Separation of RRR-α-Tocopherol by Chiral Chromatography

2020 ◽  
Vol 103 (5) ◽  
pp. 1288-1292
Author(s):  
Brendon D Gill ◽  
Harvey E Indyk
Keyword(s):  
Vitamin E ◽  
Chromatographic Separation ◽  
Chromatographic Method ◽  
Tocopherol Content ◽  
Hplc Method ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Accurate Estimation ◽  
Chiral Column ◽  
Compliance Testing

Abstract Background α-Tocopherol can exist as eight possible stereoisomers due to the presence of three chiral carbons. Regulations and industry guidelines necessitate that dietary vitamin E intakes be based on the vitamin E activity of RRR-α-tocopherol. Food products fortified with synthetic all-rac-α-tocopherol or all-rac-α-tocopheryl acetate during manufacturing will require chiral separation of the α-tocopherol stereoisomers for accurate estimation of vitamin E activity. Objective The development of an HPLC method utilizing a chiral column for the chromatographic separation of RRR-α-tocopherol from other α-tocopherol stereoisomers. Method Normal phase liquid chromatographic separation using a polysaccharide-based chiral column with fluorescence detection of α-tocopherol stereoisomers. Results The described chromatographic method achieves baseline resolution of RRR-α-tocopherol from its stereoisomers. Method selectivity, precision, and robustness were evaluated and acceptable performance was achieved. Conclusions The chromatographic method was found to be suitable for application where both RRR-α-tocopherol content and total α-tocopherol content are required for routine compliance testing. Highlights A robust and precise chomatographic method for the baseline resolution of RRR-α-tocopherol from its stereoisomers was acheived.

Analysis of α-Tocopherol Stereoisomers in Fortified Infant Formula by Chiral Chromatography

2021 ◽  
Author(s):  
Brendon D Gill ◽  
Jackie E Wood ◽  
Harvey E Indyk
Keyword(s):  
Analytical Method ◽  
Chromatographic Method ◽  
Reference Method ◽  
Tocopherol Content ◽  
Tocopheryl Acetate ◽  
P Value ◽  
Statistical Bias ◽  
Chiral Column ◽  
Compliance Testing ◽  
Tocopheryl Succinate

Abstract Background Direct measurement of the bioavailable α-tocopherol content presents a significant analytical challenge and requires chiral separation of the α-tocopherol stereoisomers. Objective The objective of the study was to validate an analytical method for the analysis of α-tocopherol stereoisomers in infant formulas and dairy products. Method Samples were saponified at elevated temperature and lipophilic components were extracted into an organic solvent, with subsequent chromatographic separation of the α-tocopherol stereoisomers achieved by HPLC with a chiral column and fluorescence detection. Results The method was shown to be accurate, with spike recoveries of 91.9–108.8% for RRR-α-tocopherol and 90.1–104.7% for α-tocopherol, with no statistical bias against NIST 1849a certified reference material (p-value = 0.54) and an HPLC-UV analytical method (p-value = 0.48). Acceptable precision was confirmed, with repeatabilities estimated at 3.5% RSDr (HorRat = 0.6) for RRR-α-tocopherol and 4.6% RSDr (HorRat = 0.4) for α-tocopherol. Conclusions A straightforward chiral chromatographic method for the analysis of stereoisomeric forms of α-tocopherol is described. In a single analytical run, the method can quantify: (i) the total α-tocopherol content; (ii) the nutritionally important RRR-α-tocopherol and/or 2R,4′-ambo,8′-ambo-α-tocopherol contents; (iii) the amount of all-rac-α-tocopherol, all-rac-α-tocopheryl acetate, or all-rac-α-tocopheryl succinate fortified into the product. Highlights An accurate and precise chiral chromatographic method for the analysis of isomeric forms of α-tocopherol is described. The method is able to distinguish between natural and synthetic tocopherol sources. The method is accurate and precise and is suitable either for routine product compliance testing during product manufacture or as a possible reference method.

