US3867555A
Expired / Lapsed
US
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Manufacture of yeast protein isolate having a reduced nucleic acid content by an alkali process
Assignee: Anheuser Busch Companies LLC
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Filing: 1972-11-29
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Granted: 1975-02-18
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Expires: 1992-11-29
Abstract
Abstract This disclosure relates to a process for producing a yeast protein isolate (IYP) by treating the protein with alkali under controlled temperature conditions to reduce the nucleic acid (RNA) content of the protein. The yeast cells are ruptured by homogenization; extracted to remove the protein from the cells; and the cell wall debris separated by centrifugation. The solubles fraction (which contains protein and nucleic acid) is treated with alkali in either a high temperature low alkali process (pH 10 to 10.5; temp. 75* to 85*C.; time 1 to 4 hours), or a low temperature high alkali process (pH 11.5 to 12.5; temp. 55* to 65*C.; and time 1 to 2 hours) to hydrolyze the nucleic acid. The protein is acid precipitated and washed to produce a final IYP of low RNA content.
Inventors
- 👤 Jon Albert Newell
- 👤 Ernest Aleck Robbins
- 👤 Robert Dudley Seeley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:52
CPC Classifications
C; C12; C12N; C12N1/00; C12N1/005; Y; Y10; Y10S; Y10S530/00; Y10S530/82; Y10S530/823; Y10S530/824
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
101 words
A PROCESS FOR PRODUCING A YEAST PROTEIN PRODUCT COMPRISING THE STEPS OF: A. RUPTURING YEAST CELLS, B. SEPARATING A SOLUBLES FRACTION CONTAINING THE NUCLEIC ACID AND PROTEIN FROM AN INSOLUBLE CELL WALL DEBRIS FRACTION, C. HYDROLYZING THE NUCLEIC ACID WITH ALKALI AT A PH OF ABOUT 9.5 TO ABOUT 12.5 AND A TEMPERATURE OF ABOUT 50*C. TO ABOUT 120*C. FOR LESS THAN 4 HOURS, D. PRECIPITATING THE PROTEIN BY THE ADDITION OF ACID TO A PH OF ABOUT 2 TO ABOUT 6 AND A TEMPERATURE OF 0*-100*C., AND E. SEPARATING THE INSOLUBLES PROTEIN PRODUCED FROM THE NUCLEIC ACID CONTAINING SOLUBLES PART.
Claim 2
Dependent Claim
101 words
A PROCESS FOR PRODUCING A YEAST PROTEIN PRODUCT COMPRISING THE STEPS OF: A. RUPTURING YEAST CELLS, B. SEPARATING A SOLUBLES FRACTION CONTAINING THE NUCLEIC ACID AND PROTEIN FROM AN INSOLUBLE CELL WALL DEBRIS FRACTION, C. HYDROLYZING THE NUCLEIC ACID WITH ALKALI AT A PH OF ABOUT 9.5 TO ABOUT 12.5 AND A TEMPERATURE OF ABOUT 50*C. TO ABOUT 120*C. FOR LESS THAN 4 HOURS, D. PRECIPITATING THE PROTEIN BY THE ADDITION OF ACID TO A PH OF ABOUT 2 TO ABOUT 6 AND A TEMPERATURE OF 0*-100*C., AND E. SEPARATING THE INSOLUBLES PROTEIN PRODUCED FROM THE NUCLEIC ACID CONTAINING SOLUBLES PART.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the yeast cells are ruptured by homogenization below about 50*C.
Claim 4
Dependent Claim
37 words
The process of claim 1 wherein the ruptured yeast cells are extracted at a pH between about 5.5 and about 11 and a temperature between about 25*C. and about 60*C. for about 5 to about 60 minutes.
Claim 5
Dependent Claim
27 words
The process of claim 3 wherein the ruptured yeast cells are extracted at pH 9.5 at a temperature between 25*C. and 60*C. for 5 to 60 minutes.
Claim 6
Dependent Claim
19 words
The process of claim 3 wherein the ruptured yeast cells are extracted at pH 9.5, 60*C., for 30 minutes.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein the insoluble cell wall material is separated by centrifugation.
