Tocopherols In Oils Research Articles

Deacidification of Crude Hazelnut Oil Using Molecular Distillation – Multiobjective Optimization for Free Fatty Acids and Tocopherol

Hazelnut oil is a good source for its high oleic acid and tocopherol contents. Since tocopherols are beneficial compounds in human diet, preservation of tocopherols in oil plays a great role in refining process. The aim of this study is to determine the optimum molecular distillation conditions for deacidification of crude hazelnut oil at which free fatty acids (FFAs) are removed while tocopherols are preserved as much as possible. A short‐path distillation column is used with evaporation temperatures ranging from 110 to 190 °C and vacuums from 0.05 to 5 mmHg for deacidification. Multiobjective optimization is performed for minimizing tocopherol loss and maximizing FFA removal simultaneously. Results reveal that higher temperature and vacuums achieve more deacidification in residual oil. FFA content is reduced to 2.05% at 190 °C and 0.05 mmHg. On the other hand, tocopherol concentrations are considerably affected at this condition while they remain almost stable at other conditions. Optimized conditions for removal of FFAs and protecting of tocopherols in crude hazelnut oil are calculated as 188.65 °C and 0.14 mmHg. For verification, an additional distillation is carried out at the calculated conditions, and the results are found very close to that of optimized conditions.Practical Applications: Physical refining or vacuum distillation process is a substitute to conventional refining which causes excessive neutral oil losses during neutralization. However, heat treatment for long periods of time may inevitably cause degradation of beneficial compounds such as tocopherols. For this purpose, this study focuses on optimizing molecular distillation conditions at which maximum tocopherol and minimum FFA could be obtained simultaneously. Outcomes would be useful for industrial physical refining plants dealing with optimum points for the same purpose.Deacidification of crude hazelnut oil using molecular distillation – multiobjective optimization for tocopherol and FFA

Influence of seed roasting on pumpkin seed oil tocopherols, phenolics and antiradical activity

To achieve the aroma and colour typical of pumpkin seed oil, production includes a roasting step, in which pressed pumpkin seeds are exposed to temperatures of 110 °C and above for up to 60 min. Our purpose was to investigate the effect of roasting temperature on pumpkin seed oil tocopherols and phenolics as important compounds for its nutritional value. In this study, pumpkin seeds of two varieties were roasted at temperatures from 90 to 200 °C, with one sample left unroasted for comparison purposes. Concentrations of α- and γ-tocopherol and phenolic compounds, as well as antiradical activity, were determined. Among the polyphenols, vanillic, caffeic, transcinnamic and p-coumaric acid were detected. The highest observed concentrations of these polyphenolic acids were 3.08, 0.42, 2.48 and 1.91 mg/kg, respectively. As roasting temperatures increased, polyphenol concentrations decreased. The least significant changes were observed in α- and γ-tocopherols, with concentrations ranging from 51 to 113 mg/kg and 356 to 646 mg/kg, respectively. Antiradical activity was determined spectrophotometrically via 2,2-diphenyl-1-picrylhydrazyl (DPPH) testing. The antiradical effect values ranged from 31.4 to 70.6% and 19.3 to 47.7% for Gleisdorf and Rustikal samples, respectively. Several chemical parameters (acid, saponification, peroxide and iodine values) were also examined.

Contribution of the Ratio of Tocopherol Homologs to the Oxidative Stability of Commercial Vegetable Oils.

The antioxidant activity of tocopherols in vegetable oils was shown to chiefly depend on the amount and the tocopherol homolog present. However, the most effective ratio of tocopherol homologs with regard to the antioxidant capacity has not been elucidated so far. The present study analyzed the effect of different tocopherol concentrations, homologs and ratios of homologs on markers of lipid oxidation in the most commonly consumed vegetable oils (canola, sunflower, soybean oil) stored in a 12 h light/dark cycle at 22 ± 2 °C for 56 days under retail/household conditions. After 56 days of storage, the α-tocopherol-rich canola and sunflower oil showed the strongest rise in lipid peroxides, yielding 25.1 ± 0.03 meq O2/kg (+25.3-fold) and 24.7 ± 0.05 meq O2/kg (+25.0-fold), respectively. ESR experiments, excluding effects of the oils’ matrices and other minor constituents, confirmed that a food representative tocopherol ratio of (γ + δ)/α = 4.77, as represented in soybean oil, led to a more pronounced delay of lipid oxidation than a lower ratio in canola (1.39) and sunflower oil (0.06). An optimum (γ + δ)/α -tocopherol ratio contributing to the oxidative quality of vegetable oils extending their shelf life has to be investigated.

