US3105844A - Method for processing tallow, palm oil, and other similar fats - Google Patents

Description

United States Patent 3,105,844 METHOD FDR PROCESING TALLOW, PALM 01L, ANE) OTHER SIMILAR FATS Yoshiyuki Toyama, Meguro-ku, Hisato Murata, Aralrawaku, and Kazutomo Maebashi, Nerima-ku, all of T okyo City, Japan, assignors to Asahidenka Kogyo Kabnshiki Kaisha, Tokyo City, Japan, a corporation of Japan No Drawing. Filed Sept. 23, 1961, Ser. No. 141,303 Claims priority, application Japan Sept. 13, 1958 4 Claims. (Cl. 260-409) This invention relates to a process for utilizing animal or vegetable fats and oils having an initial iodine value of about 40 to 70 and, more particularly, relates to a process for selectively hydrogenating and then resolving such animal fats or oils into three fractions having dilferent physical and chemical characteristics, which fractions are adapted for different uses. This application is a continuation-in-part of Serial No. 832,441, filed August 10, 1959, now abandoned. 7

Animal and vegetable fats and oils are utilized to provide fatty acids for use in making soaps, etc. or to provide glycerides which are used, for example, to form shortenings, etc. In the former case, it is of fundamental importance to have cheap raw materials and a wide range of fats and oils can be used. In the latter case, it has been found that the fats and oils due to their inherent physical and chemical properties cause an unsatisfactory variation in plasticity, creaming nature/etc. with temperature variations.

It is common practice to improve the physical and chemical properties of oil and fat glyc'erides by hydrogenation or interesterification. However, both of these techniques have disadvantages which make them less than completely satisfactory for many purposes.

In contrast to the above-mentioned procedures, this invention is based on the concept of selectively hydrogenating animal or vegetable fats and oils having an initial iodine value of about 40 to 70 to reduce the iodine value thereof by not more than 10 and then fractionating same by dissolving same in a solvent and thereafter selectively crystallizing fractions therefrom. This is particularly satisfactory since a plurality of fractions having different physical and chemical properties can be obtained with a very high :yield.

The fact that oleaginous materials can be fractionated using solvents is well known and, heretofore, such solvent fractionation has been used for a variety of purposes. For example, solvent fractionation has been used for removing a saturated component, such as stearine, from cottonseed oil, for concentrating unsaturated glycerides, for separating and extracting components other than glycerides from oils and fats, for analyzing various glyceride components, etc. However, the purpose was, in all cases, either to obtain the oil and fat component in a pure state or to obtain the main product from one definite stage of the solvent fractionation process. 7

According to this invention animal and vegetable fats and oils having an initial iodine value of about 4O to 70; such as tallow, palm oil and lard, are selectively hydrogenated to a limited extent to reduce the iodine value by an amount not in excess of about 10. Thereafter, the fats and oils are fractionated into three fractions-that is, high, middle and low melting fractions (hereinafter to be referred to as the A, B, and C fractions). Industrially, the present process is extremely advantageous because the A fraction can be used in place of stearine or hydrogenated fat, the B fraction can 'be used in place of fat which melts sharply and has a short plastic range; and the C fraction can be used in place of liquid oils. Moreover, according to this invention, it

3-,l5,844 Patented Oct. 1, 1963 is possible to adjust the softening point of the B fraction to meet various use requirements. Furthermore, according to the invention, the B fraction can also be preparedby mixing two intermediate fractions, namely first middle and second middle fractions (hereinafter to be referred to as the B and B fractions, respectively).

The selective hydrogenation of the'fats and oils is intended to convertonly polyunsaturated constituents in the fats and oils to mono-unsaturated without changing the initial mono-unsaturated constituent. This objective is realized by decreasing the iodine value by not more than 10. This is a critical feature of the invention be cause by thus limiting the degree of selective hydrogena-- natural cacao butter; (3) the stability of the B and C fractions against oxidative rancidity is improved; and (4) the color of the C fraction is improved.

Considering the above in greater detail, the so-called iso-oleic acid (elaidic acid) is a trans-isomer of normal oleic acid (9 cis-octadecanoic acid) and it has a melting point observed as high as 445 C. whereas normal oleic acid has a melting point of 13.4 to 163 0., although both are the same 'mono-unsaturated C-l8 fatty acid. Because of this different physical property, when a glyceride consists of iso-oleic acid in place of oleic acid, or when an oleic acid containing giyceride is isomerized, the resulting glyceride shows an unduly high melting point. For example, the melting point of 1 stearo diolein is reported as being 23.5" C., whereas 1 stearo dielaidin is reported as high as 59. 6 C. Both glycerides, however, show the same iodine value and saponification value.

