WO1993017566A1

WO1993017566A1 - Vegetable oil compositions

Info

Publication number: WO1993017566A1
Application number: PCT/US1992/000702
Authority: WO
Inventors: Virginia Carrick; Richard Yodige
Original assignee: The Lubrizol Corporation
Priority date: 1992-03-09
Filing date: 1992-03-09
Publication date: 1993-09-16
Also published as: CA2122907A1

Abstract

The present invention deals with stabilizing triglyceride oils of high oleic content through the use of tocopherol. This combination of the high oleic oil and the tocopherol results in a surprisingly stable composition for use in deep frying.

Description

VEGETABLE OIL COMPOSITIONS BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vegetable oil composi¬ tions and in particular to those vegetable oil compositions which are edible.

2. Introduction to the Invention

The present invention deals with a manner of stabilizing vegetable oils against oxidation. The invention in particu¬ larly deals with high oleic oils which are believed to be more healthy for the diet. In particular, high oleic content vegetable oils are believed to reduce low density lipoprotein cholesterol. Low density lipoprotein cholesterol has been referred in the literature as "bad cholesterol," which is that believed responsible for plaque buildup on the walls of blood vessels.

The use of high oleic vegetable oils has been of further interest in the diet in recent years in that it is also be¬ lieved that a high saturated fat content in the diet may also lead to the formation of plaque. Thus the present invention provides a benefit in giving an oxidatively stable oil in which two distinct mechanisms are believed to reduce choles¬ terol.

It is noted that saturated fats are more stable than unsaturated fats because of the absence of a double bond in saturated fats. Of course, as the oils of the present inven¬ tion are high in oleic content they correspondingly contain a high degree of mono-unsaturation in the oil.

The higher the degree of unsaturation in an oil the more

SUBSTITUTE SHEET li ely that the oil will go rancid (oxidize) . It is particu¬ larly critical in dietary oils which are used for frying, such as French frying, that the oil be stable for a long pe¬ riod of time. Many fast food manufacturers have utilized saturated fats, and in particular saturated animal fats, be¬ cause of their ability to withstand long periods of time at elevated temperatures in the manufacture of fried foods. Of course, as the fried food absorbs the saturated fat such is taken into the human diet. Thus while a saturated fat may be oxidatively stable for frying it is unfortunate that a di¬ etary component with the problems previously addressed are encountered.

Many antioxidants present problems especially when used at high levels in industrial applications. The tocopherol antioxidants are environmentally friendly and compliment the natural oils described herein.

Thus it remains to develop a vegetable oil which is high in oleic acid content, and low in saturates or polyunsaturat- ed oils which is oxidatively stable and which may be utilized for deep frying. Other uses of oils include crankcase, gear lubricants, transmission oils, tractor oils and hydraulic fluids.

It is known from United States Patent 2,267,224 issued December 23, 1941 to Taylor et al that lard shortening may be stabilized through the use of tocopherol at levels of 0.02% to 0.06%. The present invention does not deal with lard which contains large amounts of cholesterol (which should be avoided in the diet) , and the oil of the invention does not contain the high degree of saturates or linoleic acid moi¬ eties which are found in lard. It is further noted that the compositions of Taylor et al are suggested for use in hydro- genated lard. In fact, it is noted that the tocopherol is also hydrogenated in Taylor et al.

Hickman in United States Patent 2,349,277 issued May 23, 1944 suggests a method of preparing a deodorized relatively stable edible triglyceride. Jacobsen in United States Patent 2,363,672 issued November 7, 1941 suggests that animal and vegetable shortenings may be treated by adding a tocopherol- containing deodorizer sludge to shortening, and hydrogenating the resultant mixture.

United States Patent 2,440,606 issued April 27, 1948 to Hickman suggests methods for obtaining tocopherol or vitamin E produced during the vacuum-inert gas deodorization treatment of vegetable or animal oils. Mattill et al in United States Patent 2,333,655 issued November 9, 1943 de¬ scribes obtaining the use of beta-tocopherol in lard. Simi¬ lar disclosures are also found in United States Patent 2,333,656 and 2,333,657 both issued to Mattill et al on No¬ vember 9, 1943.

Golub, in United States Patent 3,117,866 issued January 14, 1964 discusses the use of phosphatides, oils, and tocopherol at levels of 0.25% to 2% in an oleaginous composi¬ tion. Klaui et al in United States Patent 3,637,772 issued January 25, 1972 suggests the use of tocopherols in combina¬ tion with colamine or its salt, and a higher fatty acid ester of ascorbic acid. Nelan in United States Patent 3,173,927 issued March 16, 1975 discusses various methods for obtaining tocopherol.

