Lutein extraction

Solvent extraction removes chlorophyll and other pigments to give a light-colored product but increases processing costs. Furthermore, solvent extraction removes p-carotene and reduces vitamin A activity (89) (see Terpenoids Vitamins). Supercritical CO2 extraction at 30 and 70 MPa (4,350 and 10,150 psi) and 40°C removed 90 and 70% carotene and lutein, respectively, from alfalfa LPC (96). This process avoids organic solvent residues and recovers valuable by-products. 

Fett-entziehung, /. fat extraction, -farbe, /. fat-soluble color, oil color, -farbstoff, m. color for fats (Micros.) fat stain (Bio-chem.) lipochrome, lutein, -fleck, -flecken, m. grease spot. 

A further thirty years were to pass before Kuhn and his co-workers (3) successfully repeated Tswetf s original work and separated lutein and xanthine from a plant extract. Nevertheless, despite the success of Kuhn et al and the validation of Tswett s experiments, the new technique attracted little interest and progress continued to be slow and desultory. In 1941 Martin and Synge (4) introduced liquid-liquid chromatography by supporting the stationary phase, in this case water, on silica in the form of a packed bed and used it to separate some acetyl amino acids. 

Most of this amount is in the form of fucoxanthin in various algae and in the three main carotenoids of green leaves lutein, violaxanthin, and neoxanthin. Others produced in much smaller amounts but found widely are p-carotene and zeaxanthin. The other pigments found in certain plants are lycopene and capsanthin (Figure 2.2.1). Colorant preparations have been made from all of these compounds and obviously the composition of a colorant extract reflects the profile of the starting material. Carotenoids are probably the best known of the food colorants derived from natural sources. ... 

Traditionally, dried or powdered plant material is used and extracts can be obtained by mixing the material with food-grade solvents like dichloromethane or acetone followed by washing, concentration, and solvent removal. The result is an oily product that may contain variable amounts of pheophytins and other chlorophyll degradation compounds usually accompanied by lipid-soluble substances like carotenoids (mainly lutein), carotenes, fats, waxes, and phospholipids, depending on the raw material and extraction techniques employed. This product is usually marketed as pheophytin after standardization with vegetable oils. 

Separation of lutein esters from complex plant extract mixture... 

Treatment of pre-dried natural starting materials with compressed gases (propane and/or butane) and organic solvents to facilitate complete extraction Heating pre-treated lutein-containing material in mixture of aqueous solution, alkali hydroxide, and dimethyl sulfoxide/organic solvent under catalysis at 50 to 120 C... 

Marigold petals are rich sources of xanthophyUs, mainly lutein esters. To increase the coloring power, chemical extraction of the colorant from flower meal is performed or a new enzymatic procedure is applied. It was shown that treatment with cellulases or mixed saprophyte microorganisms or solid state fermentation improved the xanthophyll extraction yield. ... 

Marigold extract (lutein-xanthophylls) E 161b 10% lutein Lutein, vegetable oil Egg yellow Chicken feeds, pet foods... 

Dunaliella natural P-carotene is distributed widely in many different markets under three categories p-carotene extracts, Dunaliella powder for human use, dried Dunaliella for feed use. Extracted purified P-carotene is sold mostly in vegetable oil in bulk concentrations from 1 to 20% to color various food products and for personal use in soft gels usually containing 5 mg P-carotene per gel. Purified natural p-carotene is generally accompanied by the other Dunaliella carotenoids, primarily lutein, neoxanthin, zeaxan-thin, violaxanthin, cryptoxanthin, and a-carotene for a total of approximately 15% of carotene concentration. This compound is marketed as carotenoids mix. ... 

An interlaboratory study using mixed vegetable reference material showed average relative standard deviations (RSDs) of 23% ranging from 11% for lutein and a-carotene to 40% for lycopene." Triplicate HPLC injections of the same extract showed RSD values of 0% for P-carotene and 6.8% for lutein. ... 

Tyczkowski, J.K. and Hamilton, P.B., Preparation of purified lutein and its diesters from extracts of marigold (Tagetes erecta). Poultry ScL, 70, 651, 1991. 

In another study of carotenoid accumulation, cultured ARPE-19 cells were treated with a lipophilic extract from tomatoes solubilized in ethanol and injected into the culture medium for 24 h. The extract, containing 3-carotene, lycopene, and lutein at relative ratios of 23, 13, and 1, respectively, led to internalization of carotenoids at ratios of 9, 1.3, and 1, respectively (Chichili et al., 2006). These results indicate preferential accumulation of (3-carotene and lutein over lycopene in ARPE-19 cells. 

The HPLC analysis of milkweed, the food-plant source for Monarch butterflies, demonstrates that it contains a complex mixture of carotenoids including lutein, several other xanthophylls, xanthophyll epoxides, and (3-carotene, Figure 25.3b. There is a component in the leaf extract that is observed to elute near 8min, which has a typical carotenoid spectrum but is not identical to that of the lutein metabolite observed at near the same retention time in the extracts from larval tissue. 

Monarch epidermis. Peaks seen at 8.7, 10, and 82min are 3-hydroxy-10 -apo-P-carotenal, lutein, zeaxanthin, and P-carotene, respectively. The peak seen eluting at 22 min is the internal standard, monopropyl lutein ether, (b) The chromatogram obtained from an extract of the leaves of the milkweed plant. Peaks eluting prior to lutein are xanthophylls and epoxy xanthophylls, identified components include lutein, zeaxanthin, P-carotene, and its crT-isomer, eluting at 10, 11, 41, 77, and 79min, respectively. 