Comparison of Emmerie-Engel Method and Gas Chromatographic Method for Determination of Supplemental α-Tocopheryl Acetate in Feed Concentrates

1987 ◽  
Vol 70 (3) ◽  
pp. 417-419
Author(s):  
Michael P Labadie ◽  
Charles E Boufford
Keyword(s):  
Gas Chromatography ◽  
Vitamin E ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Tocopheryl Acetate ◽  
High Potency ◽  
Gc Analysis ◽  
Gas Chromatographic Method ◽  
Official Procedure

Abstract The determination of supplemental a-tocopheryl acetate in high potency vitamin E powders and oils was compared using the Emmerie- Engel method and gas chromatography (GC). The Emmerie-Engel reaction requires saponification, extraction of the saponiflable fracaon, and quantitation by colorimetry. GC analysis requires only an extraction and/or dilution before quantitation. These are represented essentially by AOAC methods 43.147-43.151 (colorimetry) and 43.152-43.159 (GC) for high potency vitamin E concentrates. Each method was statistically evaluated for precision and sample-to-sample reproducibility. Each Emmerie-Engel value was divided by the GC value obtained for the same sample; an average of 1.049 with a coefficient of variation of 2.89% was obtained. It was concluded that (he GC procedure was superior to the Emmerie-Engel method, and ahould be the official procedure for determination of supplemental a-tocopheryl acetate in feed concentrates.

scholarly journals Selenium and α-tocopherol content in eggs produced by hens that were fed diets supplemented with selenomethionine, sodium selenite and vitamin E

2010 ◽  
Vol 55 (No. 9) ◽  
pp. 388-397 ◽  
Author(s):  
M. Skřivan ◽  
I. Bubancová ◽  
M. Marounek ◽  
G. Dlouhá
Keyword(s):  
Vitamin E ◽  
Sodium Selenite ◽  
Thiobarbituric Acid ◽  
Basal Diet ◽  
Tocopherol Content ◽  
Alpha Tocopherol ◽  
Dietary Vitamin ◽  
Tocopherol Concentration ◽  
The Third ◽  
Egg Yolks

The effect of supplementing dietary selenium (Se) and vitamin E was investigated in 330 24-week-old laying hens. The hens were fed a basal diet containing Se and α-tocopherol at 0.11 and 26 mg/kg, respectively, or a diet supplemented with Se at 0.3 mg/kg and vitamin E between 0 and 625 mg/kg. Se was supplied as Se-methionine or sodium selenite. The eggs were collected for analysis during the third, seventh and eleventh weeks of the experiment. Supplementation of either form of Se significantly increased the Se concentration in egg yolks and whites, with a more pronounced effect caused by Se-methionine. The egg yolk α-tocopherol concentration paralleled the dietary α-tocopherol concentration. At a high dietary α-tocopherol concentration (632 mg/kg), the retinol content in egg yolks from hens fed Se-methionine increased significantly. Supplementation of Se-methionine significantly increased the α-tocopherol content in the eggs in the third and seventh weeks of the experiment. A moderate decrease in yolk cholesterol was observed in hens fed Se-methionine and α-tocopherol at 119 mg/kg. The concentration of products from lipid peroxidation (thiobarbituric acid-reactive substances, TBARS) in egg yolks increased marginally during the refrigerated storage of the eggs for 2 weeks. The effect of dietary vitamin E on TBARS formation was generally small, although a more significant effect was observed at the highest dose tested.

scholarly journals Animal fat and vitamin E in rabbit diets: Total tract apparent digestibility, growth performance, carcass and meat quality traits

2020 ◽  
Vol 65 (No. 10) ◽  
pp. 380-388
Author(s):  
Antonella Dalle Zotte ◽  
Marco Cullere ◽  
Elizabeth Gleeson ◽  
Maria Elena Cossu
Keyword(s):  
Vitamin E ◽  
Growth Performance ◽  
Meat Quality ◽  
Tocopherol Content ◽  
Tocopheryl Acetate ◽  
Apparent Digestibility ◽  
Ether Extract ◽  
Animal Fat ◽  
Pork Lard ◽  
Digestible Protein

