US3887431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Yeast protein isolate with reduced nucleic acid content and process of making same
Assignee: Anheuser Busch Companies LLC
•
Filing: 1972-11-29
•
Granted: 1975-06-03
•
Expires: 1992-11-29
Abstract
Abstract This disclosure relates to a yeast protein isolate (IYP) with less than 9% nucleic acid (RNA) and a Protein Equivalence Ratio (PER) of greater than 1. The yeast protein is made by a process which involves rupturing yeast cells, removing the cell wall residue from an alkaline medium, incubating in such a manner that the endogenous nuclease contained in the solubles portion degrades the nucleic acid present to a soluble form, insolubilizing the protein to separate it from the hydrolyzed nucleic acid, and separating the insoluble protein from the fraction containing soluble nucleic acid. The composition of the yeast protein isolate is 65-85% protein; 0.5-9% nucleic acid (preferably less than 5% and ideally less than 3% RNA); 7-15% lipid; 1-5% ash; and 5-20% carbohydrate.
Inventors
- 👤 Ernest Aleck Robbins
- 👤 Robert William Sucher
- 👤 Jr Erich Henry Schuldt
- 👤 Daniel Robert Sidoti
- 👤 Robert Dudley Seeley
- 👤 Jon Albert Newell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:04
CPC Classifications
C; C12; C12N; C12N1/00; C12N1/005; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/911; Y10S435/94; Y10S435/941; Y10S435/942; Y10S530/00; Y10S530/82; Y10S530/821; Y10S530/823; Y10S530/824
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
69 words
A protein concentrate isolated from yeast which protein concentrate contains on a dry solids basis from about 65% to about 85% protein, about 0.5% to 9% nucleic acid, about 7% to about 15% lipid, about 1% to about 5% ash, and about 5% to about 20% carbohydrate, said protein concentrate being essentially free from cell wall residue and insoluble in water and having a PER greater than about 1.0.
Claim 2
Dependent Claim
69 words
A protein concentrate isolated from yeast which protein concentrate contains on a dry solids basis from about 65% to about 85% protein, about 0.5% to 9% nucleic acid, about 7% to about 15% lipid, about 1% to about 5% ash, and about 5% to about 20% carbohydrate, said protein concentrate being essentially free from cell wall residue and insoluble in water and having a PER greater than about 1.0.
Claim 3
Dependent Claim
16 words
The protein concentrate of claim 1 having a crude fiber content of less than about 1%.
Claim 4
Dependent Claim
14 words
The protein concentrate of claim 1 including about 0.05% to about 0.20% calcium ion.
Claim 5
Dependent Claim
13 words
The protein concentrate of claim 1 having less than about 5% nucleic acid.
Claim 6
Dependent Claim
13 words
The protein concentrate of claim 1 having less than about 3% nucleic acid.
Claim 7
Dependent Claim
62 words
A process for producing a yeast protein product comprising the steps of: a. rupturing yeast cells containing nuclease, b. separating the soluble nucleic acid, nuclease, and protein from the insoluble cell wall debris, c. hydrolyzing the nucleic acid with the nuclease, d. insolubilizing the protein, and e. separating the insoluble protein fraction from the remaining solubles fraction containing the hydrolyzed nucleic acid.
Claim 8
Dependent Claim
62 words
A process for producing a yeast protein product comprising the steps of: a. rupturing yeast cells containing nuclease, b. separating the soluble nucleic acid, nuclease, and protein from the insoluble cell wall debris, c. hydrolyzing the nucleic acid with the nuclease, d. insolubilizing the protein, and e. separating the insoluble protein fraction from the remaining solubles fraction containing the hydrolyzed nucleic acid.
Claim 9
Dependent Claim
62 words
A PROCESS FOR PRODUCING A YEAST PROTEIN PRODUCT COMPRISING THE STEPS OF: A. RUPTURING YEAST CELLS CONTAINING NUCLEASE, B. SEPARATING THE SOLUBLE NUCLEIC ACID, NUCLEASE, AND PROTEIN FROM THE INSOLUBLE CELL WALL DEBRIS, C. HYDROLYZING THE NUCLEIC ACID WITH THE NUCLEASE, D. INSOLUBILIZING THE PROTEIN, AND E. SEPARATING THE INSOLUBLE PROTEIN FRACTION FROM THE REMAINING SOLUBLES FRACTION CONTAINING THE HYDROLYZED NUCLEIC ACID.
Claim 10
Dependent Claim
62 words
A PROCESS FOR PRODUCING A YEAST PROTEIN PRODUCT COMPRISING THE STEPS OF: A. RUPTURING YEAST CELLS CONTAINING NUCLEASE, B. SEPARATING THE SOLUBLE NUCLEIC ACID, NUCLEASE, AND PROTEIN FROM THE INSOLUBLE CELL WALL DEBRIS, C. HYDROLYZING THE NUCLEIC ACID WITH THE NUCLEASE, D. INSOLUBILIZING THE PROTEIN, AND E. SEPARATING THE INSOLUBLE PROTEIN FRACTION FROM THE REMAINING SOLUBLES FRACTION CONTAINING THE HYDROLYZED NUCLEIC ACID.