High oleic vegetable oils with which the present is con¬ cerned may be obtained from any one of several sources. The first and most important source of high oleic acid content vegetable oils are described in Fick's United States Patents 4,627,192 and 4,743,402 issued respectively December 9, 1986 and May 10, 1988. The Fick patents describe obtaining in large quantities high oleic vegetable oils having greater than 80% oleic acid. The Fick oils are also noted for their high degree of stability with regard to the AOM values as hereinafter described.

It is also known from European Patent Application 88 312397.8 filed December 29, 1988 that high oleic content rapeseed (canola) may be used as a source of a high oleic content vegetable oil. Low saturated fat content oils are described in United States Patent 4,948,811 issued August 14, 1990 to Spinner et al. The vegetable oil products of the present invention pro¬ vide highly stable oils for cooking which have the desirable benefits of low saturate and low linoleic acid levels while maintaining a relatively high degree of mono-unsaturate in the oil.

To the extent that any of the foregoing references are applicable they are herein explicitly incorporated by refer¬ ence. Temperatures and pressures given herein are in degrees C and KPa absolute unless otherwise indicated. When discuss¬ ing the fatty acid content of a triglyceride oil such relates to the average molar amount of the fatty acid species which make up the triglyceride. Ranges and ratios given herein may be combined.

SUBSTITUTE SHEET SUMMARY OF THE INVENTION

The present invention describes a natural vegetable oil composition comprising triglycerides wherein at least about 70% of the fatty acid moieties in the triglyceride are oleic; less than about 20% of the fatty acid moieties in the tri¬ glyceride are linoleic, and further comprising at least about 100 ppm of a tocopherol based on the weight of the triglyc¬ eride.

A further embodiment of the present invention is a tri¬ glyceride composition wherein at least about 83% of the fatty acid moieties in the triglyceride are oleic and further in¬ cluding in said composition about 500 to about 3,000 ppm of tocopherol per part of triglyceride.

Yet a further embodiment of the present invention is a vegetable composition comprising triglycerides wherein at least about 70% of the fatty acid moieties in the triglycer¬ ide are oleic; less than about 20% of the fatty acid moieties in the triglyceride are linoleic, and further comprising an antioxidant effective amount of a tocopherol.

A still further useful composition herein is a triglyc¬ eride composition wherein at least about 83% of the fatty acid moieties in the triglyceride are oleic and further in¬ cluding in said composition about 500 to about 3,000 ppm of tocopherol per part of triglyceride.

The present invention also involves a method for stabi¬ lizing an oil utilized in deep frying comprising adding to a triglyceride wherein at least about 70% of the fatty acid moieties in the triglyceride are oleic; less than about 20% of the fatty acid moieties in the triglyceride are linoleic, and further comprising about 100 to about 3,500 ppm of a to¬ copherol based on the weight of the triglyceride.

The invention also describes an edible oil composition comprising an oleic acid content of at least 70% of the fatty acid moieties and tocopherol wherein the AOM of the composi¬ tion is at least 100. DETAILED DESCRIPTION OF THE INVENTION

When discussing an oil herein the chemical make-up of the oil is a triglyceride, e.g. three moles of a fatty acid esterifying one mole of glycerine. Thus when discussing the acid content of the oil it is this portion of the triglycer¬ ide which is discussed not the free acid or other esters con¬ taining the acid species. A natural oil as described herein is a non-hydrogenated oil obtained from plants.

The first aspect to be discussed in the present inven¬ tion is the vegetable oil. It is first noted that Fick Unit¬ ed States Patent 4,627,192 and 4,743,402 discuss obtaining high oleic content sunflower oils. The sunflower oils useful herein typically contain an oleic acid content of greater than 70% of the fatty acid moieties on average in the oil. Stated otherwise, each of the three fatty acids that make up the triglyceride are on average at least 70% oleic.

Preferably, the oleic acid content of the triglyceride is greater than 78%, most preferably greater than 80%, yet more preferably greater than 85% and most preferably greater than 87%.

The remainder of the fatty acid composition in the tri¬ glycerides is typically less than 10% linoleic acid, most preferably less than 5%, and more preferably less than 3% by weight linoleic. Most preferably the linoleic content is less than 2% or 1%. Similarly, other higher unsaturated acids such as linolenic are also present in substantially lower amounts than the linoleic acid content.

The saturated fatty acid content of the oil is typically less than 15%, typically less than 10%, preferably less than 7%, and most preferably less than 3% by weight.

It is also preferred that the oils utilized herein con¬ tain at least 85% of the fatty acid species as C18, prefera¬ bly 90% and most 92% by weight of 18 carbon species. It is noted that the total number of carbon atoms carboxylic acid portion of the oil is included in the foregoing definition.

The oils which may be utilized with the present inven¬ tion as previously noted include sunflower, rape or canola as described in published European Patent 88 312397.8. In fact any vegetable oil may be utilized including peanut, soya, corn, safflower, cottonseed, and the like. If desired, tri- ' olein might also be utilized as the source of an oil in the present invention. Triolein is a manufactured oil in which the oleic acid content of triglyceride is 100%.

The second component in the present invention is the tocopherol component. Various tocopherols are known in the present invention. Tocopherols are a member of the family of chroman compounds. The various tocopherols which are known and described in the Merck Index 8th edition include alpha, beta, delta or gamma tocopherol. Numerous of the references previously cited herein show commercially available sources of natural occurring tocopherol.

It is also possible in the present invention to use syn¬ thetic tocopherol compounds. The synthetic tocopherol com¬ pounds are typically obtained by alkylating the ring struc¬ ture to synthetically form a chroman compound. The primary difference between synthetic and natural tocopherols is that .natural tocopherols have a substantial degree of optical ro¬ tation. The synthetic tocopherols due to their formation are optically balanced in both the dextro and levo forms. Thus the synthetic tocopherols do not exhibit optical rotation.

There is some difference in the biological activity of the various tocopherols and as well of natural tocopherols over synthetic tocopherols. However, for the present inven¬ tion the differences in biological activity are not control¬ ling in the choice of which tocopherol to utilize as an antioxidant in the claimed compositions.

The amount of the tocopherol utilized in the present invention is typically from about 100 to 3,500 ppm of tocopherol based on the weight of the triglyceride. A pre- ~f ferred range for the use of the tocopherol in the present invention is at from 300 to 2,500 ppm. A more preferable ^Λ range for the use of the tocopherol in the present invention is from 500 to 2,000 ppm.

It is preferred that the triglyceride herein not be hydrogenated, and accordingly, that the oil not have any trans unsaturation in the oil.

It is further noted herein that the tocopherol may be utilized in its free form or as an acceptable salt or ester. Typically, when the tocopherol is utilized as a salt it is present as an ester such as the acetate or succinate form. The use of the salts of tocopherol are typically for the con¬ venience of the manufacturer of the tocopherol. The amount of tocopherol utilized herein is specified as the free-form of the tocopherol.

The tocopherol may be also utilized as various mixtures of alpha, beta and delta tocopherol. A further variation of the present invention is the use of the tocopherol in a mix¬ ture of the alpha and gamma forms. It is further suggested herein that the tocopherol not be hydrogenated.

The oils of the present invention enjoy AOM's (active oxygen method) of greater than 50 hours, preferably greater than 60 hours, most preferably greater than 70 hours. The following table may be utilized to show the relationship of AOM, tocopherol content of a triglyceride mixture and the oleic acid content of the oil. The AOM is determined by AOCS procedure CD 12-57.

DESCRIPTION OF THE DRAWINGS

Figure 1 shows the percentage of oleic acid in a vege¬ table oil on the x-axis and percent increase in AOM after using tocopherol at 2,000 ppm of the oil. Figure 2 shows the actual AOM versus the oleic content. Figure 4 shows the raw data used to obtain Figures 1 and 2.

Figure 3 shows 2 different types of tocopherol in an oil having an 80% oleic acid content of the triglyceride at varying tocopherol content. Figure 5 shows the raw data for Figure 3. Example I

The general method for obtaining the tocopherol treated oil is to stir the liquid oil and to add the tocopherol in the appropriate amount. The oil and tocopherol mixture are agitated. Generally, the oil is at 20°C when mixing is accomplished.

The total mixing time depends on the respective volumes and the method of addition with, generally, 10 minutes to 1 hour sufficient to disperse the tocopherol in the oil.

SUBSTITUTE SHEET

Claims

What is claimed is:

1. A natural vegetable oil composition comprising tri¬ glycerides wherein at least about 70% of the fatty acid moi¬ eties in the triglyceride are oleic; less than about 20% of the fatty acid moieties in the triglyceride are linoleic, and further comprising at least about 100 ppm of a tocopherol based on the weight of the triglyceride.

2. The composition of claim 1 wherein the tocopherol is a naturally occurring tocopherol.

3. The composition of claim 1 wherein the tocopherol is a gamma tocopherol.

4. The composition of claim 1 wherein the tocopherol is an alpha tocopherol.

5. The composition of claim 1 wherein the tocopherol is a d,l-alpha tocopherol.

6. The composition of claim 1 wherein the tocopherol is present at about 300-3,500 ppm.

7. The composition of claim 1 wherein the tocopherol is a delta tocopherol.

8. The composition of claim 1 wherein the tocopherol is a beta tocopherol.

9. The composition of claim 1 wherein the tocopherol is present as a salt or ester.

10. The composition of claim 1 wherein the tocopherol is present as an ester of gamma tocopherol.

11. The composition of claim 1 wherein at least about 80% of the fatty acid moieties in the triglyceride are oleic.

12. The composition of claim 1 wherein at least about 85% of the fatty acid moieties in the triglyceride are oleic.

13. The composition of claim 1 wherein less than about 10% of the fatty acid moieties in the triglyceride are linoleic.

14. The composition of claim 12 wherein the tocopherol is gamma tocopherol.

15. The composition of claim 1 wherein the vegetable oil is substantially free of trans-unsaturated moieties.

16. The composition of claim 1 wherein the linoleic acid content is less than about 3%.

17. A triglyceride composition wherein at least about 83% of the fatty acid moieties in the triglyceride are oleic and further including in said composition about 500 to about 3,000 ppm of tocopherol per part of triglyceride.

