Displaying publications 1 - 20 of 75 in total

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  1. Abbas Ali, Hadi Mesran, M., Nik Mahmood, N.A., Abd Latip, R.
    MyJurnal
    In the present work, the influence of microwave power and heating times on the quality
    degradation of corn oil was evaluated. Microwave heating test was carried out using a domestic
    microwave oven for different periods at low- and medium-power settings for the corn oil sample.
    The changes in physicochemical characteristics related to oil degradation of the samples during
    heating were determined by standard methods. In this study, refractive index, free fatty acid
    content, peroxide value, p-anisidine value, TOTOX value, viscosity and total polar compound
    of the oils all increased with increasing heating power and time of exposure. In GLC analysis,
    the percentage of linoleic acid tended to decrease, whereas the percentage of palmitic, stearic
    and oleic acids increased. The C18:2/C16:0 ratio decreased in all oil samples with increasing
    heating times. Exposing the corn oil to various microwave power settings and heating periods
    caused the formation of hydroperoxides and secondary oxidation products. The heating reduced
    the various tocopherol isomers in corn oil and highest reduction was detected in γ-tocopherol.
    Longer microwave heating times resulted in a greater degree of oil deterioration. Microwave
    heating caused the formation of comparatively lower amounts of some degradative products in
    the oil samples heated at low-power setting compared to medium-power setting. The present
    analysis indicated that oil quality was affected by both microwave power and heating time.
    Matched MeSH terms: Tocopherols
  2. Ahmad NS, Khalid BA, Luke DA, Ima Nirwana S
    Clin Exp Pharmacol Physiol, 2005 Sep;32(9):761-70.
    PMID: 16173934
    1. Free radicals generated by ferric nitrilotriacetate (FeNTA) can activate osteoclastic activity and this is associated with elevation of the bone resorbing cytokines interleukin (IL)-1 and IL-6. In the present study, we investigated the effects of 2 mg/kg FeNTA (2 mg iron/kg) on the levels of serum IL-1 and IL-6 with or without supplementation with a palm oil tocotrienol mixture or alpha-tocopherol acetate in Wistar rats. 2. The FeNTA was found to elevate levels of IL-1 and IL-6. Only the palm oil tocotrienol mixture at doses of 60 and 100 mg/kg was able to prevent FeNTA-induced increases in IL-1 (P < 0.01). Both the palm oil tocotrienol mixture and alpha-tocopherol acetate, at doses of 30, 60 and 100 mg/kg, were able to reduce FeNTA-induced increases in IL-6 (P < 0.05). Therefore, the palm oil tocotrienol mixture was better than pure alpha-tocopherol acetate in protecting bone against FeNTA (free radical)-induced elevation of bone-resorbing cytokines. 3. Supplementation with the palm oil tocotrienol mixture or alpha-tocopherol acetate at 100 mg/kg restored the reduction in serum osteocalcin levels due to ageing, as seen in the saline (control) group (P < 0.05). All doses of the palm oil tocotrienol mixture decreased urine deoxypyridinoline cross-link (DPD) significantly compared with the control group, whereas a trend for decreased urine DPD was only seen for doses of 60 mg/kg onwards of alpha-tocopherol acetate (P < 0.05). 4. Bone histomorphometric analyses have shown that FeNTA injections significantly lowered mean osteoblast number (P < 0.001) and the bone formation rate (P < 0.001), but raised osteoclast number (P < 0.05) and the ratio of eroded surface/bone surface (P < 0.001) compared with the saline (control) group. Supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent all these FeNTA-induced changes, but a similar dose of alpha-tocopherol acetate was found to be effective only for mean osteoclast number. Injections of FeNTA were also shown to reduce trabecular bone volume (P < 0.001) and trabecular thickness (P < 0.05), whereas only supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent these FeNTA-induced changes.
    Matched MeSH terms: Tocopherols
  3. Arlee, R., Suanphairoch, S., Pakdeechanuan, P.
    MyJurnal
    Chumphon Horticultural Research Centre (CHRC) is Thailand’s main coconut research unit. CHRC has developed three coconut cultivars: Sawi Hybrid No. 1 (Malayan Yellow Dwarf x West African Tall: MYD x WAT), Chumphon Hybrid No. 60 (Thai Tall: THT x WAT) and Chumphon Hybrid No. 2 (MYD x THT). This study compared some chemical components in virgin coconut oil (VCO) from coconut hybrids with their parents. The VCO was extracted by cold pressing and fermentation methods, and was analyzed for fatty acid profiles, triacylglycerol profile, acid value, tocopherol content, total phenolic content, and antioxidant activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals. The findings showed that hybrids contained lauric acid ranging from 46.63 to 48.34% of total fatty acid. Chumphon 60 had the highest lauric acid content, 48.34% of total fatty acids, which was not significantly different (p > 0.05) from that of the parents. In contrast, the cultivars from MYD, Sawi 1 and Chumphon 2, had significantly greater lauric acid content than the parent MYD (p ≤ 0.05). Cold pressing and fermentation provided an oil extraction yield of 25 and 20%, respectively. The proportions of lauric acid in VCO from these two methods were not significantly different (p > 0.05), but the cold pressing method resulted in higher tocopherol content (p ≤ 0.05). The VCO of Chumphon 60 from the cold pressed method had tocopherol content close to that of the parent WAT (p > 0.05) but significantly higher than that of the other parent THT (p ≤ 0.05). In addition, it contained the highest total phenolic contents among the three cultivars, 57.89 mg GAE/100 g oil, leading to antioxidant activity with a low EC50 of 0.53 mg GAE/ml. Overall, the hybrid of WAT x THT, Chumphon 60, was outstanding among the cultivars; it had the highest levels of lauric acid, total phenolic compounds, and antioxidant activity.
    Matched MeSH terms: Tocopherols
  4. Azlina A. Razak, Effat Omar, Suhaila Muid, Hapizah Nawawi
    MyJurnal
    Tocotrienols have been reported to possess potent cholesterol lowering, anti-hypertensive, antiinflammatory and anti-oxidative properties which are superior to tocopherols. Emerging evidence suggests pure tocotrienols have anti-atherogenic properties. However, optimal doses of oftocotrienolrich fraction (TRF) in progressive atherogenesis remain unclear. This animal model experiment was designed to investigate the effects of a range concentration of TRF supplementation on the extent of atherosclerosis and soluble lipids, inflammatory and oxidative stress biomarkers in high-cholesterol diet (HCD) induced hypercholesterolaemic (HC) rabbits with atherosclerosis. A total of 28 New Zealand white rabbits were given 1% high-cholesterol diet (HCD) for two months and then randomised into five groups: Placebo (n=7), TRF 15 mg/kg (n=5), TRF 30 mg/kg (n=6), TRF 60 mg/kg (n=5) and TRF 90 mg/kg (n=5) daily. The treatment was given for three months and the animals were fed HCD throughout the duration. Aortic vessels were obtained to assess the extent of atherosclerotic lesions at the end of the study. Fasting serum lipids (FSL), C-reactive protein (CRP), malondialdehyde (MDA) and 8-isoprostane levels were measured at baseline, one and two months post-HCD, one, two, and three months postintervention. There were no differences in the extent of the atherosclerotic lesions, percentage changes of FSL, MDA, 8-isoprostane and CRP levels between the placebo and TRF groups. In conclusion, TRF across all doses studied have neutral effects on atherosclerotic lesions, soluble lipids, biomarkers of oxidative stress, coronary risk and inflammation in severely atherosclerotic rabbits with progressive and continuous insult by high cholesterol feeding.
    Matched MeSH terms: Tocopherols
  5. Azlina MF, Nafeeza MI, Khalid BA
    Asia Pac J Clin Nutr, 2005;14(4):358-65.
    PMID: 16326642
    Rats exposed to stress developed various changes in the gastrointestinal tract and hormones. The present study was designed to compare the impact of tocopherol and tocotrienol on changes that influence gastric and hormonal parameters important in maintaining gastric mucosal integrity in rats exposed to restrain stress. These include gastric acidity, gastric tissue content of parameters such as malondialdehyde, prostaglandin (PGE(2)), serum levels of gastrin and glucagon-like peptide-1 (GLP-1). Sixty male Sprague-Dawley rats (200-250 g) were randomly divided into three equal sized groups, a control group which received a normal rat diet (RC) and two treatment groups each receiving a vitamin deficient diet with oral supplementation of either tocopherol (TF) or tocotrienol (TT) at 60 mg/kg body weight. Blood samples were taken from half the number of rats (non-stressed group) after a treatment period of 28 days before they were killed. The remaining half was subjected to experimental restraint-stress, at 2 hours daily for 4 consecutive days (stressed groups), on the fourth day, blood samples were taken and the rats killed. The findings showed that the gastric acid concentration and serum gastrin level in stressed rats were significantly (P<0.05) reduced compared to the non-stressed rats in the control and TF groups. However, the gastric acidity and gastrin levels in the TT group were comparable in stressed and non-stressed rats. These findings suggest that tocotrienol is able to preserve the gastric acidity and serum gastrin level which are usually altered in stressed conditions. The PGE(2) content and the plasma GLP-1 level were, however, comparable in all stressed and non-stressed groups indicating that these parameters were not altered in stress and that supplementation with TF or TT had no effect on the gastric PGE2 content or the GLP-1 level. The malondialdehyde, an indicator of lipid peroxidation was higher from gastric tissues in the stressed groups compared to the non-stressed groups. These findings implicated that free radicals may play a role in the development of gastric injury in stress and supplementation with either TF or TT was able to reduce the lipid peroxidation levels compared to the control rats. We conclude that both tocopherol and tocotrienol are comparable in their gastro-protective ability against damage by free radicals generated in stress conditions, but only tocotrienol has the ability to block the stress-induced changes in the gastric acidity and gastrin level.
    Matched MeSH terms: Tocopherols/pharmacology*
  6. Azlina MFN, Qodriyah MS, Kamisah Y
    Curr Drug Targets, 2018;19(12):1456-1462.
    PMID: 29173163 DOI: 10.2174/1389450118666171122130338
    BACKGROUND: Scientific reports had shown that stress is related to numerous pathological changes in the body. These pathological changes can bring about numerous diseases and can significantly cause negative effects in an individual. These include gastric ulcer, liver pathology and neurobehavioral changes. A common pathogenesis in many diseases related to stress involves oxidative damage. Therefore, the administration of antioxidants such as vitamin E is a reasonable therapeutic approach. However, there is conflicting evidence about antioxidant supplementation.

    OBJECTIVE: The aim of this work was to summarize documented reports on the effects of tocopherol and tocotrienol on various pathological changes induced by stress.

    RESULTS AND CONCLUSION: This review will reveal the scientific evidence of enteral supplementation of vitamin E in the forms of tocotrienol and tocopherol in animal models of stress. These models mimic the stress endured by critically ill patients in a clinical setting and psychological stress in individuals. Positive outcomes from enteral feeding of vitamin E in reducing the occurrence of stress-induced pathological changes are discussed in this review. These positive findings include their ability to reduced stress-induced gastric ulcers, elevated liver enzymes and improved locomotors activity. Evidences showing tocotrienol and tocopherol effects are not just related to its ability to reduce oxidative stress but also acting on other mechanism, are discussed.

    Matched MeSH terms: Tocopherols/therapeutic use*
  7. Babura SR, Abdullah SNA, Khaza Ai H
    J Nutr Sci Vitaminol (Tokyo), 2017;63(4):215-221.
    PMID: 28978868 DOI: 10.3177/jnsv.63.215
    Tocotrienols are forms of vitamin E that are present in several important food crops. Compared to tocopherols, less research has been conducted on these compounds because of their low bioavailability and distribution in plant tissues. Both tocotrienols and tocopherols are known for their antioxidant and anticancer activities, which are beneficial for both humans and animals. Moreover, tocotrienols possess certain properties which are not found in tocopherols, such as neuroprotective and cholesterol-lowering activities. The contents of tocotrienols in plants vary. Tocotrienols constitute more than 70% and tocopherols less than 30% of the total vitamin E content in palm oil, which is the best source of vitamin E. Accumulation of tocotrienols also occurs in non-photosynthetic tissues, such as the seeds, fruits and latex of some monocotyledonous and dicotyledonous plant species. The use of biotechnological techniques to increase the tocotrienol content in plants, their biological functions, and benefits to human health are discussed in this review.
    Matched MeSH terms: Tocopherols/metabolism; Tocopherols/chemistry
  8. Bakker MF, Peeters PH, Klaasen VM, Bueno-de-Mesquita HB, Jansen EH, Ros MM, et al.
    Am J Clin Nutr, 2016 Feb;103(2):454-64.
    PMID: 26791185 DOI: 10.3945/ajcn.114.101659
    BACKGROUND: Carotenoids and vitamin C are thought to be associated with reduced cancer risk because of their antioxidative capacity.

    OBJECTIVE: This study evaluated the associations of plasma carotenoid, retinol, tocopherol, and vitamin C concentrations and risk of breast cancer.

    DESIGN: In a nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort, 1502 female incident breast cancer cases were included, with an oversampling of premenopausal (n = 582) and estrogen receptor-negative (ER-) cases (n = 462). Controls (n = 1502) were individually matched to cases by using incidence density sampling. Prediagnostic samples were analyzed for α-carotene, β-carotene, lycopene, lutein, zeaxanthin, β-cryptoxanthin, retinol, α-tocopherol, γ-tocopherol, and vitamin C. Breast cancer risk was computed according to hormone receptor status and age at diagnosis (proxy for menopausal status) by using conditional logistic regression and was further stratified by smoking status, alcohol consumption, and body mass index (BMI). All statistical tests were 2-sided.

    RESULTS: In quintile 5 compared with quintile 1, α-carotene (OR: 0.61; 95% CI: 0.39, 0.98) and β-carotene (OR: 0.41; 95% CI: 0.26, 0.65) were inversely associated with risk of ER- breast tumors. The other analytes were not statistically associated with ER- breast cancer. For estrogen receptor-positive (ER+) tumors, no statistically significant associations were found. The test for heterogeneity between ER- and ER+ tumors was statistically significant only for β-carotene (P-heterogeneity = 0.03). A higher risk of breast cancer was found for retinol in relation to ER-/progesterone receptor-negative tumors (OR: 2.37; 95% CI: 1.20, 4.67; P-heterogeneity with ER+/progesterone receptor positive = 0.06). We observed no statistically significant interaction between smoking, alcohol, or BMI and all investigated plasma analytes (based on tertile distribution).

    CONCLUSION: Our results indicate that higher concentrations of plasma β-carotene and α-carotene are associated with lower breast cancer risk of ER- tumors.

    Matched MeSH terms: Tocopherols/blood; Tocopherols/therapeutic use
  9. Bong, S.C., Loh, S. P.
    MyJurnal
    This study was conducted to investigate and compare the fatty acids and tocopherols of lipid extracted from marine microalgae, Nannochloropsis oculata (NO) and Tetraselmis suecica (TS) using solvent extraction and supercritical fluid extraction (SFE). Fatty acids and tocopherols were determined in the extracted lipid as functions of the temperature (40, 80oC) and pressure (3000, 5000, 7000, 9000psi). Dichloromethane/methanol and hexane were the chosen conventional solvent for fatty acids and tocopherols extraction respectively. The results obtained showed that there were differences in the fatty acid composition of various lipid extracts of NO and TS. Extracts of NO were high in myristic acid (C14:0) (17-35%), palmitic acid (C16:0) (14-47%) and palmitoleic acid (C16:1) (11-42%) whereas extracts of TS were high in C14:0 (21-34%) and C16:0 (29-49%). Eicosapentaenoic acid (EPA) was detected only under certain SFE conditions in NO but was not detected in TS. α-, β- and γ-tocopherol were detected in various SFE extracts of NO but only α- and β-tocopherol were detected in TS. Hexane extraction of both NO and TS resulted in the detection of only α-tocopherol. In conclusion, the use of different extraction methods resulted in different compositions and concentrations of fatty acids and tocopherols in the microalgae studied.