The thyreotropic hormone166 from pituitary extracts appeared to be an entity separate from the luteinizing hormone and contained nitrogen, 13% carbohydrate, 3.5% and D-glucosamine, 2.5%. 

Moisture. Moisture had different effects on the extraction yield of phytochemicals. For example, the a- and (3-carotene extraction yields using SC-CO2 increased from 184 to 599 pg/g dry carrot and from 354 to 892 pg/g, respectively, with decreasing the moisture in the feed material from 84.6 to 0.8%. The lutein yield decreased from 55.3 to 13 pg/g dry carrot with a decrease in moisture from 84.6 to 0.8% (Sun and Temelli 2006). For the extraction of lycopene from tomato with 50-60% moisture content, only trace amounts of lycopene were reported (Vasapollo and others 2004). 

Lutein is a major component of many plants. It is a component of most of the carotenoid extracts suggested as food colorants. 

The success of the carotenoid extracts led to the commercialization of synthetic carotenoids, some with the same chemical structure as those in the plant extracts and others with modifications to improve their technological properties. The yellow beta-carotene was synthesized in 1950, followed by the orange beta-8-carotenal in 1962 and the red canthaxanthin in 1964. A number of others soon followed, methyl and ethyl esters of carotenoic acid, citraxanthin, zeaxanthin, astaxanthin, and recently lutein. 

Fig. 2.16. HPLC profile of carotenoids in an extract of vegetable soup. An expansion of the profile from 30 to 39 is shown in the inset (A). Monitored wavelengths were 436, 440, 464, and 409 nm for peaks 9,10,11,12, and 14, respectively, in the inset (A). Peak identification 1 + 1" = all-trans-lutein and cw-lutein 2 = 5,6-dihydroxy-5,6-dihydrolycopene (lycopene-5,6-diol) 3 = j3-apo-8 -carotenal (internal standard) 4 = lycopene 1,2-epoxide 5 = lycopene 5,6-epoxide 6 = 1,2-dimethoxyproly-copene (tentative identification) 7 = 5,6-dimethoxy-5,6-dihydrolycopene 8 = lycopene 9 = pheo-phytin b 10 = neurosporene 11 = (-carotene 12 = pheophytin a 13 = (-carotene 14 = pheophytin a isomer and (-carotene 15 = a-carotene 16 and 16" = all-trans-/fcarotene, cis-/J-carotene 17 and 17" = all-trans- or cA-phytofluene 18 and 18" = all-trans- or cw-phytoene. Reprinted with permisson from L. H. Tonucci et al. [40].

Extracts were further purified on neutral alumina cartridges conditioned by passing through 5 ml of hexane. Extracts were loaded in hexane and washed by 5 ml of hexane. The at- and /1-carotenes were removed by 3.5 ml of acetone-hexane (10 90, v/v), other carotenoids were eluted with acetone-hexane 30 70 and 70 30 v/v. Prepurification of pigments was performed in subdued light under a stream of nitrogen. Analyses were carried out in a C30 column (250 X 4.6 mm i.d., particle size 5/tm) using isocratic mobile phase composed of methyl-ferf-butyl ether (MTBE)-methanol (3 97 and 38 62, v/v) at a flow rate of 1 ml/min. The column was not thermostated separations were achieved at room temperature (about 23°C). Carotenoids were detected at 453 and 460 nm (lutein). The... 

Fig. 2.24. C30 chromatograms of carotenoids extracted from human serum (a) xanthophylls fraction, 7 93 (v/v) MTBE-methanol mobile phase (b) a- and / -carotenes fraction, 11 89 (v/v) MTBE-methanol mobile phase (c) lycopene fraction, 38 62 (v/v) MTBE-methanol mobile phase. Tentative peak identifications (a) 1, 13-c/s-lu- lutein 2, 13 r/.vlutein 3, a//-/ra s-lutein 4, zeaan-thin 5-7, unidentified P,e-carotenoids and 8, / -cyrptoanthin (b) 1-2, unidentified ae-carotene isomers 3, 15-eH -/f-carotenc 4, 13-cw-/ -carotene 5, all-trans-a-carotene 6, all-trans-P-carotene and 7, 9-ci.v-/3-carotene and (c) 1-11 and 13, c/s-lycopene isomers and 12, all-trans-lycopene. Reprinted with permission from C. Emenhiser el al. [51].

Fig. 2.26. Reversed-phase HPLC separation of (a) Sobrasada sausage extract and (b) saponified Sobrasade sausage extact in an ODS column at maximum absorbances at each point in time. Peak identification 1 - 2, 4 - 6, 8, 12, 14-17 = unidentified free 3 = capsorubin 7 = violaxanthin 9 = capsanthin 10 = anteraxanthin 11 = cw-capsanthin 13 = lutein and zeaxanthin 18 = cantaxanthin, internal standard 19 = cryptoxanthin 20, 24, 25, 28 = unidentified monoester 21 = /J-cryptoxanthin 22 = capsorubin monoester 23, 26, 27, 29 = capsanthin monoester 30, 31 = lutein-zeaxanthin monoester 32 = /1-carotene 33 = cis-f)-carotene 34, 37, 39, 41, 43 = capsanthin diester 35 = capsorubin diester 36, 38, 40, 42, 44 = unidentified diester. Reprinted with permission from J. Oliver et al. [56],...

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