US3748265A - Oxidation- and low temperature-resistant glycerides of natural fatty acids - Google Patents

Abstract

GLYCERIDE MIXTURES RESISTANT TO OXIDATION AND LOW TEMPERATURES COMPRISING 10-99% BY WEIGHT OF DIACETYL MONOMONOHEXADECANOLY TRIGLCERIDE, AND/OR UP TO 90% BY MONOHEXADECANOYL TRIGLYCERIDE, AND/OR UP TO 90% BY WEIGHT OF DIACETYL MONOTETRADECANOYL TRIGLCERIDE, AS WELL AS OPTIONALLY UP TO 10% BY WEIGHT OF AN ACETYL DIALKANOYL TRIGLYCERIDE WHEREIN THE ALKANOYL GROUPS THEREOF HAVE 1216 CARBON ATOMS.

Description

United States Patent 3,748,265 OXIDATION- AND LOW TEMPERATURE-RESIST- ANT GLYCERIDES OF NATURAL FATTY AClDS Heinrich Biinger, Witten-Bommern, and Gustav Renclrhofi, Witten, Germany, assiguors to Dynamit Nobel Aktiengesellschaft, Troisdorf, Germany N0 Drawing. Filed Mar. 1, 1971, Ser. No. 119,828

lint. Cl. C091; 3/20 US. Cl. 252-]. 13 Claims ABSTRACT OF THE DISCLOSURE Glyceride mixtures resistant to oxidation and low temperatures comprising -99% by weight of diacetyl monododecanoyl triglyceride, up to 25% by weight of diacetyl monohexadecanoyl triglyceride, and/or up to 90% by Weight of diacetyl monotetradecanoyl triglyceride, as well as optionally up to 10% by weight of an acetyl dialkanoyl triglyceride wherein the alkanoyl groups thereof have 12- 16 carbon atoms.

Liquid glycerides of natural fatty acids are employed in a great variety of fields, for example in the pharmaceutical and cosmetic industries, in [food technology, as well as in the technical sector. In most cases, they must meet the requirements of being physiologically accetpable as well as nonfreezing, capable of readily dissolving fats and waxes, and having a low vapor pressure.

Glycerides are employed, for example, which contain bound therein also unsaturated fatty acids, in addition to saturated ones. Such glycerides are prone to autoxidation; they become more or less readily rancid in dependence on the external conditions (Neuwald, F.; Winkler, A.: J. Soc. Cosmetic Chemists 16 (1965), pp. 679-85). This phenomenon can be prevented by antioxidants; however, the addition of such agents is in many cases undesirable.

Furthermore, triglycerides of fully saturated fatty acids are known which are liquid at low temperatures (for example, German Pat. 944,394). However, the glycerides contain considerable proportions of [fatty acid residues of less than 12 carbon atoms. By minor splitting reactions taking place during use, for example by lipases, a typically soapy odor develops.

Also, liquid glycerides containing aceto groups have been described in the literature (The Journal of the American Oil Chemists Society 35 (1958), pp. 122-7). However, these glycerides, due to their composition, like wise exhibit the tendency toward rancidity or toward splitting off fatty acids causing an intensely soapy odor.

It has now been found that a triglyceride fulfills all practical requirements and does not exhibit the disadvantages of the triglycerides known heretofore, i.e. a triglyceride which is oxidation-resistant, does not liberate intensely soapy smelling fatty acids upon a splitting reaction, does not exhibit any crystalline deposits after being stored for a longer period of time at 0 C., and is not hydrolyzed upon contact with Water, if the molecule of such triglyceride exhibits two acetyl groups and one dodecanoyl group.

All of these properties are also retained if this triglyceride is present in a mixture with glycerides of a specific structure modified with respect to the higher fatty acid residue. The mixture component can be a triglyceride containing, in addition to two acetyl groups, the residue of a fatty acid exhibiting more than 12 carbon atoms. Also in this case, the formation of fatty acids of an intensely soapy odor is avoided during the occurrence of a splitting reaction. In view of the requirement that a liquid 3,?43,Z05 Patented July 24, 1973 "ice consistency must be present at 0 C., there is, in this case, merely a limitation with respect to the chain length of the acid residue, which latter is to have no more than 16 carbon atoms. Such mixtures can contain, in addition to diacetyl monododecanoyl glycerol, up to 25% by weight of diacetyl monohexadecanoyl glycerol or up to by weight of diacetyl monotetradecanoyl glycerol.

It is also possible to admix to the triglyceride with two acetyl groups and one dodecanoyl group in the molecule, as well as to the above-mentioned mixtures, up to 10% by weight of acetyl dialkanoyl glycerol, wherein the alkanoyl groups, in turn, can contain l2-16 carbon atoms.

Furthermore, such a number of diglycerides can be contained therein that a hydroxyl number of up to 20 results.

The glyceride of this invention can be produced, according to one process, by the esterification of lauric acid with excess glycerol and isolation of the thus-formed mono-glyceride by molecular distillation, whereupon an acetylation of the monoglyceride is connected with acetic anhydride to produce the triglyceride. Furthermore, the triglyceride of this invention can be obtained by the interesterifieation of tridodecanoyl glycerol with triacetin and separation of the reaction product by molecular distillation.

Since the glyceride of this invention can also retain its advantageous properties in a mixture with other glycerides, it is possible to make a suitable selection, during the manufacture thereof, among the technical fatty acid blends commercially available.