    Matched MeSH terms: Tocopherols
  10. Cheong JN, Mirhosseini H, Tan CP
    Int J Food Sci Nutr, 2010 Jun;61(4):417-24.
    PMID: 20151850 DOI: 10.3109/09637481003591574
    The main objective of the present study was to investigate the effect of polyoxyethylene sorbitan esters and sodium caseinate on physicochemical properties of palm-based functional lipid nanodispersions prepared by the emulsification-evaporation technique. The results indicated that the average droplet size increased significantly (P < 0.05) by increasing the chain length of fatty acids and also by increasing the hydrophile-lipophile balance value. Among the prepared nanodispersions, the nanoemulsion containing Polysorbate 20 showed the smallest average droplet size (202 nm) and narrowest size distribution for tocopherol-tocotrienol nanodispersions, while sodium caseinate-stabilized nanodispersions containing carotenoids had the largest average droplet size (386 nm), thus indicating a greater emulsifying role for Polysorbate 20 compared with sodium caseinate.
    Matched MeSH terms: Tocopherols
  11. Chew LY, Teng SK, Neo YP, Sim YY, Chew SC
    J Oleo Sci, 2024;73(3):275-292.
    PMID: 38432993 DOI: 10.5650/jos.ess23111
    Roselle is an annual botanical plant that widely planted in different countries worldwide. Its different parts, including seeds, leaves, and calyces, can offer multi-purpose applications with economic importance. The present review discusses the detailed profile of bioactive compounds present in roselle seeds, leaves, and calyces, as well as their extraction and processing, to explore their potential application in pharmaceutical, cosmetic, nutraceutical, food and other industries. Roselle seeds with high phenolics, fiber, and protein contents, which are suitable to use in functional food product development. Besides, roselle seeds can yield 17-20% of roselle seed oil with high content of linoleic acid (35.0-45.3%) and oleic acid (27.1- 36.9%). This unique fatty acid composition of roselle seed oil makes it suitable to use as edible oil to offer the health benefits of essential fatty acid. Moreover, high contents of tocopherols, phenolics, and phytosterols were detected in roselle seed oil to provide nutritional, pharmaceutical, and therapeutic properties. On the other hand, roselle leaves with valuable contents of phenols, flavonoids, organic acid, and tocopherols can be applied in silver nanoparticles, food product development, and the pharmaceutical industry. Roselle calyces with high content of anthocyanins, protocatechuic acids, and organic acids are widely applied in food and colorant industries.
    Matched MeSH terms: Tocopherols
  12. Chew SC, Tan CP, Nyam KL
    J Food Sci, 2018 Sep;83(9):2288-2294.
    PMID: 30074623 DOI: 10.1111/1750-3841.14291
    Kenaf seed oil is prone to undergo oxidation due to its high content of unsaturated fatty acids, thus microencapsulation stands as an alternative to protect kenaf seed oil from the adverse environment. This study primarily aimed to evaluate the oxidative stability of microencapsulated refined kenaf seed oil (MRKSO) by the use of gum arabic, β-cyclodextrin, and sodium caseinate as the wall materials by spray drying. Bulk refined kenaf seed oil (BRKSO) and MRKSO were kept at 65 °C for 24 days to evaluate its oxidative stability, changes of tocopherol and tocotrienol contents, phytosterol content, and fatty acid profile. The results showed that the peroxide value, p-Anisidine value, and total oxidation value of BRKSO were significantly higher than the MRKSO at day 24. The total tocopherol and tocotrienol contents were reduced 66.1% and 56.8% in BRKSO and MRKSO, respectively, upon the storage. There was a reduction of 71.7% and 23.5% of phytosterol content in BRKSO and MRKSO, respectively, upon the storage. The degradation rate of polyunsaturated fatty acids in BRKSO was higher than that of MRKSO. This study showed that the current microencapsulation technique is a feasible way to retard the oxidation of kenaf seed oil.

