US2524732A - Treatment of glyceride oils - Google Patents

Description

or settle to the bottom of the container.

Patented Oct. 3, 1 950 UNITED STATES PATENT OFFICE TREATMENT OF GLYCERIDE OILS Karl F. Mattil, Chicago, 111., assignor to Swift & Company, Chicago, 111., a corporation of Illinois N Drawing.

Application April 18, 1947,

Serial No. 742,451

15 Claims.

often cause the oil to become cloudy. Depending upon the temperatures, the higher melting fraction, including the glycerides of stearic acid, tend to separate from the oil and cause turbidity Both the cloudiness and the deposition of the higher melting glycerides: detract from the value of a salad oil. A desirable salad oil is one which will remain liquid and clear and homogeneous throughout at the lower limits of the range of ordinary room temperatures and in the range of temperatures involved in shipping and storing the oil and prevailing at different seasons of the year. Such an oil will also exhibit good stability when it is a phase of an emulsion, as in mayonnaise. An emulsion formed with such an oil will not break so readily as is the case when an oil characterized by crystalline formation at higher temperatures is employed.

In order to measure the ability of an oil to withstand crystallization, or the deposition of solid fats, there has been developed the cold test, which is defined as the length of time a given amount of oil may stand in an ice water bath without deposition of the solid fat constituents. Thus a long cold test oil in contrast to one having a shorter cold test will remain clear longer under refrigeration and, in additionfproduce a more stablev mayonnaise type emulsion. Mayonnaise made with a long cold test oil may be stored at lower temperatures without breaking the emulsion than one made with a short cold test oil. Such rupture of emulsion is caused by crystallization of the emulsified oil.

Of the various vegetable oils, such as olive oil, cottonseed oil, corn oil, and soybean oil, cottonseed oil shows the greatest tendency to solidify and deposit stearine, at higher temperatures.

One way to prolong a cold test of an oil is to winterizeit, that is, by subjecting it to low temperatures whereby through fractional crystallization the higher melting constituents of the oil arecrystallized and the resulting solid matter may be removed from the oil. By repeating the process and employing progressively lower temperatures, oils of longer cold tests may be obtained. However, the process of Winterizing is often unsuccessful and very costly. The:

2 process comprises forming the crystals into firm and filterable crystals, 9, step which requires great caution and care and long periods of time; and a subsequent filtering or straining of'solid matter, which is a slow and different process. Therefore, in order to obviate the necessity of repeated winterizations to obtain an oil 01 olesired cold test, it has hitherto been found ad vantageous to add to a winterizedoil a crystal-,

lization inhibitor, which retards the formation of crystals. A known crystallization inhibitor is lecithin, small amounts of which added toan oil before or after winterization prolong the cold test thereof.

I have now discovered that certain crystal insuch as mayonnaise, imparts a far superior s'tability thereto than has heretofore been "ob-- tained by the use of similarly treated oils with other crystal inhibitors. The crystal inhibiting and modifying agents may be added before or after winterization. I

In Winterizing a vegetable oil, the conditioning of the oil to effectuate separation of the liquid fats, which are more suitably. used as salad oil, from the undesirable solid fats must be carefully controlled in order to obtain the solid fat in a crystalline form suitable for filtration. Under the best conditions, filtration is inefficient, for the solid fats often separate as extremely small particles and remain suspended in the oil as colloidal dispersions, thus making the straining operation very diificult. I have found that I can overcome the difficulties attending the process of Winterizing as hitherto practicedfby the incorporation into the vegetable oil of a small amount of the crystal inhibitors and modifiers, hereinafter described. I have found that the addition of such substance profoundly affects crystallization, whereby the crystals of the solid fat are rendered firmer and better defined. The form of the crystals is so improved that a more facile and complete separation of the undesirable solids from the liquid constituents of the oil is effected. This apparent incongruity is believed to be due to the prevention of colloidal suspensions. In addition, to improving winterization, these substances are usuallypresent in sufficient amounts to lengthen substantially the cold test of the-oil, although this effect is not so pronounced as that which results when the to the 1 oil crystal inhibitor is added after the oil has been winterized.

Broadly, the invention contemplates the addition to the oil, before and/or after winterization, of small amounts of a class of substances comprising the condensation products of high molecular Weight aliphatic compounds, such as paraffin wax, and aromatic hydrocarbons, such as naphthalene, prepared in accordance with the Friedel-Crafts synthesis employing aluminum chloride as a catalyst. While the Friedel-Crafts reaction is preferred in the preparation of materials contemplated by the present invention, I may employ other reactions which yield products corresponding to the aforesaid materials prepared by the Friedel-Crafts reaction. For example, the products of the present invention may be obtained by condensing a halogenated high molecular weight aliphatic hydrocarbon, such as chloroparaffin, and a halogenated aro matic hydrocarbon, such as monochloro naphthalene, in the presence of sodium catalyst.

The crystal inhibiting and modifying agents contemplated by the present invention are:

1. A parafiin-alkylated aromatic compound, such as tetra-paraffin naphthalene.

2. The resinified derivatives of the paraffinalkylated aromatic compounds.

3. The acylated derivatives of any of the above materials.

The greatest effect of prolonging the cold test of a vegetable oil is observed when the abovementioned materials are added to the oil after winterization. Examples of vegetable oils are those suitable for salad oil manufacture, such as corn oil, olive oil, cottonseed oil, and soybean oil.

In accordance with this invention, the aromatic compounds that may be used are benzene, diphenyl,

naphthalene, anthracene, phenanthrene, fluorene, toluene, and xylene, naphthalene being preferred.

The high molecular weight aliphatic compounds which have been found useful in practicing the present invention are those that characterize certain high molecular weight aliphatic hydrocarbons. These compounds usually consist of more than carbon atoms in the molecule and have molecular weights of more than 250. This invention is concerned with the halogenated derivatives of compounds such as paraffin, ceresin, ozocerite, petrolatum, and similar hydrocarbons of a waxy nature. Particularly useful is crystalline paraffin of a melting point greater than 120 F. and of about 130 F. stood that high molecular weight ester waxes of animal or vegetable nature may also be employed in place of the hydrocarbon waxes. Such suitable ester waxes are, for example, montan, carnauba, candelilla, and spermaceti.

Preparation of the parafiin-alkylated aromatic compounds In order to prepare the alkyl halide for the Friedel-Crafts synthesis, the aliphatic compound is first chlorinated by any suitable means. The chlorinatedcompound, for example, may be obtained by melting parafiin wax of a melting point of about 130 heating the molten wax to an elevated temperature of about 200 F., then bubbling gaseous chlorine through the liquid mass until the hydrocarbon has combined with about 14 per cent chlorine.

In preparing the heavy alkyl-substituted aromatic compound through the Friedel-Crafts re- It is under- 1 action, as for example, between naphthalene and chlorparafiin, the proportion of reactants are so selected as to produce a triparaflin or tetraparaifin-substituted naphthalene, the tetraparafiinsubstituted compound being preferred. In order to obtain this compound, for every equivalent of naphthalene employed, three, and preferably four, equivalents of chlorine as represented by the chlorparaffin, are employed. The chlorparaffin and naphthalene in the proper proportion are melted together and then heated to a temperature of about 150 F., after which about 3 per cent of anhydrous aluminum chloride, based on the chlorparaffin, is added a little at a time and with constant agitation to the molten mixture and then the reaction mixture is slowly heated to a temperature of about 350 F., a heating time of about 2 hours being satisfactory. If evolution of gas has not ceased by the time a temperature of 350 F. is reached, the mixture is held at this temperature until all evolution of gas has ceased. Usually at this stage of the reaction an aluminum chloride sludge will begin to settle quite rapidly to the bottom of the reaction vessel and a translucent solution layer appears above the sludge. After completion of the reaction the parafiin-alkylated aromatic compound is purified in any suitable manner, as for example, by drawing ofi the liquid layer, then washing several times with warm water to rid it of any residual hydrochloric acid, and then distilling.

Preparation of the resinified derivatives of parajfin-alkylated compounds In preparing the resinified aromatic hydrocarbon prior to condensing it with the chlorinated paraffin, various resinifying agents may be employed, such as certain aldehydes, and sulfur-containing resinifying agents, for example, elementary sulfur, and sulfur chloride. As the resinifying agent, I prefer to use formaldehyde or its derivatives, such as trioxymethylene. Examples of other suitable aldehydes are acetaldehyde and butyraldehyde.

The reaction between an aldehyde, such as formaldehyde, and an aromatic hydrocarbon, such as naphthalene, occurs readily in an acid medium. For example, the reaction between about 1 mole of naphthalene and /2 mole of formaldehyde in the presence of about cc. of glacial acetic acid solvent and 30 cc. of concentrated sulfuric acid catalyst at about 50 C. is usually completed in about 1 hour. Following the resinification reaction, the mixture may be taken up in a solvent, such as benzene, washed with an alkaline solution to neutralize the acid, and the resin then further purified by vacuum distillation to remove the solvent and unreacted products. The resulting resin is light in color and becomes soft on warming.

The condensation reaction between the resin and the chlorinated paraffin, prepared as described above, is carried out in about the same manner as the condensation of the aromatic compound and the chloroparafiin. That is, the chloroparaflin is melted, the resinified aromatic compound is mixed therewith, aluminum chloride is added, and the mixture heated to a maximum of 350 F. If diificulty is encountered in mixin the resin with'the parafiin, a solution of resin in a suitable solvent, such as ethylene dichloride, may advantageously be employed. In this case, the addition of aluminum chloride takes place at the boiling temperature of the solvent, after which the solvent is distilled off and the ele- 'vat'ed temperature 'of'about 350 F. is reached. When the reaction between the resin and chloroparafiin is complete, usuallyafter one hour, the final product is isolated in theusual manner of purifying Friedel-Crafts reactionproducts. The liquid layer is decanted, dissolved in any suitable solvent, such as ether, to aid in the subsequent washing operations; the solvent is then distilled off, and the compound further purified by disdillation, such as by vacuum distillation at mm. and at a temperature of about 350 C.

Alternatively, the resiniiied derivatives may be prepared by first alkylating the aromatic hydrocarbon to produce the wax-substituted aromatic compound, and then resinifying the resulting product, as above described. When resinifying the arafim-alkylated aromatic compound it is often advantageous to employ a greater quantity of formaldehyde than is the case when the arcmatic compound is first resi'nified and then alkylated, a ratio of 1 mole of formaldehyde to 1"mole of the wax-substituted aromatic hydrocarbon being satisfactory.

Preparation of the acylated derivatives of the parajfin-alkylated and the resim'fied aromatic compounds As acylating agents a wide number of acid chlorides or anhydrides are suitable. The following are suitable organic acylating agents: the monobasic saturated aliphatic acids from acetic acid up to and including montanic acid; monobasic unsaturated aliphatic acids, such as acrylic; aliphatic saturated and unsaturated polybasic acids, such as oxalic and fumaric acid, respectively; substituted aliphatic mono and polybasic acids, the substituent groups being halogen, amino, or hydroxyl groups; aromatic mono and polybasic acids, such as benzo'ic and phthalic, respectively; alkene-substituted aromatic monobasicacids, such as cinnamic; substituted mono and polybasic aromatic acids, such, as chlorobenzoic, salicylic, to'luic, etc. aryl-substituted mono and polybasic aliphatic acids with the carboxyl group occurring in the aliphatic portion of the molecule; heterocyclic acids, such as furoic; alicyclic acids, such as abietic. In general, I prefer a dibasic acid acylating agent, such as ,ph'thalic anhydride.

