Free Tocopherols Research Articles

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.

Comprehensive Composition of Flavor Precursors in Kopi Luwak and Jacu Exotic Green Bioprocessed Coffees

Exotic coffees may be defined as extravagant and unique coffees, primarily due to their production mode, including unusual bioprocessing or fermentation conditions associated with superior sensorial characteristics. The aim of the present study was to investigate the influence of bioprocessing and of growing conditions on flavor precursors of Jacu and Kopi Luwak exotic green coffees, respectively. Moreover, this is the first study to perform a detailed chemical analysis of these exotic coffees. Thirteen green Coffea arabica bean samples were obtained, five from Espírito Santo state, Brazil, and eight Kopi Luwak from different regions of Indonesia. Samples were analyzed regarding their proximate composition, chlorogenic acids (CGA), sucrose, alkaloids, triacylglycerols (TAG), diacylglycerols, free fatty acids, sterols, diterpenes and tocopherols. Scanning electron micrography confirmed bioprocessing of Jacu and Kopi Luwak coffee samples. Bioprocessing by the Jacu bird caused reductions of 69 and 28% in caffeine and CGA contents, respectively. The TAG profile of Jacu coffee was modified. TAG containing two saturated fatty acids were preferably hydrolyzed in detriment to those containing two unsaturated fatty acids. Other coffee components were not affected by the bird's digestion of the beans. Kopi Luwak coffee samples had a chemical composition in accordance with reported ranges for non-bioprocessed green C. arabica samples, except for caffeine (0.48 g/100 g) and CGA (5.09 g/100 g), which were found in low amounts. Crop year rather than location or post-harvest processing discriminated Kopi Luwak coffee samples, suggesting that weather conditions would be the most crucial aspect for their chemical composition, especially in terms of total lipids, ashes, total CGA, sucrose and proteins.

Determination of Free Radical Scavenging Activity in Some Economic Bivalve Species

In this study, free radical scavenging activity, alpha tocopherol and total carotenoid contents of extracts of Mytilus galloprovincialis, Ruditapes philipinarum, Donax trunculus and Chamelea gallina bivalve species collected from Denizkent in the Marmara Sea are determined. As a result of the monthly samplings, the amount of alpha tocopherol is quite high in all species, whereas the total amount of carotenoids is highest in Donax trunculus (2435 µg/g), then in Mytilus galloprovincialis (2189.6 µg/g), and in the other two species parallel results are obtained. When the free radical scavenging activity is evaluated, on average, Ruditapes philipinarum (22.8%) is the highest, Mytilus galloprovincialis (16.75%) and Chamelea gallina (17.98%) are close to each other, 11% in Donax trunculus, it has been determined that 85. In addition, other parameters obtained in this study were examined by considering statistical evaluations

17129 Comparative analysis of clinical benefits provided by two facial daily care regimens with the antioxidants ascorbyl glucoside and tocopheryl glucoside for 8 weeks in Brazilian women

Background: The well known instability of vitamin C to thermal and oxidative degradation stimulated the research for more stable molecules with gradual release and effect on the skin. Ascorbyl glucoside is a vitamin C precursor. It is an ascorbic acid molecule with an additional C2-glucose, more chemically stable which prevents the low effectiveness of vitamin C in the presence of different degradation mechanisms. In addition, tocopheryl glucoside is a vitamin E precursor metabolized into free tocopherol in the skin, with a considerable reservoir effect, associated with gradual delivery.

Effect of heat treatment prior to extraction on the yield and quality of red fruit (Pandanus conoideus) oil

