Spent brewers' yeast based alternative meat

Abstract

Alternative meat from a material comprising spent brewers' yeast as the primary ingredient is provided herein. The product contains from 20% to 80% dry weight spent brewers' yeast, has a meaty flavor and texture, and a reduced RNA content, making it safe for human consumption.

Description

FIELD

The present disclosure relates to alternative meat made from spent brewer's yeast (SBY) as the primary ingredient with the inclusion of more than 20%.

BACKGROUND

Spent brewer's yeast is a by-product of the brewing industry. The spent yeast cells are removed at the end of the bulk fermentation. A small amount of it is used to start the next batch of fermentation, the remaining part of the spent yeast is discarded. This discarded yeast is high in nutrients, in particular proteins, vitamins, and minerals, as well as containing functional and biologically active compounds such as polyphenols, antioxidants, β-glucans and mannoproteins.

Production of meat substitutes from spent brewers yeast and soy protein as promising applications was described by D. L. Gibson and B. K. Dwivedi in Can Inst. Food Technol. J Vol 3, No. 3, 1970. Side effects concerns of high levels of yeast feeding on uric acid metabolism of young men, expressed by J. C. Edozien et al in Nature vol 228, 1970 set safe limits of Ribonucleic acid (RNA) for human diet at 2 g per day. Spent brewer's yeast contains about 10-15% of RNA, limiting the use of SBY in food applications by 20% inclusion.

Currently, the majority of the spent brewers' yeast is composted or used as animal feed. Animal agriculture contributes to climate change with greenhouse gas emissions, new methods of processing spent brewers' yeast for direct human consumption are required.

SUMMARY

Alternative meat from a material comprising spent brewers' yeast as the primary ingredient is provided herein. The product contains from 20% to 80% dry weight spent brewers' yeast, has a meaty flavor and texture, and a reduced RNA content, making it safe for human consumption.

It is understood that the inventions disclosed and described in this specification are not limited to the aspects summarized in this Summary. The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of various non-limiting and non-exhaustive aspects according to this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the examples, and the manner of attaining them, will become more apparent, and the examples will be better understood, by reference to the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a chicken skewer made according to Example #1.

FIG. 2 is a hop-char burger made according to Example #2.

FIG. 3 is a beef stew made according to Example #3;

FIG. 4 is a pulled pork lemongrass veggie bowl made according to Example #4.

The exemplifications set out herein illustrate certain embodiments, in one form, and such exemplifications are not to be construed as limiting the scope of the appended claims in any manner.

DETAILED DESCRIPTION OF NON-LIMITING EMBODIMENTS

Various examples are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed methods, systems, compositions, and products. The various examples described and illustrated herein are non-limiting and non-exhaustive. Thus, the invention is not limited by the description of the various non-limiting and non-exhaustive examples disclosed herein. Rather, the invention is defined solely by the claims. The features and characteristics illustrated and/or described in connection with various examples may be combined with the features and characteristics of other examples. Such modifications and variations are intended to be included within the scope of this specification. As such, the claims may be amended to recite any features or characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Further, Applicant reserves the right to amend the claims to affirmatively disclaim features or characteristics that may be present in the prior art. The various examples disclosed and described in this specification can comprise, consist of, or consist essentially of the features and characteristics as variously described herein.

Any patent, publication, or other disclosure material identified herein is incorporated herein by reference in its entirety unless otherwise indicated but only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material expressly set forth in this specification. As such, and to the extent necessary, the express disclosure as set forth in this specification supersedes any conflicting material incorporated by reference herein. Any material, or portion thereof, that is said to be incorporated by reference into this specification, but which conflicts with existing definitions, statements, or other disclosure material set forth herein, is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Applicant reserves the right to amend this specification to expressly recite any subject matter, or portion thereof, incorporated by reference herein.

Reference throughout the specification to “various examples,” “some examples,” “one example,” or “an example”, or the like, means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example. Thus, appearances of the phrases “in various examples,” “in some examples,” “in one example”, or “in an example”, or the like, in places throughout the specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more examples. Thus, the particular features, structures, or characteristics illustrated or described in connection with one example may be combined, in whole or in part, with the features structures, or characteristics of one or more other examples without limitation. Such modifications and variations are intended to be included within the scope of the present examples.

In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term “about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

All ranges recited herein are inclusive of the endpoints of the recited ranges. For example, a range of “1 to 10” includes the endpoints 1 and 10. Also, any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of “1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification.

The grammatical articles “a,” “an,” and “the,” as used herein, are intended to include “at least one” or “one or more,” unless otherwise indicated, even if “at least one” or “one or more” is expressly used in certain instances. Thus, the foregoing grammatical articles are used herein to refer to one or more than one (i.e., to “at least one”) of the particular identified elements. Further, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of the usage requires otherwise.

In this specification, unless otherwise indicated, all percentages (e.g., weight percent protein, percent protein, percent moisture) are to be understood as being based on weight.

Alternative meat from a material comprising spent brewers' yeast as the primary ingredient is provided herein. The product contains 30% dry weight spent brewers' yeast, 10% dry weight Soy protein isolate, has a meat-like appearance and palatability, 24.4% by weight total protein content similar to animal meat and 0.099% RNA by weight, which is unexpected.

Such a low RNA content allows safely eating up to 10 times the FDA recommended daily amount of protein, which is equivalent to about 2 kg of animal meat, which is 8 times higher than average daily meat consumption from red meat, poultry, and fish (boneless weight) in the US according to USDA.

TABLE 1
Methods for RNA reduction for increased SBY-based protein consumption
			Phosphate		Current
			solution,		invention,
			heat	Alkaline	mix of
			shock,	Hydrolysis	30% SBY	Upper
	Spent	Enzymatic	dialysis or	and heat	and 10%	safe level
	brewers'	hydrolysis	washing	treatment,	Soy	of RNA
	yeast	Marson,	Canepa,	Trevelyan,	protein	per day,
	untreated	2020	1972	1976	isolate	g
RNA level, %	10.00-15.00
RNA level for 50 g protein		3.33-5.00	1.67-2.00	0.57-2.39	0.20	<2
(according to FDA RDA
based on 2000 cal diet), g
RNA level for 60 g protein		4.00-6.00	2.00-2.40	0.68-2.87	0.24	<2
(average amount of protein
consumed from red meat,
poultry, and fish (boneless
weight) in the US), g
Safe amount of protein for		20.00-30.03	50.00-59.88	41.84-175.44	492.93
daily consumption based
on RNA content, g
Maximum amount of meat		0.08-0.12	0.19-0.23	0.16-0.67	1.90
to eat safely per day
(based on animal
equivalent containing 26 g
protein per 100 g), kg

Spent brewers' yeast is a broad term, which describes spent yeast derived from multiple sources. In some embodiments, the source of spent yeast is chosen from spent brewers' yeast, spent distillers' yeast, surplus yeast from ethanol manufacturing, bakers' yeast, nutritional yeast. In some embodiments, the spent yeast is derived from various strains of Saccharomycetes class, such as Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces carlsbergensis, etc.

Although currently spent brewer's yeast is mostly used for human consumption in the dried form, the use of liquid spent brewer's yeast (containing about 8-11% solids) and liquid concentrated spent brewer's yeast (containing about 15-25% solids) may benefit the manufacturing of high moisture meat analogs, simultaneously reducing costs for drying. In some embodiments, the spent yeast can be used in the dry, concentrated, liquid form, or a combination thereof. In some embodiments, the spent yeast may contain from about 10% to about 100% solids. In some embodiments, the primary ingredient can be debittered, autolyzed, or hydrolyzed.

Co-extrusion of spent brewers' yeast with secondary protein ingredients clears the aftertaste, adds meaty flavor and BBQ-like color, and reduces costs for debittering and drying. Low RNA concentration allows to increase the inclusion of spent brewers' yeast and to tweak the appearance and the taste towards chicken, fish, beef, and pork-like applications, reducing costs for secondary ingredients such as maskers, bitter blockers, flavors, and colors resulting in costs cheaper than animal meat.

In various examples, the product can comprise 80% of the spent brewers' yeast and 20% secondary protein ingredients. In various examples, the product can comprise 70% of the spent brewers' yeast and 30% secondary protein ingredients. In various examples, the product can comprise 60% of the spent brewers' yeast and 40% secondary protein ingredients. In various examples, the product can comprise 50% of the spent brewers' yeast and 50% secondary protein ingredients. In various examples, the product can comprise 40% of the spent brewers' yeast and 60% secondary protein ingredients. In various examples, the product can comprise 30% of the spent brewers' yeast and 70% secondary protein ingredients. In various examples, the product can comprise 20% of the spent brewers' yeast and 80% secondary protein ingredients.

Co-extrusion of spent brewers' yeast with secondary protein ingredients in their native form helped to improve succulent mouthfeel because of native fiber, capable of retaining more moisture without adding gums and binders. In some embodiments, the secondary protein ingredient is chosen from vegetable protein in its native, concentrated or isolated form, microbial protein, fungal protein, animal protein, cultured protein, or a combination thereof.

Despite having meat-like characteristics, spent brewers' yeast-based food products may benefit from the inclusion of secondary ingredients enhancing the sensory properties of the finished product. In some embodiments, the spent brewers' yeast food product may contain fat, carbohydrate, flavor, color, or a combination thereof. In some embodiments, the ingredients may contain 1-15% Fat, 0.5-2% dry weight Calcium Chloride, 0.5-1.5% dry weight gums (such as Sodium Alginate), 0.2-0.6% dry weight Lecithin.

Given different serving sizes set for different food products in some embodiments, the RNA content in the food product is easier to calculate as less than 4% of the food product's protein dry weight. In some embodiments, the RNA content in the food product is better to calculate as less than 2 g per serving.

EXAMPLES

The present disclosure will be more fully understood by reference to the following examples, which provide illustrative non-limiting aspects of the invention. It is understood that the invention described in this specification is not necessarily limited to the examples described in this section.

Example 1—Chicken Skewers, 22.2% by Weight Dry Equivalent of Spent Brewers Yeast

65% by weight liquid spent brewers' yeast, containing 11% solids, containing 49.6% protein, and 15% by weight dried spent brewers yeast, containing 51.2% protein were mixed with 20% by weight Soybean meal containing 50.4% protein and subjected to high moisture extrusion cooking at a temperature 150 C, pressure 20 bar, RPM 400 for 2 minutes.

Chicken-like skewers were prepared according to instructions: 0.5 kg of SBY-based meat cut into 25 mm square pieces. Marinated 2-6 hrs in a refrigerator (marinade: 2 tablespoons Miso paste, ¼ cup Lime juice, 1 teaspoon vegan fish sauce, 1 teaspoon shoyu, 2 teaspoons honey, 1 Jalapeno thin-sliced, 1 tablespoon toasted sesame oil). Vegetables for skewers: Crimini or shiitake mushrooms, sweet onion, Sweet pepper. Grilled on each side for 30 seconds.

The resulting product had a clean chicken-like taste with miso lime flavor and a muscle-like fibrous texture as shown in FIG. 1. The resulting product had 22.2% by weight dry equivalent of spent brewers yeast, 59.5% moisture content, 21.3% protein, and 0.072% RNA. The protein content was measured according to AACC 46-30 and AOAC 992.15. RNA extraction was performed, RNA quantification was measured via spectrophotometer and the residual RNA percentage was calculated based on the RNA concentration.

Example 2—Hop-Char Burger, 27.5% by Weight Dry Equivalent of Spent Brewers Yeast

70% by weight liquid concentrated spent brewers' yeast, containing 25% solids, containing 49.6% protein, and 10% by weight dried spent brewers yeast, containing 51.2% protein were mixed with 20% by weight Soybean meal containing 50.4% protein and subjected to high moisture extrusion cooking at a temperature 150 C, pressure 20 bar, RPM 400 for 2 minutes.

Hop-char burger was prepared according to instructions: 1 lb SBY-based meat, 6 oz cooked shiitake mushrooms, 1 tablespoon smoked paprika, 1 tablespoon honey, 1 tablespoon dark soy sauce, Irish moss equivalent of 2 small eggs, Salt & Pepper about 0.05% total weight. Meat processed in a food processor till broken down but not fully blended; mushrooms, spices, honey, soy sauce, herbs added and blended till ground beef consistency and transferred to a bowl to mix with the egg substitute till moisture content looks to match fresh ground beef. Patties formed 35 mm thick and cooked on the charbroiler.

The resulting product had a succulent mouthfeel, umami flavor, and texture of ground beef as shown in FIG. 2. The resulting product had 27.5% by weight dry equivalent of spent brewers yeast, 57.6% Moisture content, 23.9% protein, and 0.089% RNA. The protein content was measured according to AACC 46-30 and AOAC 992.15. RNA extraction was performed, RNA quantification was measured via spectrophotometer and the residual RNA percentage was calculated based on the RNA concentration.

Example 3—Beef Stew, 30% by Weight Dry Equivalent of Spent Brewers' Yeast

30% by weight dried spent brewers yeast, containing 51.2% protein were mixed with 10% by weight Soy protein isolate, containing 90% protein and subjected to high moisture extrusion cooking at a temperature 150 C, pressure 20 bar, RPM 400 for 2 minutes.

Beef stew was prepared according to instructions: 1 lb SBY-based meat cut into approximate 25 mm triangles, 8 oz yellow onion, large dice, 8 oz carrot, 1″ dice or oblique cut, 6 oz russet potatoes, peeled, large dice, ½ cup tamari (or soy sauce), 3½ cups room temperature water, 3 tablespoons raw sugar, 2 tablespoons curry powder, 3-3.5 oz prepared curry roux, 3 tablespoons neutral oil (grapeseed, avocado, canola). Marinade: combine tamari, sugar, curry powder, and 1 cup of water and whisk everything together until the sugar is dissolved. Sear SBY-based meat in a medium saucepan with 2 tablespoons of the oil for approximately 2 minutes per side. Once it's browned, plunge meat into the marinade and let it stand 10 minutes at room temperature. Using the same pan, add the remaining oil and sauté the carrots and onion over medium heat for about 3 minutes; stirring frequently. Add the potatoes, give it all a stir, and then crumble in your curry roux and then stir until it appears to be evenly distributed—about 30 seconds. Add the remaining water (2½ cups), stir, and bring the whole mixture to a boil. Once boiling, reduce heat to low, cover and simmer for about 15 minutes stirring frequently because it will want to stick. The potatoes and carrots should be slightly tender when poked with a knife at this point indicating that it's done. Serve with steamed rice.

The resulting product had a strong beefy umami flavor and a muscle-like fibrous texture as shown in FIG. 3. The resulting product had 30% by weight dry equivalent of spent brewers' yeast, 60% Moisture content, 24.4% protein, and 0.099% RNA. The protein content was measured according to AACC 46-30 and AOAC 992.15. RNA extraction was performed, RNA quantification was measured via spectrophotometer and the residual RNA percentage was calculated based on the RNA concentration.

Example 4—Pulled Pork, 40% by Weight Dry Equivalent of Spent Brewers Yeast

40% by weight dried spent brewers yeast, containing 51.2% protein were mixed with 10% by weight Soy protein isolate, containing 90% protein and subjected to high moisture extrusion cooking at a temperature 150 C, pressure 20 bar, RPM 400 for 2 minutes.

Pulled pork lemongrass veggie bowl was prepared according to instructions: Ingredients to make 1 large bowl: 4 oz. SBY-based meat, shredded, 1 cup Rice noodles, cooked, ⅓ cup Purple Cabbage, sliced, 1/Mango, sliced, 5 each Snap Peas, 4 leaves head Little Gems Lettuce, 5 thin slices Watermelon Radish, Sprinkle of Black Sesame & Lime wedges. Marinade & dressing to make 2 cups: ½ cup Lime Juice & Lime zest, 2 Tablespoons Soy Sauce, ⅓ cup Fish Sauce, ¼ cup Maple Syrup, ¼ Oil, 4-8 gloves Garlic, 2-3 stalks Lemon Grass, tender white parts only, chopped, 1 shallot, peeled & halved. To make marinade & dressing: Combine all ingredients in a blender or food processor. Season with Salt & pepper. Divide marinade in half. With ¼ cup of marinade marinate shredded Planetarian meat in a small bowl for 5 minutes. To assemble bowl: Heat a cast iron pan until very hot. Sear shredded SBY-Based meat until caramelized and crispy. Adding more marinade if needed. In a large serving bowl arrange all the remaining fresh bowl ingredients. Place your seared SBY-Based meat on top. Drizzle with a few tablespoons of the remaining marinade. Indulge and enjoy.

The resulting product had a pronounced meaty flavor and muscle-like fibers as shown in FIG. 4. The resulting product had 40% by weight dry equivalent of spent brewers yeast, 50% moisture content, 29.5% protein, and 1.32% RNA. The protein content was measured according to AACC 46-30 and AOAC 992.15. RNA extraction was performed, RNA quantification was measured via spectrophotometer and the residual RNA percentage was calculated based on the RNA concentration.

One skilled in the art will recognize that the herein described methods, processes, systems, apparatus, components, devices, operations/actions, and objects, and the discussion accompanying them, are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific examples/embodiments set forth and the accompanying discussions are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components, devices, operations/actions, and objects should not be taken as limiting. While the present disclosure provides descriptions of various specific aspects for the purpose of illustrating various aspects of the present disclosure and/or its potential applications, it is understood that variations and modifications will occur to those skilled in the art. Accordingly, the invention or inventions described herein should be understood to be at least as broad as they are claimed, and not as more narrowly defined by particular illustrative aspects provided herein.

TABLE 2
SBY-based alternative meat applications according to examples
		Example	Example
		1.	2.	Example	Example
		Chicken	Hop-char	3. Beef	4. Pulled
		skewer	burger	stew	pork
1st SBY	Liquid or	65%	70%
source	concentrated SBY
	Solids	11%	25%
	Protein	49.6%	49.6%
	SBY-based protein	4%	9%
2nd SBY	Dry SBY	15%	10%	30%	40%
source
	Solids	100%	100%	100%	100%
	Protein content	51.2%	51.2%	51.2%	51.2%
	SBY-based protein	8%	5%	15%	20%
Dry SBY		22.2%	27.5%	30.0%	40.0%
equivalent
2nd protein	Soy isolate	20.0%	20.0%	10.0%	10%
source
	Protein content	50.4%	50.4%	90.0%	90%
	Total protein	21.3%	23.9%	24.4%	29.5%
	Moisture	59.5%	57.6%	60.0%	50%
	RNA	0.072%	0.089%	0.099%	0.132%

REFERENCES

• 1. Gibson, D.; Dwivedi, B. Production of Meat Substitutes from Spent Brewers' Yeast and Soy Protein. Can. Inst. Food Technol. J. 1970, 3, 113-115.
• 2. Dietary Guidelines for Americans, Ninth edition, 2020 https://www.dietaryguidelines.gov
• 3. USDA Food Availability (Per Capita) Data System, 2021 https://www.ers.usda.gov/data-products/food-availability-per-capita-data-system/
• 4. J. C. Edozien et al. Effects of high levels of yeast feeding on uric acid metabolism of young men. Nature vol 228, 1970
• 5. Marson, G. V.; Saturno, R. P.; Comunian, T. A.; Consoli, L.; Machado, M. T. D. C.; Hubinger, M. D. Maillard conjugates from spent brewer's yeast by-product as an innovative encapsulating material. Food Res. Int. 2020, 136, 109365.
• 6. Canepa, A.; Pieber, M.; Romero, C.; Tohá, J. C. A method for large reduction of the nucleic acid content of yeast. Biotechnol. Bioeng. 1972, 14, 173-177.
• 7. Trevelyan, W. E. Chemical methods for the reduction of the purine content of baker's yeast, a form of single-cell protein. J. Sci. Food Agric. 1976, 27, 225-230.

Claims

1. A meat substitute suitable for human consumption comprising: at least 20% of a yeast by weight based on the dry weight of the meat substitute; anda ribonucleic acid (RNA) content less than 4% of the meat substitute's protein dry weight, andwherein the meat substitute is made by extruding a mix comprising a range of 40% to 80% of a liquid yeast by weight, inclusively, based upon the total weight of the mix.

2. The meat substitute of claim 1 wherein the liquid yeast comprises spent brewers' yeast, spent distillers' yeast, surplus yeast from ethanol manufacturing, bakers' yeast, nutritional yeast, or a combination thereof.

3. The meat substitute of claim 1 further comprising a secondary protein ingredient, wherein the secondary protein ingredient comprises vegetable protein, microbial protein, fungal protein, animal protein, or cultured protein, and wherein the secondary protein ingredient is in a native, concentrated, or isolated form, or a combination thereof.

4. The meat substitute of claim 1 wherein the liquid yeast comprises 8 to 25% solids, inclusively, based on the total weight of the liquid yeast.

5. The meat substitute of claim 1 wherein the liquid yeast comprises 8 to 11% solids, inclusively, based on the total weight of the liquid yeast.

6. The meat substitute of claim 1 wherein the liquid yeast comprises 15 to 25% solids, inclusively, based on the total weight of the liquid yeast.

7. The meat substitute of claim 1 wherein mix comprises from 65 to 70% liquid yeast by weight, inclusively, based upon the total weight of the mix.

8. The meat substitute of claim 1 wherein the liquid yeast comprises one or more of debittered, autolyzed, or hydrolyzed yeast.

9. The meat substitute of claim 1 wherein the extrusion comprises a heat treatment and a pressure treatment.

10. A meat substitute suitable for human consumption comprising: at least 20% of a yeast by weight based on the dry weight of the meat substitute; anda ribonucleic acid (RNA) content less than 4% of the meat substitute's protein dry weight, and wherein the meat substitute is made from a mix comprising a range of 40% to 80% of liquid yeast comprising spent brewers' yeast.

11. The meat substitute of claim 10 further comprising a secondary protein ingredient wherein the secondary protein ingredient comprises vegetable protein, microbial protein, fungal protein, animal protein, or cultured protein, and wherein the secondary protein ingredient is in a native, concentrated, or isolated form, or a combination thereof.

12. The meat substitute of claim 10 wherein the RNA content is less than 0.14% of the meat substitute's dry weight.

13. The meat substitute of claim 10 wherein the RNA content is greater than 0.07% and less than 0.14%, inclusively, of the meat substitute's dry weight.

14. The meat substitute of claim 10 wherein the extrusion comprises a heat treatment and a pressure treatment.

15. A meat substitute suitable for human consumption comprising: 10 to 20% yeast protein by weight, inclusively, based on the total dry weight of the meat substitute;at least 30% by weight of at least one secondary protein ingredient based on the total weight of the meat substitute; anda ribonucleic acid (RNA) content less than 4% of the meat substitute's protein dry weight.

16. The meat substitute of claim 15 wherein the source of the yeast protein comprises spent brewers' yeast, spent distillers' yeast, surplus yeast from ethanol manufacturing, bakers' yeast, nutritional yeast, or a combination thereof.

17. The meat substitute of claim 15 wherein the secondary protein ingredient comprises vegetable protein, microbial protein, fungal protein, animal protein, or cultured protein.

18. The meat substitute of claim 15 wherein the RNA content is less than 0.14% of the meat substitute's dry weight.

19. The meat substitute of claim 15 wherein the RNA content is greater than 0.07% and less than 0.14%, inclusively, of the meat substitute's dry weight.

20. The meat substitute of claim 16 wherein the meat substitute is made by co-extruding the source of the yeast protein and the second protein ingredient, wherein the co-extruding comprises a heat treatment and a pressure treatment.