Claim 11
Dependent Claim
16 words
The process of claim 6 wherein the yeast cells are ruptured by homogenization below about 50*C.
Claim 12
Dependent Claim
38 words
The process of claim 6 wherein the ruptured yeast cells are extracted at a pH above about 5.5 and a temperature below about 60*C. to place the nuclease, the nucleic acid, and the protein in the solubles fraction.
Claim 13
Dependent Claim
48 words
The process of claim 8 wherein the solubles fraction after separation of the cell wall debris is incubated at a pH of 4.5 to 8.5 for 15 to 120 minutes and a temperature of 40* to 65*C. to increase the nuclease activity and reduce the nucleic acid content.
Claim 14
Dependent Claim
23 words
The process of claim 9 wherein the temperature during the separation of the protein from the solubles fraction is at least above 60*C.
Claim 15
Dependent Claim
20 words
The process of claim 6 wherein CaCl2 is added after hydrolyzing the nucleic acid prior to separating the protein fraction.
Claim 16
Dependent Claim
55 words
The process of claim 6 including the step of recovering an isolated yeast protein having a composition on a dry solids basis of about 65% to about 85% protein, about 0.5% to about 9% nucleic acid, about 7% to about 15% lipid, about 1% to about 5% ash, and about 5% to about 20% carbohydrate.
Claim 17
Dependent Claim
19 words
The process of claim 12 wherein the recovered product has a nucleic acid content of less than about 3%.
Claim 18
Dependent Claim
140 words
A process comprising the steps of: a. growing a food grade yeast containing endogenous nuclease on a nutrient media. b. harvesting and washing the yeast cells, c. rupturing the yeast cells at a temperature between 0* and about 50*C., d. holding the ruptured cells at a pH between about 5.5 and about 11.0 and at a temperature not greater than about 60*C. for a time not greater than about 60 minutes, e. removing the yeast insolubles at a temperature not greater than about 60*C. f. incubating the yeast solubles at a temperature not greater than about 60*C. and at a pH between 5 and about 8 for a time sufficient to decrease the nucleic acid content of the harvested protein, and g. removing the yeast protein at a temperature between 0*C. and 100*C. at a pH between 4 and 10.
Claim 19
Dependent Claim
140 words
A process comprising the steps of: a. growing a food grade yeast containing endogenous nuclease on a nutrient media. b. harvesting and washing the yeast cells, c. rupturing the yeast cells at a temperature between 0* and about 50*C., d. holding the ruptured cells at a pH between about 5.5 and about 11.0 and at a temperature not greater than about 60*C. for a time not greater than about 60 minutes, e. removing the yeast insolubles at a temperature not greater than about 60*C. f. incubating the yeast solubles at a temperature not greater than about 60*C. and at a pH between 5 and about 8 for a time sufficient to decrease the nucleic acid content of the harvested protein, and g. removing the yeast protein at a temperature between 0*C. and 100*C. at a pH between 4 and 10.
Claim 20
Dependent Claim
29 words
A process according to claim 14 in which the food grade yeast is selected from a strain of Saccharomyces cerevisiae, Saccharomyces fragilis, Saccharomyces carlsbergensis, Candida utilis, and Saccharomyces elipsoideus.
Claim 21
Dependent Claim
21 words
A process according to claim 14 in which the yeast cells are ruptured at a temperature falling between 0*C. and 10*C.
Claim 22
Dependent Claim
20 words
A process according to claim 14 in which the ruptured yeast cells are adjusted to pH 8.5 to pH 10.5.
Claim 23
Dependent Claim
17 words
A process according to claim 14 in which the ruptuRed yeast cells are adjusted to pH 9.5.
Claim 24
Dependent Claim
26 words
A process according to claim 14 in which the yeast solubles are incubated between pH 6 and pH 7 and a temperature of 45*C. and 55*C.
Claim 25
Dependent Claim
26 words
A process according to claim 14 in which calcium chloride is added after the incubation of the yeast solubles and before the removal of the protein.
Claim 26
Dependent Claim
24 words
A process according to claim 20 in which the calcium chloride addition amounts to 0.1 and 1.0% of the weight of the solids present.
Claim 27
Dependent Claim
24 words
A process according to claim 20 in which the calcium chloride addition amounts to 0.2 to 0.4% of the weight of the solids present.
Claim 28
Dependent Claim
19 words
A process according to claim 20 in which the yeast protein is concentrated and deflavored by treatment in vacuo.
Claim 29
Dependent Claim
20 words
A process according to claim 14 in which the yeast protein is removed at a temperature between 50*C. and 85*C.
References Cited (Backward Citations)
US3268412A
Cited
US3585179A
Cited
US3615654A
Cited
US3681195A
Cited
US3718541A
Cited
US3634194A
Cited
US3725075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |