CA1103511A - Texturization of protein - Google Patents

Abstract

A B S T R A C T

A process for producing a texturized protein product comprising introducing a slurry of untexturized protein in an aqueous dispersant having a pH of from 4 to 6.7 into a confined treatment zone, injecting steam into said zone to produce a temperature and pressure sufficient to texturize said protein and removing the texturized protein from said zone.

Description

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BACKGROUND OF THE INVENTION
In recent years, substantial efforts haYe bee~ directed toward the treatment of untexturized protein materials to imbue them with greater chewiness. These protein materials, which o~dinarily comprise vegetable protein, are thereby changed into a more textured and desirable form.
Many methods and apparatus are being used to texturize protel~.
Not only do these methods and apparatus differ, but also the physical charac-teristics of their texturized products may vary.
One such pr-lor ~rt method for texturi~ing protein i~volves eætrusion This method is exempli~ied by United States Patent 3,488,770 of Atkinson. In accordance therewith, a moistened paste of a de~at~ed ~egetable flour is treated with heat and pressure in an extrusion chamber.
Upon release from the cham~e~ through a restrictive orifice, the protéin is expanded to produce a porous, te~turlzed product.
Another texturization technique invol~es the spinning of protein fibers. Spinning is typically performed by one of two means. As in United States Patent 2,682~466 of Boyer, an aqueous solution of protein . may be ~orced through a spin~eret to .__ .. . . .
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produce fine streams ~hich are fixed into protein fibers in a bath of chemical coagulants. Alternatively, as in United States Patent 3,~21,453 of Hoer, heat-coagulation is substituted for the chemical bath.
More recently, the approach of texturization with steam has been explored. This technique, which is exemplified in United States Patent 3r836,677 of Freck et al., ordi.narily requires the inclusion of a starch or other gelling agent to implement the texturization. In United States Patent 3,863,019 of Strommer, howevex, there is disclosed a process where such an additional gelling agent appears to be unnecessary. There, a slurry of un-texturized protein is sprayed into a pressurized steam flow, and, upon release of the pressure, the protein is te~turized and rendered porous through flash evaporation of ~ater.
Each of the foregoing techniques has drawbacks. In most, only particular forms of vegetable material can be texturized. ~lso, the texturized products resulting from the various techniques are normally peculiar to, and dependent upon, the specific technique employed. Eurther, many of these techniques can be performed only under ri~idly controlled conditions and/or utilizing complex and expensive machlnery.
INTRODUCTION OF THE INVENTION
According to the present invention there is provided a process for texturizing protein which is useful with the many different forms of untex-turized protein which are available.
The process also permits the presence of additive materlals during ~` texturization of the protein. The resultant product then comprises a dispersed mixture of components.

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The process of the present invention also can be performed without careful control of processing conditions and with simple, inexpensive equipment.
- Still further, the process of this invention permits the produckion of texturized protein having a spectrum of physical characteristics and appearances, so as to permit selection of the properties of the resultant product, having regard for the specific intended use.
Yet further advantages are described hereinunder which are achieved through the present invention.

DESCRIPTION OF THE INVENTION
This invention involves the texturization of protein with steam.
More particularly, untexturized protein is converted into a product of desired consistency by exposing an aqueous slurry of the protein at appropriate pH to steam at elevated temperature and pressure. Afker treatment, -the texturized protein may be recovered as an aqueous slurry.
More specifically, the present invention provides a process for '~ producing a texturized protein product comprising introducing a slurry of untexturized protein in an aqueous dispersant having a pH of from 4 to 6.7 into a confined treatment zone, injecting steam into -the zone to produce a temperature and pressure sufficient to texturize the protein and removing the texturized protein from the zone.
This process may be performed very simply using minimal apparatus.
The~essential feature of the apparatus is that, i~ include a treatment zone of confined dimensions which permits maintenance of appropriate texturizing conditlons. Most conveniently, the treatment zone should be one suitable for , ~, _ B

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continuous processing. ~or example, thi6 zone may comprise a short length of tubing having, at one end, a pressure ~alve which permits the exit of treated slurry while maintaining the pressure and temperature within the zone. ~t the other end of the ~one, there should be entrance ports for both the steam and the slurry of unte~turiæed protein. Although back pressure valves can be disposed at these ports, they are unnecessary. The pressure within the confined treatment zone can be maintalned simply by generating steam at the desired pressure and pumping ~he slurry with adequate means.
The aqueous slurry of untexturized protein need not be at any particular te~perature be~ore introduction to the treatment zone. Any con-venient temperature, for example from 0 to 90C, may be used. Lower tempera~
tures of from 15 to 60C are ordinarily employed, however, to avoid unnecessary heating.
Only a very short time is required for this texturization of protein. Under many conditions of operation, texturization is virtually instantaneous. Thus, the residence time of protein in the zone is ordinarily ~` within the range of from l to 60 seconds, with 2 to 30 seconds being preferred.
~ Still longer periods of residence time are not, however, detrimental.
-~ Although some increase in the resiliency or toughness of the ~- 20 particles occurs with longer residence times, almost none occurs after about - 30 seconds. Within the preferred period of 2 to 30 seconds, some control of the eventual texture of the present proteins is permitted by increasing or decreas mg the residence time as desired. Accordingly, the shorter periods ~ o~ residence are most preferred because they permit increased speed of ; processing and consequently higher production of texturized protein.
The conditions of temperature and pressure required for the texturization may also vary greatly in accordance with the present invention.
The practical limits of operation depend upon the concentration of protein in ~3 ~ ;

~335~1 the slurry, residence period of treatment in the zone, the particular protein being treated, the presence or absence of other slurry constituents, and the desired degree of texturization. Ordinarily, however, the temperature and pressure conditions in the æone will be maintained between 100 to 200C and .5 to 15 kg/cm2. Particularly preferred conditions of operation are 120 to 160 C and 2 to 10 kg/cm .
To ensure most efficlent texturization of protein, the untex-turized protein in the slurry should be fully exposed to the steam. This may be accomplished by, for example, maintaining the aqueous slurry as a shallow stream or sheet as it passes through the zone. Contact between the protein and steam is then effected at the interface of the aqueous slurry.
More preferably, however, steam is injected into the aqueous slurry It may, for example enter from the bottom of the zone and pass up-wardly through the slurry. The steam then a~itates the slurry in the treat-ment zone, thus ensuring homogeneous texturization of dispersed protein. This technique of steam injection permits higher slurry volumes to be te~turized and is particularly preferred.
During texturiza~ion treatment, the slurry is heated to a higher temperature-by virtue of the contact with steam. Thus, for example, the exlt temperature wil]. normally range up to 100C., more usually from about ; 60 to 100C. The slurry ls not ordlnarily heated suficiently during the steam texturization to cause boiling or substantial evaporation o the aqueous dispersan~. Substantial amounts of water are absorbed by the slurry solids mcident to treatment, thus reducing the content of free water. However, at the same time, steam is ordinarlly llquified by loss of heat to the cooler slurry. The texturized protein product is thereore normally recovered in combination with at least some free - as oppoced to absorbed - water. Thus the material exiting the treatment zone may also be termed a slurry and normally - 6 ~
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contains about the same amount, or mo~e~ of total ~oisture as the slurry of untexturized protein.
The fact that this texturization process does not require vapori-zation of water affects the physical characteristics of the present products.
In contrast to prior art proteins texturized at least in part by flashing sub-stantial volumes of water from within the protein particles, the products of this invention are dense and unexpanded. This further enhances their meat-like appearance and properties.
~pon exit ~rom the treatment zone, the slurry may cool somewhat as the steam pressure is released and the gaseous stea~ expands, This expansion ` occurs au~omatically. To control this expanding steam, it is ordinarily desirable to vent the steam. This may be done, ~or example, by removing the slurry and steam through an open-ended conduit connected to the treatment zone.
In the conduit, the steam and slurry separate thus permitting controlled vent-,: .
ing of the former.

~lthough cont~ol of the e~panding steam is desirable~ it is not :~ ,i intended to suggest that cooling of the slurry need be minimized. This is not ; the case and the texturized protein is not adversely affected. Indeed, in a further desired e~bodiment, the exiting slurry is quenched by rapid cooling.

This may be performed by, for example, injecting the slurry into cold water.
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~uenching to a temperature of ~rom 0 to 50C, more usually from 5 to 25C, has been dlscovered to enhance the product characteristics by yielding more distinct particles resembling cooked ground beef in appearance.
~ critical aspect of the present method resldes in the condition o the untexturized protein during treatment with stea~. hs described abo~e, this protein ~ust be dispersed in water as a slurry. In addition, howe~er, it is essential that this slurry be of proper acidity. It has been dlscovered that, unless the aqueous slurry of untexturized protein has a pH o~ from 4.0 to ~ 7 -~35~

6.7, the desired texturizat~on will not occur.
Where the acidity o the aqueous slurry of untexturized protein is such that the pH lies below 4, the present treatment with steam has no apparent effect on the protein. ~fter treatment with steam, the slurry remains essentially unchanged. ~t a pH hlgher than 6.7, an aqueous slurry of untex-turized protein treated in accordance herewith exists as an undesir~ble liquor.
Such a liquor may gel if cooled sufficiently, however, it does not exhibit the ;.
desired texture and other characteristics.
Within the foregoing range of 4.0 to 6.7, texturized protein having variant physical characteristics and degrees of texturization is pro~
duced. ~ithin the lower portion of the present pH range, from about 4.0 to 5,8, most preferably from 4.0 to 5.0, separate and highly texturized particles are obtained. These particles have an appearance similar to that of hamburger or shredded beef. At higher pH within the present range, ordinarily from about ; 5.0 to 6.7 preferably ~rom 5.0 to 6.0, there is obtained a homogeneous and - plastic product. This product is more similar to the consistency and appearance of a luncheon meat such as bologna or o~ cheese.
This disco~ery that the consistency and appeara~ce of the tex-turized meat-like products of the present invention can be controlled and varied dependent upon the pH of the untexturlzed protein during steam treatment is highly advantageous. It permits, in contrast to most prior art techniques, selectlon of a product consistency from a spectrum of desired alternatives.
Thus, it significantly expands the utllity o~ the present process by permitting the production of different products tailored to specific intended uses.
~ lthough the pH of the untexturized protein during steam treat-ment is the primary factor determing the eventual consistency of the present products, it is not the only such factor. As previously indicated, the period of steam treatment, or residence time ~n the treatment zone, in~luences these product characteristics.