Electrochemical detection of tocopherols in vegetable oils by supercritical fluid chromatography equipped with carbon fiber electrodes

The oxidation current of tocopherol was obtained by a flow-through column electrolytic cell in supercritical carbon dioxide.

Effects of Microwave Roasting Process and Time on Chemical Composition and Oxidative Stability of Sunflower Oil

Purpose: In this study, sunflower seeds (Helianthus annuus) were treated with an industrial microwave oven under 700 W for 8, 12, 16 and 20 min and oil was extracted using mechanical press technique. A suitable roasting treatment (20 min) is advantageous to oil extraction yield and tocopherol contents. The extracted oil results showed no variations in the contents of fiber, ash, and protein that were attributable to the roasting. However, the color, FFA, p-anisidine, saponification and density values of oils were increased significantly as the roasting time increased. The iodine values of the oils were noticeably decreased. The oxidative stability revealed that, as the roasting time increased, the oxidative stability of sunflower oil decreased. Tocopherol contents were identified, namely, - and β- tocopherols, whereas no -tocopherol was detected. The main tocopherol found in sunflower oil was -tocopherol. The content of -tocopherol in sunflower oil at 15 min of roasting gradually increased from 895.1 to 1108.83 mg/kg as roasting time increased. The fatty acid compositions of sunflower oil did not change with the roasting time. The major fatty acid was linoleic acid.

Dynamics of oil and tocopherol accumulation in sunflower grains and its impact on final oil quality

Tocopherols are one of the most important bioactive compounds in vegetable oils. It is known that these antioxidants present a dilution like relationship with oil weight per grain but the mechanism underlying this relationship are unknown. The aim of this work was to analyze the dynamics of tocopherol accumulation in sunflower grains, its relationship with oil accumulation and its effects on final oil quality in genotypes with different fatty acid composition. Three field experiments were conducted with genotypes with different potential fatty acid composition (a traditional, a high oleic and a high stearic−high oleic) and treatments with different source (intercepted solar radiation) or sink (grains) during grain filling to obtain varied grain filling conditions and grains with different oil concentration and oil unsaturation. Intercepted solar radiation modified oil per grain but did not affect tocopherol per grain. The rate of accumulation explained 79% and 74% of the oil and tocopherol per grain variation, respectively. When intercepted solar radiation increased, the duration of the period of oil and tocopherols accumulation increased, being the first the most responsive. These differences in the duration of accumulation periods are reflected in a larger relative increase in oil than tocopherols per grain and thus a dilution of the latter in the oil. These differences in the dynamics of oil and tocopherol accumulation are common to genotypes with different level of unsaturation. These results help to understand the mechanism associated with the dilution curve of oil tocopherol concentration reported in the literature.

Bidimensional modeling applied to oil extraction kinetics of microwave-pretreated canola seeds

The effect of microwaves on canola oil extraction kinetics and on tocopherol and canolol content in oil was studied. Oil was extracted with hexane at constant temperature (298–333 K) at different times (300–64800 s). In general, for each temperature and time, a significant yield increase was achieved by effect of the pretreatment. A modified Fick's diffusion model was proposed to explain the extraction process; the parameters were adjusted to obtain washing fractions and the effective diffusion coefficient, which presented an Arrhenius-type temperature-dependence. The analysis of the parameters allowed to develop a modified bidimensional diffusion model (temperature and time-dependent), appropriately correlating the data for pretreated and untreated samples. An increase in the pre-exponential parameter due to pretreatment was observed, evidencing the influence of microwave radiation on the sample structure. The pretreatment did not significantly affect the oil quality indices, but increased the content of canolol and β and δ-tocopherol isomers.