The present study tested the effect of a dietary inclusion with vitamin E and pork lard on the apparent digestibility of the nutrients, the growth performance, the carcass traits, the physical meat quality, and the α-tocopherol content. A total of 60 hybrid rabbits were reared in individual cages from weaning (35 days of age) until slaughter (78 days of age). A control diet with no supplements, one diet supplemented with 2% pork lard, and two diets that used the aforementioned diets supplemented with an additional 200 mg/kg α-tocopheryl acetate were designed. The diets were isoprotein and isoenergy. The fat inclusion increased the crude protein (P < 0.05) and ether extract (P < 0.001) total tract apparent digestibility, and the same was observed for the vitamin E inclusion (P < 0.001 for both variables). This improved the dietary digestible protein content (P < 0.05), which increased the digestible protein to digestible energy ratio (P < 0.001). The fat × vitamin E interaction was observed for the total tract apparent digestibility of the ether extract (P < 0.001), the neutral detergent fibre (P < 0.05) and the acid detergent fibre (P < 0.01). The growth traits were unaffected, with the exception of the feed conversion ratio that improved with the vitamin E addition (P < 0.05). Similarly, the carcass traits remained unaffected, with the exception of the perirenal and total fat incidence that increased with the fat supplement (P < 0.05), and the scapular fat that was reduced with the vitamin E inclusion (P < 0.05). The meat L* (lightness), a* (redness), b* (yellowness) colour values and ultimate pH were unaffected by the experimental treatments, even though a fat × vitamin E interaction was observed for the a* and chroma values of the Longissimus thoracis et lumborum muscle (P < 0.05). Both the fat (P < 0.05) and vitamin E (P < 0.001) dietary inclusion increased the meat α-tocopherol content. Based on the results, it was concluded that the 2% dietary inclusion of animal fat did not provide more benefits for the considered parameters than the sole α-tocopheryl acetate incorporation, but contributed to the increase in the vitamin E content in the meats.

Re-evaluation of the vitamin E requirements of juvenile tilapia (Oreochromis niloticus ✕ O. aureus)

2001 ◽  
Vol 72 (3) ◽  
pp. 529-534 ◽  
Author(s):  
S. Y. Shiau ◽  
L. F. Shiau
Keyword(s):  
Lipid Peroxidation ◽  
Vitamin E ◽  
Oreochromis Niloticus ◽  
Control Diet ◽  
Dietary Treatment ◽  
Dietary Lipid ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Feeding Trial ◽  
Protein Deposition

AbstractA 10-week feeding trial was conducted to re-evaluate the level of dietary vitamin E (DL- α-tocopheryl acetate) that was adequate for juvenile tilapia Oreochromis niloticus ✕ O. aureus given diets containing two dietary lipid concentrations. Purified diets with eight levels of vitamin E (0, 25, 50, 75, 100, 150, 200, 400 mg/kg diet) at either 50 or 120 g lipid per kg were each given to three replicate groups of tilapia (mean weight: 0·69 (s.e.0·02) g) reared in a closed, recirculating system. Food efficiency and protein deposition were significantly (P < 0·05) higher in fish given 50 mg vitamin E per kg diet and 75 mg/kg diet in the 50 and 120 g lipid per kg groups respectively, compared with fish given the unsupplemented control diet. Mortality of fish was not affected by dietary treatment. Weight gain and liver microsomal ascorbic acid-stimulated lipid peroxidation data analysed by broken-line regression indicated that the optimum dietary vitamin E requirements in juvenile tilapia are 42 to 44 mg vitamin E per kg and 60 to 66 mg vitamin E per kg in 50 and 120 g lipid per kg diets, respectively.

scholarly journals Biopotency of vitamin E in barley

1984 ◽  
Vol 52 (2) ◽  
pp. 335-349 ◽  
Author(s):  
R. V. Juhani Hakkarainen ◽  
Jouko T. Työppönen ◽  
Saifeldin Hassan ◽  
Gösta Bengtsson ◽  
S. R. Lennart Jönsson ◽  
...  
Keyword(s):  
Vitamin E ◽  
Chemical Reduction ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Total Vitamin ◽  
Tissue Samples ◽  
Chemical Determination ◽  
The Individual ◽  
Dose Responses ◽  
Liver Storage

1. Investigations were carried out to establish the total biopotency of the natural vitamin E isomers in barley compared with that of DL-α-tocopheryl acetate.2. The chick was used as an experimental animal. Prevention of nutritional encephalomalacia (NE) and chick liver-storage and plasma-storage assays of vitamin E were the methods used in the study. The individual tocopherols and tocotrienols, both in the tissue samples and in the grain and barley oil, were analysed using high-pressure liquid chromatography (HPLC) with fluorescence detection. The diagnosis of NE was based on careful clinical and histopathological observations.3. It can be concluded from the results that full protection against NE in the chicks was obtained with a supplementation level of 7.5 mg DL-α-tocopheryl acetate/kg diet (i.e. a total vitamin E content of 11.20 mg/kg diet) or with a supplement of 8.7 g barley oil/kg diet (i.e. a total vitamin E content of 22.99 mg from barley oil/kg diet). This gave a biopotency factor of 0.49 for barley for prevention of NE of the chicks, as compared to that of DL-α-tocopheryl acetate.4. Using regression analysis a statistically linear relationship could be observed between the total dietary vitamin E level and the response, as measured by the total vitamin E content in the liver and plasma, both in the groups supplemented with DL-a-tocopheryl acetate and in the groups supplemented with corresponding amounts of vitamin E in barley oil. The liver and plasma responses to the total vitamin E in the barley-oil diet compared with those of the DL-a-tocopheryl acetate reference diet gave identical values for the regression coefficients, i.e. in both liver-storage and plasma-storage assays the value for slopes of dose-response lines was 0.37. This means that the biopotency of the total vitamin E in barley was 37% of that of dietary DL-a-tocopheryl acetate. Thus, barley is not as rich a source of vitamin E as could be supposed on the basis of the chemical determination of its total vitamin E content.5. It was possible to verify this experimentally established biopotency of 0.37 for the total vitamin E in barley by converting the chemically determined amounts of the vitamin E isomers in barley into DL-α-tocopheryl acetate equivalents by multiplying them with internationally accepted potency factors for the individual natural isomers (DL-α-tocopheryl acetate 1.00, D-α-tocopherol 1.49, D-β-tocopherol 0.60, D-gamma;-tocopherol 0.1 5, D-α-tocotrienol 0.37).6. In spite of the high proportion of α- and β-tocotrienols in the barley-oil diets (about 60% of the total vitamin E content), only traces of these isomers could be detected in the plasma and none could be detected in the liver. On the other hand, calculation of the individual hiopotencies for the different isomers in the barley-oil diet by comparing the dose responses, diet: liver, separately for each isomer with those of DL-α-tocopheryl acetate, resulted in biopotency values for α- and β-tocopherol which were twice as high as the internationally accepted conversion factors. These results of the present study tempted the authors to draw the conclusion that there may have been a chemical reduction of the α- and β-tocotrienols to the corresponding tocopherols before entering the liver.

scholarly journals Effects of protein and vitamin E on haemoglobin formation in rats

1968 ◽  
Vol 22 (4) ◽  
pp. 751-755 ◽  
Author(s):  
J. Bunyan ◽  
J. Green ◽  
M. A. Cawthorne
Keyword(s):  
Vitamin E ◽  
Dietary Supplement ◽  
Tocopheryl Acetate ◽  
Dietary Vitamin ◽  
Deficient Diet ◽  
Growth Depression ◽  
Low Protein ◽  
Protein Diets ◽  
Severe Growth ◽  
Haemolysis Test

1. Young rats were given, for 9 weeks, vitamin E-deficient diets containing either 20% or 10% casein, with and without a dietary supplement of 350 ppm D-α-tocopheryl acetate. For the next 5 weeks the casein content of the low-protein diets was decreased to 7%.2. The low-protein diets induced severe growth depression.3. The dialuric acid-induced haemolysis test showed that the rats given the 20% casein vitamin E-deficient diet were depleted of vitamin E, but that the rate of depletion on the lowcasein diet was slower.4. Haemoglobin levels were slightly decreased by the 10% casein diets after 9 weeks, but this difference was not found after 14 weeks, comparing 20% and 7% casein. Dietary vitamin E had no effect on haemoglobin levels or erythrocyte counts.

Effects of Dietary Carnosine and Vitamin E on Antioxidant and Oxidative Status of Rats

2008 ◽  
Vol 78 (45) ◽  
pp. 230-237 ◽  
Author(s):  
Wissam Ibrahim ◽  
Vickie Tatumi ◽  
Che-Chung Yeh ◽  
Chuen Bin Hong ◽  
Ching Kuang Chow
Keyword(s):  
Vitamin E ◽  
Antioxidant Status ◽  
Conjugated Dienes ◽  
Oxidative Status ◽  
Tocopheryl Acetate ◽  
Protein Carbonyls ◽  
Dietary Vitamin ◽  
Sprague Dawley ◽  
Deficient Diet ◽  
Sprague Dawley Rats

The purpose of this study was to determine if moderate levels of carnosine supplement, alone or in combination with vitamin E, enhance antioxidant status and/or provide protection against oxidative stress. Fiftyfour one-month-old male Sprague-Dawley rats were fed a basal vitamin E-deficient diet supplemented with either 0, 200, or 1000 mg L-carnosine, and either 0, 10, or 100 IU vitamin E (as all rec-α-tocopheryl acetate) per kg diet for 15 weeks. The antioxidant and oxidative status were assessed in the skeletal muscle, liver, and blood. Dietary vitamin E, but not carnosine, increased levels of vitamin E, decreased tissue peroxidizability, prevented incidence of myodegeneration, and reduced erythrocyte hemolytic stress. The levels of conjugated dienes, protein carbonyls, ascorbic acid, and nonprotein sulfhydryls, and activities of catalase, glutathione (GSH) peroxidase, and aldehyde dehydrogenase were not significantly altered by dietary carnosine or vitamin E. The results obtained suggest that supplementation of carnosine at levels of up to 1000 mg/kg diet does not significantly affect the antioxidant and oxidative status of rats.

scholarly journals Effects of α-tocopheryl acetate addition to the chicken feed on the sensory characteristics and α - tocopherol content in meat

2003 ◽  
Vol 19 (1-2) ◽  
pp. 49-56 ◽  
Author(s):  
Anamarija Mandic ◽  
Aleksandra Pavlovic ◽  
Natalija Dzinic ◽  
Jovanka Popov-Raljic ◽  
Djurdjica Kelemen-Masic
Keyword(s):  
Vitamin E ◽  
Tocopherol Content ◽  
Sensory Characteristics ◽  
Thigh Muscle ◽  
Tocopheryl Acetate ◽  
Control Group ◽  
Group A ◽  
Group B ◽  
Meat Samples ◽  
Thermally Treated

Effects of ? -tocopheryl acetate addition to the chicken feed (A-control group: common broiler feed, B and C groups: feed supplemented with a-tocopheryl acetate at 50 mg/kg and 75 mg/kg of feed, respectively) on sensory characteristics of meat of chicken breasts have been investigated as well as the content of vitamin E, expressed as a- tocopherol, in liver thigh muscle, and meat of chicken breasts. Sensory characteristics (colour, texture, tenderness and juiciness, odour and flavor) of thermally treated meat samples have been evaluated by analytical-descriptive (point) system. Regarding obtained results, it can be noticed that the color of samples scored with high grades, has been almost unvarying between samples. Tenderness as the quality of texture and juiciness has been evaluated using oral technique. Samples of groups Band C have been qualified as the most tender. Samples of group A have been slightly less tender. The juiciest samples have been of group C, followed by samples of group B and group A. Flavor of thermally treated chicken meat breast samples has been evaluated true the taste and odour characteristics (Popov-Raljic i Radovanovic, 2001) The most intensively expressed characteristic taste and odour have the samples of group A, and have been given the highest grade, while the similar grades have been given to group C samples. Also, content of vitamin E expressed as ? -tocopherol has been determined by reverse phase high-performance liquid chromatography (HPLC) method, with DAD detector on 295 nm. Results of chicken tissues study show that: content of (l-tocopherol in liver is always greater than in thigh muscle, greater than in meat of chicken breasts. Content of ? -tocopherol increased 4.17 times in meat of chicken breasts, 3.87 times in thigh muscle and 1.82 times in liver when the chicks were fed 42 days with feed supplemented with 50 mg (? -tocopheryl acetate/1 kg diet (B group). Further increase in tissues has been obtained by feed that contained 75 mg (? -tocopheryl acetate/1 kg diet (C group): 2.6 times has been greater content of ? -tocopherol in thigh muscle, 2.27 times in chick breast meat samples, 1.14 times in liver when comparing to group A. Finally, regarding all the results, the best final score for sensory evaluation of appearance, texture and flavour has been given to group B (28.25), and very similar scores, slightly lower, for group A (27. 50) and group C (27.80). HPLC results clearly indicate that ? -tocopherol content is elevated by dietary supplementation in all investigated chicken organs and is always greater in liver than in thigh muscle and in meat of chicken breasts, which improves its efficient absorption in investigated range.

Sign in / Sign up

Export Citation Format

Share Document