US2282807A - Treatment of rendered glyceride oils - Google Patents

Description

Patented May 12, 1942 UNITED STATE SVPATENT OFF 2,282,807: ICE

TREATMENT OF RENDERED GLYCERIDE OILS Y Sidney Musher, New York, N. Y., assignor to Musher Foundation Incorporated, New York, N. Y., a corporation of New York No Drawing. Original application July 31, 1940, Serial No. 348,825. Divided and this application February 27, 1942, Serial No. 432,646

6 Claims.

The present invention relates to the stabilization of glyceride oils and particularly to the sta- It has now been found that when such glycer- 51 ide oils are heated to relatively high temperatures with finely divided, preferably deoiled, soya bean flour, sesame flour, peanut flour, cottonseed flour, or' the flours of other seeds and nuts, orig-.- inally containing at least about to of glyceride oil against the solids content of the seeds and preferably from which some or a major part of the oil has been removed, instead of losfrom which some or a major part of the oil has been removed.

The finely divided seed or nut flours which,

are preferably in substantially oil exhausted form, and which flours are referred to herein as the seed flours, are dispersed in the glyceride oil which is then heated or they may be added to the oil during high heat treatment to develop marked antioxygenic effectiveness.

For example, the oil may have been removed from the soya beans, sesame seeds, peanuts, c0t-,

tonseed or corn germ by expeller expression, hy-

draulic expression or by solvent extraction and the residue thus obtained, preferably finely divided to about mesh and desirably to over 100 mesh, may be added to the oil and'heated therein.

The seed flour is added in an amount of less than 10% and desirably less than 5%. As little as 0.05% will give highly desirable stabilizing results when the glyceride oils are treated in accordance with this invention.

After dispersing the seed flours in the oil, the

oil is heated to an elevated temperature, desir-.

above the melting point of the glyceride if normally be solid at room temperature.

During the heating period, the flour maybecome burnt or charred and, where desired, the

- burnt residue may be removed as by filtration or centrifuging from the body of the oil, as the stabilization of the oil will already have been effected.

This charring apparently enhances the action of the fiour on the oil and it has been found par- 0 ticularly desirable for the heating to be suffi-' ciently high so as to produce charring in order to obtain the fully desirable results of the present invention.

The oil which. has been heated with the flour will be darker as the result of the elevated tem perature treatment and the stabilization will have been effected even though the charred residue be removed from the oil as by filtration or centrifuging. v

It, however, has been found that the original light color of the oil may be restored by a bleaching process as, for example, with fullers earth or other decolorizingmaterials and "still retaining a substantial enhancement in the stability of the oil.

The results of the present invention are particularly surprising since antioxidants are recognized as losing at least a portion of, and in most; cases a major portion of their effectiveness when heated to elevated temperatures such as 400 F. or more. 7

' Example I Bleached refined lard was treated by adding thereto and mixing therein 1% of soya, flour press cake which had been finely divided to about mesh. The lardcontaining the flour was then heatedto 400 F. for 1 minute, allowedto cool, and filtered to remove the charred soya solids. The lard was thereupon tested by bubbling air througha 20 cc. sample of the lard at 208 F; until rancidity as determined organoleptically and by peroxide value was observed.- A

sample of lard from the same lot to which 1% of soya flour press cake was added but without being subjected to the 400 F. heat treatment was similarly tested. along with a sample of the original untreated lard, with the following results:

Rancid after- Untreated lard 2 hours Lard containing 1% soya flour press cake unheated Lard containing 1% soya 'flour press cake heated to400 F. for 1 minute, 1 cooled and filtered 13 hours The glyceride may, where desired, be bleached or otherwise refined after treatment at the ele.- vated temperature with the seed flour and a dis,

.. 4 hours tinct enhancement of the antioxygenic efiect will be obtained, such enhancement being far in excess of normal expectation.

It is not desirable for the heating to be conducted in a small body of the oil and that oil used as a base for addition to a large body of oil. The most desirable method is for the fiour to be dispersed in the entire'body of material to be stabilized, followed by subjecting the oil to a high heat in order to produce the desired interaction or result. I

Apparently a chemical reaction occurs with-the completely with these unsaturated oils at the elevated temperatures.

The seeds should be finely ground or crushed, as, for example, placed in fiour form. They may also be made into paste form by grinding with from 50% to 100% of an oil or by placing the combination through a colloid mill so as to E disintegrate the cell structures and release the 'anti'oxygenic" effect more readily at the higher temperatures.

The seed flours are 'usually charred in the oxidizable materials such as lard or fish oils,

oil at the elevated temperature whereby the stabilization is effected, as this reaction does not appear to be related to ordinary negative oxidation catalysis by means of which antioxidants normally exercise activity.

The higher the temperature to which the 011 containing the soya fiour is-subjected, the greater the stabilizing action although the sharpest increase in stabilization is between about 300 and. 400 F.

Example II Bleached refined lard was prepared inthe following manners:

The lards were then tested for stabil-i-ty'as in Example I with the following results:

- Rancid after of soya fiour press cake was disof soya flour presscake was disheated to 400 F. for minutes,

Lard A -3h0urs Lard B 4 hours Lard C I71/2 hOllI'S Lard D 1-3 hours Lard E 21 hours heated to 300? F. for 5 minutes,

whereby the necessary interaction is obtained.

Although the seed flours may already have some antioxygenic effect when added to the glyceride oils andwithout the heat treatment, nevertheless such antioxidant power is limited The heat treatment need not be prolonged,

the enhanced antioxygenic effect being obtained in relatively short periods particularly where the higher temperatures are employed. Normally, the oil containing the seed fiour may merely be heated to the desired temperature and allowed and fats including cottonseed oil, corn oil, peanut oil, linseed oil, soya bean oil, olive oil, etc., the animal oils and fats including lard, tallow, oleo oil, cod liver oil, halibut liver oil,j,macke'rel oil, menh'aden oil, herring oil, shark liver oil, butter, etc., the glyceride soap oils andthe sulfonat'ed oils. I

This invention is, however, particularly beneficial in the treatment of those glycerideswhich contain large proportions'of unsaturated fatty acids, as the 'seed flours'app'ear-to react-more and is much less than the stabilizing effect obtained after the addition of the .fiours and dispersion in the oil to be stabilized, followed by the heat treatment'to over 250 F. and preferably to- 325 F. to 450 F.

The stability of the treated oils will often be enhanced from 50% to 500% or more by the heat treatment in the presence of these substances as compared to the stability which would be obtained by the addition of the flours without the, heat treatment described in this invention. The most important features of thepresent 0 invention reside in the fact that the added material is not normally present in the oil or oxidizable material to be stabilized and upon addition is thoroughly dispersed in such oil. The heat treatment is'carried out for a suflicient length of time to increase the stability by usually .not less than 50% over the stability of th'e unheated .oil. I

As a preferred method for the heating, the .entire body of oil containing the seed flours thoroughly dispersed therein :may :be raised to the desired temperature with agitation, maintaining a uniform temperature throughout, and then permitted to remain at this temperature while agitating. The oil may then be allowed to cool without refrigeration.

While the fiour is dispersed in the oil at the elevated temperature of about 400 F., ,superheated steam may, where desired, be continuously injected into the oil over a period as long as 4 to 6 hours and the objectionable flavors and odors originally present in the oil may be removed therefrom while the flour is exerting its enhanced antioxygenic effect.

' It has been found particularly desirable for a small amount of seed hour to be added to high fat containing animal products, heating at atmosph'eric or elevated pressures to temperatures of about250 F. so that the glyceride on'or fat contained therein is released from the meato'r -fish animal product and a highly'stabilized animal glyceride is obtained.

For example, to a kettle of hog "fat containing total glycerides may be added 0.5% of soya flour press cake against the weight 'of the hog fat and the combination placed in a steam kettle with steam being injected into the kettle to produce about 45 pounds pressure. After a 4 to 6 hour treatment, the pressure-may be released and the rendered lard removed. The stability of the lard obtained in this manner will be much greater than if the soyapress cake had merely been added to the lard after rendering.

For example, when asmall amount of a seed flour is-addedt'o hog fat afnd the hog fat containingthe fiour is then rendered at a temperature of, for example, 275 F. for 4 ho'u'rs,the rendered lard removed from-the renderingkettle has afar greater stability than where a proportionate amount of the seed flour is added to the lard after rendering and the improvement in stability is even greater than Where the seedflour-is added to the lard after rendering and the lard containing the flour is then heated to 275 F. for 4 hours. Apparently a further interaction takes-placeby adding the flour to the rendering kettle where.

the rendering is conducted at over 2503-1ikresulting inamost highly stabilized oil. 1' In a similar manner, asmall amount .of-seed flour may be added to'the rendering kettle in the rendering of other meat and fish'oils' and'fats including tallow, menhaden oil, herring oil, etc., or to the cooking kettles in the-manufacture of fish meals, particularly highgl'yceride containing fish meals, and where the temperature is at least about 250 F., the desired interaction will result producing enhanced stabilization. 1 H

Where the glyceride oils are'heated over long periods to temperatures over 250 F. anddesirably to temperatures over-300 F., small amounts of the seed flours may be'added to the oils at regular intervals of 5 to hours followed by filtration to remove the insoluble portion before adding a fresh amount of the seed flours. In this manner, the glycerides will beheld in highly stabilized and non-rancid condition over verylong periods. y f 2 One of the highly unsaturated glyceride" oils that has been found particularly desirable for treatment in accordance with the present invention is the crude unrefined corn oil obtained from the hydraulic or expeller expression of dry milled corn germ and where neither the corn nor the corn germ has been subjected to steeping in sulphurous acid water prior to removal of the germ.

There may be added to the crude corn oil a small proportion of the seed flour followed by elevated temperature treatment of at least about 250 F. and a highly stabilized glyceride oil product will be obtained.

It has been found most important to use the corn oil as expressed from the dry milled germ and which corn oil has not been subjected to any of the usual refining processes.

Together with or in lieu of the seed flours, there may also be employed their extracts and particularly those extracts obtained by the use of an alcohol soluble solvent. The extracts are desirably chosen from a solvent having the formula XOH where X is hydrogen or a low molecular weight aliphatic group. There may be particularly utilized water, methyl alcohol, ethyl alcohol, propyl alcohol or butyl alcohol.

The extracts may be prepared by immersing the finely divided flours in the solvent such as in methyl alcohol, using about from 5 to 15 parts of alcohol to each part of flour, agitating for from 5 minutes to 1 hour at a slightly elevated temperature, filtering out or otherwise removing the alcohol containing the dissolved extracted material, and then removing the alcohol, preferably under reduced pressure, whereby the extracted material remains substantially free of the solvent.

These extracts may be applied in the manner analogous to that described above for the seed fiours themselves and will show an enhanced anti-oxygenic activity when added to oils followed by treating said oils at a temperature of at least 250 F. or more.

In addition to treating the glyceride oils and fats with the seed flours, the essential oils and particularly the oxidizable unsaturated essential and perfume oils such as lemon oil and orange oil may similarly be treated followed by an elevated temperature treatment to enhance the antioxygenic effect.

The seed flours also exert an enhanced antioxygenic effect when added in small proportions to thesubstantially non-volatile, high molecular weight, hydrocarbon oils and particularly the lubricating oils followed by temperature treatme'nts of over 250 F. and preferably'between 350 F. and 500 F.

In carrying out the above described high temperature treatment, it is important that the solids of the seeds be uniformly dispersed or distributed throughout the bodyof the oil in substantially fine particles and that the heating be carried out with substantial exclusion of the atmosphere or without contact with air. 7 I It ismoreover desirable for the seeds to be maintained in dispersed condition during the heat treatment and so that they will not'tend to settle or conglomerate 0r be present in the formof large lumps or particles since in the latter case the fullydesirable results of the present invention are not obtained. 7

It is desirable that the oil after treatment in accordance with the present invention will not be materially changed in odor or flavor. The oil will, however, have a darker color which may be removed by subjecting it to a bleaching operation. The seeds orseed flours may where-desired be subjected to boiling or treatment with acid such as by boiling soya flour in a 2% aceticacid solution for a period of from 20 minutes to 4 hours, followed by neutralization and drying and then utilized in accordance with the present invention.

