Vitamins, extraction

Perretti, G. Marconi, O. Montanari, L. Fantozzi, P. 2003. Fat-soluble vitamin extraction by analytical supercritical carbon dioxide. J. Am. Oil Chem. Soc. 80 629-633. 

Figure 5.11. Structure of vitamin extracted from serum.

Even though vitamins are required only in very small quantities, to ensure that the adequate intake of vitamins in the diet is received, people can consume foods eruriched with vitamins, for example, in the form of functional foods with vitamins as nutraceuticals. In addition, certain vitamins extracted from natural sources such as seaweeds have antioxidant activity and other health benefits such as decreasing of blood pressure, prevention of cardiovascular diseases, or reducing the risk of cancer. 

Two molecules of vitamin A are formed from one molecule of -carotene. Vitamin A crystallizes in pale yellow needles m.p. 64 C. It is optically inactive. It is unstable in solution when heated in air, but comparatively stable without aeration. Vitamin A is manufactured by extraction from fish-liver oils and by synthesis from / -ionone. The role of vitamin A in vision seems to be different from its systemic function. See also relincne and rhodopsin. 

The vitamin deficiency is often due to failure to absorb B12 from the stomach and can be alleviated by giving mg doses with extracts of hog s stomach which contains the intrinsic anti-pernicious anaemia factor (a muco-protein), which promotes the absorption. 

Cobalt compounds have been in use for centuries, notably as pigments ( cobalt blue ) in glass and porcelain (a double silicate of cobalt and potassium) the metal itself has been produced on an industrial scale only during the twentieth century. Cobalt is relatively uncommon but widely distributed it occurs biologically in vitamin B12 (a complex of cobalt(III) in which the cobalt is bonded octahedrally to nitrogen atoms and the carbon atom of a CN group). In its ores, it is usually in combination with sulphur or arsenic, and other metals, notably copper and silver, are often present. Extraction is carried out by a process essentially similar to that used for iron, but is complicate because of the need to remove arsenic and other metals. 

Vitamins. The preparation of heat-sensitive natural and synthetic vitamins (qv) involves solvent extraction. Natural vitamins A and D are extracted from fish Hver oils and vitamin E from vegetable oils (qv) Hquid propane [74-98-6] is the solvent. In the synthetic processes for vitamins A, B, C, and E, solvent extraction is generally used either in the separation steps for intermediates or in the final purification. 

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. 

Cranberry juice, too acidic to be consumed as a 100% juice drink, has been sold since 1929 as cranberry juice cocktail. Juice extraction usually involves pressing the juice from thawed cranberries in a tapered screw press, which affords a 60—64% juice yield. The juice is diluted with two volumes of water and sugar is added to raise the °Brix to 15 to produce a juice cocktail. Under the Federal Food, Dmg and Cosmetic Act, cranberry juice cocktail must contain not less than 25% single-strength cranberry juice with soluble soHds content of 14—16 °Brix, vitamin C content of 30—60 mg/177 mL (6 02), and... 

Inhibition of nitrosation is generally accompHshed by substances that compete effectively for the active nitrosating iatermediate. /V-Nitrosamine formation in vitro can be inhibited by ascorbic acid [50-81-7] (vitamin C) and a-tocopherol [59-02-9] (vitamin E) (61,62), as well as by several other classes of compounds including pyrroles, phenols, and a2iridines (63—65). Inhibition of iatragastric nitrosation ia humans by ascorbic acid and by foods such as fmit and vegetable juices or food extracts has been reported ia several instances (26,66,67). 

A considerable quantity of oil can be extracted from waste material from shelling and processing plants, eg, the inedible kernels rejected during shelling and fragments of kernels recovered from shells. About 300 t of pecan oil and 300—600 t of English walnut oil are produced aimuaHy from such sources. The oil is refined and used for edible purposes or for the production of soap the cake is used in animal feeds (see Feeds and feed additives). Fmit-pit oils, which closely resemble and are often substituted for almond oil, are produced on a large scale for cosmetic and pharmaceutical purposes (143). For instance, leaves, bark, and pericarp of walnut may be used to manufacture vitamin C, medicines, dyes and tannin materials (144). 

The total antioxidant activity of teas and tea polyphenols in aqueous phase oxidation reactions has been deterrnined using an assay based on oxidation of 2,2 -azinobis-(3-ethylbenzothiazoline-sulfonate) (ABTS) by peroxyl radicals (114—117). Black and green tea extracts (2500 ppm) were found to be 8—12 times more effective antioxidants than a 1-mAf solution of the water-soluble form of vitamin E, Trolox. The most potent antioxidants of the tea flavonoids were found to be epicatechin gallate and epigallocatechin gallate. A 1-mAf solution of these flavanols were found respectively to be 4.9 and 4.8 times more potent than a 1-mAf solution of Trolox in scavenging an ABT radical cation. 

