United States Patent [191

[11]

4,418,086

Marino et a1.

[45]

Nov. 29, 1983

[54]

EXPANDED TEXTURED PROTEIN
PRODUCT AND METHOD FOR MAKING
SAME

[56]

References Cited
U.S. PATENT DOCUMENTS
3,623,885 11/1971
3,745,021 7/1973

[75] Inventors: Richard P. Marino, Bedford Hills;

Hamdy .......................... .. 426/802 X
Middlesworth et a1. ..... .. 426/805 X

3,857,968 12/1974
3,968,269 7/1976

Haas et a1. .................... .. 426/805 X
Payne et al. ..
.... .. 426/802 X

Richard J. Rothamel, Ossining, both of N.Y.; William C. Rieken, Jackson,

4,031,267

6/1977

Berry et a].

NJ.

4,190,679

2/1980

Coffee et a1. ................. ., 426/805 X

[73] Assignee: General Foods Corporation, White
Plains, NY.

..i....

. . . . .. 426/802 X

Primary Examiner——R0bert A. Yoncoskie
Attorney, Agent, or Firm—Thomas R. Savoie; Daniel .1.
Donovan

[21] Appl. No.: 343,603

[57]
ABSTRACT
An expanded protein product is made by extruding a

[22] Filed:

mix containing a proteinaceous material, an animal or vegetable fat, a non proteinaceous and non-farinaceous

Jan. 28, 1982

extrusion agent, sulfur and/0r sulfur compound, plasti

[51]
[52]

Int. ‘Cl.3 .......................... .. A23L 1/31; A23J 3/00
U.S. Cl. .................................. .. 426/302; 426/331;

[53]

cizers and water from a high pressure zone to a low

Field of Search ............. .. 426/641, 656, 657, 802,

426/623; 426/641; 426/656; 426/657; 426/805
426/805, 104, 302, 331, 623

pressure zone preferably followed by rehydration of the extrudate. 2 Claims, No Drawings

1

4,418,086

2

meat substitute after extrusion by coating, impregnating or otherwise infusing the material with a liquid fat.

EXPANDED TEXTURED PROTEIN PRODUCT
AND METHOD FOR MAKING SAME

Note, for example, British Pat. No. 1,225,557. However, it is most dif?cult by such techniques to obtain the inti mate association of protein and carbohydrate as is found

The present invention is concerned with the produc tion of porous hydratable protein food products having

in real meat products, and the fat will often settle out

within short periods of time severly detracting from

a texture and appearance similar to the muscle and tis sue protein found in meats or fowl. More particularly

product palatability.
Two methods of overcoming some of the problems of

this invention relates to a method for producing a fat

containing expanded proteinaceous composition by

t. .

working and heat extrusion‘ of a mixture of protein aceous material, fat, a non-proteinaceous and non farinaceous extrusion agent, sulfur and/or a sulfur com

pound, plasticizer and water.
There is a major effort in the world today to produce nutritious, protein meat substitute products for both animal and human consumption. A signi?cant effort has been directed toward the utilization of protein flours

the prior art is taught in US. Pat. No. 4,031,267 to
Berry et al and US. Pat. No. 3,480,442 to Atkinson.
However, essential to producing an expanded and tex

tured protein product is the requirement of having a protein content of at least 30% by weight. This level of protein permits the formation of a porous expanded and texturized proteinaceous material. One of the disadvan tages of these products, is its requirement of high pro tein materials. Thus, the product is very costly. Another

disadvantage of the processes taught is the products and meals derived from oil seed such as soy beans, pea nuts, cottonseeds, and the like as raw materials in the 20 produced from the extruder are not full feeding prod ucts. That is the products are not nutritionally balanced production of said products. Recent developments in as produced and requires further processing to make the this area have focused on the production of meat-like

protein products produced by extrusion or otherwise heat treating soy protein. For example, U.S. Pat. No.
3,537,859 discloses a method for preparing protein food products simulating bacon in texture by extruding a homogeneous mixture of defatted soy meal, fat, water and flavoring. .The extrudate is characterized as non

expanded and contains entrained moisture and fat. US.
Pat. No. 3,488,770 deals with a method for preparing an

expanded porous protein food product having an open cell structure wherein a mixture comprising defatted soy meal and water is masticated at temperatures above about 250° F. and extruded from a zone of high pressure into a zone of lower pressure. The product is character ized as having a meat-like ?brous structure when hy

products a full feeding nutritionally balanced food.
Other methods of producing a textured pet food in clude U.S. Pat. No. 4,190,679 to Coffee et al. This pa tent teaches a dry pet food in combination with an inter

mediate moisture food product.
Still other methods of producing an unexpanded ex- _

trusion vegetable protein based meat analogue is taught in US. Pat. No. 4,042,715 to Wenger et al. This unex panded product is quite dense in structure and is not a

preferred meat-like texture. The resultant product does not mimic choice meat but rather is more like meat

grissle. Moreover, the process requires an undesirable

hydration process.
Other attempts at providing an expanded, textured,

drated. US. Pat. No. 3,496,858 discloses the preparation of an expanded protein product similar to the above

soft moist food product is taught in British Pat. No.

chemically interact with the protein molecules during

achieve bacteriological stability while maintaining the

1,583,644 to Turton et al.
Within the art, it is well known that when producing except sulfur or a sulfur compound is added to the defat ted soy meal prior to extrusion. These sulfur additives 40 products having intermediate moisture contents, to

processing giving rise to an extrudate having a high degree of expansion and very desirable ?brous struc ture. Protein processed, according to the teachings of the latter two patents discussed above does indeed have a texture and ?brous structure closely resembling meat.
However, most meat products such as beef, poultry, lamb and pork contain a fat content varying from about
5% to 30% or more depending on the type and cut of

soft and moist characteristics of the product, one has to

employ speci?c levels of sugars, plasticisers such as polyhydric alcohols, antimycotics, food acids and salts in amounts suf?cient to stabilize the foodstuff but with

out being detrimental to the nutritional requirements and acceptability to the pet. It is further known in the

art that when producing expanded textured vegetable proteins, the presence of such sugars, plasticisers, anti mycotics, acids and salts in suf?cient quantities to stabi

meat. Much of this fat remains in the meat even after cooking and it is this fat which contributes to the

lize an intermediate moisture food, impedes, if not com

smooth texture, nutrition, juicyness and pleasing orga~

tein into a texture analogous to that of meat. Further

pletely prevents, the texturization of the vegetable pro

noleptic qualities associated with good quality cooked

more, it is known to those skilled in the art of producing meats. Thus it would be most desirable to produce a 55 pet foods that textured vegetable proteins, as exempli
?ed by textured soya protein, are not highly palatable to simulated meat product based on expanded protein aceous materials which contains a certain amount of fat

pets.

or oil in intimate association with the ?brous protein

It is further known within the art that enzymatically digested meat, meat offals or meat by-products are par ticularly palatable to pets. Until now the use of such

structure of the expanded protein.
Prior art workers have discovered that the presence of signi?cant amounts of a fat or oil in the proteinaceous material to be extruded severly interferes with expan

sion of the extrudate and the formation of ?brous struc ture. As a result, it is recommended that the protein material be substantially free of oil and that no fat be 65

added to the proteinaceous material prior to extrusion.
It has been suggested by the prior art that fat or oil may be combined with the expanded proteinaceous

digested products has been restricted to use in dry pet foods as coatings or as an integral part of the pet food before being extruder expanded. ‘

SUMMARY OF INVENTION
It has now been found that an expanded protein prod uct containing up to about 35% by dry weight of a fat or oil can be prepared by forming a mixture comprising

3

4,418,086

a proteinaceous material, fat or oil, and farinaceous

material, plasticizer, sulfur and/or sulfur compound and water. The expanded product having a meat-like tex ture is prepared by subjecting the mix to heat and me chanical working such as in a cooker-extruder, and extruding the composition from a zone of higher pres sure into a zone of lower pressure.

As indicated hereinabove, it had previously been the experience of prior art workers that the presence of signi?cant amounts of a fat or oil in a proteinaceous

4

full-feeding food, but is also necessary for the proteins to function properly under processing conditions to provide the desired chewy, resilient, meat-like texture.
The proteinaceous admixture can contain from about

25% to 45% protein by weight. Preferably the admix ture will contain from 28% to 35% protein by weight.
Whereas the prior art has heretofore required larger amounts of protein for texturization, it has been found that the present process does not require it.
Suitable as proteinaceous materials according to this invention are proteinaceous meaty materials and vege— table protein sources, as well as, if required, ration balancing proteins. The term “proteinaceous meaty

composition prior to extrusion severly inhibits the ex pansion and texturization of the protein such that a porous product having a meat like texture when hy drated cannot be prepared. By means of the present material” refers to the group consisting of meat, meat invention it is now possible to prepare expanded protein 5 by-products and meat meal as well as mixtures of these. product containing signi?cant amounts of a fat or oil in

intimate association with the protein molecules, which product not only texturally resembles meat, but also has

The term “meat” is understood to apply not only to the

?esh of cattle, swine, sheep and goats, but also horses,

whale and other mammals, poultry and ?sh. The term
“meat by-products” is intended to refer to those non~
20
rendered parts of the carcass of slaughtered animals
It is an object of the present invention to provide a including but not restricted to mammals, poultry and process for preparing an economical textured pet food the like and including such constituents are embraced in the form of a soft, moist, textured, resilient, meat-like by the term “meat by-products” in the De?nitions of chunks of relatively high palatability. The process of this invention provides for the texturization of a full 25 Feed Ingredients published by the Association of Amer a smoother, moist fatty feed inherent in genuine meat

products.

feeding nutritionally balanced pet food without the necessity of resorting to infusing of nutritional supple ments and stabilizers. The product of this invention is a

cohesive, resilient, ?brous, expanded, texturized prod uct which very closely resembles natural meats.

DETAILED DESCRIPTION
The textured product is achieved in the preferred embodiment by processing a mixture comprising a pro

ican Feed Control Of?cials, Incorporated. Likewise, the term “meat meal” refers to the ?nely ground, dry rendered residue from animal tissues including those dried residues embraced by the term in the aforesaid of?cial de?nition of the Association of American Feed
Control Of?cials, Incorporated. Indeed, the terms

“meat”, “meat by-products,” and “meat meal” are un

derstood to apply to all of those animal, poultry and marine products de?ned by said associattion.

teinaceous matrix, fat or oil, sulfur and or sulfur com

The term “vegetable protein source or concentrate”

pound, farinaceous material, plasticizer, and water.
In preparing the product of this invention, the ingre

applies to oil seeds and legumes; as well as the oil ex pressed or extracted meals and cakes and protein iso lates and concentrates thereof recovered by known

dients are blended prior to introduction into the ex truder or in the extruder itself. The mix, as it is moved

procedures including acid or alkali digestion and pre progressively forward in the extruder will be subject to 40 cipitation; typical of such vegetable protein sources are soybeans, soybean meal, cotton seed meal, alfalfa pro shear forces, mechanical work, heat and pressure such tein, peanuts, peanut meal, etc., all of which terms are that the product temperature prior to discharge is at well understood and similarly de?ned or understood by least 280° F. The pressure and some of the heat is gener said association. ated as a result of the progressive advancement of the product in the extruder screw chamber against a re 45

stricted ori?ce at the discharge section of the chamber and also by internal frictional forces. Pressure and tem perature can be varied by altering the screw con?gura tion, screw speed, the size of the die extruding the com position in the manner hereinabove described.
The amount of sulfur or sulfur compound employed

in preparing the expanded proteinaceous material will

Other protein source material such as peanuts, cot

tonseeds, meat meal, ?sh meal and the like may be simi larly de-oiled and the oil replaced with any animal or vegetable fat desired. This is a particularly advanta geous procedure where it is desired to replace saturated

fats found in meat protein with unsaturated vegetable oil. In those cases in which a high protein content food is desired, wherein the protein content is greater than

vary depending upon the amount protein present in the source material, the nature of the sulfur compound and
45% by weight, a ration-balancing protein supplement the degree of expansion desired. In general, sulfur or may be added. This may have particular application sulfur compounds may be added in the range of 0.01% when producing a pet food especially formulated for to 2.5% by weight of the composition to be extruded. growing pets whose nutritional requirements necessi
Preferred levels range from 0.1% to 0.6% by weight. tate a high level of protein for growth and develop
Typical sulfur containing materials which aid in the ment. The term “ration-balancing protein supplement” preparation of the "expanded porous proteinaceous ma 60 is intended principally to refer to milk products as de terial of this invention are elemental sulfur, and sulfur
?ned by said association and hence includes such addi compounds such as cysteine, cystine, methionine, lower tives as dried buttermilk, dried skimmed milk, dried alkyl mercaptans and the like. It is preferred to use whole whey, casein and cheese rind, although it also elemental sulfur. includes yeast as that term is de?ned by said association

The proteinaceous materials should provide both 65 and hence refers to such materials as distillers’ dried yeast, primary dried yeast, irradiated dried yeast, brew

nutritional and functional characteristics. Thus, not only is it necessary as a practical matter of pet nutrition to provide the proper balance of protein necessary for a

ers’ dried yeast and torula dried yeast. However, the term protein supplements is not to be understood as

5

4,418,086

6

restricted to the aforesaid de?nition and includes such

bind up any fatty glyceride material in the composition

things as single cell protein and the like.

are not deemed necessary in the present invention. Thus it has been found that when employing a twin screw

While economy products containing no fresh meat are within the scope of this invention preferably, the product will contain at least 10% and up to about 40%

expander-extruder the, typical extrusion agent such as silicone dioxide, or microcrystalline cellulose may be excluded and still be able to texturize the proteinaceous

fresh meat of the total composition. Preferably, soy

fat mixture.
It has been found that when approximately 0.2% to

flour or other like protein source is employed in an

amount of from 12% to about 25% of the weight of the

total composition.

2% by weight of ?nished product of commercially

The fat or oil present in the expanded protein prod

available extrusion agent is added, processing is facili-' tated. However, satisfactory results are achieved with

uct, hereinafter referred to as fat, may be the fat or oil

which is‘ naturally present in the proteinaceous material,

out this ingredient, but one will need to monitor temper ature of the expander-extruder more carefully. Cellu lose materials found useful as known extrusion agent include materials sold under the trade name “Avicel”.

or it may be overtly added to the proteinaceous material as will be hereinafter described. Examples of such fats are vegetable oils such as cottonseed oil, soybean oil, peanut oil, coconut oil and the like and animal fats such as tallow, lard, chicken fat, ?sh oil and the like.

The degree of expansion and texturization of the proteinaceous material of this invention is affected by the amount of fat present in the composition. The amount of fat present in the mixture to be expanded will

be greater than 5% by dry weight. Preferably the fat content will be greater than 5% and up to about 35% by

weight. Where the amount of fat is significantly higher than about 35% by weight of the composition to be extruded, expansion and texturization is markedly inhib ited. The farinaceous component also provides both nutri tional and functional characteristics in the food. Among

This cellulose material which is generally produced by acid hydrolysis of cellulosic materials, has an average particle size within range of about 0.01 to about 50 microns. 20

The use of an extrusion agent does result in accentu

ated fiber formation. The ?bers appear to be longer when the extrusion agent is employed. It has been found that when the ?bers are longer, a greater control of

expansion of the meat piece is possible resulting in a
25 more meat like texture. Moreover, the product has a

better cohesiveness than without the extrusion agent.
Not suitable as an extrusion agent are the silica acid, solicoaluminetes and carbon black.
To obtain the desired soft, resilient texture and to i

the suitable farinaceous materials are grains such as 30 provide a controlled water activity in the product, a plasticizing is employed at a level of at least 1% to 10%, corn, wheat, barley, oats, and the like, as well as the

but preferably from 2% to less than 5% by weight of normal milling products of these materials such as
?nal product.- Suitable for use as the plasticizing agent whole ground wheat, corn flour, and the like. While the are any of the normally liquid, edible di-, or tri-hydric farinaceous material can comprise from 0% up to 55% of the total pet food and be derived from a single 35 alcohols or sugar alcohols or other polyhydric alcohols effective for this purpose. Typical among vthese are source, it is preferred, for best nutrition, functionality and economy to employ at least two different farina
1,2-propanediol, 1,3-butanediol, glycerol, and mixtures of these. It has been found that due to its highly effec ceous materials at a combined level of from 1% to 20%.
One preferred combination is wheat and corn at a

tive plasticizing effect, and preservation properties,

40 propylene glycol is a preferred material. weight ratio of from 3:2 to 2:3.
In processing these formulations toobtain the unique
In addition to these materials, the preferred pet food formulations will also contain vitamin and mineral sup textural characteristics of the soft, meat-like piece de

sired according to the present invention, the ingredients plements necessary to provide a full feeding nutrition ally balanced food. Additionally, due to the relatively are mixed, plasticized under heat and pressure, extruded high moisture contents of these foods as opposed to dry 45 under conditions which cause expansion and texturiza tion, and cut into chunks. These chunks are then prefer foods and the incapability of most of the noted osmotic ably coated with a layer of a palatability improving agents to inhibit all microbial growth, effective levels of material such as fat, meat-derived flavors, hydrolyzed antimycotic agents such as potassium sorbate are desir vegetable protein, meat slurries and the like. ably employed to assure stability against microbial

growth.
The dog foods of the present invention are full feed

ing nutritionally balanced. It is important that each

The ingredients can be mixed in any manner which is

effective to provide a suf?ciently homogenous blend to permit ef?cient plasticization in the extruder. In a typi cal processing arrangement, the ingredients are mixed

ration be nutritionally complete. Where this can be in a suitable mixing device, such as a 'ribbon blender. assured by the manufacturer, it is not necessary for the dog owner to balance the quantities of different foods 55 While the resulting mixture may then be fed directly to supplied. The nutritional intake of the dog is then as the extruder for texturization, it is preferred to precon dition the blend. In a preferred processing arrangement, sured so long as it intakes a minimum amount of food.

Full feeding nutritionally-balanced foods will contain protein, carbohydrates, fats, vitamins and minerals in

the resulting mixtureis fed intova steam preconditioning

Non-proteinaceous and non-farinaceous ?nely di

are prepared. In the ?rst ingredient stream, all the dry

chamber where it is 'mixed with live steam and suf?cient amounts established by feeding tests to be suf?cient for 60 water to maintain the moisture at a level of from about
10% to about 40% to assure the desired ?nal moisture proper growth and maintenance. The preferred product content. A residence time of about 0.25 to 2 minutes is of this invention will meet the nutritional requirements suf?cient to cook and adequately plasticize the mixture as set forth in Handbook Number 8, entitled, Nutrient
Requirement of Dogs, which is published and amended‘ which will achieve a temperature of from about 150° F. by the National Research Council of the National 65 to about 210° F. upon exit.
In a more preferred process, two ingredient streams
Academy of Sciences. vided extrusion agent material which functions so as to

ingredients are mixed in a suitable container until an

7

4,418,086

admixture is obtained. In the second ingredient stream, an enzymatically digested slurry of proteinaceous mate rial is obtained. These two streams are combined per the

8

suf?cient to facilitate processing and yield an extrudate
‘having a moisture content after extrusion and after

formulation to be extruded. Although all of the formu~ lation that is to be extruded may form an enzymatically

flashing off of moisture, the moisture content will be about 15% to 30%, and more preferably from about
17% to 25%.

digested slurry, it is preferred to only enzymatically digest the proteinaceous meaty materials.
The term “enzymatically digested slurry” refers to the digestion of proteinaceous materials by the addition

most preferable conducted in a twin screw extruder.
Typical twin screw extruders have two screws within

of a proteolytic enzyme, for example papain bromalin,
?cin or other proteolytic enzyme derived from plant, fungal, bacterial or animal gland sources or by the addi tion of such bacterial or fungal cultures themselves or

by the addition of proteolytic enzyme-containing ani mal glands themselves or as admixtures with any one or more of the aforementioned enzymes or enzyme

It has been found that the plasticizing-extrusion is its extrusion barrel and enable the product matrix to be subjected to a high shear pro?le. This shear pro?le serves several functions in providing conditions neces

sary for texturization. It provides a vigorous mixing pattern where the product matrix is intimately mixed and kneaded. The product matrix is worked between
5 the two screws which may be co-rotating or counter

rotating. Another function provides ef?cient heat trans

sources. In addition, the enzymatically digested slurry refers to the digestion of farinaceous ingredients by the

fer from the jacketed barrel of the extruder. The screw pro?le further functions to create the necessary resi use of an amylase enzyme. Among the suitable enzymes dence time within the extruder. are alpha amylase, derived from plants, animals or mi 20
It is important not to over-work or over-shear the croorganisms. Preferably a non heat stable bacterial product matrix so as to destroy texturization. Thus, the alpha-amylase and fungal alpha-amylase are employed. screw pro?le will contain a feed section, mixing section
Generally the process requirements for a meat enzy which contains the necessary elements to mix water into matic digestion slurry involve ?ne comminution of the the dough matrix, followed by one or more work zones proteinaceous meaty materials and adjustment of the 25 which contain the necessary elements to shear the pH to that most suited for the enzyme or enzyme source dough matrix and raise the dough matrix temperature to employed in the digestion, by the use of acid, alkali or the desired temperature range. In the work zone, the buffer solutions. The pH range is suitably 45-10 but is major shear and heat transfer will occur. Following the preferably 6-8. Following comminution and pH adjust work zone, will be a forming zone which aids in pro ment, the digest is adjusted to a temperature most suit cessing control to enhance product formation. Depend able for the action of the employed enzyme system ing upon manufacturer of the twin screw extruder, the within a temperature range of 120° F. to 160° F., but screw pro?les may vary but the parameters of tempera preferably within the range 130° F. to 150° F. The en ture, residence time, moisture content, and shearing zyme or enzyme source or mixtures thereof is now force will remain the same. added to the comminuted, pH and temperature con
The advantage of a twin screw extruder is that it

trolled proteinaceous meaty materials at a level depend ing on the proteolytic activity of the enzyme or enzyme source employed. The digestion is continued with agita

provides positive conveying characteristics allowing the product to be worked in a shorter work zone area than that of a single screw extruder. In the twin screw

tion for 5 minutes to 6 hours until such time as the meat

extruder the product matrix is worked between each

material is suf?ciently digested. The digested protein

screw as well as between the screw and the extruder

aceous material is then heated to approximately 170° F. and held at this temperature for 3 minutes to inactivate

barrel. In the single screw extruder, the product matrix

is only worked between the extruder screw and barrel.
As is known to those skilled in the art, the twin screw extruder allows better control of the mechanical work
The formulation as prepared above is then fed into a 45 of the product matrix. Typical twin screw extruders are

the enzyme and provide a degree of bacteriological sterilization. plasticizer-extruder wherein it is further heated and plasticized under pressure. The formula will attain a temperature of at least about 280° F. within the extruder

while being subjected to pressures above 100 psig. The upper limit of temperature is determined by the temper ature at which the ingredients may undergo undesirable quality degredation. Temperatures of from about 280°

manufactured by Werner Pfleiderer andCreusot Loire.
Twin screw extrusion enables production of the prod uct of this invention at production rates much greater than single screw extrusion.
An ideal degree of expansion provides about 1.75 to
2.25 times expansion based on the diameter of the ex

trudate as. compared to the diameter of the die ori?ce
F. to about 450° F. are preferred. Even more preferred ‘ from which it is expressed with acceptable degrees of is a temperature range from 280° F. to 400° F. This expansion providing an extrudate being from about 1.50 plasticization prepares the material for providing a soft, 55 to 2.75 times the diameter of the ori?ce. The extrusion resilient texture upon extrusion and heats the material to conditions will be varied as required to obtain the de such a degree under requisite pressure to assure texturi

sired degree of expansion.

zation of the formulation upon exiting the extruder. The

The product is severed as it issues from the ori?ce die

moisture content within the extruder is in the range of

face at the end of the extruder. By spacing the cutting

15% to 40% by weight.
The pressure drop upon exiting the extruder should

blade a small distance from the die face, a pleasing, irregularly-shaped chunk can be obtained due to a rip

be at least about 25 psig, but less than 300 psig. Prefera bly, the pressure drop upon exiting the extruder will be from about 50 psig to about 200 psig. Formulations

ping action caused by this arrangement. The blade is spaced from about 5 inch to about % inch from the die plate. Preferably, the extrudate forms a continuous rope

having lower moisture contents will need to be sub

which is then diced to desired dimensions by a Urshel dicer. The chunks formed show a moderately ex

jected to higher pressures within this range, and higher moisture formulations will require the lower pressures within this range. The amount of water used will be

panded, meat-like interior with a substantially-continu ous, ?brous and highly-irregular surface. When ex

4,418,086

10

. 9

multitude of products such as soups or stews, chili-con carni, animal food and the like. Due to the porous na

trudated and cut in the preferred manner, the product shows a bulk density of from 15 to 25 lb/ft3, and is preferably from about 17 to 21 lb/ft3, these densities being necessary to obtain the desired ?brous, resilient, meaty texture and product appearance. The product at this point will have a moisture range of from about 15% to 30%. More preferred the product will have a mois ture range of from about 17% to 25% by weight. The

ture of the product it is capable of absorbing water or other liquids. When rehydrated, it has the ?brous ap pearance of meat as well as the fatty feel and smooth texture of meat due to the intimate association of fatty

glyceride with the protein ?bers. The expanded product may be diced into small pieces and mixed with meat or meat by-products for use as an animal food. The ex

Aw of the product at this point will be greater than 0.90.
While the expanded textured protein product at this point will‘provide a full feeding nutritionally balanced pet food, a coating of material can be applied. Coatings

panded product may also be coated with liquids con taining flavorings, preservatives such as sugar or edible glycols, colorants and the like to provide a more palat

able and moist appearing product.

of beef tallow, sprayed on in an amount of from about

The following examples are illustrative of the pre

2% to about 8% based on the weight of the pet food, have proved to be desirable. Likewise other coatings such as meat meal, meat ?avors, gravy formers, and the like can be applied.

this invention. It should be kept in mind that methods

In a preferred process, the expanded textured protein product will be coated with a liquid composition ap plied at a ratio of from about 80 parts expanded product

which impart mechanical work, pressure and tempera

ferred methods for preparing the expanded products of other than twin screw extrusion such as mechanical milling or pressing or even single screw extrusion

ture will not be adequate for the production of an ex

to 20 parts liquid composition to a ratio of from about 65

panded proteinaceous composition according to this

parts expanded product to 35 parts liquid composition.
The liquid composition comprises water, an enzymati cally digested slurry, polyhydric alcohol, fat and mate— rials capable of arresting microbial growth. Among

invention.

EXAMPLES
25

these are the low molecular weight materials capable of providing osmotic pressure effects, of the type sug gested by Burgess et al in U.S. Pat. No. 3,202,514. This

The following formulations were prepared. All amounts are in parts by weight, unless indicated other wise. Burgess et a1 patent is, therefore, incorporated by refer

High

ence. Of these, sugars and salts are the most preferred; 30 with sugars such as corn syrups and sucrose, and salts

Beef
No. 1

such as sodium chloride, being the preferred water activity, aw, lowering materials. It has been found ac cording to the invention that high fructose corn syrups

Wheat gluten

Protein
No. 3

Protein
No. 4
25.0

mm

and those having dextrose equivalent, DE, values of from about 30 to 75 are especially desirable ingredients

Low

Chicken
No. 2

because they not only have an aw lowering effect, but

they also provide a degree of palatability desired by dogs and help to maintain product plasticity. The liquid composition enhances the products’ cosmetics and pal~

Soy bean oil meal
Soy ?our, fullfat

Wheat flour
Vitamins, minerals

material is intended as a meat substitute or extender, it

may be desirable for flavor and nutritional purposes to remove some or all of the vegetable oil prior to extru

sion by solvent extraction, pressing or other techniques, and replace the oil with an animal fat such as tallow or

lard. For example, expanded soy containing 10%, 20% or 35% tallow may be prepared by thoroughly blending de-oiled soy meal with the appropriate amount of tal 55

-

25.0

—-—

24.7

—

15.8

15.8

25.0 .

5.0

2.2
3.7-

2.2
3.7

2.2
3.7

23.0
3.7

0.2
0.8

0.2
0.8

0.2
0.8

0.2
0.8

--

—-

10.0

—

and flavorings
Sulfur
Avicel

Ingredients to

atability. The resultant moisture will be in the range of
ML
Meats from 20% to 35%. Even more preferred the moisture
Chicken/Poultry
range will be from 25% to 30%. The Aw of the product
Enzymes
will be in the range of 0.85 to 0.93. This product has a
Water
bulk density of from about 20 to 35 lbs/ft3 and more 45 Polyhydric alcohol
Color, ?avors preferable from 23 to 32 lbs/ft3.

In applications where the expanded vegetable protein

24.7

l0
—-

0.02

—

—

0.02

0.02

—-

0.02

2.8

2.8

4.8

2.8

3.0
0.16

3.0
0.2

3.0
0.2

3.0
0.2

3.9

3.9

10.0

3.90

Corn syrups

8.3

8.3

20.0

8.3

Meat Slurry

10.0

--

—-

10.0

Fat

Coating Solution
Chicken slurry

—-

10.0

—-

—

Polyhydric Alcohol

3.6

3.6

3.6

3.6

Oil
Emulsi?er

0.5
0.1

0.5
0.1

0.5
0.1

0.5
0.1

The dry ingredients are mixed in a suitable container

low in a ribbon mixer or other suitable device, further

until an admixture is obtained. Typically the dry ingre

thoroughly blending this mixture with ?ller, sulfur or sulfur compound and any other ingredients which are to be included in the composition, and extruding the composition in the manner hereinabove described. 60

dients are mixed for 5 minutes in a ribbon blender. The

Other protein source material such as peanuts, cotton

slurry ingredients are separately enzymatically di gested. Typically, the meats and water are combined with the enzyme and heated to approximately 140° F.
The mixture is allowed to react suf?ciently. The mix ture is then heated to inactivate the enzymes. Typical inactivation temperature is about 170° F. After inactiva tion, the remainder of the slurry ingredients are added

seeds, meat meal, ?sh meal and the like may be similarly de-oiled and the oil replaced with any animal or vegeta ble fat desired. This is a particularly advantageous pro cedure where it is desired to replace saturated fats 65 and mixed. The remaining ingredients include the poly hydric alcohol, color, ?avors and fat. found in meat protein with unsaturated vegetable oil.
The dry admixture is then combined with the slurry
The expanded product of this invention is ideally as prepared above, and fed to a steam injected precondi suited as a partial or total replacement for meat in a

11

4,418,086

tioner where the blend is subjected to vigorous mixing, pre-moistening and pre-heating. The mixture is cooked

12

mately 28% to 31%. Extrudate No.’s 1 through 4 are

microbiologically stable.

for approximately 2‘ minute to a ?nal temperature of about 180° F. to about 210° F. Suf?cient water is added during this stage to maintain the moisture content at

What is claimed:
1. A method for preparing an expanded, resilient protein product which has an open cellular, ?brous structure, a fat content of at least 5% up to about 35% dry weight basis, and a moisture content of from 15% to

approximately 16% to 35%.

The formulation as prepared above is then fed into a plasticizer twin screw extruder wherein it is further
30% by weight. The steps comprising: heated and plasticized under pressure. The formula will
(a) forming a mixture containing, on a weight basis, attain a temperature of from about 280° F. to 400° F. 0
10% to 40% fresh meat, 12% to 25% soy ?our, 1% within the extruder while being subjected to pressures to 20% combined wheat and corn, 0.01% to 2.5% above 100 psig. This plasticization prepares the material elemental sulfur or a sulfur compound, and from for providing a soft, resilient texture upon extrusion and
1% to 10% of a polyhydric alcohol plasticizing heats the material to such a degree under requisite pres agent, said mixture being free of any non-proteina sure to assure texturization of the formulaton upon exit cious and non-farinaceous extrusion agent and said ing the extruder. The pressure drop upon exiting the mixture containing suf?cient water to produce the extruder will be about 100 psig. The amount of water
15% to 30% moisture content in the expanded used will be suf?cient to facilitate processing and yield product; an extrudate having a moisture content of about 20%.

The protein content of Extrudate No. 1 is. approxi 20 mately 38% to 40% protein. The protein content of
Extrudate No. 2 is approximately 39% to 42%. Extrud ates No’s 1 through 4, are microbiologically stable, however, it is preferred to coat them with the coating solution. 25
The extrudate is thereafter coated with the coating

(b) heating the mixture of step (a) to a temperature of above 280° F. while mechanically working the heated mixture at a pressure above 100 psig in a twin screw extruder;

(c) extruding the mixture from the twin screw ex truder such that the mix expands from about 1.75 to
2.25 times in size as compared to the ori?ce size;

(d) cutting the extruded material into chunks; and

solution to provide a moist appearance and increase
(e) coating the chunks with a layer of a palatability palatability. The ?nal moisture content will be in the improving material. range of from 25% to 30%. The Aw of the product will
2. The method of claim 1 wherein the mixture of step be in the range of 0.90 to 0.92. This product has a bulk 30 (a) is fed into a steam preconditioning chamber where it density of from about 24 to 29 1bs/ft3. The protein con is contacted with live steam and water before being fed tent of extrudate No. 1 is approximately 27% to 30% to the twin screw extruder.

while the protein content of extrudate No. 2 is approxi

Ill

35

45

50

55

60

65

*

Ii

*

1k