The presence of iso-oleates in the fats and oils before fractionation inevitably causes deficiencies in the prod ucts, especiallywhen the B fraction is intended for the same uses as cacao butter. Thus, when the melting point of the B fraction is selected to be close to that of natural cacao butter, the B fraction will have a higher iodine value and a lower softening point than cacao butter and the desired sharp melting property is not achieved. When the iodine value of the B fraction is selected to be close to that of natural cacao butter, the B fraction will have anunduly higher melting point than. cacao butter. l 7

Thus, if the selectivehydrogenation prior to fractionation decreases the iodine value more than-10, the following will result.

(A) Middle melting fraction:

('1) Will have higher iodine value and lower softening point when its melting point is the same as that of cacao butter.

(2) Will have an unduly high melting point when its iodine value is the same as that of cacao butter.

(3) Will have a substantially different mono-unsaturated to di-unsaturated glyceri-de ratio as compared with that of cacao butter.

(4) Because of 1) to (3), its sharp melting property around human body temperature will be somewhat difierent and inferior to that .of cacao butter.

.(5) Its glyceride configuration will be fundamentally different and, therefore, it will .be less compatible with cacao butter than a product comprising normal monoand di-unsaturated glycerides.

point will which, under normal conditions, are gaseous, as well as hydrocarbons and their derivatives containing halogen, oxygen and nitrogen and having carbon numbers of less ,than ten, can, in all cases, be used, either singly or in various combinations. Generally, since mixtures of two or more types of solvents give properties suitable for fractionation, by combining nonpolar solvents of dissolvable oils and fats with polar solvents the conflicting properties of the respective solvents are counteracted. The term solvent as used hereinafter shall refer not only to a single solvent but also to mixtures thereof.

Fractionation is carried out by dissolving ina suitable selective solvent the selectively hydrogenated animal or vegetable fats and/or oils of the type mentioned above,

and then separating from this mixture (hereinafter to be referred to as the miscella), three portions, namely, the

A, B and C fractions. Fractionation should be controlled so that the A fraction will contain essentially tri-saturated glycerides and the C fraction will contain some of the mono-saturated glycerides and substantially all of the tri-unsaturated glycerides. Furthermore, it is necessary that the B fraction contain di-saturated glycerides and the rest of the mono-saturated glycerides and not contain any appreciable amounts of tri-saturated and tri-unsaturated glycerides.

In order to adjust the softening point of the B fraction, it is necessary to change the ratio of the'di-saturated to the mono-saturated glycerides. This may be done by conducting the fractionation operation so that the said ratio will be varied by transferring part of the monosaturated glyceridcs from B fraction into the C fraction or vice versa. Further, as mentioned before, especially for commercial operations the B fraction can be obtained in the form of two separate intermediate frac' tions B and B B fractions of various softening points can be formed by mixing selected amounts of the said two fractions. In this case, the fractionation of the B fraction should be conducted so that, one of the fractions B will contain over 60% of di-saturated glycerides and the rest mono-saturated glycerides and the other fraction B will contain over 60% of mono-saturated glycerides and the rest di-saturated glycerides.

The order of fractionation may be either to first fractionate A from B and C and then from the remainder of the solution fractionate B from C or to first fractionate C from A and B and then from the remainder of the solution fractionate A from B. V

The physical conditions for a particular fractionation operation, that is, the type of solvent to be used, the ratio of the solvent to oils and fats, the temperature for separating crystals, etc. will be selected depending on the characteristics of the raw material to provide fractions of the desired qualities.

Usually, the operational conditions are selected so that the physical and chemical characteristics of one of the fractions will be Within a certain range. For example, according to the inventors experiments, it is usually desired to select the operating conditions so that the A fraction is a solid having an iodine value of less than 20 and a melting point of more than 50 degrees C. and the C fraction is a liquid having an iodine value of more T than 58 and a clouding point of less than 10 degrees C.

The B fraction consists of the remainder of the material and has physical and chemical characteristics within the aforementioned range.