The quality of red fruit (Pandanus conoideus) oil (RFO) was strongly influenced by the processing and extraction method. The effect of heat treatment of red fruit using steam pressure at 100, 110 and 120°C during 3-45 mins prior extraction using dry method, againts the oil yield, free fatty acid (FFA), total carotenoids and tocopherols of RFO were investigated, using experimental method. Heat treatment of the red fruit drupa (grains) using pressurized steam (autoclave) at the temperatures of 100, 110 and 120°C, with the pressure of 14.9 psi, for 3 to 45 mins before the oil is extracted by compression using Hydraulic Jack. Furthermore, RFO was analyzed for oil yield, FFA level, total content of carotenoids and tocopherols. The results showed that heating treatment prior extraction increased the oil yield, but decreased carotenoid and tocopherol content. Heating treatment also increased the FFA levels; but tend to decrease with the increasing of temperature and heating time. The minimum FFA level was obtained from heat treatment at 120°C for 20 mins, with the highest oil yield (11.5±0.3% of total grains extracted), and the carotenoids and tocopherols content of 6148±65 ppm and 1515±24 ppm, respectively, as well as the FFA level of 0.76±0.1%, no significant difference (P<0.05) with the control (0.71±0.2%). To further reduce the FFA content, it is recommended to study the effects of heat treatment of red fruit immediately after harvest.

Simultaneous Determination of Free Phytosterols and Tocopherols in Vegetable Oils by an Improved SPE–GC–FID Method

In this work, a simple and rapid SPE–GC–FID method for simultaneous determination of free tocopherols and phytosterols in vegetable oils was developed. The use of this SPE approach for the extraction of naturally occurring tocopherols and phytosterols provides advantages such as simplicity, high speed, and ease of use. The whole method was validated, and the limits of detection of tocopherols and phytosterols were 0.05 and 0.03 mg/100 g of oil, respectively. The precisions for the determination of tocopherols and phytosterols in vegetable oils were < 10.1% in relative standard deviations. The recoveries of selected tocopherols and phytosterols spiked at low, middle, and high concentrations ranged from 83.4 to 97.7%. The developed approach was successfully applied to the analysis of free tocopherols and phytosterols in rapeseed, sunflower seed, linseed, sesame, and maize oils.

The Effect of Microwave Pretreatment on Micronutrient Contents, Oxidative Stability and Flavor Quality of Peanut Oil.

The purpose of the present study is to investigate the changes in extraction yield, physicochemical properties, micronutrients content, oxidative stability and flavor quality of cold pressed peanut oil extracted from microwave (MW) treated seeds (0, 1, 2, 3, 4, 5 min, 700 W). The acid value and peroxide value of extracted oil from MW-treated peanuts were slightly increased but far below the limit in the Codex standard. Compared with the untreated sample, a significant (p < 0.05) increase in extraction yield (by 33.75%), free phytosterols content (by 32.83%), free tocopherols content (by 51.36%) and induction period (by 168.93%) of oil extracted from 5 min MW-treated peanut were observed. MW pretreatment formed pyrazines which contribute to improving the nutty and roasty flavor of oil. In conclusion, MW pretreatment is a feasible method to improve the oil extraction yield and obtain the cold pressed peanut oil with longer shelf life and better flavor.

Variability of growth and oil characteristics of Jatropha curcas L. in North-east India

ABSTRACTSuccess of improvement of Jatropha curcas depends on wide germplasm from different agro-ecological regions showing specific and attractive traits. The present study aimed to compare characteristics of 28 jatropha accessions in the light of enhancing the viability of the oil-based biodiesel chain. The tested jatropha accessions showed a wide range of responses. The plant morphology (height, branching and leaves) also indicated some vigorous genotypes. The growth was accompanied by a wide range of leaf gas exchange (CO2 and moist) that gave water use efficiency values ranging between 0.5 and 8.5. The morphological and physiological differences had no significant influence on seed weight (67–76 g/100 seeds). Oil yield with a mean value of 27.93% can be considered a medium yield for jatropha; only few accessions had oil over 30%. However, differences were well evident in free fatty acid (1.4–28.7%), phorbol ester (PE, 1.1–4.3 mg/g oil), tocopherol (73.7–907.8 ng/mg oil) and unsaturated fatty acid (78.8–90.8%) contents. The present data support studies to correlate genetic, morphological, physiological and biochemical traits in each genotype considered for future selection of ideotypes with low undesirable free fatty acid contents, and potential valorisation of secondary oil products (PEs, tocopherols) to enhance the economic viability and sustainability of the jatropha oil-based biodiesel chain.

Occurrence of tocopheryl fatty acid esters in vegetables and their non-digestibility by artificial digestion juices

Tocopheryl fatty acid esters (TFAE) consist of tocopherols esterified to fatty acids, but only little is known about this substance class. In this study, twelve vegetable groups were screened on TFAE and contents of (free) tocopherols and TFAE were determined in red bell pepper, red chili pepper, cucumber and walnut (n = 5, respectively). Intact TFAE were separated by solid phase extraction from free tocopherols and analyzed by GC/MS. Highest TFAE values were determined in chili pepper (4.0–16 mg/100 g fresh weight, FW) and walnut (4.1–12 mg/100 g FW), followed by bell pepper (1.3–1.5 mg/100 g FW) and cucumber (0.06–0.2 mg/100 g FW). Contribution of TFAE to the total tocopherol content ranged from 7–84%. Neither the treatment with artificial digestion juices nor exposure to sunlight showed degradation of TFAE. This substance class might represent a hitherto overlooked storage form for free tocopherols in plants as they occur to be more stable. But as the ester bond in medium chain TFAE seems not to be fissile in the human body, they might not contribute in the same way as free tocopherols to the vitamin E activity of vegetables and might have to be determined separately.

Physico-Chemical Characteristic and Fatty Acids Compositions of Cottonseed Oils

In this study, three cotton genotypes of species Gossypium hirsutum L., Cukurova 1518, PAUM 15 and BA 119 were investigated for their some physicochemical properties of oils such as free fatty acids, peroxide value, iodine value, unsaponifiable matter, total carotenoid and tocopherol contents and fatty acids composition in Cukurova region in Turkey. Seed oil content ranged 17.2-19.6% and PAUM 15 was found to be genotype with the highest oil content. The range of other physicochemical properties and their values are as follows; free fatty acids 1.7-2.8%, peroxide value 5.3- 6.0 meq O2 kg-1, unsaponifiable matters 2.1-2.3%, iodine value 102-110, total carotenoid content 119-140 mg kg-1, total tocopherol content 887-920 mg kg-1, linoleic acid 52.00-55.82%, palmitic acid 24.85-25.63%, oleic acid 14.06-17.00%, stearic acid 3.01-3.13% in the cottonseed oils. PAUM 15 was determined to be more suitable for food consumption as edible oil due to its highest oil content and quality characteristics than the others genotypes.

Free tocopherols as chemical markers for Arabica coffee adulteration with maize and coffee by-products

Coffee adulteration with coffee by-products is increasing, due mostly to its chemical and sensorial similarity with ground roasted coffee. Based on the recognized effectiveness of tocopherols as markers for coffee adulteration with maize, we have further explored their ability to distinguish adulterations with coffee husks, the main residue of coffee dry processing. For the purpose, a ground roasted arabica coffee sample was adulterated with 5–50% (w/w) of roasted husks, cleaned roasted husks (without the inner parchment layer), and roasted maize. Extracted lipids were analysed by normal-phase HPLC, with florescence detection, and the tocopherol amounts analysed by mean tests, regression analysis, PCA, LDA and SIMCA. γ–tocopherol, detected in residual amounts in roasted coffee, was inversely proportional to coffee purity, being the compound that better contributed for adulteration detection, independently of the adulterant tested. Coffee richness in β–tocopherol, in opposition to all the adulterants tested, also contributes for this discrimination. Based on the tocopherol profiles, adulterations can be perceived at the lowest amounts tested (5%), but higher amounts are necessary for identification of the adulterant, namely ≥10% for maize and from 20% upwards for coffee by-products. For heavy adulterations is even possible to distinguish between husks and cleaned husks. This method is simple to implement in food analysis laboratories, with applicability for adulteration screening or to complement other instrumental methods.