18. The composition of claim 17 wherein the predominant triglyceride source is selected from the group consisting of sunflower oil, soya oil, corn oil, safflower and rapeseed oil and mixtures thereof.

19. The composition of claim 17 wherein less than about 5% of the fatty acid moieties in the triglyceride are linoleic.

20. The composition of claim 17 which is substantially free of hydrogenated oils.

21. The composition of claim 17 wherein the vegetable oil is substantially free of trans-unsaturated moieties.

22. The composition of claim 17 wherein the linoleic acid content is less than about 3%.

23. The composition of claim 17 wherein the tocopherol is a mixture of alpha and gamma tocopherol.

24. The vegetable oil composition of claim 17 wherein the tocopherol is at least two of alpha, beta and delta tocopherol.

25. The triglyceride composition of claim 18 wherein the predominant triglyceride is sunflower oil.

26. The triglyceride composition of claim 18 wherein the predominant triglyceride is safflower oil.

27. The triglyceride composition of claim 18 wherein the predominant triglyceride is rapeseed oil.

28. A natural vegetable oil composition comprising tri¬ glycerides wherein at least about 70% of the fatty acid moi¬ eties in the triglyceride are oleic; less than about 20% of the fatty acid moieties in the triglyceride are linoleic, and further comprising an antioxidant effective amount of a to¬ copherol.

ET 28. The composition of claim 28 wherein the tocopherol is a naturally occurring tocopherol.

29. The composition of claim 28 wherein the tocopherol is a gamma tocopherol.

30. The composition of claim 28 wherein the tocopherol is an alpha tocopherol.

31. The composition of claim 28 wherein the tocopherol is a d,l-alpha tocopherol.

32. The composition of claim 28 wherein the oil is se¬ lected from the group consisting of rapeseed oil, safflower oil, and sunflower oil and mixtures thereof.

33. The composition of claim 28 wherein the tocopherol is a delta tocopherol.

34. The composition of claim 28 wherein the tocopherol is a beta tocopherol.

35. The composition of claim 28 wherein the tocopherol is present as a salt or ester.

36. The composition of claim 28 wherein the tocopherol is present as an ester of gamma tocopherol.

37. The composition of claim 28 wherein at least about 80% of the fatty acid moieties in the triglyceride are oleic.

38. The composition of claim 28 wherein at least about 87% of the fatty acid moieties in the triglyceride are oleic.

39. The composition of claim 28 wherein less than about 10% of the fatty acid moieties in the triglyceride are linoleic.

40. A triglyceride composition wherein less than about 15% of the fatty acid moieties in the triglyceride are lino¬ leic and further including in said composition about 500 to about 3,000 ppm of tocopherol per part of triglyceride.

41. The composition of claim 40 selected from the group consisting of sunflower oil, soya oil, corn oil, sunflower and rapeseed oil and mixtures thereof.

42. The composition of claim 40 wherein less than about 5% of the fatty acid moieties in the triglyceride are linoleic.

43. The composition of claim 40 which is substantially free of hydrogenated oils.

44. The composition of claim 40 wherein the vegetable oil is substantially free of trans-unsaturated moieties.

45. The triglyceride composition of claim 40 wherein the linoleic acid content is less than about 3%.

46. The vegetable oil composition of claim 40 wherein the tocopherol is a mixture of alpha and gamma tocopherol.

47. The vegetable oil composition of claim 40 wherein the tocopherol is at least two of alpha, beta and delta tocopherol.

48. A method for stabilizing an oil useful in deep fry¬ ing comprising adding to a triglyceride wherein at least about 70% of the fatty acid moieties in the triglyceride are oleic; less than about 20% of the fatty acid moieties in the triglyceride are linoleic, and further comprising about 100 to about 3,500 ppm of a tocopherol based on the weight of the triglyceride.

49. The method of claim 48 wherein the oil is used in deep frying.

50. The method of claim 48 wherein the AOM of the oil is at least 100 hours.

51. The method of claim 48 wherein the AOM of the oil is at least 150 hours.

52. An edible oil composition comprising an oleic acid content of at least 70% of the fatty acid moieties and to¬ copherol wherein the AOM of the composition is at least 100.

53. The oil composition of claim 52 wherein the oleic acid content is at least 78% and the AOM is at least 150.