The seed flours may also befirst treated with saturated or superheated steam under pressure or under vacuum at temperatures substantiallyabove 250 F., particularly in an acid medium having a pH of less than 6 and preferably less than 4.5. Such flours may then be utilized in accordance with the present invention.

It has also been found that desirable results are obtained where the finely divided seeds are mixed with the oil or fibrous materials containing 1 the glyceride oil and then the oil is heated to a temperature of, say from 250 F. to 500 F. under such a reduced pressure, such as under a gas pressure less than 1 pound per square inch, to cause distillation of part or all of the glyceride oil composition and it has been observed that such distilled fraction is highly stable and is also free of the finely divided flour which has served as the stabilizing agent at the elevated temperature of distillation.

By the term seeds, as used herein, there are also included such additional materials as the seed germs such as corn germ, wheat germ, and rice germ, preferablyin deoiled condition, rice bran, peach kernel, watermelon seed, tomato seed and olives.

Instead of utilizing the seeds when they have fully ripened or matured upon the vine, it is also possible to remove them from the plant when they are still unripened and have a high moisture content. They may then be dried to a moisture content of under 20% andpreferably under 10% and then converted to a flour with or without deoiling and added to an oil followed by heating as described to enhance the antioxygenic effect.

Although this is particularly applicable to the field of the oil containing seeds when removed from the flesh or pods, it is also possible sometimes to dehydrate the entire unripe pods or fruit containing the. seeds sothat it may be powdered with or without deoiling and for addition'to'oils. Although these materials have some antioxygenic effect, the effect is considerably enhanced when the material is added to an oil and heated to over 250 F.

Less preferably, there maybe also utilized in accordance with the present invention the grasses or stalks of the cereals or forage legumes and grasses and their extracts in substantially unripe condition.

The present application isadivision of application Serial No. 348,825, filed July 31, 1940, and through said application continues the subject matter of application Serial No. 247,631, filed December 24-, 1938. Through said latter application the present application continues the subject matter of applications, Serial No. 135,169, filed April 5, 1937; Serial No. 294,633, filed September 13, 1939, now Patent 2,198,204; Serial No. 249,166, filed January 3, 1939, now Patent 2,198,210, and Serial No. 260,898, filed March 10, 1939, now Patent 2,198,211. Through application Serial No. 135,169, filed April 5, 1937, the present application continues the subject matter of application Serial No. 733,517, filed July 2, 1934, now Patent 2,097,252.

Having described my invention, what I claim is:

1. A process of rendering fatty animal products which comprises adding a small amount of a finely divided seed to a fat containing animal product, subjecting the combination to an elevated temperature of at least 250 F., followed by removing the fat which will be in substantially stabilized condition.

2. A process of rendering fatty animal products which comprises adding a small amount of a finely divided seedto-a fat containing animal product atsa temperature sufficiently high to char the seed, followed by removing the fat which will be in substantially stabilized condition.

8. A process of rendering hog fat which comprises adding a small amount of a finely divided seed to the' hogfat, subjecting the combination to" an elevatedtemperature of at least 250? F., followed by removing. the lard which will be in substantially stabilized condition.

4. A process of' rendering fatty fish products whichcomprises adding a small amount of a finely divided: seed to an oil containing fish product, subjecting the combination to an elevated temperature'of at least 250 F., followed by removing the fish oil which will be in substantially stabilized condition;

5. A process of rendering fatty animal products which comprises adding'a small amount of a finely divided soya flour to a fat containing animal product, subjecting the combination to an elevated temperature of at least 250 F., followed by removing, the fatwhich will be in substantially stabilized condition.

6; A process of rendering fatty animal products which comprises adding a small amount of a finely divided soya; flour to a fat containing animal'product at atemperature sufiiciently high to char the soya flour, followed by removing the fat which will be in substantially stabilized condition.

SIDNEY MUSHER.