Comparación de aceite de semilla de calabaza de tres especies y ocho aceites comerciales mediante un método multivariado

Four different pumpkin seed from Cucurbita pepo L. (hull and hull-less), C. argyrosperma and C. ficifolia previously bred by our research team were characterized by their chemical composition. The Official Methods of the American Oil Chemists´ Society were used to determine the quality parameters oil content, free fatty acids, anisidine, peroxide, tocopherols, and fatty acids profile. A cannonical discriminant analysis to the fatty acids profile of the pumpkin seed oil and other oils was applied. The cannonical variables indicated oleic and linoleic acid contents were the principal components that established differences among the material evaluated here and other vegetable oils. The results indicated that the pumpkin oil from hull and hull-less seed have a potential for healthy human consumption.

Production of trans‐Free Margarine with Stearidonic Acid Soybean and High‐Stearate Soybean Oils‐Based Structured Lipid

Omega-3 fatty acids (n-3 FAs) have been positively associated with prevention and treatment of chronic diseases. Intake of high amounts of trans fatty acids (TFAs) is correlated with increased risk of coronary heart disease, inflammation, and cancer. Structured lipid (SL) was synthesized using stearidonic acid (SDA) soybean oil and high-stearate soybean oil catalyzed by Lipozyme(®) TLIM lipase. The SL was compared to extracted fat (EF) from a commercial brand for FA profile, sn-2 positional FAs, triacylglycerol (TAG) profile, polymorphism, thermal behavior, oxidative stability, and solid fat content (SFC). Both SL and EF had similar saturated FA (about 31 mol%) and unsaturated FA (about 68 mol%), but SL had a much lower n-6/n-3 ratio (1.1) than EF (5.8). SL had 10.5 mol% SDA. After short-path distillation, a loss of 53.9% was observed in the total tocopherol content of SL. The tocopherols were lost as free tocopherols. SL and EF had similar melting profile, β' polymorph, and oxidative stability. Margarine was formulated using SL (SLM) and EF (RCM, reformulated commercial margarine). No sensory difference was observed between the 2 margarines. The SL synthesized in this study contained no TFA and possessed desirable polymorphism, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL was trans-free and SDA-enriched. The current research increases the food applications of stearidonic acid (SDA) soybean oil. trans-Free SDA containing SL was synthesized with desirable polymorph, thermal properties, and SFC for formulation of soft margarine. The margarine produced with this SL had no trans fat and had a low n-6/n-3 ratio. This may help in reducing trans fat intake in our diet while increasing n-3 FA intake.

α-Tocopherol release from active polymer films loaded with functionalized SBA-15 mesoporous silica

The aim of the present work is the study of the migration from active LDPE polymer films of α-tocopherol adsorbed onto purely siliceous and amino-functionalized SBA-15 mesoporous silica. In particular, the effect of the pore size and the chemical functionality of the internal walls of the mesophase was thoroughly investigated.Co-condensation of tetraethylorthosilicate and aminopropyltriethoxysilane was exploited to bind amino groups on the pore surface of SBA-15. The synthesized mesoporous powders were characterized by means of X-ray diffraction and N2 adsorption/desorption at 77K. Powders loaded with tocopherol were characterized by infrared spectroscopy and thermogravimetric analysis. Results show that the maximum of the pore size distribution reduces from 90Å for purely siliceous SBA-15 to 73Å for amino-functionalized SBA-15. Infrared analysis shows that tocopherol interacts with the amino groups of functionalized SBA-15.Migration tests were performed at 25°C, using 96% v/v ethanol as fatty food simulant, on both polymer films containing about 1% wt/wt of free tocopherol and about 3% wt/wt of tocopherol loaded onto purely siliceous and amino-functionalized SBA-15. The tocopherol diffusivity of films containing functionalized mesoporous silica decreased of about 60% with respect to films containing free tocopherol. This is due to the decrease in the pore size and to the increase in diffusion resistance caused by the functionalization of the internal pore walls with the amino groups. Moreover, the oxygen radical absorbing capacity assay of the produced active polymer films proved the antioxidant effectiveness of tocopherol released from samples after manufacturing process.