Claim 8
Dependent Claim
43 words
The process of claim 1 wherein the solubles fraction after the separation of the cell wall debris is treated with alkali at a pH between about 9.5 and about 12.5, a temperature between about 50*C. and about 120*C., for up to 4 hours.
Claim 9
Dependent Claim
32 words
The process of claim 7 wherein the solubles fraction is treated with alkali at a pH of 10.0 to 10.5, a temperature of 75*-85*C., for a time of 1 to 4 hours.
Claim 10
Dependent Claim
31 words
A process according to claim 7 wherein the solubles fraction is treated with alkali at a pH of 11.5-12.5, a temperature of 55*-65C., for a time of 1 to 2 hours.
Claim 11
Dependent Claim
25 words
A process according to claim 7 wherein the solubles fraction is treated with alkali at pH 9.5 at 115*-120*C. for Not greater than 1 hour.
Claim 12
Dependent Claim
35 words
A process according to claim 1 wherein the protein product is precipitated by the addition of acid to a pH between about 3.5 and about 5.5, at a temperature between about 5*C. and about 90C.
Claim 13
Dependent Claim
37 words
A process according to claim 11 wherein the protein product is precipitated by the addition of hydrochloric or phosphoric acid to pH about 4.0 to about pH 5.0 at a temperature between about 50*C. and about 80*C.
Claim 14
Dependent Claim
30 words
The process according to claim 12 wherein the precipitated protein is recovered by centrifugation at pH about 4.0 to about 5.0 at a temperature between about 50*C. and about 80*C.
Claim 15
Dependent Claim
16 words
The process of claim 13 wherein the recovered yeast protein contains less than about 5% RNA.
Claim 16
Dependent Claim
16 words
The process of claim 13 wherein the recovered yeast protein contains less than about 3% RNA.
Claim 17
Dependent Claim
30 words
The process according to claim 1 wherein the precipitated protein is recovered by centrifugation at pH about 4.0 to about 5.9 at a temperature between about 0* and about 100*C.
Claim 18
Dependent Claim
16 words
A process according to claim 16 wherein the recovered protein is concentrated and deflavored in vacuo.
Claim 19
Dependent Claim
23 words
A process according to claim 17 in which the food grade yeast is selected from the strain of Saccharomyces cerevisiae and Candida utilis.
Claim 20
Dependent Claim
52 words
The process of claim 1 including the step of recovering a yeast protein product comprising: about 65% to about 85% protein; about 0.5% to about 9% RNA; about 7% to about 15%; lipid; about 1 to about 5% ash; about 5 to about 20% carbohydrate; and about 0% to about 1% fiber.
Claim 21
Dependent Claim
148 words
A process comprising the steps of: a. Growing a food grade yeast on nutrient media, b. Harvesting and washing the yeast cells, c. Rupturing the yeast cells at a temperature between 0* and 50*C., d. Holding the ruptured cells at a pH between about 7.0 and about 11.0 at a temperature not greater than about 70*C. for a time not greater than about 5 minutes, e. Removing the yeast insolubles at a temperature not greater than about 75*C., f. Incubating the yeast solubles at a temperature of about 80*C. and at a pH between about 10.0 and about 10.5 for a time sufficient to decrease the nucleic acid content of the harvested protein, g. Precipitating the protein by the addition of a food grade acid to pH about 4.0 to pH about 5.0, and h. Removing the yeast protein at a temperature between about 0*C. and about 80*C.
Claim 22
Dependent Claim
148 words
A process comprising the steps of: a. Growing a food grade yeast on nutrient media, b. Harvesting and washing the yeast cells, c. Rupturing the yeast cells at a temperature between 0* and 50*C., d. Holding the ruptured cells at a pH between about 7.0 and about 11.0 at a temperature not greater than about 70*C. for a time not greater than about 5 minutes, e. Removing the yeast insolubles at a temperature not greater than about 75*C., f. Incubating the yeast solubles at a temperature of about 80*C. and at a pH between about 10.0 and about 10.5 for a time sufficient to decrease the nucleic acid content of the harvested protein, g. Precipitating the protein by the addition of a food grade acid to pH about 4.0 to pH about 5.0, and h. Removing the yeast protein at a temperature between about 0*C. and about 80*C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |