Carotenoic Acid Ethyl Ester Research Articles

Carotenoid radical ions: A laser flash photolysis study

Laser excitation of a single precursor, namely 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (HHEMP), has been used for generating the radical cations and radical anions of various carotenoids in methanol. In the presence of oxygen, laser excitation of HHEMP undergoes an efficient α-cleavage reaction (Norrish type I) to form acyl radicals, which react with O2, in a nearly diffusion-controlled reaction, to form their corresponding strong oxidizing acylperoxyl radicals (RO2•) (E = ~1.1 V (v SHE)), which are capable of oxidizing almost all carotenoids. Under argon-saturated conditions and in the presence of strong base (0.01 M NaOH or tetrabutylammonium hydroxide (TBAOH)), the initially formed 2-hydroxy-2-propyl radical (ACH•), generated after LFP of HHEMP, is deprotonated to form the strong reducing acetone ketyl radical (AC•-) (E {acetone/ AC•-} = −2.1 V (v SHE)), which is capable of reducing all carbonyl-containing carotenoids. To validate this new proposed approach, retinal and β-apo-8′-carotenal (APO), with known spectroscopic data, were investigated in methanol, acetonitrile and tetrahydrofuran (THF). In addition, the radical ions of newly investigated carotenoids, namely 4-oxo-β-apo-15′-carotenoic acid (4-oxo-15′), crocetindial, 4-oxo-β-apo-10′-carotenoic acid ethyl ester (4-oxo-10′) and 4-oxo-β-apo-8′-carotenoic acid ethyl ester (4-oxo-8′) have been reported. Moreover, the scope of this approach has been extended to investigate the radical ions of chlorophyll b.

Determination of vitamin A and vitamin E esters in infant formulae and fortified milk powders by HPLC: Use of internal standardisation

An HPLC method is described using normal phase conditions with an unbonded silica column to determine concentrations of supplementary vitamin A and vitamin E esters and β-carotene in infant formulae. The method utilises selective dual-channel fluoresence for vitamins A and E and visible absorbance for β-carotene. An attribute of the method is the use of retinol propionate, α-tocopheryl propionate and all-E-β-apo-8′-carotenoic acid ethyl ester internal standards to compensate for analytical variations associated with these labile vitamins. Extraction is performed without saponification, with the aid of protease to remove vitamin encaspsulation and facilitate vitamin partition into hydrocarbon solvent. Figures of merit indicate the method is suitable for its intended purpose in the highly regulated infant formula environment, including liquid formulations. The method is extendable to whole milk powders where total vitamin A content data can be calculated by summing the innate long-chain vitamin A esters with the added esters.

A simplified and small-scale sample preparation technique for determining astaxanthin, canthaxanthin, and β-apo-8′-carotenoic acid ethyl ester in hen’s egg yolk

This paper described a fast, simple, and small scale method of sample preparation followed by high-performance liquid chromatography (HPLC) coupled photodiode array (PDA) detector for simultaneous quantification of astaxanthin, canthaxanthin, and β-apo-8′-carotenoic acid ethyl ester in hen’s egg yolk. The HPLC-PDA was performed on a C18 column with an isocratic mobile phase. Analytes were extracted from the sample using a handheld ultrasonic homogenizer, and purified by MonoSpin®-SI, a centrifugal monolithic silica spin mini-columns, and quantified within 30 min. The proposed method obtained average recoveries for the three analytes in the range of 70.5–101.1% with relative standard deviations ≤5.0%. The quantitation limits were 0.3 μg g−1 for AX, 0.5 μg/g for CX, and 1.0 μg g−1 for ACAEE, respectively.

Effect of Domestic Cooking Methods on Egg Yolk Xanthophylls

Xanthophylls are a class of bioactive compounds known to play an important role in preventing age-related macular degeneration. Egg yolk is a rich source of highly bioavailable xanthophylls including lutein and zeaxanthin. The effects of domestic cooking methods (boiling, frying, microwaving) on egg yolk xanthophyll content were investigated. A LC-(APCI)-MS/MS method was used to identify and quantify all-E- and Z-isomers of lutein, zeaxanthin, canthaxanthin, and β-apo-8'-carotenoic acid ethyl ester in fresh and cooked egg yolks. Both fresh and cooked yolks showed similar xanthophyll profiles but with higher contents of Z-isomers in cooked samples. All-E-lutein was the most affected, with 22.5%, 16.7%, and 19.3% reductions in boiled, microwaved, and fried yolk extracts, respectively. Total xanthophyll losses ranged from 6% to 18%. The results presented here could be useful in calculating the dietary intake of xanthophylls and also in assessing the xanthophyll profiles and contents of egg-containing products.

Separation and quantification of 15 carotenoids by reversed phase high performance liquid chromatography coupled to diode array detection with isosbestic wavelength approach

The manuscript presents the development of a new reverse phase high performance liquid chromatography (RP-HPLC) photo diode array detection method allowing the separation and quantification of 15 carotenoids (adonirubin, adonixanthin, astaxanthin, astaxanthin dimethyl disuccinate, asteroidenone, beta-apo-8′-carotenal, beta-apo-8′-carotenoic acid ethyl ester, beta-carotene, canthaxanthin, capsanthin, citranaxanthin, echinenone, lutein, lycopene, and zeaxanthin), 10 of which are feed additives authorised within the European Union. The developed method allows for the reliable determination of the total carotenoid content in one run using the corresponding E-isomer as calibration standard while taking into account the E/Z-isomers composition. This is a key criterion for the application of the method, since for most of the analytes included in this study analytical standards are only available for the E-isomers. This goal was achieved by applying the isosbestic concept, in order to identify specific wavelengths, at which the absorption coefficients are identical for all stereoisomers concerned. The second target referred to the optimisation of the LC conditions. By means of an experimental design, an optimised RP-HPLC method was developed allowing for a sufficient chromatographic separation of all carotenoids. The selected method uses a Suplex pKb-100 HPLC column and applying a gradient with a mixture of acetonitrile, tert-butyl-methyl ether and water as mobile phases. The limits of detection and limits of quantification ranged from 0.06mgL−1 to 0.14mgL−1 and from 0.20mgL−1 to 0.48mgL−1, respectively.

Antioxidant Activity of β-Carotene Compounds in Different in Vitro Assays

β-Carotene (BC) is the most abundant carotenoid in human diet, almost solely as (all-E)-isomer. Significant amounts of (Z)-isomers of BC are present in processed food as well as in mammalian tissues. Differences are described for the activity of various BC isomers in forming retinal and protecting against cancer and cardiovascular diseases. Eccentric cleavage of BC leads to degradation products such as carotenals. A variety of negative consequences were published for the non-vitamin A active BC metabolites, such as inducing the carcinogenesis of benzo[a]pyrene, impairing mitochondrial function, or increasing CYP activity. To increase the knowledge on the antioxidant activity, a variety of BC isomers and metabolites were tested in various in vitro assays.In the present study, no ferric reducing activity (FRAP assay) was observed for the BC isomers. Between the major BC isomers (all-E, 9Z, and 13Z) no significant differences in bleaching the ABTS●+ (αTEAC assay) or in scavenging peroxyl radicals (ROO●) generated by thermal degradation of AAPH (using a chemiluminescence assay) were detected. However, the (15Z)-isomer was less active, maybe due to its low stability. The degradation to β-apo-carotenoids increased FRAP activity and ROO● scavenging activity compared to the parent molecule. Dependence on chain length and character of the terminal function was determined in αTEAC assay with following order of increasing activity: β-apo-8’-carotenal < β-apo-8’-carotenoic acid ethyl ester < 6’-methyl-β-apo-6’-carotene-6’-one (citranaxanthin). The results indicate that BC does not lose its antioxidant activity by degradation to long chain breakdown products.

Influence of Pasteurization, Spray- and Freeze-Drying, and Storage on the Carotenoid Content in Egg Yolk

A liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [LC-(APCI)MS] method was developed to identify and quantify the carotenoids present in fresh, pasteurized, and freeze- and spray-dried egg yolk in two independent batches. The egg yolk powders in each batch were stored in the dark for 6 months at -18 or 20 degrees C. Carotenoids were isolated by solvent extraction without saponification and analyzed by HPLC using a C(30) column coupled to a photodiode array and mass detector. The most abundant carotenoids were all-E-canthaxanthin, all-E-lutein, all-E-zeaxanthin, 9-Z-canthaxanthin, and beta-apo-8'-carotenoic acid ethyl ester. Pasteurization of the egg yolk caused no critical changes in the carotenoid content. On the contrary, drying to a dry matter of 98-99% led to higher carotenoid contents, induced by a denaturation of binding proteins, and a destabilization of the cell matrix. After the 6 months of storage, the contents of all main carotenoids in the egg yolk powder were significantly lower. The synthetic carotenoids canthaxanthin and beta-apo-8'-carotenoic acid ethyl ester showed a higher retention rate, and the greatest losses occurred within the first 8 weeks. Statistical tests (ANOVA, P < 0.05) also proved that after 26 weeks, the egg yolk powders stored at -18 degrees C showed only a slightly higher retention of carotenoids when compared to the powders stored at 20 degrees C.

Xanthophylls in Commercial Egg Yolks: Quantification and Identification by HPLC and LC-(APCI)MS Using a C30 Phase

The xanthophylls lutein and zeaxanthin have attracted a lot of interest since it was presumed that an increased nutritional uptake may prevent adult macula degeneration (AMD). Although egg yolks serve as an important dietary source of lutein and zeaxanthin, data on xanthophyll concentrations in commercial egg yolks are not available. Thus, an high-performance liquid chromatography-diode array detector (HPLC-DAD) method was developed allowing for simultaneous separation of eight xanthophylls used to fortify poultry feed. Peak identification was carried out by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [LC-(APCI)MS]. Egg yolks of four types of husbandry (seven batches each) were examined. Lutein and zeaxanthin were the predominant xanthophylls in egg yolks produced in accordance with ecological husbandry (class 0) because the concentrations of these xanthophylls ranged from 1274 to 2478 microg/100 g and from 775 to 1288 microg/100 g, respectively. Analysis of variance (ANOVA) proved that both mean lutein and mean zeaxanthin concentrations of eggs from class 0 were statistically discriminable from mean lutein and zeaxanthin concentrations from eggs of all other classes (P < 0.01). Mean concentrations of synthetic xanthophylls in eggs of classes 1 (free range), 2 (barn), and 3 (cage) were as follows: canthaxanthin, 707 +/- 284 microg/100 g; beta-apo-8'-carotenoic acid ethyl ester, 639 +/- 391 microg/100 g; and citranaxanthin, 560 +/- 231 microg/100 g. Experiments with boiled eggs proved that beta-apo-8'-carotenoic acid ethyl ester was the xanthophyll with the highest stability, whereas lutein was degraded to the largest extent (loss of 19%). Detailed knowledge about the xanthophyll amounts in eggs is indispensable to calculate the human uptake.

Simultaneous HPLC determination of carotenoids used as food coloring additives: applicability of accelerated solvent extraction

A sensitive HPLC multimethod was developed for the determination of the carotenoid food additives (CFA) norbixin, bixin, capsanthin, lutein, canthaxanthin, β-apo-8 ′-carotenal, β-apo-8 ′-carotenoic acid ethyl ester, β-carotene, and lycopene in processed food using an RP C30 column. For unequivocal identification, the mass spectra of all analytes were recorded using LC–(APcI)MS. For extraction, a manual process as well as accelerated solvent extraction (ASE) was applied. Important ASE parameters were optimized. ASE was used for the first time to extract CFA from various food matrices. Average recoveries for all analytes ranged from 88.7–103.3% (manual extraction) and 91.0–99.6% (ASE), with exception of norbixin using ASE (67.4%). Limits of quantitation (LOQ) ranged from 0.53–0.79 mg/L. The presented ASE method can be used to monitor both, forbidden application of CFA or the compliance of food with legal limits.