Generally speaking, the fractionation operation is carried out by dissolving the fat and/ or oil in a suitable solvent of the type discussed above. The solution is then held at such a temperature that a portion thereof crystallizes and this portion is then separated from the remain-.

ing solution by filtering. Depending on the above-mentioned temperature, the remaining solution may contain either the C and B fractions or just the C fraction. 7 Thus, if the crystallizing temperature is relatively high,l

as 5 degrees C., the A fraction will be crystallized and B and C fractions will remain in solution. If the crystallizing temperature is relatively low; as 15 degrees C. the A and B fractions will be crystallized and the C fraction will remain in solution. If the solution contains just the C fraction, the crystals are again dissolved in a solvent and then held at a temperature higher than the first-mentioned temperature to cause the A fraction to crystallize so that it can be separated from the remaining solution which then contains the B fraction. 0n the other hand, if the first-mentioned solution contains both the B and C fractions, the. solution is then placed at a temperature lower than the first-mentioned temperature so that the B fraction crystallizes and can then be separated from the C fraction which TABLE I.-TALLOW AND SIMPLE SOLVENT Liquid J Li 111d Temperature for Percent, Portion Percent; Po r tion Fractionating 801- of Solid (Dissolved) of Solid (Dissolved) ids (Crystals), C. Separated 1 Separated Percent LV. Percent LV.

R 5 n-Hexane R =7 n-Hexane 18. 6 81. 4 45. 0 21. 2 78. 8 -44. 5 24. 9 75. l 48. 6 23. 6 76. 4 47. 7 29. 9 70.0 52. 2 31. 1 68. 91 52. 9 36. 2 63. 8 55. 6 31. 1 68. 9 53. 5 55. 0 45. 0 61. 4 52. 5 47. 5 60. 4 67. 5 32. 5 67. 4 62. l 37. 6 6G. 5

R=5 Acetone R=7 Acetone R=7' 1,2 Dichlorcethane 14. 8 S5. 2 53. O 14. 4 85. 6 52. 1 21. l. 78. 9 55. l 15. 6 84. 4 54. 2 27. 8 72. 2 58. 6 22. 7 77 3 56. 7 47. 4 52. 6 66. 3 4.1. 4 68. 6 67. 4

R=10 Methylacetate 2. 0 98. 0 47.6 12. O 88. 0 52. 3 19. 0 81. 0 19. 1 26. O 74. 0 53. 6 20. 0 8D. 0 52. 1 43. 0 57. 0 57. 4 39. 0 61. 0 61. 4 65. O 35. 0 65. 0 77. 0 23. 0 63. l. 91. 0 9. 0 73. 6

TABLE -II.PALM OIL AND SIMPLE SOLVENT Liquid Liquid Temperature for Percent Portion Percent Portion 'Fractionating 501- of Solid (Dissolved) of Solid (Dissolved) ids (Crystals), C. Separated Separated Percent I.V. Percent I.V.

R=5 n-Hexane R=7 n-Hexane R=5 Acetone R=7 Acetone R=5 1,2 Dichloroethane R=7 1,2 Dichloroethane R= Methylethyl- R=10 Methylacetate TABLE III.TALLOW A'ND BINARY SOLVENT Liquid Liquid Temperature for Percent Portion Percent Portion Fractionating 801- of Solid (Dissolved) of Solid (Dissolved) ids (Crystals), C. Separated Separated Percent I.V. Percent I.V.

Acetone 90%; Benzene 10% Methylethylketone 90%; Benzene 10% 1,2 Dichloroethane 50%; Ethylalcohol 50% 1,2 Dichloroethane 70% (50%); ISopropyl Alcohol 3 0 6 TABLE IV .PALM OIL AND BINARY SOLVENT Liquid Liquid Temperature for Percent Portion Percent Portion Fractionating Solof Solid (Dissolved) of Solid (Dissolved) ids (Crystals), C. Separated Separated Percent I.V. Percent I.V.

Acetone Benzene 10% Methylethylketone 90%; Benzene 10% 20 8. 5 91. 5 50. 2 4. 6 95. 4 48. 6 10- 14. 9 85. 1 53. 7 15. 3 84. 7 51. 8 18. l 81. 9 54. O 16. 3 83. 7 54.3 40. 4 59. 6. 60. 4 33. 3 66. 7 5G. 8

(50%); Isopropyl Alcohol R=e R=6 (50/50) 6. 5 93. 5 51. e 10. 9 89. 2 53. s 12. 7 s7. 3 55. 3 1s. 6 s3. 4 55. 5 22. 2 77. 8 34. 5 65. 5 e2. 4 46. 0 57. 0 63. 9 53. 8 4e. 2 64. 9

' Examples Examples 1 to 6.l0 0 grams of refined and bleached taliow (Example 1) arid palm oil (Example 4) were melt-ed and dissolved in 760 m1. of 1,2 dichloroetl'iane as solvent. Two additional 190' gm. samples or tallo w (Examples 2 and 3) were selectively hydrogenated to change the initial iodine value thereof from 45.2 to 43.2 and then were melted and dissolved in 600 ml. of 1,2 dich-loroethane as solvent. Two additional gm. samples of palm oil (Examples 5 and 6) were selectively hydrogenated to change the initial iodine value from 51.6 to 46.8 and then were melted and dissolved in 600 ml. of 1,2 idichloroothane as solvent. The iniscella of each sample was then gradually agitated for four hours to cool same to 0 C. (or 5 C.). The precipitate thus formed in the miscella was filtered out and washed with a. small amount of solvent cooled in advance. The A fraction was then obtained by evaporating the solvent from the precipitate. The filtrate was next combined with the washings and after agitating it again for four hours until cooled to l5 C. (or 20 C. or'25 C.), the precipi tate was filtered out and washed with solvent cooled in advance. The B fraction was then obtained by evaporating the solvent. The C fraction was next, obtained by evaporating the solvent from the combined filtrate and washings. The following results were obtained by these operations.

OPERATING CONDITIONS Tempera- Example Material Oil and Solvent Separating ture C.)

No. Fat (ml.) A llrbcnd 1 Tallow 700 15 2 S. H. Tallow. 600 3 d0 600 5 4-- Palm oil 700 0 15 600 5 20 600 5 RESULTS OBTAINED Yield of Fraction A B C Ex- (percent) ample A" B" 0 Loss lVLP. I.V. M.P. I.V. 0.1. I.V.

Remarks: S. H.-seleetively hydrogenated; M. P.Inelting point;

C. P.cloud point.

Examples 7 to 12.l00 grams of refined and bleached palm oil (Example 7), tallow (Example 9) and lard (Example 11) were melted and dissolved in 600 ml. of mixed solvent containing 90% acetone and 10% benzene by weight. Additional 100 gm. samples of palm oil (Example 8), tallow (Example 10) and lard (Example 12) were prepared. Selective hydrogenation was carried out to reduce the iodine value of palm oil from 51.3 to 48.2, of tallow from 51.3 to 48.0 and of hog grease from 63.5 to 56.4. These samples were then melted and dissolved in 600 ml. of mixed solvent containing 90% acetone and 10% benzene by weight. The miscella thus formed was slowly agitated for four hours until cooled down to the required temperature. The precipitate formed was then filtered and washed with a small amount of solvent, of the same filtering temperature prepared in advance. The A fraction was then obtained by distilling oil the solvent. The filtrate and the washings were next combined and agitated again for four hours until cooled down to the required temperatures. Then the B fraction was obtained in the same way as in the case of the A fraction. The filtrate and washings were again combined and cooled down to the required temperature. The B and C fractions were then obtained from the precipitate and the combined filtrate and washings respectively.

OPERATION CONDITIONS RESULTS OBTAINED Yield of Fraction(1?ercent) A Loss Example N0. (peru u UB1" B211 cent) .1) LV "B1" B2 C17 Example No M.P. LV. Ml. I.V. 0.1. I.V.

Remarks: M.P.melting point; I.V.iodine value; C.P.clouding point.

changes. Table V lists the data observed in a micro- In the table, the larger the value the penetration test. softer is the sample tested. The plasticity of cacao'butter is such that no distinct change in hardness is observed up to 25 degrees C. but it undergoes a rapid softening in the range between 25 degrees C. to 3-0 degrees'C. In contrast to this, though B-2, B-3, B-5 and B-6 are 13" frac-;

tions obtained from palm oil and tallow respectively (Examples 2, 3, 5, 6), 13-2 and B6 are completely similar in plasticity to natural cacao fat. In contrast, though B-3 and B6 have a lower softening temperature, they I show, nevertheless, the same narrow plastic range and sharp melting property. Furthermore, though their softening temperatures are different, the B and B ffractions show the same narrow plastic range and by mixing B and B intermediate fractions, the resulting mixture softens somewhere between the softening points of the respective fractions and still has a narrow plastic range and a sharp melting property.

TABLE V.RESULT OF MICROPENETRATION TEST Observation Temperature 0.) Sample Cacao Butter 5 7 11 Coconut Oil 22 26 82 M.M.F.B Example 2-- 7 7 l3 M.M.F.B Example 3-- 7 8 4D -M.M.F.B Example 5. 5 8 14 1\ LM.F.-B Example 6.. 9 10 45 M.M.F.-B Example 8. 4 5 7 M.M.F.B Example 8- 7 8 30 Mixture of above B1 and by wt.) 4 4 7 M.M.F.-Bi Example 4 4 8 'M.M.F.Bz Example 10 6 7 10 Mixture of above 13 and B by wt.) 6 8 9 M.M.F.-middle melting point fraction.