Chemical and Enzymatic Interesterification of a Blend of Palm Stearin: Soybean Oil for Low trans‐Margarine Formulation

AbstractA blend of palm stearin and soybean oil (70/30, wt%) was modified by chemical interesterification (CIE) and enzymatic interesterification (EIE), the latter batch‐wise (B‐EIE) and in continuous (C‐EIE). Better oil quality, mainly in terms of acidity, free tocopherol and partial acylglycerol content, was obtained after EIE. The clear melting point after any interesterification process was similar and about 9 °C lower as result of the modification in the TAG profile, which approaches the calculated random distribution. Interesterification changed the SFC profile significantly. For the fully refined interesterified blends, the SFC profile was similar and clearly different from the starting blend. Interesterification decreased the content of solids at temperatures &gt;15 °C and increased the content of solids at temperatures &lt;15 °C. This increase was less remarkable after C‐EIE, suggesting that full randomization was not achieved in the used conditions, probably caused by a too short residence time of the oil in the enzymatic bed. During B‐EIE, variations in SFC with time, principally at low temperatures, were still observed although the TAG composition was stable. At low temperatures, the reaction rate calculated from SFC was very low, confirming an important effect of the acyl migration on this parameter.

Enhancement of intracellular γ-tocopherol levels in cytokine-stimulated C3H 10T1/2 fibroblasts: relation to NO synthesis, isoprostane formation, and tocopherol oxidation

BackgroundStimulation of C3H 10T1/2 murine fibroblasts with interferon-γ(IFN) and bacterial lipopolysaccharide (LPS) generates reactive oxygen and nitrogen species leading to DNA damage, lipid oxidation, and tocopherol oxidation. The tocopherols possess unique chemical and biological properties that suggest they have important roles related to intracellular defense against radical-mediated damage.ResultsDespite increased levels of reactive oxidants and decreased media tocopherol, cellular levels of γ-tocopherol, but not α-tocopherol, were observed to increase significantly when cells were treated with IFN/LPS. Inhibition of nitric oxide (NO) synthesis by a specific inhibitor of inducible NO synthase (iNOS) increased both intracellular α-tocopherol and γ-tocopherol concentrations, but did not significantly alter the reduction in media tocopherol levels caused by IFN/LPS treatment. Both exposure to exogenous NO and cellular synthesis of NO in cell culture increased media levels of 8-epi-prostaglandin F2α, a marker of oxidative lipid damage, whereas inhibition of endogenous NO synthesis reduced media 8-epi-prostaglandin F2α formation to control levels.ConclusionElevated intracellular levels of γ-tocopherol in response to the cellular inflammatory state may indicate that it serves a unique role in minimizing cellular damage resulting from endogenous NO synthesis. Results of the current study suggest that NO is an important mediator of damage within the cell, as well as in the oxidation of both α- and γ-tocopherols. The paradoxical increase in cellular tocopherol associated with the induction of NO synthesis may indicate either enhanced cellular transport/decreased export for tocopherols or recruitment of free tocopherol from tocopherol storage molecules.

Synthesis and study of the cancer cell growth inhibitory properties of α-, γ-tocopheryl and γ-tocotrienyl 2-phenylselenyl succinates

Vitamin E succinate selenium-conjugated molecules were synthesized and their apoptogenic properties were evaluated. 4-Methyl-2-phenylselenyl succinate ( 4) was prepared by the reaction of sodium benzeneselenolate with 2-bromosuccinic anhydrite in methanol solution. The methyl ester was converted to the acid ( 5) by hydrolysis with aqueous hydrochloric acid. Reaction of the 2-phenylselenyl succinic anhydrite ( 6) with α-tocopherol ( 1a), γ-tocopherol ( 1c), and γ-tocotrienol ( 2c) in acidic conditions gave the respective esters. The free radical scavenging properties of α-tocopheryl-2-phenylselenyl succinate ( 7), γ-tocopheryl-2-phenylselenyl succinate ( 8), and γ-tocotrienyl-2-phenylselenyl succinate ( 9) were evaluated in comparison with those of α-tocopheryl succinate ( 10), γ-tocopheryl succinate ( 11), and γ-tocotrienyl succinate ( 12), respectively, and the free tocopherols and γ-tocotrienol. Compounds 7– 9 induced a statistically significant decrease in prostate cancer cell viability compared to 10– 12, respectively, or 5, exhibiting features of apoptotic cell death and associated with caspase-3 activation. These data show that structural modifications of vitamin E components by 5 enhance their apoptogenic properties in cancer cells.

