US2434788A - Fat-soluble vitamin concentrates - Google Patents

Description

patents.

Patented J ao, 194s Loran 0. Buxton, Newark, N. 3., assignor to Nopco Chemical Company, Harrison, N. J., a corporation of New Jersey, i

No Drawing. Application April 3, 1944,

Serial No. 529.418 a The present invention relates to the production of vitamin concentrates.

esters.

In the fractionation of marine oils containin vitamins to produce concentrates therefrom, a

' substantial loss has occurred during fractionation. In other words, the percentage of vitamin found in the extract fraction, and that remaining'behind in the residue has been very much less than 1 the vitamin contained in the original oil. AJ-

though this loss might have been expected in the v fractionation of refined marine oils, "particularly those refined in such a manner as to destroy most fof the naturalantioxidants, such a loss would ordinarily not be expected to occurduring the fractionation of crudemarine oils still containing a large proportion of natural antioxidants.

It has now been discovered, however, that if a small quantity of antioxidant is added to marine qoils prior to fractionation, ,whether or not these marine oils have been previously refined in such a manner as to destroy a large proportion of the natural antioxidants or are'the crude, relatively stable oils, a verysubstantial increase in the yields of vitamin A ester in theconcentrate or extract portion and of vitamin content in the residue OCCLII'S j There is further produced in accordance with I the present invention, a, vitamin ester concentrate which is relatively stable, and this is particularly true if an antioxidant is used which is largely soluble in the solvent used for fractionation. :Such .an antioxidant is that prepared in accordance with copending' applications Serial Nos. 397,547, new Pat. No. 2,345,578, dated Apr, 4, 1944, and 351,909, now Pat. No.'2,345,576 dated Apr. 4,1944, 'i. e; antioxidant concentrates pro- ,duced by solvent extraction of antioxidant-containing vegetable oils or solids. The present procass is particularly applicable to' fractionation processes for producingvitamin esters, wherein the solvent used for fractionation is very similar to the solvent usedior the extraction of antioxidants in accordance with theaforementioned It is, therefore, one of the objects of the present invention to fractionate a vitamin-containing marine oil with a solvent capable of extracting a large proportion of the vitamin esters from the marine oil in the presence of a suitable anti- "oxidant.

A second object of the present invention is to More particularly, the present invention relates tothe fractionation of vitamin-containing marine oils in order to produce a concentrate consisting largely of vitamin 2 can. (01. 167 -81) produce stabilized vitamin estenfconcentrates from .vitamin containing marine .-oils, whether theseoilsberefinedorcrudel A third object of the present invention is to fractionate a vitamin-containing marine oilby means of a suitablesolvent capable of extracting vitamin esters therefrom, and particularly vitai min A, so as to produce a vitamin concentrate fromthe marine oil, said ractionation being performed in the presence of an antioxidant concentrate produced by extraction of antioxidantcontaining vegetable materials with a solvent similar to that used in the fractionation,

Otherobjects andadvantagesof the present in vention will become apparent from the subsequent description and claims.

As before stated, thepresent process includes the-treatment of various types of marine oils and marine oilconcentrates to separate and'concentratethe ester portion thereof. Among the materials-which maytbe treated in accordance with the present process are fish oils such as cod liver oil, tuna liver oil, shark liver oil, halibut liver oil, and fish oils from sardine, menhaden, herring and the like. These oils may be previously concentrated in accordance with well known methods, or they may be crude oils. By proceeding in accordanceswith the present process, marine oils may be treated which have previously undergone a treatment with. activated carbon, so that, these oils are substantially free of fishy taste'andloidor and also substantially, devoid of natural antioxidants. When' such a carbo'n refined oil is treated, a vitaminiester concentrate is produced which is odor.-

To such a marine oil there is added a relatively small-amount, as for example from about 0.5 to