Abstract 5235: Dietary administration of δ- and γ-tocopherol inhibits estrogen-mediated mammary tumorigenesis in ACI rats

Abstract Tocopherols (T), members of the vitamin E family, occur in four forms designated as α, β, δ and γ. Epidemiological studies suggest that tocopherols could reduce the risk of cancer. α-T is known as the classical vitamin E, being the predominant form of tocopherol found in human blood and tissues. However, clinical studies with α-T to substantiate the role of tocopherols in cancer prevention have provided inconclusive results. Such outcomes indicate that the cancer preventive activity of tocopherols might be attributed to the other forms of tocopherols, but not α-T. γ-T, which is the most abundant tocopherol in vegetable oils, is our major dietary source of tocopherols. Recent studies have demonstrated that δ-T and γ-T have higher anti-cancer activity than α-T in several animal models of cancer. The present study investigated the cancer preventive activity of individual purified forms of tocopherols α-T, δ-T, γ-T as well as a naturally occurring γ-T rich mixture of tocopherols (γ-TmT) in an in vivo model of estrogen receptor (ER)-positive breast cancer, namely estrogen supplemented August-Copenhagen Irish (ACI) rats. ACI rats were subcutaneously implanted with 9 mg of 17β-estradiol (E2) in silastic tubings and administered with diets containing 0.2% α-T, δ-T, γ-T or γ-TmT. Rats were euthanized at 30 weeks of mammary carcinogenesis when the E2 control group exhibited 100% tumor incidence. α-T had no effect on estrogen-induced mammary tumors. However, treatment with 0.2% δ-T, γ-T and γ-TmT reduced the tumor volume by 51% (p<0.05), 60% (p<0.01) and 59% (p<0.01), respectively. Administration of α-T, δ-T and γ-T resulted in a 2.1-, 80- and 62-fold increase of these tocopherols, respectively, in the serum of ACI rats. Supplementation with the individual tocopherols also increased the levels of their respective short chain metabolite, carboxyethyl hydroxychromans (CEHCs) in the serum. Administration of δ-T and γ-T was associated with 185- and 99-fold increase in their CEHC metabolites, respectively. The high serum levels of δ- and γ-CEHC metabolites could contribute to the enhanced chemopreventive activity of δ-T and γ-T. In conclusion, δ-T, γ-T and γ-TmT could be potential natural agents for the prevention of estrogen-induced mammary tumorigenesis. (This work was supported by the NIH grant R01 AT007036 and the New Jersey Commission on Cancer Research Postdoctoral Fellowship to Soumyasri Das Gupta). Citation Format: Soumyasri Das Gupta, Joseph Wahler, Min Ji Bak, Mao-Jung Lee, Yong Lin, Weichung Joe Shih, Chung S Yang, Nanjoo Suh. Dietary administration of δ- and γ-tocopherol inhibits estrogen-mediated mammary tumorigenesis in ACI rats. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5235.

Quality characteristics of soybean germ oil obtained by innovative subcritical butane experimental equipment

Subcritical butane extraction (SBE) was used to extract oil from soybean germ and was compared with conventional n-hexane extraction (CHE) and supercritical CO2 extraction (SC-CO2E) methods. By analysing the extraction yield, composition of fatty acids and characteristic functional contents such as tocopherol, phytosterols and phospholipids in soybean germ oil (SGO), the selective extraction characteristics of subcritical butane were evaluated. The results indicate that compared to CHE and SC-CO2E, SBE had no significant difference on oil yield, fatty acid compositions, acid value and peroxide value of SGO. However, the contents of phytosterol and tocopherol in the oil extracted by SBE (2,772.9 and 188.9 mg/100 g) were evidently higher than those extracted by CHE (1,437.2 and 171.3 mg/100 g), with both being lower than those of supercritical CO2 extracted oil (3,982.4 and 227.6 mg/100 g). And, the content of phospholipids in SGO extracted by SBE (23.92 mg/g) was lower than that extracted CHE (38.47 mg/g)....

Sterol, aliphatic alcohol and tocopherol contents of Quercus ilex and Quercus suber from different regions

Quercus ilex and Quercus suber are grown typically in the Mediterranean area. The aim of the present work was to study the content of sterols, aliphatic alcohols and tocopherols in acorn oil of Q. ilex and Q. suber from different locations in Tunisia. The level of total sterols ranged from 4632.71 to 10985.10mg/kg (Q. ilex) and from 6563.40 to 11576.09mg/kg (Q. suber), and β-sitosterol was the predominant form (ca. 90%). The total content of aliphatic alcohols was between 1650.39 and 2969.99mg/kg for Q. ilex and from 1532.81 to 3575.39mg/kg for Q. suber, and tetracosanol was the most abundant (ca. 50%). The average tocopherol content was slightly higher in Q. ilex (ca. 190mg/kg) than Q. suber acorn oil (ca. 140mg/kg). Two isoform (α and γ) were detected and γ- tocopherol was the major compound (more than 90%). All these results highlight the possibility of using Q. ilex and Q. suber as a potential resource of biomolecules for the development of functional foods.

Involvement of α-, γ- and δ-Tocopherol Isomers from Pumpkin (Cucurbita pepo L.) Seed Oil or Oil Mixtures in the Biphasic DPPH˙ Disappearance Kinetics.

The antioxidant activity of three types of pumpkin seed oil or oil mixtures (cold- -pressed, produced from roasted seed paste and salad) produced in the northern part of Croatia and the kinetics of their behaviour as free radical scavengers were investigated using DPPH˙. In addition, the involvement of oil tocopherol isomers (α-, γ- and δ-) in different steps of DPPH˙ disappearance and their impact on the rate of reaction were analysed. The kinetics of DPPH˙ disappearance is a two-step process. In the first step, rapid disappearance of DPPH˙ occurs during the first 11 min of the reaction, depending on the oil type, followed by a slower decline in the second step. To describe DPPH˙ disappearance kinetics, six mathematical models (mono- and biphasic) were tested. Our findings showed that γ- and δ-tocopherols affected DPPH˙ disappearance during the first step, and α-tocopherol in the second step of the reaction. Moreover, α-tocopherol demonstrated 30 times higher antioxidant activity than γ- and δ-tocopherols. The results indicated the biphasic double-exponential behaviour of DPPH˙ disappearance in oil samples, due to the complexity of reactions that involve different tocopherol isomers and proceed through different chemical pathways.

Effect of Maturation Degree on Composition of Fatty Acids and Tocopherols of Fruit Oil from Pistacia atlantica Growing Wild in Algeria

Pistacia atlantica fruit oil has been used for a long time by local populations for culinary and medicinal purposes. In this study, the fatty acid composition and tocopherol content were determined in twelve samples of P. atlantica fruit oil at three stages of maturation (immature, intermediate maturity and mature) collected in three different sites from the region of Laghouat. The results indicated a significant difference between the oil of mature fruits (green and black) and the immature ones (light red), which were distinguished by richness in unsaturated fatty acids and tocopherols. The oil from fruits of intermediate maturity (dark red) seems to combine these properties with those of the mature group, including oil yields. Such data emphasize the value of this oil, which needs further investigation.

Developing the complex antioxidant from walnut leafs and calendula extracts

This article is devoted to research the oils and fats oxidation processes. The methods of protection oils, fats and fat-containing products from oxidative damage are given. The most attention is paid to products protection from oxidation with the help of inhibitors. Natural antioxidants from plant material are reviewed. Complex antioxidant based on walnut leaves and calendula extracts are developed and investigated. The ability of the developed oxidation inhibitor to inhibit the oxidation of sunflower oil is demonstrated. The antioxidant feature was estimated from the values of induction periods. By adding an extract of the walnut leaves in amount of 0,025 % (counting dry substance) and calendula extract in amount of 0,025 % (counting dry matter) into sunflower oil, the induction period is doubled. The synergy between sunflower oil tocopherols and antioxidants based on walnut leaves extracts and calendula extract was found. Thus, the complex herbal antioxidant that can increase the stability of sunflower oil to oxidation is developed.

Physicochemical characterisation and radical-scavenging activity of Cucurbitaceae seed oils

Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2–83.5%, with linoleic acid being the dominant fatty acid (62.4–72.5%), followed by oleic acid (10.8–22.7%) and palmitic acid (9.2–9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable.

Variations in oil, fatty acid and tocopherol contents of some Labiateae and Umbelliferae seed oils

In this study, the oil content, fatty acid and tocopherol contents of the seeds of some selected Labiateae and Umbelliferae species from Turkey were determined. The total lipid of the studied plant seeds were found between 12.74 (Hyssopus officinalis) to 28.95% (Pimpinella anisum). The highest percentages of oleic acid was determined in Coriandrum sativum (79.2%), Foenicum vulgare (sweet) var. dulce (70.7%), Petroselinum crispum (68.9%), P. anisum (59.3%) and Cuminum cyminum (54.2%). Linoleic acid was determined as the major constituent of all the seed oils (except in F. vulgare and P. crispum seed oils). Linolenic acid in both family seed oils was generally found to be lower than 1.0%, except in a few samples like Satureja hortensis (60.4%), H. officinalis (50.7%), Lavandula angustifolia (64.8%) and Melissa officinalis (53.9%).

Determination of tocopherols as lipid antioxidants in vegetable oils and animal fats

The content of vitamin E (tocopherols) in natural vegetable oils and fats has been determined by microcalorimetry. This technique belongs to kinetic methods for determining vitamin E, which are based on the capacity of tocopherol to inhibit liquid-phase radical oxidation reactions. It has been shown on a model reaction of initiated oxidation of cumene that fatty oils inhibit the radical reaction with an induction period proportional to the content of tocopherols in oil. From experimental curves, the content of tocopherols in oils obtained by different technological methods has been estimated. It has been shown that the amount of tocopherols is an indicator of the oil quality; therefore, the method proposed can be used to control the way of oil manufacture, oil quality, and the presence of synthetic antioxidants.

PO-0588 Neonatal Outcomes Of Very Low Birth Weight Infants Who Received Enteral Nutrition With And Without Olive Oil Support: Randomised Controlled Pilot Study

Background and aims Very low birth weight (VLBW) infants have a greater risk for the oxidative stress related diseases (OSRDs) like retinopathy of prematurity, bronchopulmonary dysplasia, periventricular leukomalacia and necrotizing enterocolitis. Naturel antioxidant activity of phenols, flavonoid and tocopherols in extra virgin olive oil (EVOO) may be preventive for the OSRDs. The purpose of conducting a randomised controlled pilot study is to compare the weight gaining, length of hospitalisation and the OSRDs of VLBW infants who received early enteral nurtition with and without EVOO support. Methods VLBW newborns were divided into two groups in this pilot study. Group 1 received enteral nutrition and EVOO, Group 2 received only enteral nutrition. Nutritional analysis was undertaken for EVOO that was added as 0.5 ml/day in 100 ml enteral nutrition. Total parenteral nutrition (TPN) and minimal enteral nutrition was initiated both of two groups. Results A total of 26 VLBW infants were divided into two groups (Group 1)(n = 13) and (Group 2) (n = 13) and assessed the birth weight: Group 1= 1,329 ± 35 g, Group 2 = 1,276 ± 32 g. gestational age: Group 1= 31 ± 2.79, Group 2 =29 ± 2 weeks. There was no significant difference between two groups for weight gaining, length of hospitalisation and the OSRDs. Conclusions EVOO is very important natural antioxidant and anti-inflammatory nutrients for preterm infants particularly VLBW. A larger randomised controlled trials are needed to show the antioxidant and anti-inflammatory effects of olive oil for prevention of OSRDs in this high risk group.

Influence of industrial physical refining on tocopherol, chlorophyll and beta‐carotene content in sunflower and rapeseed oil

The main purpose of this article was to investigate the influence of individual processes in physical refining on tocopherol content in sunflower and rapeseed oils. During refining some chemical parameters, the oxidative stability of oils and some minor compounds such as chlorophyll and beta‐carotene, were determined. Those analytical data with explained chemical backgrounds gave more qualitative overview of what happened to the same lot of oils being processed in a continuous operation. Some processes were compared with a laboratory oil refining. Crude rapeseed oil contained 656 mg/kg of total tocopherols, followed by high oleic sunflower with 373 mg/kg of tocopherols and classic sunflower oil with 332 mg/kg of tocopherols. The most serious refining processes were bleaching and physical deodorization process, the tocopherol losses being 14.9–17.4% and 20.2–27.1%, respectively. In the refined oils, chlorophylls and FFAs were almost completely removed and the oxidative stability increased 2–3 times. Vegetable oil refining process caused relatively great losses of minor compounds but this, in turn, prolonged the shelf life of edible oils.Practical applications: It was proved that refining of sunflower and rapeseed oils in the oil refinery improves their basic chemical parameters. The loss of tocopherols can be minimized by shortening the time and lowering the temperature during the final step of physical refining, but it has to remain within requirements on quality of refined edible oils.The refining processes of sunflower and rapeseed oils lead to 39.0–45.5 % loss of total tocopherol content. The most serious refining processes were bleaching and physical deodorization process, the tocopherol losses being 14.9–17.4 % and 20.2–27.1 %, respectively. Degumming process can caused 6.6–8.4 % decrease of tocopherols in sunflower and rapeseed oil. Most gentle process was winterization of sunflower oils which caused only 2.9–5.8 % tocopherols decrease.

Composition of Fatty Acids and Tocopherols in Cherry and Lychee Seed Oils

The fruit seed from two small fruits namely cherry (Prunus avium L.) and lychee (Litchi chinensis Sonn.) were analyzed for their oil yields, fatty acids and tocopherols composition. The oil content, extracted with hexane, from cherry and lychee fruit seed was found to be 4.1 and 3.2 %, respectively. Cherry fruit seed oil was characterized by the presence of high content of oleic acid (47.3%), followed by linoleic acid (30.6%) and I±- eleostearic acid (9.2%) while lychee seed oil mainly contained dihydrosterculic acid (46.9%), oleic acid (29.3%) and linolenic acid (3.6%). The ratio of polyunsaturates to monounsaturates to saturates varied considerably between the seed oils tested. Besides, the oils from cherry and lychee exhibited appreciable amount (mg/kg) of I±-, I³- and I´- tocopherols with contribution of 126.7, 223.1, 18.2 and 235.8, 97.3, 132.6, respectively. The results of this study advocate the uses of these under-utilized small fruit resources for oil production. The characterized oils, being a good source of unsaturated fatty acids and antioxidant totocopherols, could be explored for edible or oleochemical uses.

Biochemical Seed Traits of Camelina sativa – An Emerging Oilseed Crop for Biofuel: Environmental and Genetic Influences

Camelina (Camelina sativa (L.) Crantz) is an attractive alternative and sustainable oilseed crop for multipurpose uses, including as a biofuel feedstock. To evaluate the value of C. sativa in Lombardia (north Italy), seven genotypes were cultivated under different climates of two consecutive years and growing seasons; quality and quantity of seed, oil, and flour were analyzed. Genotypes mainly influenced seed weight (0.98–1.56 g/1000 seeds), protein (245-401 mg/g), glucosinolates, and phytic acid. Oil content (27.5%–37.2%) and fatty acid (FA) composition varied with year and growing season among genotypes. Oils were rich in linolenic and linoleic acids (68.4%–80.8%). The monounsaturated acids ranged from 16.4%–25.6%, although erucic acid was much lower at 4.30%. Saturated FAs represented a small fraction. Low free FAs content (0.01%–0.81%) and different amounts of tocopherols (0.44-2.69 μg/mg) in oils depended on years. Correlations among seed and biochemical traits were found. Genotypes with low protein and high phytic acid contents would not be the best for flour quality. Genotypes showing high levels of protein and C18:3/C18:2 fatty acids ratio could be useful for humans and livestock. Genotype with relatively high C18:1 fatty acid content can be used mainly for biofuel production. Altogether, the data indicated that C. sativa cultivation could be promoted as an economically profitable oilseed crop in north Italian environments.