In this period, the empirical healing of certain diseases by foods was estabUshed. Examples (3) were the treatment of night blindness (vitamin A deficiency) with hver ia many cultures over centuries, of beriberi (vitamin deficiency) by use of unpoHshed rice by the Japanese navy, of scurvy (vitamin C deficiency) by citms fmits ia the British navy or piae needle extracts by North American natives, and pellagra (niacia deficiency) by a dietary shift away from corn-based foods ia many countries. Other, nondietary empirical treatments iavolved, eg, exposure of children ia northern latitudes to sunlight to cute tickets (vitamin D deficiency) (4). 

The first clues to the treatment of scurvy occurred in 1535—1536 when Jacques Cartier, on advice from Newfoundland Indians, fed his crew an extract from spmce tree needles to cure an epidemic. Various physicians were recommending the use of citms fmits to cure scurvy in the mid-sixteenth century. Two hundred years later, in 1753, it was proved by Dr. James Lind, in his famous clinical experiment, that scurvy was associated with diet and caused by lack of fresh vegetables. He also demonstrated that oranges and lemons were the most effective cure against this disease. In 1753, inM Treatise on the Scurvy[ Lind pubhshed his results and recommendations (7). Eorty-two years later, in 1795, the British Navy included lemon juice in seamen s diets, resulting in the familiar nickname "limeys" for British seamen. Evidence has shown that even with undefined scorbutic symptoms, vitamin C levels can be low, and can cause marked diminution in resistance to infections and slow healing of wounds. 

Parallel to the activities in the treatment of pernicious anemia were observations in the 1930s that most farm animals had a requirement for an unknown factor beyond the vitamins then known. The lack of this factor became apparent, eg, when chicks or pigs fed a diet with only vegetable protein evidenced slow growth rate and high mortahty. It became apparent that the requited factor, termed animal protein factor, was present in animal sources such as meat and tissue extracts, milk whey, and cow manure. Subsequent to its isolation, it was rapidly shown that vitamin B 2 is the same as animal protein factor. 

After its separation from Hver extracts, vitamin B 2 was also isolated from cultures of Streptomjces aureofaciens (12). AH vitamin sold commercially is produced by microbial fermentation. 

Radioisotope dilution assays are based on the principle of competition between radioactive labeled ( Co) vitamin B 2 and cobalamins extracted from matrices for binding sites on the intrinsic factor (a glycoprotein). Binding is in proportion to the concentration of the radioactive and nonradio active B 2 with the concentration of intrinsic factor as the limiting factor. Free cobalamins are separated from those bound on the intrinsic factor by absorption... 

Spectrophotometric deterrnination at 550 nm is relatively insensitive and is useful for the deterrnination of vitamin B 2 in high potency products such as premixes. Thin-layer chromatography and open-column chromatography have been appHed to both the direct assay of cobalamins and to the fractionation and removal of interfering substances from sample extracts prior to microbiological or radioassay. Atomic absorption spectrophotometry of cobalt has been proposed for the deterrnination of vitamin B 2 in dry feeds. Chemical methods based on the estimation of cyanide or the presence of 5,6-dimethylben2irnida2ole in the vitamin B 2 molecule have not been widely used. 

The standard chemical and biological methods of analysis are those accepted by the JnitedStates Pharmacopeia XXIII as well as the ones accepted by the AO AC in 1995 (81—84). The USP method involves saponification of the sample (dry concentrate, premix, powder, capsule, tablet, or aqueous suspension) with aqueous alcohoHc KOH solvent extraction solvent removal chromatographic separation of vitamin D from extraneous ingredients and colormetric deterrnination with antimony trichloride and comparison with a solution of USP cholecalciferol reference standard. 

The elemental and vitamin compositions of some representative yeasts are Hsted in Table 1. The principal carbon and energy sources for yeasts are carbohydrates (usually sugars), alcohols, and organic acids, as weU as a few other specific hydrocarbons. Nitrogen is usually suppHed as ammonia, urea, amino acids or oligopeptides. The main essential mineral elements are phosphoms (suppHed as phosphoric acid), and potassium, with smaller amounts of magnesium and trace amounts of copper, zinc, and iron. These requirements are characteristic of all yeasts. The vitamin requirements, however, differ among species. Eor laboratory and many industrial cultures, a commercial yeast extract contains all the required nutrients (see also Mineral nutrients). 

The most widely available yeast biomass is a by-product of the brewing industry, where the multiplication of yeast during brewing results in a surplus of ceUs. Eor every barrel (117 L) of beer brewed, 0.2—0.3 kg of yeast soHds may be recovered. In the U.S., a substantial fraction is recovered and made available about 40 x 10 kg of brewers yeast aimually. The yeast is recovered from beer by centrifuging and dried on roUer dmms or spray dryers and sold as animal feed or a pet-food supplement. It can be debittered by alkaline extraction to remove the bitter hop residues, and is then sold mainly by the health-food industry. It is available as tablets, powder, or flakes and is often fortified with additional vitamins. Distillers yeast caimot be readily separated from the fermented mash and the mixture is sold as an animal feed supplement. 

---