30%, andpreferablyfrom about 1% to 5%,of-

an antioxidant concentrate, produced by solvent extraction of antioxidant-containing materials, Such concentratesmay be obtained not only by extracting vegetable oils, but oil-bearing solids. Thelvegetable oil oroil-bearing solids may be any oil-bearing solid'orjoil containing naturally occurring antioxidants. The oil-bearing solid may contain all the oil,'fat, or waxpresent in said solid in its natural state, or it may have had a cottonseed,cocoa bea ,ip ln kernels, copra, rice, rice germ, flax seed; -teaseed, hemp seed,lperilla 1 seed, alfalfa seed, etc.,may be used as a type of substantial proportion of the fatty material or oil removed. Thus, vegetable materials such assoybean meal or cake, wheat bran, wheat germ, corn germ,corn, grain. oat ye, olives, sesame seed,

substantially devoid of fishy taste andmaterial from which antioxidant concentrates are extracted. In some instances, antioxidant concentrates may be extracted from fish livers themselves or from fish oils. Various vegetable seeds such as tomato seeds, and animal materials such as egg yo ks may also serve as the basic materials from which such antioxidant concentrates are prepared. Vegetable oils and-fats such as soybean oil, wheat germ oil, cottonseed oil, palm oil, etc., are also suitable.

As pointed out in the aforementioned patents, Nos. 2,345,576 and 2,345,578, these antioxidants are recovered from fatty materials with which they are associated by extraction with a suitable solvent. The solvent employed in accordance with the aforementioned patents is aliphatic in character and a. member of well-recognized chemical classes. Further, the number of carbon atoms in the solvent used is an important factor in determining the availability thereof for use in extracting antioxidants.

The following table sets forth the classes of solvents particularly useful in the production of antioxidant concentrates.

Table 1. Aliphatic and alicyclic monohydroxy alcohols 4. Aliphatic ketones containing notmore than 6 carbon atoms.

Solvents falling within the classes above listed are all liquid aliphatic organic compounds having the properties of being substantially miscible with fatty materials at temperatures above room temperature, i. e. 20 to 25 C., and partially immiscible therewith at temperatures substantially below room temperature, and experiments have shown that solvents falling within these classes of compounds are particularly desirable.

Some of the solvents of the character above described are as follows: n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, n-amyl alcohol, isoamyl alcohol, secondary amyl alcohol, furfury alcohol, allyl alcohol, diacetone alcohol, betahydroxy ethyl acetate, methyl formate, ethyl formate, ethyl acetate, methyl acetate, isopropyl acetate, glycol diformate, glycol diacetate, methyl levulinate, ethyl levulinate, methyl aceto acetate, ethyl aceto acetate, methyl furoate, vinyl acetate, furfuryl propionaldehyde, crotonaldehyde, acetone, methyl ethyl ketone, acetonyl acetone, and propylene chlorhydrin, Mixtures of these solvents belong to that class of aliphatic organic compounds which has the properties of being miscible with fatty oils at temperatures above room temperature and partially immiscible therewith at temperatures substantially below room temperature; furthermore, it will be noted that the majority of these solvents have-relatively low freezing points.

Occasionally, it may be found that certain of the solvents hereinabove mentioned may be too miscible with some of the fatty materials which may be treated to effect aseparation of antioxidants therefrom; thus, for example, acetone is too miscible with many fatty materials. However, this condition may be easily corrected by diluting or with some liquidallphatic organic solvent relathe solvent with either a small amount of water from the fatty material, this difficulty may generally be overcome by the addition of a small amount of water to the solvent.

The solvents preferably employed for the production of the antioxidant concentrates are the aliphatic alcohols containing from 3 to 6 carbon atoms. Of these solvents, isopropanol and diacetone alcohol have proved to be the most successful. The presence of the hydroxyl group seems to impart to these solvents, properties which make them particularly useful.

In carrying out the extraction of the antioxidants from the oils and oil-bearing solids with which they are associated, the material to be treated is first mixed with the particular solvent to be employed. The relative proportion of material to solvent may vary widely; preferably, the ratio of solvent to material should be greater than one and, in most cases, mixtures containing between about 2% and about 25% oil are most suitable. Where oil is being treated, it is preferable to cause substantially all the oil to dissolve in the solvent; when employing the preferred solvents complete solution is ordinarily effected most readily by heating the mixture to a temperature substantially above room temperature. However, it is not necessary to cause the oil to dissolve completely in the solvent, since highly active antioxidant fractions may be extracted from the oiland oil-bearing solids by agitating the oil or solid with the solvent at a temperature such that only partial solution is effected. The extraction is preferably carried out in an inert gas atmosphere; furthermore, if fat-soluble vitamins are present in the oil being extracted, it is not advisable to heat the mixture to temperatures substantially in excess of C. if recovery of the vitamins is desired.

