PROCESS FOR IMPROVING THE COOKING STABILITY OF SOYBEAN OIL

• US 3,758,532 A
• Filed: 09/11/1970
• Issued: 09/11/1973
• Est. Priority Date: 09/11/1970
• Status: Expired due to Term

• Current Assignee: Walter P. Gibble
• Original Assignee: Walter P. Gibble
• Inventors: Gibble, Walter P.
• Primary Examiner(s): Gotts, Lewis
• Assistant Examiner(s): Love, Ethel G.
• Application Number:
  US05/071,328
• Time in Patent Office: 1,096 Days
• Field of Search: 260/420,428,419
• US Class Current: 554/191
• CPC Class Codes: A23D 9/02 characterised by the production or working-up

Abstract

Unhydrogenated or partially hydrogenated refined soybean oil is degassed under vacuum to remove a substantial proportion of the air dissolved in the oil; the degassed oil is gassed with carbon dioxide and heated to a temperature above 100* C. in the presence of a copper chromite catalyst, optionally in the presence of activated charcoal. After the heat treatment the oil is cooled, filtered, bleached, and deodorized to yield the finished treated oil. The finished treated oil exhibits a frying and odor stability far surpassing soybean oil treated in any other manner.

Claims

2. The process according to claim 1 wherein the mixture contains about 0.01% to about 0.2% by weight of copper chromite.

3. The process according to claim 1 wherein the mixture is heated for a period of at least one-half hour.

4. The process according to claim 1 wherein the copper chromite contains by weight from about 7% to about 65% nonelemental copper and from about 4% to about 41% by weight nonelemental chromium.

5. The process according to claim 4 wherein the copper chromite includes by weight from about 4% to about 14% nonelemental barium.

6. The process according to claim 4 wherein the copper chromite includes by weight from about 2% to about 6% zirconium.

7. The process according to claim 1 wherein the mixture further contains a predetermined amount of activated charcoal.

8. The process according to claim 7 wherein the mixture contains about 0.01% to about 0.2% by weight of activated charcoal.

9. The process according to claim 1 including the additional steps of:

degassing the filtered oil to remove a substantial portion of the carbon dioxide gas contained therein; and

gassing the degassed oil with nitrogen gas before deodorization.

10. In a method of improving the flavor stability at frying temperature of unhydrogenated and partially hydrogenated refined soybean oil which comprises the steps of:

degassing refined, unhydrogenated or partially hydrogenated soybean oil under vacuum conditions to remove a substantial portion of the atmospheric gases from the oil; and

saturating the soybean oil with carbon dioxide gas, adding a predetermined amount of copper chromite and finely powdered activated charcoal to the oil to form a mixture, and heating the mixture in a carbon dioxide gas atmosphere at a temperature from about 90*C to about 300*C for a period of at least one-half hour.

11. The process according to claim 10 wherein the copper chromite contains by weight about 7% to about 65% nonelemental copper and about 4% to about 41% nonelemental chromium.

12. The process according to claim 11 wherein a copper chromite includes about 4% to about 14% nonelemental barium.

13. The process according to claim 10 wherein the copper chromite is powdered Girdler brand copper chromite catalyst G-22.

14. The process according to claim 13 wherein the mixture is heated to a temperature of about 250*C during the heating step.

15. The process according to claim 10 including the additional steps of:

cooling the heated oil mixture to a temperature below 75* C.after the heating step;

filtering the cooled oil mixture to remove the solids therefrom;

degassing the filtered oil under vacuum conditions to remove a substantial portion of the carbon dioxide gas therefrom; and

gassing the degassed oil with nitrogen gas.

16. The process according to claim 15 including the additional steps of:

bleaching the treated oil with bleaching clay at an elevated temperature in a nitrogen gas atmosphere after gassing the degassed oil with nitrogen gas; and

deodorizing the bleached oil with steam under vacuum conditions.

17. The process according to claim 10 wherein the mixture contains about 0.065% to about 0.1%, by weight, of the copper chromite and with about 0.065% to about 0.1% by weight, of the charcoal.

18. The process according to claim 17 wherein the mixture is heated to a temperature of about 250*C for about 1 hour.

19. In a method of improving the stability of unhydrogenated and partially hydrogenated refined soybean oil for frying purposes which comprises:

heating carbon dioxide saturated unhydrogenated or partially hydrogenated refined soybean oil with, by weight, about 0.065% to about 0.1% of a copper chromite and about 0.065% to about 0.1% of a finely powdered activated charcoal in a carbon dioxide gas atmosphere at a temperature of about 250* C. for about 1 hour, said soybean oil being substantially free of atmospheric gases.