US2255875A - Process of refining vitaminiferous oils - Google Patents

Description

Patented Sept. 16, 1941 2,255,875 raoonss F nnrnglgg VITAMINIFEBOUS Loran 0. Buxton, Harrison, N. 1., and Eric J. Simons, New York, N. Y., assignors to National Oil Products Company, Harrison, N. 1., a corporation of New Jersey No Drawing. Application August 30, 1938, Serial No. 227,600

12 Claims.

The invention relates in general to the refining of vegetable and marine oils and in particular to a process for refining vitamin-containing oils.

Heretofore; the free fatty acids in animal, vegetable and marine oils, including the vitamincontaining oils, have been removed by various processes, the most common of which is known as the alkali refining process wherein the free fatty acids are saponified by means of an alkali. In the refining of vitamin and provitamin oils, such as the fish liver oils, palm oil, carrot oil and the like, the process of saponifying the free fatty acids contained therein in the presence of a water-immiscible solvent has proved quite advantageous in that a more efficient separation of the resulting soap and the acid-free oil is af-' forded. Difliculties have been encountered, however, in the vitamin field as the refined oil has invariably been characterized by having an obnoxious taste and odor and a dark color. In an attempt to rid the refined oil of these undesirable properties, the use of earths, clays and activated carbons was resorted to, but the results were none too encouraging. This factor has worked a hardship on the producers of refined vitamin oils and concentrates thereof as the value of such products depends largely upon the taste, odor, color and clarity thereof.

The general object of the invention is to obviate the foregoing and other disadvantages.

Another object of the invention is to provide an improved process for refining oils containing vitamins A and/ or D.

A specific object of the invention is to provide after disclosed, and the scope of the invention will I a process which will yield a highly refined vitamin oil possessinga light color with substantially no odor or taste.

Other-objects of the invention will in part be obvious and will in part appear hereinafter.

It has now been found that the foregoing and other objects may be realized by the practice of the process of the invention which comprises removing a portion of the free fatty acids by means of an alkaline agent, subjecting the partially represence of a solvent in which water and soap will not dissolve.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others thereof,

,by saponification with an alkaline agent.

be indicated in the claims.

The first step in carrying out the process of the invention comprises removing the major portion of the free fatty acids from a vitaminiferousoil This step is preferably, though not necessarily, carried out in the presence of a water-immiscible solvent which will not dissolve the soap formed in situ. Such solvents include, inter alia, heptane, ethylene dichloride, trichlorethylene, dichlorethyl ether, ethyl ether, petroleum ether, chloroform, cyclohexane, etc., the first two named being highly preferred. In the event that the oil is solvent-extracted from its original source as from fish livers, for example, the resulting vitaminiferous oil-solvent mixture may be directly processed according to the invention thereby eliminating the usual step of freeing the oil from solvent after the extraction step. Any suitable alkaline agent such as potassium hydroxide, sodium hydroxide, sodium carbonate, etc. may be used to neutralize the free fatty acids. The alkaline agent may be added to the oil-solvent batch in any suitable form, a relatively concentrated aqueous solution being preferred. The concentration of the aqueous alkaline solution should be adjusted according to the specific gravity of the solvent used. If a heavy solvent such as ethylene dichloride is used, amore concentrated alkaline solution may be used which produces a relatively heavy soap, but which will easily fioat on the heavy solvent. 0n the other hand, a less concentrated alkaline solution should be used when a lighter solvent such for example as heptane is used to insure the formation of a lighter soap which will also separate and float to the surface of the solvent. An amount of alkaline agent sufficient to neutralize all but about 3% to-15% of the free fatty acids present should be stirred into the oil. Upon completion of saponification, the soap formed may be readily removed from the oil andextracted with solvent to recover the oil occluded therein.

The next step in the process of the invention comprises subjecting the vitaminiferous oil-solvent mixture to the action of an activated carbon. Any suitable activated animal or vegetable carbon may be employed, examples of which include, inter alia, the following well-known products available on the market under the tradenames of Nuchar XXX, Nuchar #2, Nuchar 000, Nuchar Aqua, Nuchar 0-145, Nuchar Wa, Darco 60, "Darco 90, Darco K, etc.

which will be exemplified in the process herein- The foregoing and other similar products may be used alone or in combination with each other as well as in combinations with colloidal clays, earths, etc. Likewise in certain cases a filter-aid. may also be used to facilitate filtration of the treated oil, although the use of colloidal clay with the activated carbon renders the use of a filteraid unnecessary. After selection of the desired carbon or carbon-mixture has been made, it is admixed with a suitable solvent which will dissolve or appropriately serve as a vehicle for the oil-solvent mixture during treatment thereof.