Selective absorption of carotenoids in the common green iguana ( Iguana iguana)

In the animal kingdom, species-specific differences with regard to the absorption of intact carotenoids are observed. The causes of these differences are not entirely understood. To investigate the absorption of selected carotenoids, 20 juvenile green iguanas ( Iguana iguana) were fed a carotenoid deficient basal diet for 56 days. Thereafter, the iguanas were assigned to receive a basal diet supplemented with different carotenoids (80 mg/kg diet) such as β-carotene, canthaxanthin and apo-8′-carotenoic acid ethyl ester for 28 days. Changes in plasma carotinoid concentrations associated with the individual diets were used as indicators of carotenoid absorption. In both the experimental and control groups, only the oxygenated carotenoids (xanthophylls), lutein, zeaxanthin and canthaxanthin, were found in the plasma. Canthaxanthin and apo-8′-carotenoic acid ethyl ester were readily absorbed and recovered from the plasma. However, the supplementation of β-carotene caused no increase in plasma β-carotene concentration. Additionally, β-carotene, canthaxanthin or apo-8′-carotenoic acid ethyl ester did not affect the concentrations of retinol and α-tocopherol in plasma. In conclusion, the study demonstrates that iguanas appear to be selective accumulators of polar xanthophylls. The iguana might, therefore, be a valuable model to investigate the selectiveness of carotenoid absorption as well as the function of xanthophylls in animals.

Pigmenting Efficacy of Several Oxycarotenoids on Egg Yolk

This experiment was conducted to test the influence of three dietary sources of yellow (YEW) and two sources of red (RED) oxycarotenoids when combined at two different YEW to RED ratios (a 3x2x2 factorial arrangement of treatments) on egg yolk color. Pigmentation was measured visually by the Roche color fan (RCF) and by reflectance colorimetry using a Minolta CR-300 colorimeter. Source of YEW, RED, and YEW:RED ratio influenced yolk pigmentation. Beta-apo-8’-carotenoic acid ethyl ester pigmented the yolk more efficiently than either of two natural saponified marigold extracts. A natural saponified marigold extract rich in zeaxanthin obtained by isomerization pigmented the yolk better than a standard saponified marigold concentrate. Canthaxanthin pigmented the yolk better than a natural saponified red pepper extract. A YEW:RED ratio of 8:4 improved pigmentation over a ratio of 12:3 (RCF of 13.3 and 12.9, respectively; P<.001). The ratio of redness to yellowness obtained by reflectance colorimetry gave scores similar to those obtained by RCF. Thus, industry use of RCF or reflectance colorimetry to evaluate egg yolk color will yield indistinguishable results in practical application.

Recent progress in commercial retinoids and carotenoids

Abstract

Utilisation d'un caroténoide de synthèse comme marqueur nutritionnel pour l'omble de fontaine (S. fontinalis) élevé en pisciculture

It is possible to differenciate farmed brook trout (20-23 cm) from wild ones by the incorpora­ tion of /3-apo-8'-car otenoic acid ethyl ester (CAEE) in the diet. In contrast with canthaxanthin this synthetic carotenoid is absent from wild trout flesh. After 4 and 6-week feeding periods with a meal containing 100 fjg of CAEE/g, most trout of marketable size (150 g and more) show small, but significant muscular CAEE concentration. Moreover there is no difference in flesh coloration bet­ ween experimentally marked trout and controls. This inexpensive marker could be used to prevent a possible increase of poaching on wild

Use of the synthetic oxycarotenoids, β-apo-8′-carotenoic acid ethyl ester and citranaxanthin, in diets low in natural pigments to enhance egg yolk colour

The effects of synthetic yellow and red oxycarotenoids, G-apo-8'-carotenoic acid ethyl ester (CAEE) and citranaxanthin (CTX), respectively, on egg yolk colour were evaluated in three experiments. In experiment 1,192 hens of two breeds (White Leghorn x Australorp and White Leghorn hybrid) were given a basal diet supplemented with CAEE in six concentrations from 1.75 to 3.00 mg/kg in the periods 35-38,47-50 and 59-62 weeks of age. Yolk colour (averaged over both breeds and all periods) increased linearly from 4.4 to 5.3 Roche units with CAEE concentration. The hybrids and crossbreds averaged 4.1 and 5.6 respectively. Although yolk colour was related to feed consumption, a difference of 17.7 g/bird.day between breeds accounted for only 0.2 of the 1.5 difference in yolk colour. Experiment 2 utilized the same birds as experiment 1. The same concentrations of CAEE were combined with 1.50 or 1.75 mg/kg CTX in the periods 39-42, 51-54 and 63-66 weeks of age. Yolk colour (averaged over all other effects) increased linearly from 8.7 to 9.1 with CAEE concentration. Yolk colour averages were 8.5 and 9.3 for CTX at 1.50 and 1.75 mg/kg respectively. In the third experiment, 180 White Leghorn x Australorp hens were given CAEE (1.50, 1.75 or 2.00mg/kg) and CTX(1.50, 1.75 or2.00mg/kg) from 18 to 62 weeks of age. Average yolk colour increased linearly from 10.0 to 10.3 with CAEE and from 9.9 to 10.4 with CTX, as the respective concentrations were increased.

The Deposition of Synthetic Oxycarotenoids in Egg Yolks

SummaryThe relative efficiencies with which synthetic oxycarotenoids are deposited in egg yolks were examined in three experiments using either White Leghorn x Australorp (W x A) or White Leghorn (WL) hens. The oxycarotenoids measured were β-apo-8′-carotenoic acid ethyl ester (CAEE), canthaxanthin (CHX) and citranaxanthin (CTX). The effect of time and duration of administration of CAEE on its utilization was also measured.W x A hens, aged 36 weeks, deposited 30–46, 13–17 and 4.4-4.9% of the intake of CAEE, CHX and CTX, respectively in their egg yolks. The comparable values for W x A hens aged 53 weeks were 26–35, 17–18 and 3.2-3.3%, respectively.WL hens, aged 32 weeks, deposited 49–50 and 13–15% of the intake of CAEE and CHX, respectively.The deposition of CAEE tended to increase when it was given for 20 days rather than 10 days and when given daily at 15.00 h rather than 08.30 h.

Variation in the Biological Availability of Xanthophyll Within and Among Generic Sources

Xanthophyll depleted, fasted broilers were intubated with various xanthophyll sources in a series of six experiments. The increase in serum xanthophyll per milligram xanthophyll intubated per kilogram body weight was used to estimate xanthophyll availability. Statistically significant differences among samples within and among generic sources were obtained. As a result, β-apo-8′-carotenoic acid ethyl ester (apo-EE) was used as a reference standard in Experiments 4 to 6. When the availability of apo-EE was given a relative value of 100, the availability of xanthophyll from corn gluten meal ranged from 47.7 to 89.1% (four samples), from dehydrated alfalfa, 34.6 to 65.4% (eight samples), and from Coastal Bermudagrass, 18.8 to 27.9% (three samples).

The performance of cross‐bred hens given free choice feeding of whole grains and a concentrate mixture and the influence of source of xanthophylls on yolk colour

1. Cross‐bred hens were offered, from 25 to 73 weeks of age, diets based on either wheat or barley in the form of either a mash or as whole grains plus a concentrate mixture; four sources of xanthophylls were also compared. 2. Wheat reduced food intake by 8%, increased efficiency of food conversion and live‐weight gain while barley increased litter moisture content, and, during the first half of the laying year decreased egg production by 3.3% and yolk colour by 4%. 3. Hens offered whole grains ate 11% less food, converted food into eggs more efficiently, were heavier and laid larger eggs than those given the mash diets. 4. With whole grains yolk colour was less than with mash diets during the first 24 weeks of lay but this was reversed during the last 24 weeks of lay. 5. Either canthaxanthin or citranaxanthin or β‐apo‐8'‐carotenoic acid ethyl ester plus canthaxanthin in diets containing lucerne meal produced eggs with acceptable yolk colours.

Effect of triticale, lucerne pellets, furazolidone, ethoxyquin and oxycarotenoids on egg yolk colour and performance of crossbred layers

In the first of two factorial experiments, 26-week-old crossbred pullets were fed for a period of 24 weeks diets with lucerne either in the form of meal or crumbled pellets, with or without 25 p.p.m. furazolidone and with 1 p.p.m. of either G-apo-8'-carotenoic acid ethyl ester or canthaxanthin. In the second experiment, crossbred hens aged 58 weeks were fed for a period of 16 weeks either triticale or wheat, or triticale plus wheat or wheat plus oats on a free choice basis with a concentrate mixture containing either 0 or 333 p.p.m. of ethoxyquin. Lucerne pellets reduced rate of egg production, hen-housed production, efficiency of feed conversion and the income per bird. It increased feed intake by 3.2 per cent and egg yolk colour by 2 per cent. Furazolidone increased hen-housed production and efficiency of feed conversion but had no effect on egg yolk colour. Pullets given diets with canthaxanthin laid eggs with higher yolk colour scores and specific gravity and converted feed more efficiently than those given the diets with G-apo-8'-carotenoic acid ethyl ester. The depressive effect of lucerne pellets on egg production and feed conversion was overcome by both furazolidone and canthaxanthin. Triticale reduced the concentration of oxycarotenoids in egg yolks, Hens given triticale tended to eat more, convert feed less efficiently and gained less liveweight than those given wheat, but rate of egg production and egg weight were unaffected. The performance of hens given triticale plus wheat fell between that of those given either triticale or wheat as the sole cereal. Hens given wheat plus oats tended to lay fewer but heavier eggs with lower yolk colour and gained less liveweight than those given wheat. Ethoxyquin increased the concentration of oxycarotenoids in egg yolks but had no effect on other production traits.

Zeaxanthin as a Broiler Pigmenter

Zeaxanthin in a stabilized gelatin beadlet formulation was evaluated as a broiler pigmenter in 2 trials. In the first experiment, low oxycarotenoid basal broiler starter and grower rations were fed continuously for 7 weeks with zeaxanthin added to both of the rations at concentrations of 11, 22 and 33 mg./kg. Zeaxanthin was compared to three other pigmentation sources: β-apo-8’-carotenoic acid ethyl ester, marigold petal meal and a concentrated extract from marigold petal meal.In the second experiment, zeaxanthin was added at a concentration of 2.75 to 11 mg./kg. to broiler grower rations containing <1.0, 5.5, 11, 16.5, or 22 mg. oxycarotenoids/kg. from feed ingredients and fed from the 29th through the 49th day.The birds from both experiments were processed under simulated commercial conditions. Shank color was visually scored by 3 or 4 persons using the Roche Yolk Color Fan and breast feather tract pigmentation was measured using the Purina Skin Pigmentation Guide.Zeaxanthin was shown to be a very effective broiler pigmenter producing a highly acceptable yellow to yellow-orange color in both the shanks and breast skin.

Egg Yolk and Broiler Skin Pigmentation with Sweet Potato Vine Meal , ,

Dehydrated sweet potato vine meal (SPVM) was evaluated as a xanthophyll pigment source for broiler skin and egg yolks. In the experiment with hens SPVM was compared with alfalfa meal in a diet in which these sources provided the only source of pigment. The two diets were formulated to contain the same quantity of pigmenting xanthophylls based on chemical analysis. Egg yolk pigmentation was evaluated by use of the Roche color fan and by chemical analysis. The results indicated that the pigments of this particular sample of SPVM, which was of below average quality, were ingested, absorbed, and deposited in the egg yolk 79% as well as the pigments of alfalfa meal. In the broiler experiment the SPVM as the sole pigment source was evaluated by comparison with standard skin pigmenting substance β-apo-8′-carotenoic acid ethyl ester (apo-ethyl-ester, or AEE). Skin pigmentation was evaluated by chemical analysis of toe web samples. On this basis each gram of dietary SPVM containing 0.417 mg. of total xanthophylls or 0.365 mg. of dihydroxy pigment equivalents per gram was equivalent to 0.276 mg. of AEE. Relative to literature reports of good quality alfalfa meal evaluated under similar conditions the SPVM appeared to be an equally good pigment source for broilers. Chemical analyses of SPVM samples taken at different times during the growing season indicated that there were greater amounts of protein and carotenoids in early season as compared with late season and time of root harvest. It is concluded that the foliage of the sweet potato plant is a potential source of xanthophyll pigments for poultry.