*Too soil: to be tested. Unit for observed figures: 1/10 mm.

' 9 TABLE VI.EFFECTS OF SELECTIVE HYDRO- GENATION ON OXIDATIVE STABILITY OF B AND C FRACTIONS B" Fraction Fraction Example No.

A.O.M. Test (hours) A.O.M. Test (hours) Organoleptic Test (hours) Organoleptic Test (hours) 19 over 48 9 moon:

over 48 6 H N a \ncqwoooo 3. over 48 38 A.O.M. test Was carried out according to the method reported in Oil and Soap, vol. 10, page 105 (1933). Organoleptic test was carried out by pouring 80 ml. of melted sample into a test tube (30 mm. inside diameter and 190 mm. in length), which was placed in a boiling Water bath, taking care to avoid exposure to strong light. From time to time, several drops of the heated fat was tasted using a clean glass rod every time. The time required for the taste of the fat to become definitely rancid was recorded. However, the test was discontinued after 48 hours.

While selective hydrogenation of the fats and oils can be effected in any suitable way, such as by mixing the fats and oils with a nickel catalyst and introducing hydrogen, it is especially preferred to use a copper binary catalyst of the type disclosed in Serial No. 4,231, filed January 25, 1960, and assigned to the assignee of the present invention. Such catalysts are comprised of coprecipitates of copper and a combining metal other than alkaline earth metals and heavy metals, chromium, aluminum and zinc being the preferred combining metals. The copper binary catalyst is formed by coprecipitation at a controlled pH between 7 and 11. It has been found that copper binary catalysts can effect the desired lowering of the iodine value much more easily than other types of hydrogenation catalysts.

It is to be understood that the invention is not limited to the specific details of the examples herein described but can be practiced in other ways Without departure from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. A process for treating animal and vegetable fats and oils having an iodine value of about to 70, which comprises selectively hydrogenating the material to a slight degree to lower the iodine value thereof not more than 10 in order to change the poly-unsaturated constituents to mono-unsaturated without changing the initial mono-unsaturated constituents and without forming stearates and iso-oleates, dissolvingthe hydrogenated material in a solvent and fractionating the solution into three fractions which respectively consist mainly of (a) trisaturated glycerides, (b) di-saturated glycerides and monosaturated glycerides, and (c) mono-saturated glycerides and tri-unsaturated glycerides.

2. A process according to claim 1 in which the fractionating step is carried out by holding the temperature of the solution at a first level to cause crystallization of one fraction of the solution and then holding the remainder of the solution at a second level to cause crystallization of the second fraction therefrom and then utilizing the remaining solution to form the third fraction.

3. A process according to claim 2 in which the temperature levels lie Within a range between 20 degrees C. and 30 degrees C.

4. A process according to claim 1 in which the fraction (a) has a melting point in excess of about degrees C. and an iodine value of less than about 20, the fraction (c) has an iodine value of greater than about 5 8 and a clouding point of less than about 10 degrees C., and the fraction (b) includes the remainder of the material.

References Cited in the file of this patent UNITED STATES PATENTS 2,380,408 Buxton July 31, 1945 2,898,211 Barsky et a1. Aug. 4, 1959 2,942,984 Wissebach June 28, 1960 FOREIGN PATENTS 504,884 Canada Aug. 3, 1954

Claims (1)

1. A PROCESS FOR TREATING ANIMAL AND VEGETABLE FATS AND OILS HAVING AN IODINE VALUE OF ABOUT 40 TO 70, WHICH COMPRISES SELECTIVELY HYDROGENATING THE MATERIAL TO A SLIGHT DEGREE TO LOWER THE IODINE VALUE THEREOF NOT MORE THAN 10 IN ORDER TO CHANGE THE POLY-UNSATURATED CONSTITUENTS TO MONO-UNSATURATED WITHOUT CHANGING THE INITIAL MONO-UNSATURATED CONSTITUENTS AND WITHOUT FORMING STEARATES AND ISO-OLEATES, DISSOLVING THE HYDROGENATED MATERIAL IN A SOLVENT AND REFRACTIONATING THE SOLUTION INTO THREE FRACTIONS WHICH RESPECTIVELY CONSIST MAINLY OF (A) TRISATURATED GLYCERIDES, (B) DI-SATURATED GLYCERIDES AND MONOSATURATED GLYCERIDES, AND (C) MONO-SATURATED GLYCERIDES AND TRI-UNSATURATED GLYCERIDES.