The antioxidant fraction extracted from the oil may be recovered in any suitable manner. When the oil is completely dissolved in the solvent at somewhat elevated temperatures, the recovery of the antioxidant extract is most conveniently accomplished by cooling the solution to a temperature substantially below room temperature, e. 8. between about 0 C. and about 70 0., whereby two layers form.

The solvent layer obtained from the extraction above described may be filtered and then treated to remove the solvent therefrom, e. g., by vacuum distillation, whereby an extract is recovered containing relatively large amounts of highly active antioxidants. If desired, water may be added to the extract in order to precipitate some of the glycerides contained therein or some of the sterols may be removed; however, these steps are not essential, since the glycerides and sterols do not inhibit the antioxidant properties of the extract. If the extract contains an excessive amount of free fatty acids, these are preferably removed by treatment with alkali in a solvent medium or by other suitable methods. The extract ordinarily possesses the characteristic odor and color ofthe oil from which it is obtained and is generally slightly more viscous than the original oil.

Although it is preferred to use antioxidant concentrates extracted from various fatty maantioxidants, ammonia-treated antioxidant concentrates of thehighest potency.

and vitamin alcohol.

te'rials as above set forth and more completely described and claimed in Patents 2,345,576 and 2,345,578, the present process may be carried out by using other types of antioxidant concentrates than those obtained by solventextraction of'antioxidant-containing vegetable oils or solids.

However, it is preferred to use antioxidant con- 1 previously set-forth in the table. The solvent,

however, may be varied in order to produce con- In general this extraction will produce a solvent layer containing most of the vitamin A ester fraction of the vitamin. Where, however, the solvent is diluted with water, the solvent layer may con .tain a mixture of both vitamin ester and vitaof vitamin ester, whereas 91% isopropanol will giv a solvent layer containing both vitamin ester Preferably, the mixture of marine oil and solvent together with antioxidant'is heated for a substantial period. However, temperatures should not exceed'175" C. or considerable lossof vitamin content will result. In general, the temperaturepreferably employed is equivalent to the reflux temperature. of the particular solvent used and is of the order of 50 C. In some instances,'however, mixing the solvent, marine oil, and antioxidant at ordinary room temperature and allowing the same to stand for a substantial period of time, i. e. from 4 to.12 hours, may be sufiicient to extract the vitamin ester content of the marine oil and produce a concentrate. Upon standing at room temperature, two layers will form and the sol- I 'vent layer will contain the large proportion of the ester, and upon vaporization of the solvent in the presence of nitrogen gas and under a vacuum, a vitamin ester concentrate will be pro- .duced.

In general, however, in order to obtain a sharp fractionation, it is desirable to cool the mixture of solvent, marine oil, and antioxidant concentrate to temperatures below 0 C. Preferably, such a quantity of solvent is used as substantially exceeds the quantity of marine oil. From invention is not limited to the specific materials or conditions therein set forth.

Example I Fifty grams of carbon-refined shark liver Oil containing 56,000 units of vitamin A per gram were mixed with 200 ml. of 99% isopropanol in the presence of an atmosphere of nitrogen gas, and the mixture heated to 50 C. After thorough mixing, the mixture was cooled to 16 C.

'After 12 hours at the'low temperature, the supernatant isopropanol xtract was decanted, and the residual oil layer treated three more times with similar volume portions of isopropanol in exactly the same manner. The four combined isopropanol extract fractions, as well as the residual isopropanol insoluble layer, were freed of isopropanol by distillation in the presence of nitrogen under reduced pressure. The combined extracts yielded 19.5 grams of a vitamin concentrate having a specific vitamin A value of 68,500 U. S. P. units of vitamin A per gram. This consisted largely of vitamin A ester. The residue, which consisted of 28.1 grams, had a specific vitamin A value of 37,400 U. S. P. units per gram. The total oil yield was therefore 95.2% of the original oil, and the total A yield was 89.6%. Example If The same carbon-refined shark liver oil of Example I was treated in precisely the same manner, except that 5% of soybean extract antioxidant was added-to the carbon-refined shark liver oil. The soybean oil antioxidant concentrate was obtained by extracting 66.5 pounds of after, the solvent oil mixture was stirred at 50 C. for 15 minutes and then cooled rapidly to 23 C. It was withdrawn from the treatment kettle and then placed in the low temperature refrigerator at -25 C. for 2 days. Thereafter, the supernatant liquid wa decanted'and the solid portion reextracted with 206 lbs. of 91% isopropanol in a manner similar to the first extraction. The two extracts were combined and the solvent removed under a vacuum and in the presence of nitrogen gas to form the antioxidant concentrate. The results of the treatment of the refined shark liver oil in the presence of the aforementioned antioxidant concentrate were subof the solvent therefrom. Preferably, the proc-- centrate obtained after volatization of the solvent from the extract portion was very much more stable than the concentrate of Example I.

