US2518917A - Treatment of glyceride oils - Google Patents

Description

- UNITED STAT Patented Aug. 15, 1,950

TREATMENT or enrcsams OILS Karl F. Matti], Chicago Ill.,assignor to Swift &

Company, Chicago, I a corporation of Illinois No Drawing.

Application October 22, 1945, Serial No. 623,861 I 15 Claims. (on. zoo-398. 5)

This'inve'ntion relates to treating fatty material and it'has to do more particularly with the manufacture of an improved salad oil.

In the preparation of salad oils, an important problem is the removal of those glycerides which are normally solid at room temperatures and 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 or settle to the bottom of the container. 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 rangeof 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 addition, produce a more stable mayonnaise type emulsion. Mayonnaise made with a long cold test oilmay 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, cotton seed oil shows the greatest tendency to solidify and deposit stearin at higher temperatures.

Early in the manufacture of cottonseed oil. it was found that cottonseed oil allowed to remain in the cold during the winter would separate into two fractions, a top liquid layer and a bottom solid fraction. The top liquid fraction was found to have a greater degree of stability against cloudiness and stearindeposition when artificially cooled than oil which had not been so winterized.

One way to prolong a cold test of an oil is to winterize it, that is, by subjecting it to low temperatures whereby through fractional crystallization thehigher melting constituents of the oil are crystallized and the resulting solid matter 7 may be removed from the oil. By repeating the peratures, oils of longer cold tests may be obtairied. However, the process of Winterizing is often unsuccessfuland very costly. The process comprises forming the crystals, into firm and filterable crystals, a 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 difficult process. Therefore, in order to obviate the necessity of repeated winterizationsto obtain an oil of desired cold test, it has hitherto been found advantageous to add to a winterized oil a crystallization inhibitor, which retards the formation of crystals. A known crystallization inhibitor is lecithin, small amounts of which added to an oil before or after winterization prolong the cold test thereof.

I have now discovered that certain crystal inhibiting and modifying agents, hereinafter to be described, are far superior in prolonging the cold test of salad oils than any hitherto employed. Moreover, the use of an oil treated with these agents in the manufacture of emulsions, such as mayonnaise, imparts a far superior stability thereto than has heretofore been obtained by the use of similarly treated oils with other crystal inhibitors. The crystal inhibiting and modifying agents may be added to the oil before or after winterization.

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 fatsmust be carein 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 difficult. I have found that I can overcome the difiiculties attending the process of Winterizing as hitherto practiced, by 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 believedfi inhibitor is added after the oil has been winter ized.

process and employing progressively lower tem- Broadly, the invention contemplates the addition to the oil, before or after winterization, of

small amounts of a class of substances comprising aluminum chloride condensation products of high molecular weight aliphatic compounds, such as paraffin wax, and hydroxyaromatic coming and modifying agents I have reference to are:

0. The product obtained as a result of the con-- densation reaction between a resinified hypounds, such as phenol. The crystalline inhibitdroxyaromatic compound and chlorinated paranln.

The greatest effect of prolonging the cold test of a vegetable oil is observed when the abovementioned materials are added to the 011 after winterization. Examples of vegetable oils are.

wherein R. is a radical chosen from a group consisting of hydrogen, hydroxy, alkyl, aryl, alkaryl, alkoxy, and aroxy radicals. Preferably those compounds in which R is hydrogen or the hydroxyl group and which are represented by the single ring formula I are preferred. Accordingly,

the preferred specific compound is phenol. As examples of other specific compounds which may be mentioned, are catechol, resorcinol, B-naphthol, benzyl phenol, p-cresol, hydroquinone, xylenol, phenyl ethyl phenol, methyl hydroxydiphenyl, ethyl hydroxyd'iphenyl, guaiacol, the monoethyl ether of catechol, methyl naphthol, tolyl naphthol, xylyl naphthol, benzyl naphthol, methoxyhydroxy naphthalene, anthranol, phenyl methyl anthranol, phenanthrol and the like.

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 chlorine derivatives of compounds such as ceresin, ozocerite, paraffin wax, heavy parafiln oils, 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.

- 4 l 'reparatton o] the paramn-alkulated hydrostaromatic commands In order to prepare the alkyl halide for the Freidel-Crafts synthesis, the aliphatic compound is first chlorinated by any suitable means. The chlorinated compound, for example, may be obtained by melting parailln wax of a melting point of about F., 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% chlorine.

