Protein product of reduced nucleic acid content and low allergenicity
AssigneePhillips Petroleum Company
InventorsEugene H. Wegner, Lucas K. Shay
Life of this patent
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Abstract
A nucleic acid-reduced substantially allergen-free single cell protein product is obtained by culturing a yeast, fungi or bacterium on an ultra-low sulfate medium, treating the produced cells with a base at a pH of about 9.5 with moderate heat, thereafter treating the base-treated cells with acid to a pH of about 4 with moderate heat, and treating the base-treated acid-treated cells with a relatively high temperature short time heat shock, followed by extrusion. Optionally, the extruded product is annealed.
Claims14
A process to produce microbial cellular derived protein product which comprises the steps:
- (1) growing single cell microorganisms on ultra-low sulfur medium wherein said medium contains less than about 0.44 grams sulfur per liter of aqueous ferment, under aerobic aqueous fermentation conditions employing a carbon energy substrate;
- (2) creaming the resulting single cells in admixture with sufficient water to form a cream containing about 10 to 25 weight percent cells;
- (3) base-treating the said cream employing sufficient base to produce a pH of about 7 to 10, at a temperature of about 65.degree. C. to 99.degree. C., for a time of about 15 to 120 minutes;
- (4) thereafter acid-treating the base-treated cells as said cream employing sufficient acid to produce a pH of about 3 to 4.5, at a temperature of about 75.degree. C. to 95.degree. C., for a time of about 15 to 120 minutes;
- (5) heat-shocking the base-treated acid-treated cells as said cream at a temperature of about 100.degree. C. to 150.degree. C. for a time of about 30 to 120 seconds;
- (6) reducing the water content of said cream to about 15 to 40 weight percent, thereby forming a paste of said base-treated acid-treated cells;
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- (7) extruding the base-treated acid-treated heat-shocked cells as said paste at a temperature of about 65.degree. C. to 205.degree. C., under a pressure of about 10 to 100 psig;
- thereby producing an extruded microbial cellular derived protein product exhibiting low nucleic acid content and low alergens content toward human consumption.
A process to produce microbial cellular derived protein product which comprises the steps:
- (1) producing single-cell microorganisms by growing a Pichia pastoris innoculum on ultra-low sulfur medium containing less than about 0.44 grams sulfur per liter of aqueous ferment under aerobic aqueous fermentation conditions employing carbon energy substrate;
- (2) forming an aqueous cream of the resulting cells containing about 10 to 25 weight percent cells,
- (3) base-treating said cream with sufficient base to produce a pH of about 7 to 10, at a temperature of about 65.degree. C. to 99.degree. C., for a time of about 15 to 120 minutes;
- (4) thereafter acid-treating the base-treated cream with sufficient base to produce a pH of about 3 to 4.5, at a temperature of about 75.degree. C. to 95.degree. C., for a time of about 15 to 120 minutes;
- (5) heat-shocking the base-treated acid-treated cream at a temperature of about 100.degree. C. to 150.degree. C., for a time of about 30 to 120 seconds;
- (6) preparing a paste of said base-treated acid-treated heat-shocked cells to contain about 15 to 40 weight percent water;
- (7) extruding said paste at a temperature of about 65.degree. C. to 205.degree. C., under a pressure of about 10 to 100 psig;
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- (8) time-tempering the extruded nroduct from said step (7) for a time of about 1 to 30 months, protected from air, such that said product is subjected to at least one high temperature cycle of about 90.degree. F. to 100.degree. F. for about 5 to 30 days, and at least one low temperature cycle of about 0.degree. F. to 30.degree. F. for about 5 to 30 days;
- thereby preparing an extruded protein product of reduced nucleic acid content and substantially allergens free content for human consumption.
Dependencies are inferred from the claim text.