    PRACTICAL APPLICATION: There is increasing research on the functional properties of crude kenaf seed oil, but the crude kenaf seed oil is not edible. This study offered in developing of microencapsulated refined kenaf seed oil by spray drying, which is suitable for food application. The microencapsulation of refined kenaf seed oil with healthier wall materials is beneficial in developing a diversity of functional food products and supplements.

    Matched MeSH terms: Tocopherols/analysis
  13. Chin KY, Mo H, Soelaiman IN
    Curr Drug Targets, 2013 Dec;14(13):1533-41.
    PMID: 23859472
    Osteoporosis is posing a tremendous healthcare problem globally. Much effort has been invested in finding novel antiosteoporotic agents to stop the progression of this disease. Tocotrienol, one of the isoforms of vitamin E, is poised as a potential antiosteoporotic agent. Previous studies showed that tocotrienol as a single isomer or as a mixture demonstrated both anabolic and antiresorptive effects in various rodent models of osteoporosis. In vitro experiments further demonstrated that tocotrienol could up-regulate genes related to osteoblastogenesis and modify receptor activator of nuclear factor kappa B signaling against osteoclastogenesis. Additionally, tocotrienol was also shown to be a strong 3- hydroxy-3-methyl-glutaryl-CoA reductase down-regulator with a mechanism different from that of statins. Inhibition of the mevalonate pathway affects both osteoblast and osteoclast formation in favor of the former. Tocopherol, a more commonly used isoform of vitamin E does not possess similar effects. Tocotrienol is also a potent antioxidant. It can scavenge free radicals and prevent oxidative damage on osteoblast thus promoting its survival. It may also up-regulate the antioxidant defense network in osteoclast and indirectly act against free radical signaling essential in osteoclastogenesis. The effects of tocotrienol on Wnt/β-catenin signaling essential in osteoblastogenesis have not been determined. More mechanistic studies need to be conducted to illustrate the antiosteoporotic effects of tocotrienol. Clinical trials are also required to confirm its effects in humans. In conclusion, tocotrienol demonstrates great potential as an antiosteoporotic agent and much research effort should be invested to develop it as an agent to curb osteoporosis.
    Matched MeSH terms: Tocopherols/pharmacokinetics
  14. Choo YM, Ma AN, Chuah CH, Khor HT, Bong SC
    Lipids, 2004 Jun;39(6):561-4.
    PMID: 15554155
    The concentration of vitamin E isomers, namely, alpha-tocopherol (alpha-T), alpha-tocotrienol, gamma-tocotrienol, and delta-tocotrienol in palm mesocarp at 4, 8, 12, 16, and 20 wk after anthesis (WAA) were quantified using HPLC coupled with fluorescence detection. alpha-T was detected throughout the palm fruits' maturation process, whereas unsaturated tocotrienols were found only in ripe palm fruits. These developmental results indicate that tocotrienols are synthesized between 16 and 20 WAA.
    Matched MeSH terms: Tocopherols/analysis*
  15. Dezfouli MG, Eissazadeh S, Zade SM
    Microsc Microanal, 2014 Aug;20(4):1167-79.
    PMID: 24735566 DOI: 10.1017/S1431927614000701
    This study examines histometrical changes induced by sodium arsenite (SA), as an environmental pollutant, and investigates the protective effect of α-tocopherol on ovaries of SA-treated rats during the prenatal stage until sexual maturity. Rats were classified into groups: control, SA (8 ppm/day), α-tocopherol (100 ppm/day), and SA+α-tocopherol. Treatment was performed from pregnancy until maturation when the rats and ovaries were weighed. The Cavalieri method was used to estimate volume of the ovaries, cortex, medulla, and corpus luteum. The mean diameter of oocytes, granulosa cells, and nuclei were measured and volume was estimated using the Nucleator method. The number of oocytes and thickness of the zona pellucida (ZP) were determined using an optical dissector and orthogonal intercept method, respectively. SA reduced the body and ovary weight, the number of secondary, antral and Graafian oocytes, volume of the ovaries, cortex, medulla and corpus luteum, mean diameter and volume of oocytes in primordial and primary follicles, mean diameter and volume of oocyte nuclei in all types of follicles, and mean thickness of the ZP in secondary and antral follicles. Also, the mean diameter and volume of granulosa cells and their nuclei in antral and Graafian follicles decreased significantly. Vacuolization and vascular congestion in the corpus luteum and an increase in the number of atretic oocytes were seen in the SA group. Most of these parameters were unchanged from the control level in the SA+α-tocopherol group. It was concluded that α-tocopherol supplementation reduced the toxic effects of SA exposure on ovarian tissue in rats.
    Matched MeSH terms: Tocopherols/administration & dosage; Tocopherols/pharmacology*
  16. Elouafy Y, El Idrissi ZL, El Yadini A, Harhar H, Alshahrani MM, Al Awadh AA, et al.
    Molecules, 2022 Nov 09;27(22).
    PMID: 36431794 DOI: 10.3390/molecules27227693
    Walnut oil, like all vegetable oils, is chemically unstable because of the sensitivity of its unsaturated fatty acids to the oxidation phenomenon. This phenomenon is based on a succession of chemical reactions, under the influence of temperature or storage conditions, that always lead to a considerable change in the quality of the oil by promoting the oxidation of unsaturated fatty acids through the degradation of their C-C double bonds, leading to the formation of secondary oxidation products that reduce the nutritional values of the oil. This research examines the oxidative stability of roasted and unroasted cold-pressed walnut oils under accelerated storage conditions. The oxidative stability of both oils was evaluated using physicochemical parameters: chemical composition (fatty acids, phytosterols, and tocopherols), pigment content (chlorophyll and carotenoids), specific extinction coefficients (K232 and K270), and quality indicators (acid and peroxide value) as well as the evaluation of radical scavenging activity by the DPPH method. The changes in these parameters were evaluated within 60 days at 60 ± 2 °C. The results showed that the levels of total phytosterols, the parameters of the acid and peroxide value, K232 and K270, increased slightly for both oils as well as the total tocopherol content and the antioxidant activity affected by the roasting process. In contrast, the fatty acid profiles did not change considerably during the 60 days of our study. After two months of oil treatment at 60 °C, the studied oils still showed an excellent physicochemical profile, which allows us to conclude that these oils are stable and can withstand such conditions. This may be due to the considerable content of tocopherols (vitamin E), which acts as an antioxidant.
    Matched MeSH terms: Tocopherols
  17. Elouafy Y, El Yadini A, El Moudden H, Harhar H, Alshahrani MM, Awadh AAA, et al.
    Molecules, 2022 Nov 08;27(22).
    PMID: 36431782 DOI: 10.3390/molecules27227681
    The present study investigated and compared the quality and chemical composition of Moroccan walnut (Juglans regia L.) oil. This study used three extraction techniques: cold pressing (CP), soxhlet extraction (SE), and ultrasonic extraction (UE). The findings showed that soxhlet extraction gave a significantly higher oil yield compared to the other techniques used in this work (65.10% with p < 0.05), while cold pressing and ultrasonic extraction gave similar yields: 54.51% and 56.66%, respectively (p > 0.05). Chemical composition analysis was carried out by GC−MS and allowed 11 compounds to be identified, of which the major compound was linoleic acid (C18:2), with a similar percentage (between 57.08% and 57.84%) for the three extractions (p > 0.05). Regarding the carotenoid pigment, the extraction technique significantly affected its content (p < 0.05) with values between 10.11 mg/kg and 14.83 mg/kg. The chlorophyll pigment presented a similar content in both oils extracted by SE and UE (p > 0.05), 0.20 mg/kg and 0.16 mg/kg, respectively, while the lowest content was recorded in the cold-pressed oil with 0.13 mg/kg. Moreover, the analysis of phytosterols in walnut oil revealed significantly different contents (p < 0.05) for the three extraction techniques (between 1168.55 mg/kg and 1306.03 mg/kg). In addition, the analyses of tocopherol composition revealed that γ-tocopherol represented the main tocopherol isomer in all studied oils and the CP technique provided the highest content of total tocopherol with 857.65 mg/kg, followed by SE and UE with contents of 454.97 mg/kg and 146.31 mg/kg, respectively, which were significantly different (p < 0.05). This study presents essential information for producers of nutritional oils and, in particular, walnut oil; this information helps to select the appropriate method to produce walnut oil with the targeted quality properties and chemical compositions for the desired purpose. It also helps to form a scientific basis for further research on this plant in order to provide a vision for the possibility of exploiting these oils in the pharmaceutical, cosmetic, and food fields.
