to 24.43 % (v/w) linoleic acid at harvest-1 and harvest-4, respectively. The γ-tocopherol content of Hacihaliloglu ranged from 47.63 mg/100 g (v/w) to 27.15 mg/100 g depending on maturation.

Improvements in the quality of sesame oil obtained by a green extraction method using enzymes

The quality of vegetable oils is related to the presence of bioactive compounds, in which its contents may vary according to the extraction process. This study aimed to evaluate a clean technology for sesame oil extraction by enzymatic aqueous extraction, comparing to conventional extraction methods, such as pressing and solvent, in relation to the composition of bioactive lipophilic compounds. Two enzymes were used: Pectinex Ultra SPL and Alcalase 2.4L, and three factors were evaluated: concentration of enzymes (mL 100 mL−1), sample/water ratio (g mL−1) and extraction time (hours) through a 23 factorial design with center point in triplicate. The results showed variations in extraction yield and composition. The sesame oil extracted using enzymes showed the highest antioxidant capacity in the DPPH and L-ORAC (against peroxyl radical) assays, 128,54 and 349,98 μmol Trolox g−1 of oil, respectively, as well a higher content of total phytosterols (249 mg 100 g−1 of oil), total polyunsaturated and omega-6 fatty acids. No significant difference in γ-tocopherol content was observed, by Tukey test (p < 0.05), among the extraction methods. The enzymatic aqueous extraction improved the quality of sesame oil using a green methodology, free of toxic solvents.