Solvents of the aforementioned type are suitable and the same solvent as is already in the oil should be used or one that is at least miscible therewith. The activated carbon-solvent mixture should preferably be completely deaerated before treating the vitamin-containing oil therewith. The deaeration step may be conveniently efiected by merely stirring the carbon and solvent-in a vessel with or without the aid of heat and/or reduced pressure. It is very important to completely deaerate the carbon-solvent mixture to guard vagainst the subsequent loss of any of the vitamin A which is highly sensitive to oxygen.

1 After complete deoxygenation of the carbonsolvent mixture has been efl'ected, the vitaminifficiently to provide a solvent vapor airfree zone immediately above the surface of the liquid thus inhibiting any possible oxidation by the ambient atmosphere. The carbon treatment may be accelerated by the use of heat it so desired. Upon completion of this operation, the purified oil and.

solvent may be separated from the carbon and the impurities adsorbed thereon by filtering, de-

canting, centrifuging or the like, filtering being preferred. The resulting product when freed jfrom solvent displays a marked improvement in taste, odor and color.

, The resulting purified oil and solvent which still contains some of the original free fatty acids is then subjected to a final treatment with an alkaline agent. An amount of alkaline agent sufilcient to just neutralize (or a slight excess) the remaining free fatty acids present in the oil is added.- The soap thus formed separates out from the unsaponified oil and solvent and is removed therefrom. The soap is usually extracted with fresh solvent to ensure recovery of all the vitaminiferous oil. The solvent is then distilled 7 off from the refined ,oil in the presence of a suit- Weigh into a vessel 40 parts of crude liver oil able inert gas. The final step of neutralizing the remaining free fatty acids may be effected after removal of the solvent if desired.

1 The present process is adapted for use in the refining of any suitable vitaminiferous oils such as crude or partially refined fish liver oils derived from cod, ling cod, Jew fish, pollack, shark, swordfish, tuna, herring, halibut, sardine and other fish as well as palm oil and carrot oil (which contain provitamin A) and wheat germ oil or rice bran oil (which contain vitamin E). In those cases where the original crude oil contains only about 25% or less of free fatty acids, the first saponification step may be omitted if deinterpreted as the U. S. P." units of the given vitamin.

3 For a fuller understanding of the nature and 5 being by weight.

chloride.

25 F. F. A per cent erous oil-solvent mixture is slowly added or vice objects of the invention, reference should be had to the following examples which are given merely to further illustrate the invention and are not to be construed in a limiting sense, all parts given Example I Weigh into a vessel 20 parts of crude halibut liver oil (F. F. A.-52.5%, potency 25,000 U. S. P. units vitamin A/gm.) and 80 parts ethylene di- While stirringrnadd suflicient 38% KOH (4.3 par-ts) to neutralize'all but per cent of the F FI A. ,Extract the soap four times with 10 'p0rti6ns of ethylene dichloride. Combine-the extracts and treat with a deaerated mixwe of "2 parts of Nuchar XXX" in ethylene ,"dichloride. Agitate for 30 minutes and filter. Extract residue 5 times with 10 part portions of ethylene dichloride. To the filtrate add adequate 38% KOH (1 part) to neutralize the remaining 10% of F. F. A. Remove the soap and re-extract twice with 10 part portions of ethylene dichloride. Remove the solvent by vacuum distillation in the presence of nitrogen gas. Yield oil: 9.4 parts.

0.2 Potency units A/gm.-- 53,000

Color is a golden yellow; taste is bland; and the odor is very much improved.

Example II Weigh into a vessel 20 parts of crude blue tuna fish liver 011 (F. F. A.%, potency 30,000 units D and 25,000 units A per gram) and 80 parts ethylene dichloride. While stirring, add sufficient KOH (2.1 parts) to neutralize all but 5% of the F. F. A. Extract the soap four times with 10 part portions of ethylene dichloride. Combine extracts and treat with a deaerated mixture of 2 parts of Nuchar #2 in ethylene di- 1 chloride. Agitate for 1 hour at room temperature and filter. Extract residue 5 times with 10 1 part portions of ethylene dichloride. To the filtrate add adequate 45% KOH (0.45 part) to neutralize the remaining 5% of F. F. A. Remove 45. the soap and re-extract twice with 10 part portio'ns of ethylene dichloride. Remove the solvent by vacuum distillation in the presence of nitrogen gas. Yield oil 14 parts.

r. r'. A. -per cent 0.0 Potency units A/gram-- 35,000

Color is a light golden yellow; taste is bland; odorless.

Example III but 15% of the F. F. A. Extract the soap six times with 10 part portions of ethylene dichloride. Combine the extracts and treat with a deaerated mixture of 8 parts of "Nuchar XXX" in ethylene dichloride. Agitate for 1 hour and filter. Ex-

tract residue 5 times with 10 part portions of ethylene dichloride. To the filtrate add sufficient 45% KOH (2.5 parts) to neutralize the remaining 15% F. F. A. Extract the soap three 1 times with 10 part portions of ethylene dichloride.

Remove the solvent by vacuum distillation in the presence of nitrogen gas. Yield oil: 12 parts.

F. F. A per cent 0.5 Potency .'A/gm. 195,000

Color is a golden yellow; taste is bland; odorless.

Example IV Weigh into a vessel 30 parts of crude fish liver oil (F. F. A.50%, potency 120,000 units A per gram) and 70 parts heptane. While stirring add; sufilcient 30% KOH (7.6 parts) to neutralize all but 10 of the F. F. A. Extract soap four times with 10 part portions of 'heptane. Combine the extracts and treat with a deaerated mixture con-' taining 3 parts of Nuchar XXX" in heptane. Agitate for 30 minutes (temperature 60 C.) and filter. Extract the residue times with part portions of heptane. To the filtrate add adequate 30% KOH (1.9 parts) to neutralize the remaining 10% of 'F. F. A. Extract the soap three times with 10 part portions of heptane. Remove the solvent by vacuum distillation in the presence of. nitrogen gas. Yield oil: 14.8 parts.

F. F. A per cent 0.6 Potencyunits A/gm 235,000

Color is a light golden yellow; taste is blandp odorless.

Example V in the presence of nitrogen gas. Yield oil: 16 I p I 1". F. A per cent 02 Potency units A/gm.-- 75,000 Color is light yellow; taste is bland; odorless.

Example VI Weigh into a container 4 parts of Nuchar xxx" and 60 parts of ethylene dichloride. Stir for 5 minutes to deaerate the carbon and add slowly parts of crude swordfish liver oil F. F. A.-l2% potency 160,000 units A/gm.) Continue agitation for 30-minutes and filter. Wash residue 5 times with 10 part portions of ethylene dichloride. While agitating add sufficlent 30% KOH (3.1 parts in gms.) to the filtrate to completely neutralize the free fatty acids. Remove the soap and re-extract three times with 20 part portions of ethylene dichloride. Remove the solvent by vacuum distillation in the presence of nitrogen gas. Yield oil: 35 parts.

F. F. A "per cent 0.3 Potency- U. S. P. units vitamin A/gm- 180,000

Color is a light yellow; tasteless; odorless.

The process of the invention makes possible the production of refined vitamin oils which are far superior in every respect to oils produced by prior known refining methods. The products produced by the novel process are characterized by being greatly improved as to color, taste and odor. The success of the present process is attributed to the order of the steps as executed. This fact is based upon the theory that unrefined vitaminiferous oil's contain colloidal and/or suspended impurities which impart the undesirable dark color, taste, and odor thereto. When such an oil is alkali refined at the outset to remove all the free fatty acids, the alkali serves to solubilize the impurities in the 11, thereby fixing the objectionable impurities therein. After these impurities have thus been fixed in the oil, activated carbon appears to haveless power to adsorb the: same. In the present process only a portion of the free fatty acids are removed before treatment with activated carbon. No fixation 'of impurities takes. place in this stepiof removing only a por-x tion of the free fatty acids. This result is due to the fact. that afmajor portion. of the fatty acids are readily s'aponifi'edso' that the alkali becomes completely spent in' a relatively short period of time and thereby it has notime to at'tack and solubilize the impurities.v The fatty acids which do' not readily react with the alkali remainin the oil and are not s'a'p'onified and removeduntil after the colloidal and/6 1 suspended-impurities have been removed by the treatmentjf'with ac} tivated carbom It has further been found that activated carbon functions 'much' more efficiently when the oiicontains at leastasmall percentage of free fatty acids which further. enhances the value of the present process, Moreover by removing the maior portion of the free fatty acids at the outset the effici nc Of the process is increased as less activated carbon, whichadsorbs some. of these acids,' is used. f f I Since certain changes may be made in carrying out the above process without departing from the scope of the invention, it is intended that all matter contained in the above'description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention, which as a matter of language might be said to fall therebetween.

Having described our invention, what we claim as new and desire to secure by letters Patent is:

1. In a process of refining fat-soluble vitamincontaining oils the step which comprises subjecting the oil to the action of activated carbon before the removal of all of the free fatty acids present therein.

2. In a process of refining vitaminiferous oils the step which comprises subjecting a partially refined fat-soluble vitamin-containing oil to the action of activated carbon before the removal of all of the free fatty acids present therein.

3. A process of refining vitaminiferous oils which comprises removing a portion of the free fatty acids from a fat-soluble'vitamin-containing oil, subjecting the partially refined oil to the action of activated carbon and finally removing the remaining free fatty acids.

4. A process of refining vitaminiferous oils which comprises removing a major portion of the free fatty acids from a fat-soluble vitamincontaining oil, subjecting the partially refined oil to the action of a completely deaerated mixture of activated carbon and solvent and finally removing the remaining free fatty acids from the oil.

portion of the free fatty acids by treating the oil with an alkaline agent, subjecting the partially refined oil to the. action of activated carbon and finally removing the remaining free fatty acids by treatment with an alkaline agent.

6. A process of refining a fat-soluble vitamincontaining oil which comprises removing a major portion of the free fatty acids by treating the 5. A process of refining a fat-soluble vitamincontaining oil which comprises removing a major oil with an alkaline agent, subjecting the par- 1 tiallyrefined oil to the action or a completely ,de'aerated; mixture of activated: carbon and; solvent and finally removing the remaining'free 1 fatty acids by treatmentwith an alkalineeagent.

7-. A-process;of refining afat' soluble-vitamincontaining. oil which-comprises removingja major portion of thefreefatty acids. by' the oil with an alkali? in: the presence of a solvent,v I

subjecting: the solvent-oil mixture to the action of activated carbon,,andl-finallyremovinz the remaining free: fatty acids-by treatment with: 1

alkali.

a; a process of: refining a fat-somble' vitamincontaining oil 'which comprisesremovinga majorportion of the; free fatty acidsJfrom the oil by j saponlflcatlon in the presenceof asolvent, treating the partially refined: oil with a completely deaerated; activated carbon-solvent and finally removing the remainingfree fatty-acids from the oil by saponification.

9 A .process of refining; vitaminiferous: oils? which comprises removing a major portion: of the free fatty acids from a fish liver. oil, by saponification in the presenceof a solvent, treating: the partially refined, oil: with activated. carbon and finally removing the remaining free; fatty acids from the oilby saponification.

10. A process of refining a vitaminiferous oil which comprises removing a" or portion of the free fatty acids from a fish liver oil by saponification in the presence of ethylene dichloride, treating the oil-solvent mass was a completely deaerated mixture of activated carbon in ethylene dichloride, separating the oil and solvent from. the carbon and impurities adsorbed thereon and finally removing the remaining free fatty acids from the oil by saponification.

1-1. A process of refining a vitaminiferous oil which comprises removing a major portion of the: free; fatty acids from a fish liver oil by saponification'in the presence of heptane, treating the oil-solvent mass with a completelydeaerated chlorethylene, separating the oil and solvent from; the carbon and impurities adsorbed thereon and finally removing the remaining free fatty acids from the oil by saponlfication.

LORAN 0. BUXTON. ERIC J. SIMONS.