Skin absorption and metabolism of a new vitamin E prodrug, δ-tocopherol-glucoside: in vitro evaluation in human skin models

The aim of this study was to investigate the cutaneous penetration and metabolism of the new vitamin E prodrug δ-tocopherol glucoside (δ-TG), as compared to those of common vitamin E acetate, in vitro, both in reconstituted human epidermis and in viable human skin. Better diffusion was observed with α-tocopherol acetate (α-TAc) than with δ-tocopherol glucoside in both skin models, at 0.1% and 0.05% in a myritol solution; however, no metabolism was detected with α-tocopherol acetate. In all conditions tested (two skin models, two concentrations, three test times, and compartmental analysis) the δ-tocopherol glucoside was metabolized into free tocopherol. In the reconstituted human epidermis, after 18 h, over 90% of the δ-tocopherol glucoside was bioconverted. In the viable human skin, the extent of metabolism was about 20%, with 0.12 and 0.10 μg/cm 2 of δ-tocopherol glucoside in the stratum corneum and epidermis, respectively. After topical application, the δ-tocopherol glucoside had a considerable reservoir effect, associated with gradual delivery of free tocopherol. The use of this gluco-conjugated vitamin E at a low concentration shows the capability of the skin to metabolize the prodrug in a slow and prolonged manner, making this gluco-conjugated vitamin E an excellent candidate for continuous reinforcement of antioxidants in the skin.

Determination of alpha-tocopherol in infant foods by liquid chromatography combined with atmospheric pressure chemical ionisation mass spectrometry.

A novel, sensitive and specific method for the quantification of alpha-tocopherol in two infant foods (milk and cereals) using liquid chromatography on-line with positive atmospheric pressure chemical ionisation mass spectrometry detection (LC/APCI-MS) has been developed. The samples were first saponified in order to eliminate fats and to transform tocopherol esters into free tocopherol, followed up by a liquid-liquid extraction of the analyte in petroleum benzine/diisopropyl ether (75:25, v/v) prior to injection onto the LC system. For the quantification, deuterium-labelled tocopherol was used as internal standard and the samples were monitored in selected ion monitoring (SIM) mode. Calibration curves between 1-40 microg/mL of alpha-tocopherol showed a good linear correlation (r(2) = 0.99994), and the detection limit was determined to be 2.5 ng/mL. The within-day and between-day precision were determined for several dietetic infant formulae and certified reference samples, and found to be below 3.5%. The accuracy determined on a Nestlé reference sample (milk powder) was calculated to be 115.2 +/- 1.2%, which confirms the robustness of the proposed method. This study shows that single quadrupole LC/MS can be applied for the quantification of vitamins in food and the method offers better sensitivity and selectivity than traditional method such as LC-UV. This would simplify the preparation of the food samples and consequently enhance the vitamin analysis throughput in the food area.

Tocopherols in sea buckthorn (Hippophaë rhamnoides L.) berry oil

AbstractThe free tocopherol content in whole berries of six sea buckthorn cultivars grown in northeastern Poland and Belorussia was determined with HPLC. The total free tocopherol content in oil from whole berries was 101.4–128.3 mg/100 g of oil. α‐Tocopherol was the predominant tocopherol of sea buckthorn berries, and only traces of γ‐tocopherol were detected in the oil. α‐ and δ‐Tocopherols constituted 62.5–67.9% and 32.1–37.5% of total tocopherol, respectively. The total free tocopherol content in oil of sea buckthorn cv. Nadbaltycka increased during maturation from 40.4 to 109.8 mg/100 g of oil. Green berries contained a marked amount of γ‐tocopherol, but its content rapidly declined to traces when the color of berries turned from green to olive‐yellow.