Example 111 Fifty grams of carbon-refined halibut liver oil having a specific vitamin A value of 86,000 units sheaves 7 per gram were-stabilized with of soybean oil antioxidant prepared as described in Example II. The oil was then extracted with 3-200 ml. portions of 99% isopropanol at -l6 C. in precisely the same manner as described in Examples I and II. The combined extracts -ylelded l3.7 grams of oil having a specific value of 151,000 U. S. P. units of vitamin A per gram. The residue yielded 35.6 grams of oil having a specific value of 62,200 U. S. P. units of vitamin A per gram. The total oil yield was 98.6% of the original oil, and the total vitamin A yield was 100%.

The same oil treated in precisely the same manher but without the addition of the antioxidant concentrate gave a total A'vltamin yield of only 84.2%.

Although, as previously pointed out, it is preierred to use antioxidant concentrates produced by solvent extraction of various types of vegetable materials, other well-known antioxidants may be used.. Such antioxidants may include phosphatides in combination with compounds which exert a synergistic action with the phosphatides. Such compounds include cyclic oxy types of compounds, as, for example, quinones, hydroquinones, naphthoquinones, naphthols, naphtho-hydroquinones, chromans, chromens, coumarones and coumarans. These latter compounds are, 01 course, antioxidants by themselves and may be used in the proportions hereinbefore set forth, either alone or in combination with phosphatides. Typical examples of such compounds are the alpha-beta-gamma tocopherols', the chroman 5-6 quinones and their precursors which are associated with vitamin E.

As will be noted, the present invention is particularly applicable to vitamin-containing marine oils. The vitamins contained in these oils are predominantly vitamin A, and a lesser proportion of vitamin D. It is therefore desired to point out that when in the claims a vitamin-containing marine oil is referred to, it is intended to include all the various types of oils of marine origin and the vitamins, l. e. A and D, normally occurring therein.

Having described my invention, what I claim as new and desire to be secured by Letters Patent i 1. A process for producing a fat-soluble vitamin concentrate from a fat-soluble vitamin-containing marine oil, which comprises mixing in vitamin-containing marine oil with a solvent selected from the group consisting of aliphatic and alicyclic monohydroxy alcohols'containing from 3 to 6 carbon atoms, esters formed by the reaction 5 of aliphatic and alicyclic alcohols with aliphatic monocarboxylic acids, said esters containing not mere than 8 carbon atoms, aliphatic and allcyclic aldehydes containing not more than 6 carbon atoms and aliphatic ketones containing not more than 6- carbon atoms, to form a substantially homogeneous solution, cooling the 'mass to form a solvent layer containing a relatively potent concentrate and a residue layer and separating the solvent layer from the residue layer, the antioxidant concentrate serving to inhibit the loss of vitamin potency through oxidation during the process.

2. A process for producing a fat-soluble vitamin,concentrate from a fat-soluble vitamin-containing marine oil, which comprises mixing in the presence of an antioxidant concentrate obtained by the normally liquid organic solvent extraction of a natural antioxidant-containing fatty material of vegetable origin a fat-soluble vitamin-containing marine oil with isopropanol to form a substantially homogeneous solution, cooling the mass to form an isopropanol layer containing a relatively potent concentrate and a residual low potency oil layer and separating the isopropanol layer from the residual layer, the antioxidant concentrate serving to inhibit the loss of vitamin potency through oxidation during th process;

LORAN O. BUXTON.

REFERENCES CITED The following references are oi record in the flle of this patent: V

UNITED STATES PATENTS Number Name 7 Date 2,282,795 Musher May 12, 1942 2,282,812 Mush'er May 12, 1942 2,345,576 Buxton Apr. 4, 1944 2,345,578 Buxton Aug. 4, 1944 2,380,418 Dombrow July 31, 1945 2,221,692 Hickman Nov. 12, 1940 2,327,766 Cawley Aug. 24, 1943 1,983,654 Black Dec. 11, 1934 2,389,955 Buxton Nov. 27, 1945 FOREIGN PATENTS Number Country Date 220,697 Great Britain Aug. 14, 1924