EXAMPLE 1 Lauric acid monoglyceride was enriched by molecular distillation from a lauric acid partial glyceride mixture This monoglyceride was pure, as determined by gas chromatography, and exhibited the following characteristics:

Melting point C 63.0 Acid number 0.88 Saponification number 207 Hydroxyl number 409 Fifty grams of this monoglyceride was refluxed with g. of acetic anhydride under normal pressure for two hours. Then the acetic acid and excess acetic anhydride were distilled off, at last under vacuum. Thereafter, steam was passed through the product for two hours at C. and 20 torr (mm. Hg). The product, after this step, exhibited a hydroxyl number of 0, an acid number of 0.8, and a saponification number of 467 (calculated value: 469). The refractive index at 20 C., measured by dylight, was 1.4475; the substance solidified at 2l.0 C. and boiled at 197 C. and 1.5 torr.

EXAMPLE 2 A lauric acid partial glyceride fraction obtained during molecular distillation with the following data: melting point, 60 C.; hydroxyl number, 381; saponification number, 214; acid number, 2.2; consisted, in accordance with analysis by gas chromatography, of 90.5% monoglyceride and 9.5% diglyceride. This fraction was acetylated in correspondence with Example 1, thus resulting in a product having a hydroxyl number of 0, a saponification number of 462, and an acid number of 2.35. This product remained completely clear after being stored for one week at 0 C.

EXAMPLE 3 Analogously to Example 1, 100 g. of myristic acid monoglyceride (diglyceride content: 8.8% by weight;

melting point: 69 0.; hydroxyl number: 330.0; saponification number: 117.5; acid number: 1.28) was reacted with 100 g. of acetic anhydride and then worked up. A mixture of 85 parts by Weight of the product (hydroxyl number: saponification number: 469; acid number: 0) with 15 parts by weight of diacetyl monododecanoyl glycerol remained completely clear after a longer period of storage at 0 C.

EXAMPLE 4 78 parts by weight of diacetyl monododecanoyl glycerol was mixed with 22 parts by weight of diacetyl monohexadecanoyl glycerol. The mixture remained completely clear after a longer period of storage at 0 C.

EXAMPLE 5 Ten parts by weight of diacetyl monohexadecanoyl glycerol, 40 parts by Weight of diacetyl monotetradecanoyl glycerol, and 50 parts by weight of diacetyl monododecanoyl glycerol were mixed with one another. The mixture remained completely clear after being stored at 0 C. for a longer period of time.

We claim:

1. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of to 99% by weight of diacetyl monododecanoyl triglyceride, up to 90% by weight of diacetyl monotetradecanoyl triglyceride, and up to 25% by weight of diacetyl monohexadecanoyl triglyceride.

2. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with Water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride and up to 90% by weight of diacetyl monotetradecanoyl triglyceride.

3. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 75 to 99% by weight of diacetyl monododecanoyl triglyceride and 1 to 25% by weight of diacetyl monohexadecanoyl triglyceride.

4. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 25% by weight of diacetyl monohexadecanoyl triglyceride, and up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms.

5. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 25% by weight of diacetyl monohexadecanoyl triglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms, and up to 90% by weight of diacetyl monotetradecanoyl triglyceride.

6. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits of 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze'with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 90% by weight of diacetyl monotetradecanoyl triglyceride, and up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms.

7. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to by weight of diacetyl monotetradecanoyl triglyceride, up to 25% by weight of diacetyl monohexadecanoyl triglyceride, and suflicient diglycerides that the resultant glyceride mixture has a hydroxyl number of up to 20.

8. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl tri-= glyceride, up to 90% by weight of diacetyl monotetradecanoyl triglyceride, and sufiicient diglycerides that the resultant glyceride mixture has a hydroxyl number of up to 20.

9. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 75 to 99% by weight of diacetyl monododecanoyl triglyceride, 1 to 25% by weight of diacetyl monohexadecanoyl triglyceride, and sufiicient diglycerides that the resultant glyceride mixture has a hydroxyl number of up to 20.

10. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 25% by weight of diacetyl monohexadecanoyl triglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms, and sufficient diglycerides that the resultant glyceride mixture has a' hydroxyl number of up to 20.

11. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 25 by weight of diacetyl monohexadecanoyl triglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms, up to 90% by weight of diacetyl tetradecanoyl triglyceride, and sufficient diglycerides that the resultant glyceride mixture has a hydroxyl number of up to 20.

12. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits of 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of 10 to 99% by weight of diacetyl monododecanoyl triglyceride, up to 90% by weight of diacetyl monotetradecanoyl triglyceride, up to 10% by weight of an acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms, and sufiicient diglycerides that the resultant glyceride mixture has a hydroxyl number of up to 20.

13. An oxidation-resistant glyceride mixture, which does not exhibit crystalline deposits at 0 C., does not liberate fatty acids having an intensely soapy odor when cleaved and does not hydrolyze with water, consisting essentially of: (a) 10 to 90% by weight of diacetyl monododecanoyl triglyceride and another triglyceride component selected from the group consisting of (b) up to 25% by weight of diacetyl monohexadecanoyl triglyceride, (c) up to 10% by weight of acetyl dialkanoyl triglyceride, the alkanoyl groups thereof having from 12 to 16 carbon atoms, (d) up to 90% by weight of diacetyl monotetradecanoyl triglyceride and a combination of (b), (c), and (d); and (e) sufficient diglycerides that the resultant glyc- 3,748,265 5 6 eride mixture has a hydroxyl number of up to 20, each OTHER REFERENCES weight percent being based on the total weight of the I. Am Oil Chemists, Soc March 1958 VOL XXXV glyceride mixtufe- No. 3, p. 122-127, Present Status of Acetoglycerides.

References Cited UNITED STATES PATENTS 5 GEORGE F. LESMES, Primary Examiner 2,091,988 9/1937 Hubbuch et al 260-106 W- X J Assistant i er. 3,006,771 10/1961 Babayon 99 11s 2,745,749 5/1956 Peoge 61:31. 99 -11s 2,480,332 8/1949 Little 260--410.8 260-4103