In the acylating operation, the acid halide or anhydrlde is preferably added after the Friedel- Crafts reaction between the chlorinated aliphatic hydrocarbon and the aromatic or resinified aromatic compound is complete, that is, when all evolution of gas at a temperature of around 350 F. has ceased. The mixture is thencooled to a point below 350 F. but above 100 F. The acylation reaction proceeds rapidly and is complete upon cessation of all evolution of gas. The acylated parafiinea'lkylated product may then be purified in a similar manner in which, for example, the paraffin-alkylated aromatic compound is isolated by drawing off the liquid layer, washing the layer extensively with water and subsequently distilling.

Effective amounts of my crystal modifiers range from 0.005 to 0.2 per cent. 'In case it is desired to add the crystal modifier prior to the winterizing operation to modify the stearine crystals, and thereby facilitate the filtration thereof, it is often advantageous to add additional small amounts, of a degree near the lower limit of the range, of the crystal modifier to the filtrate to allow for that which was removed with the solid matter upon filtration.

. 6 The following examples illustrate how the invention may be practiced and are not intended to be limiting 0n the scope thereof:

Example I To a sample of winterized cottonseed oil having a cold test of 4. hours there was added 0.2 per cent of a high molecular weight parafiinalkylated naphthalene compound prepared as hereinabove described. The cold test of the treated oil was 15 hours.

Example 11 To a blend of winterized cottonseed oil and cottonseed oil having a cold test of 7 hours there was added 0.02 per cent of a wax-substituted naphthalene which had been acylated with phthalyl chloride. The cold test run on the mixture was 32 hours.

Example III To a salad oil having a cold test of 8 hours there was added 0.2 per cent of a crystal inhibiting agent obtained by resinifying a wax-substituted naphthalene, as hereinabove described. The cold test of the oil was increased to 36 hours.

'Eccample V To '7 pounds of refined cottonseed oil there was added 0.2 per cent of a triand tetra-wax substltuted naphthalene subsequently acylated with phthalic chloride. This mixture together with a control sample of untreated refined cottonseed oil were placed in a cooler at 42 F. to 43 F. Although crystals appeared sooner in the control sample, on standing three days the crystals in the sample containing the additive settled to the bottom while crystals in the untreated control sample remained dispersed throughout the oil. Filtration by gravity of the treated sample was completed in about an hour and a half, while the control sample was completely filtered only after the filtration was allowed to continue overnight. The yield on the control sample was 62 per cent, and 93 per cent on the treated sample.

Example VI Mayonnaise made with salad oil containing 0.04 per cent of the phthalyl acylated wax-substituted naphthalene stood up about '7 days at 28 F., and about 2 days at 24 F. The same type of mayonnaise made with oil which had not been treated with the additive broke in less than one day at 24 F. and less than 3 days at 28 F.

As hereinbefore mentioned, the above described crystal inhibitors and modifiers may be added to the vegetable oil before or after winterization. The addition of the crystal modifier before winterization, serves primarily to facilitate and him prove the Winterizing operation. Although crystal formation is retarded in th presence of the additive, once the crystals are formed they are of such form as to settle quickly, and because of the nature of the crystals 'a sharp separation of the undesired solids from the liquid constitucuts of the oil is possible. An advantage of the improved filtering operation is that the yields of salad oil are greatly increased over the winterizing process as hitherto practiced. Often it is desirable to add an additional small amount of the additive after the winterization operation so as to replace that which was filtered out along with the high-melting glyceride crystals.

In case it is desired to have a salad oil of very long cold test, the materials described above are added to the oil after it has been winterized, the extent of lengthening the cold test depending on the quality of oil chosen, the additive being more effective in an oil having an original longer cold test than in an oil of shorter cold test.

The materials of the present invention are also effective in producing oils of exceptionally long cold test when used in a double winterization proc- This process involves a preliminary chilling operation to separate a preliminary stearine fraction, and then a second chilling step to separate additional stearine. For example, the oil may be first cooled to about 45 F., the stearine separated, and then the oil further cooled to about 30 F. for the removal of more stearine. I have found that the foregoing operations may be improved by the addition of a small amount of the herein-described crystal modifying agents to the oil in only one of the chilling steps or in both.

Another important advantage of the invention fiows from the use of oil treated with the de scribed agents in emulsions. An emulsion, such as mayonnaise, containing such an oil will remain stable for much longer periods of time than has been hitherto possible to maintain such emulsions.

While I have described the invention as having particular application to the manufacture of salad oils, the invention is not limited to such an operation. It is contemplated that the invention may be useful in treating various fatty oils wherein a solid or crystalline fraction is separated from a liquid fraction as in the separation of a crystalline fraction from animal oils, such as oleo oil, greases and sperm oil. In treating various vegetable and animal oils it is often desirable to separate a solid fraction such as stearine, palmitin, spermaceti and other highmelting point fractions by crystallizing' such fraction with or without the presence of a solvent and then separating the crystallized fraction by cold settling, pressing, centrifuging or filtration. The crystal modifying agents herein described may be used to modify the crystal structure of the solid phase whereby it may be more readily separated from the liquid phase.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A vegetable oil composition of improved cold test comprising: a vegetable oil having incorporated therein in an amount between approximately 0.005 and 0.2 percent of an improving agent comprising a phthalyl acylated tetraparaffin alkylated naphthalene condensation product, said paraffin melting between approximately 120 F. and 130 F. and being combined with naphthalene in such proportions that four hydrogen atoms of the naphthalene molecule are replaced by the alkyl radical of the parafiin and said agent being acylated with phthalyl chloride.

2. A method of improving the cold test of a vegetable oil which comprises: admixing with a vegetable oil between approximately 0.005 and 0.2 percent of an improving agent comprising a phthalyl acylated tetra-paraffin alkylated naphthalene, said condensation product parafiin melting between approximately F. and F. and being combined with naphthalene in such proportions that four hydrogen atoms of the naphthalene molecule are replaced by the alkyl radical of the paraffin and said agent being acylated with phthalyl chloride; whereby the cold test of the said oil is substantially prolonged.

3. An improved vegetable oil composition comprising a vegetable oil having incorporated therein as an improving agent a small amount of an oil-soluble condensation product comprising a high molecular weight alkyl substituted naphthalene, said naphthalene having as the alkyl substituent for at least 3 hydrogen atoms thereof a high molecular weight aliphatic hydrocarbon radical having a chain length of approximately 20 carbon atoms.

4. An improved vegetable oil composition substantially as described in claim 3 wherein the improving agent is acylated with an aromatic acylating agent.

5. An improved vegetable oil composition substantially as described in claim 3 wherein the improving agent is acylated with phthalyl chloride.

6. An improved vegetable oil composition substantially as described in claim 3 wherein the improving agent is acylated with an aliphatic acylating agent.

'7. An improved vegetable oil composition substantially as described in claim 3 wherein the aliphatic hydrocarbon is obtained from paraffin having a melting point between about 120 F. and 130 F.

8. A vegetable oil composition of improved cold test substantially as described in claim 3 wherein the naphthalene molecule is condensed in the presence of an aromatic hydrocarbon resinifying agent to form an oil-soluble resinous product.

9. An improved vegetable oil composition substantially as described in claim 3 wherein the improving agent is present in an amount between about 0.005 and 0.20 per cent by weight.

10. A glyceride oil composition of improved cold test comprising a glyceride oil having incorporated therein as an improving agent a small amount of a high molecular weight aliphatic hydrocarbon alkylated naphthalene, said aliphatic hydrocarbon having approximately 20 carbon atoms per molecule and being combined with said naphthalene in such proportions that at least 3 hydrogen atoms of the naphthalene molecule are replaced by the alkyl radical of the aliphatic hydrocarbon, whereby the cold test of the said oil is prolonged.

11. A method of obtaining a glyceride oil of improved cold test which comprises admixing with a glyceride oil containing stearin a small amount of an improving agent comprising a high molecular weight aliphatic hydrocarbon alkylated naphthalene, said aliphatic hydrocarbon having approximately 20 carbon atoms per molecule and being combined with said naphthalene in such proportions that at least 3 hydrogen atoms of the naphthalene molecule are replaced by the alkyl radical of the aliphatic hydrocarbon, whereby the cold test of the said oil is prolonged.

12. An improved method of separating a glyceride fatty material into higher and lower melting point constituents which comprises dispersing throughout a liquefied glyceride fatty material a small amount of a high molecular weight aliphatic hydrocarbon alkylated naphthalene, said aliphatic hydrocarbon having approximately 20 carbon atoms per molecule and being combined with the said naphthalene in such proportions that at least 3 hydrogen atoms of .the naphthalene molecule are replaced by the alkyl radical of the aliphatic hydrocarbon, cooling the said oil to crystallize the higher melting point constituents, and then separating the said constituents from the lower melting point components, the

crystals of said higher melting point components formed on cooling being firmer and better defined to facilitate separation from the said oil.

13. A glyceride oil composition of improved cold test comprising a glyceride oil having incorporated therein a small amount of a condensation product comprising an aromatic hydrocarbon of not more than 3 benzene rings per molecule having high molecular weight aliphatic hydrocarbon substituents therein, said aliphatic hydrocarbon having approximately 20 carbon atoms per molecule and being combined with the said aromatic hydrocarbon in such proportions that at least 3 hydrogen atoms oi the said aromatic hydrocarbon molecule are replaced by the alkyl radical of the aliphatic hydrocarbon.

14. A method of improving the cold test of a glyceride oil which comprises admixing with a glyceride oil containing stearin a small amount of condensation product comprising an aromatic hydrocarbon of not more than 3 benzene rings per molecule having high molecular weight aliphatic hydrocarbon substituents therein, said aliphatic hydrocarbon having approximately 20 carbon atoms per molecule and being combined with the said aromatic hydrocarbon in such proportions that at least 3 hydrogen atoms of the said aromatic hydrocarbon molecule are replaced by the alkyl radical of the aliphatic hydrocarbon.

15. An improved method of separating a glyc eride fatty material into higher and lower melting point constituents, which comprises dispersing throughout a liquefied glyceride fatty material a small amountrof a condensation product 'and then separating the said constituents from the lower melting point components, the crystals of said higher melting point components formed on cooling being firmer and better defined to facilitate separation from the said oil.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,147,547 Rein" et al Feb. 14, 1939 2,377,610 Brown June 5, 1945 2,393,744 Brown Jan. 29, 1946 2,418,668 Royce Apr. 8, 1947 Certificate of Correction October 3,1950

the

Patent No. 2,524,732

KARL F. MATT d specification of eby certified that error appears in red patent reqmrlng correction as iollovvs.

2, line 5, for the Word ifierent read difficult;

comma and Word said and insert the same after It is her above numbe Column column 8, line 4:, strike out the product, same line;

and that the sin same may conform Signed and sealed thls 12th day 0 so that the [SEAL] F. MU PHY,

THOMAS Commissioner of Patents.

Assistant

Claims (1)

1. A VEGETABLE OIL COMPOSITION OF IMPROVED COLD TEST COMPRISING: A VEGETABLE OIL HAVING INCORPORATED THEREIN IN AN AMOUNT BETWEEN APPROXIMATELY 0.005 AND 0.2 PERCENT OF AN IMPROVING AGENT COMPRISING A PHTHALYL ACCYLATED TETRAPARAFFIN ALKYLATED NAPHTHALENE CONDENSATION PRODUCT, SAID PARAFFIN MELTING BETWEEN APPROXIMATELY 120*F. AND 130*F. AND BEING COMBINED WITH NAPHTHALENE IN SUCH PROPORTIONS THAT FOUR HYDROGEN ATOMS OF THE NAPTHALENE MOLECULE ARE REPLACED BY THE ALKYL RADICAL OF THE PARAFFIN AND SAID AGENT BEING ACYLATED WITH PHTHALYL CHOLORIDE.