In preparing the heavy alkyl-substituted hydroxyaromatic compound through the Friedel- Crafts reaction, as for example, between phenol and chlorparaflln, the proportion of reactants are so selected as to produce a triparafljln or tetraparaflln-substituted phenol, the tetraparaf- --fin-substituted compound being preferred. In

order to obtain this compound, for every equivalent of phenol employed, three, and preferably four, equivalents of chlorine as represented by the chlorparaffln, are employed. The chlorparaffln and phenol in the proper proportion are melted together and then heated to a temperature of about F., after which about 3% of anhydrous aluminum chloride, based on the chlorparaflln, 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 two 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 paramn-alkylated hydroxyaromatic compound is purified in any suitable manner, as for example, by drawing 08 the liquid layer, than washing several times with warm water to rid it of any residual hydrochloric acid, and then distilling.

Preparation of the ester of a parajfin-alkylated hydrozyaroma tic compound As hereinbefore mentioned, ester derivatives of the paraffln alkylated hydroxyaromatic com--v pounds are suitable crystal inhibitors and modiflers. As esterifying or 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 a 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 benzoic and phthalic, respectively; alkene-substituted aromatic monobasic acids such as cinnamic; substituted mono and polybasic aromatic acids, such as chlorobenzoic, salicyclic, toluic, 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, such as phthalic, as the esterifying acid.

In the acylating operation, the acid halide or anhydride is-added after the Friedel-Crafts reaction is'completed, that is, when all evolution of gas at a temperature of around 350 F. has

ceased. The mixture-is then cooled to a point below 350 F. but above 100 F- The esterifi- .ing, off the liquid layer, washing this layer extensively with water, and subsequently distilling.

Preparation of the condensation product between a resinified hydroxyaromatic compound and chlorinated paraflin i In the preparation of the resinified hydroxyaromatic compound prior to condensing it with the chlorinated paraifin by means of the Friedel- Crafts reaction, suitable resinifying agents are halogenated organic compounds, halogenated aralkyl or aryl hydrocarbons, as for example, benzyl chloride and chloronaphthalene; aldehydes, which eliminate water in the reaction with the hydroxyaromatic' compound, such as formaldehyde; alcohols, ketones, and polyhydric compounds such as butyl alcohol, acetone and glycol, which also eliminate water in the reaction; elementary sulfur and sulfur compounds, such as sulfur monochloride, with the elimination of hydrogen sulfide. In'general, preference is for the aldehyde type of resinifying agent.

The, reaction between an aldehyde and a hydroxyaromatic compound readily occurs in an acid or basic medium. For example, the reaction between butyraldehyde and phenol readily takes place at a temperature of about 212 F. inthe presence of about 1 per cent hydrochloric acid catalyst, the proportion of the reactants'being /2 mole of the aldehyde to -1 mole of phenol. After completion of the resinification reaction, the resin may be purified by subjecting it to a vacuum distillation to remove unreacted products.

In preparin the hydroxyaromatic-sulfur resin either elementary sulfur or a compound thereof,

such as sulfur monochloride is suitable. The reaction between sulfur monochloride and the hydroxyaromatic compound occurs readily, and no ,catalyst is necessary. Since the solubility of the sulfur resin depends on the degree of combined sulfur, that is, the greater the sulfur content the less the solubility, the most suitable hydroxyaromatic-sulfur resin is one that has not more than one atomic weight of sulfur combined with each mole of hydroxyaromatic compound.

While the foregoing describes the preparation of the resin by reacting a hydroxyaromatic compound with a suitable resinifying agent, I may also prepare the resin through the reaction of anoxyaromatic compound with a suitable resini- 'oxyaromatic compound and an aldehyde, such as formaldehyde, may be accelerated by employing a higher concentration of an acid catalyst, concentrated sulfuric acid being preferred. Often is is desirable to use a solvent for the mixture. A suitable solvent is glacial acetic acid.

In preparing the oxyaromatic-aldehyde resin, anisole, acetic acid, and trioxymethylene are mixed together. For every mole of anisole, 10.8 g. of trioxymethylene, and 1 /2 mole of glacial acetic acid are employed. To this mixture about 43 cc. of concentrated sulfuric acid are added slowl with cooling, so that the reaction temperat e is maintained below 50 C. After the addition of all the sufuric acid, the mixture is stirredfor about 2 hours at 50' C. The resin is then purified by washing with water, dissolving in a suitable solvent such as benzene, washing with alkali to rid the product of all acid, distilling off the solvent, and further purifying by vacuum distillation.

The condensation reaction between the resin and the chlorinated paraflin is carried out in about the same manner as is employed in condensing the unresinified hydroxyaromatic compound with thechlorparaflin, that is, the chlorparaflin, is melted, the resinified hydroxyaromatic compound or oxyaromatic compound is mixed therewith, aluminum chloride is' added, and the mixture heated to a maximum of 350 F. If difliculty is encountered in mixing the resin with the paraffin, a solution of resin in a suitable solvent, such as ethylene dichloride, may be advantageously 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 elevated temperature of 350 F. is reached. When the reaction between the resin and ohlorparaffln is completed, usually after one hour, the final product is isolated in the usual manner of purifying Friedel-Crafts reaction products. 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 furthcrpurified by distillation, such as by vacuum distillation at 5 mm. and at a temperature of about 350 C.

Effective amounts of my crystal modifiers range from .005 to 0.2 per cent. In case it is desired to add the crystal modifier prior to the winterizin; operation to modify the stearine crystals, and thereby facilitate the filtration thereof, it

is often advantageous to add additional small Grams Chlorparafnn 1,000.0 Phenol 92.5 Aluminum chloride 30.0

Then grams of tetraparafiin phenol were reacted with 10.1 grams of phthalyl chloride for 15 minutes at a temperature of between F. to 350 F. to give the high molecular weight alkyl phenyl V phthalate.

. Example I To 100 grams of winterized cottonseed oil having a cold test of 4 /2 hours there was added 0.03 gram of the compound described above. A cold test run on the salad oil mixed with the crystal inhibitor gave a value of 43 hours. To a sample of the same batch of winterized cottonseed oil, 0.1 per cent of lecithin gave a cold test of 9 /2 .hours.

Example II To a blend of winterized cotton seed oil and cottonseed oil having a cold test of 7 hours there was added 0.02 per cent of the acylated tetra-, paraflin alkylated phenol prepared as described above. The cold test run on the mixture was 46 hours.

Example 111 Example IV To a cotton seed oil having a cold test of 36 hours; addition of 0.02 per cent of the phthalyl chloride acylated paraflin-substituted phenol srystal inhibitor lengthened the cold test to 265 hours.

Example V To 7 pounds of refined cottonseed oil was added 0.2 per cent of the crystal modifying agent used in the previous examples. This mixture and a control sample of refined cottonseed oil to which no crystal growth modifier was added were placed in a cooler at 42 to 43 F. Although crystals appeared sooner in the control sample, on standing 3 days the crystals in the sample containing the additive settled to the bottom while crystals in the control sample remained dispersed throughout the oil. Filtration by gravity in the sample containing the additive was completed in little over an hour, whereas the control sample was sompletely filtered only after allowedto continue over night. The yield on the control sample was 62 per cent; on the treated sample, 97 per cent.

Emample VI Mayonnaise made with salad oil containing 0.02 per cent of the above compound stood up more than '7 days at 28 F., and nearly 3 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 improve the winterizing operation. Although crys-' tal formation is retarded in the 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 constituents of the oil is possible. An advantage of the improved filtering operation is that the yields of salad oil are greatly increased over the winter- 0.2 per cent of the material added to izing process as hitherto practiced. Often it is desirable to add an adidtional 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 igntger cold test than in an oil of shorter cold Another important advantage of the invention flows from the use of oil treated with the described agents in emulsions. An emulsion, such as mayonnaise, containing such an oil will remain stable for much longer periods of time than has bieen hitherto possible to maintain such emuls ons.

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 stearin, 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 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 to prolong the cold test thereof a small amount of an improving agent having a hydroxyaromatic compound containing not more than 3 benzene rings condensed with a high molecular weight aliphatic hydrocarbon having at least 20 carbon atoms per molecule, the said condensation product having at least three hydrogen atoms of the hydroxyaromatic compound replaced with alkyl radicals of the aliphatic hydrovcarbon and being soluble in said oil.

2. A vegetable oil composition of improved cold test comprising a vegetable oil containing stearin having incorporated therein to prolong the cold test thereof a small amount of an improving agent having a hydroxyaromatic compound containing from one to three benzene rings per molecule separately condensed with an aliphatic hydrocarbon containing at least 20 carbon atoms per molecule and reacted with a hydroxyaromatic re-, sinifying agent which condenses with the said hydroxyaromatic compound to form a resinous product soluble in said oil.

3. A vegetable oil composition of improvedcold test comprising a vegetable oil' having incorporated therein to prolong the cold test thereof a small amount of an improvin a ent having a hydroxyaromatic compound containing not more than 3 benzene rings condensed with a high molecular weight aliphatic hydrocarbon having at least 20 carbon atoms per molecule and at least 3 hydrogen atoms of the hydroxyaromatic compound being replaced with alkyl radicals of the said aliphatic hydrocarbon and which has been acylated, said improving agent being soluble in said oil and prolonging the cold test of the said oil.

4. A composition or matter substantially as described in claim 3, wherein the acylating agent is an aliphatic acylating substance.

5. A composition of matter substantially described in claim 3, wherein the acylating agent is an aromatic acylating substance.

6. A composition of matter substantially as described. in claim 3, wherein the acylating agent is phthalyl chloride.

'7. A composition of matter substantially as described in claim 6, wherein the aliphatic hydrocarbon is chlorinated paraflin of a melting point between about 120 F. and 130 F.

8. A composition of matter substantially as described in claim '7, wherein the improving agent is present in an amount between about 0.005 and 0.20 per cent by weight.

9. A glyceride oil composition of improved cold test, comprising a glyceride oil having incorporated therein to prolong the cold test thereof a small amount of an improving agent having a hydroxyaromatic compound containing not more than 3 benzene rings with relatively high molecular weight aliphatic hydrocarbons having at least 20 carbon atoms per molecule as substituents therein, the said improving agent having at least three hydrogen atoms oi the hydroxyaromatic compound replaced with alkyl radicals or the aliphatic hydrocarbons and being soluble in said oil.

a 10. As a composition of matter, a glyceride oil having admixed therewith to prolong the cold test thereof a small amount of tetraparaflin alkylated phenol.

11. As a composition of matter, a glyceride oil having admixed therewith to prolong the cold test thereof a small amount of phthalyl chloride acylated tetraparaflln-substituted phenol.

12. As a composition of matter a glyceride oil having admixed therewith to prolong the cold test thereof a small amount oi. phenolformaldehyde resin with a high molecular weight aliphasoluble in said oil.

13. The method of improving the cold test of a glyceride oil which comprises admixing with the glyceride oil containing stearin a small amount of a crystal modifying material having a hydroxyaromatic compound containing not more than 3 benzene rings with high molecular weight aliphatic hydrocarbons having at least 20 carbon atoms per molecule as substituents therein, the said material having at least 3 hydrogen atoms of the hydroxyaromatic compound replaced with alkyl radicals of the said hydrocarbons and being soluble in said oil.

14. The method of separating a glyceride oil into higher and lower melting point components which comprises forming a solution of the glyceride oil and a small amount or a hydroxyaromatic compound containing not more than 3 benzene rings having as substituents therein high molecular weight aliphatic hydrocarbons having at least 20 carbon atoms per molecule in such proportions that at least 3 hydrogen atoms of the said hydroxyaromatic compound are replaced with alkyl groups of said aliphatic hydrocarbons and having the said hydroxyaromatic compound acylated, cooling the said solution to crystallize the higher melting point components, and then separating the said components 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.

15. A method as described in claim 14 wherein the hydroxyaromatic compound is acylated with phthalyl chloride.

KARL F. MATTIL.

REFERENCES crrun The following references are of record in the file 01' this patent:

UNITED STATES PATENTS Number Name Date 2,115,040 Nitardy Apr. 26, 1938 2,131,904 Salzburg Oct. 4, 1938 2,138,809 Reifi ,et a1 Nov. 29, 1938 2,282,810 Musher May 12, 1942 2,377,610 Brown June 5, 1945

Claims (1)

1. 9. A GLYCERIDE OIL COMPOSITION OF IMPROVED COLD TEST, COMPRISING A GLYCERIDE OIL HAVING INCORPORATED THEREIN TO PROLONG THE COLD TEST THEREOF A SMALL AMOUNT OF AN IMPROVING AGENT HAVING A HYDROXYAROMATIC COMPOUND CONTAINING NOT MORE THAN 3 BENZENE RINGS WITH RELATIVELY HIGH MOLECULAR WEIGHT ALIPHATIC HYDROCARBONS HAVING AT LEAST 20 CARBON ATOMS PER MOLECULE AS SUBSTITUENTS THEREIN, THE SAID IMPROVING AGENT HAVING AT LEAST THREE HYDROGEN ATOMS OF THE HYDROYAROMATIC COMPOUND REPLACED WITH ALKYL RADICALS OF THE ALIPHATIC HYDROCARBONS AND BEING SOLUBLE IN SAID OIL.