    Matched MeSH terms: Tocopherols/analysis
  18. Fairus S, Nor RM, Cheng HM, Sundram K
    Nutr J, 2012;11:5.
    PMID: 22252050 DOI: 10.1186/1475-2891-11-5
    Tocotrienols (T3) and tocopherols (T), both members of the natural vitamin E family have unique biological functions in humans. T3 are detected in circulating human plasma and lipoproteins, although at concentrations significantly lower than α-tocopherol (α-T). T3, especially α-T3 is known to be neuropotective at nanomolar concentrations and this study evaluated the postprandial fate of T3 and α-T in plasma and lipoproteins.
    Matched MeSH terms: Tocopherols/blood
  19. Fairus S, Cheng HM, Sundram K
    J Integr Med, 2020 Jan;18(1):68-79.
    PMID: 31812339 DOI: 10.1016/j.joim.2019.11.005
    OBJECTIVE: Tocotrienols (T3s) have been hypothesized to have greater antioxidant capacity than tocopherols (Ts) due to differences in biokinetics that affect their absorption and function. The present trial compares the antioxidant effectiveness following postprandial challenge of two different doses of α-T or palm T3-rich fraction (TRF) treatments and evaluates their dose-response effects on antioxidant status.

    METHODS: Ten healthy volunteers were given four different doses of vitamin E formulations (268 mg α-T, 537 mg α-T, 263 mg TRF or 526 mg TRF) in a cross-over postprandial trial. Blood was sampled at 0, 2, 4, 5, 6 and 8 hours after meal consumption and plasma antioxidant status including total glutathione, superoxide dismutase, malondialdehyde (MDA), ferric reducing antioxidant potential and trolox-equivalent antioxidant capacity, was analyzed.

    RESULTS: Supplementation with the different doses of either α-T or TRF did not significantly improve overall antioxidant status. There was no significant difference in overall antioxidant status among treatments at the different doses compared. However, a significant dose-response effect was observed for plasma MDA throughout the 8-hour postprandial period. MDA was significantly lower after the 537 mg α-T treatment, compared to the 268 mg α-T treatment; it was also lower after the 526 mg TRF treatment compared to the 263 mg TRF treatment (P 

    Matched MeSH terms: Tocopherols/administration & dosage*
  20. Fasahat, P., Abdullah, A., Muhammad, K., Wickneswari, R.
    MyJurnal
    Tocochromanols (tocopherols and tocotrienols) unitedly known as vitamin E, are the necessary antioxidant components of both human and animal diets. There is a considerable interest in plants with increased or customized vitamin E content, due to their potential health benefits. To quantify the tocochromanol content and determine the expression of a key tocotrienol biosynthesis gene among a set of contrasting red pericarp and light brown rice genotypes of advanced breeding lines together with their parents; expression pattern of homogentisate geranylgeranyl transferase (HGGT), the key gene was studied by semi-quantitative RT-PCR in milky and matured grain stages. Vitamin E analysis was carried out by high performance liquid chromatography (HPLC). The chloroform-methanolic extracts prepared from red pericarp and light brown rice advanced breeding lines showed significant differences for vitamin E content. Averaged across all samples, the content of γ-tocotrienol > α-tocopherol > α-tocotrienol > γ-tocopherol > δ-tocotrienol, and total E vitamin content ranged from 10.30 to 31.65 µg/g. Genotype G37 (red pericarp) was found to have higher expression than G7 (light brown) and G33 (red pericarp) at both grain development stages but lower than both parents whereas their transcript levels were comparatively lower in mature grain, which indicates their possible regulation by plant growth stage. HPLC results of γ-tocotrienol content supported gene expression results with the exception of the recurrent parent MR219.
    Matched MeSH terms: Tocopherols
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