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Additionally, some modif-ication of these characteristics may be obtained through variation of the steam conditions at which the untexturized protein is treated. In general, lower temperatures and pressures of tex-turi2ation result in more plastic and less resilient prod~lcts, with more complete texturization being obtained at higher temperatures and pressures within the foregoing ranges. Also, the sizes of the products vary with these conditions, The texturized protein produced at lower temperature and pressure is composed of fine particles, ordinarily having a volume of as little as .03 to .3cm3. Higher conditions ordinarily produce particles of up to 1 to 2 cm3.

~other parameter which affects the eventual appearance of the products of this invention is the concen~ration of solids and solubles in the slurry during steam treatment. The total concentration is ordinarily within the range of ~rom about 2 to 60%, pre~erably ~0 to 50%, by weight of slurry, with the amount of untexturized protein being from about 2 to 35%, more preferably from lO to 25% by weight o~ slurry, The slurry concentration of untexturized protein may be provided by untexturized protein in any of its available forms of protein material.
~- Exemplary of protein materials which have been successfully texturized are 10urs, defatted flours, concentrates and isolates of proteins of soy~, peanut and other well-known vegetable sources.
The concentrations of untexturized protein in these various forms differ, Protein flours normally contain from about 30 to 50% by total weight of untexturized protein. Defatted flours normally exhibit about 50%
untexturized protein. Concentrates and isolates are conventional terms in the art which refer to still more concentrated protein sources having about 70 and 90%, respectlvely, of untexturized protein by total weight. Collsequently, the amount of protein material added to the slurry should reflect these differences in untexturiÆed protein content.

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Protein isolates and concent~ates ~re pre~erred in accordance with this invention. These ~orms of protein dif~er from others in that they do not contain carbohydrates such as raffinose and stachyose. These carbo-hydrates - which are common to soy and certain other vegetable protein sources -have been discovered to be most undesirable. After ingestion, they produce gases in the lower intestinal tract. These gases as well as the beany or - bitter note of such materials as soy - are primarily responsible for the poor consumer acceptance of many prior art texturized meat substitutes. Concentrates and isolates, however, are produced by methods which include aqeuous, acld and/or alcohol leaching which remove undesirable flavorants and carbohydrates.
Consequently the texturized proteins produced from them avoid these drawbacks and represent higbly ad~antageous sources of untexturized protein.
A further advantage to the present invention is that, in addition . .
~: to the uutextuFized protein, the slurry to be treated may contain numbers of ~ additional additives which will contribute to the desirable characteristics of :- the eventual ~roducts. Although many such additional additives are incompatible wlth prior;art texturization technlques, the present process is substantially ~unaffected by their presence. At most, these addi~ional ingredients (and any :~ non-protein content of the slurried protein material) appear to interfere only slightly with texturization. Consequently, fully texturized products remain ~ available and additives may be included in the initial slurry to permit their ; homogeneous dispersion within the eventual texturized products.

~ One~such desirable additional ingredient is fat. Being a normal :
constituent o~ natural meat, cheese and other foods, the presence of ~at in the present products renders them even more like the foods they are intended to replace. Moreover, it has been discovered that the presence of from O to 25%, preferably ~rom about 4 to 10%, by total weight of the slurry significantly impro~es the mouthfeel o~ the eventual texturized product. ~ccordingly, it is : : : i ~r~
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preferred to incorporate such a ~at, most preferably a solid ~at having a melting point of at least about 50C, most preferably at least about 70C into the initial slurry. These fats may be any which are a~ailable in the art, including unsaturated, saturated and modified fats o~ animal or vegetable origin.
~ nother desirable ingredient comprises 0 to ~0%, ordinarily 1 to 10% of a carbohydrate or gelling agent filler such as starch or corn syrup solids. In addition to the economic advantage oE incorporating one or more of these fillers, they further improve the appearance and texture of the eventual products. Suc~ a ~iller mày be utilized to increase the siæe of the eventual texturized particle.s. In addltion, they imbue the product with a more solid and chewy mouth-feel, thus rendering them still more meat-like.
~ lavorants may also be added to the initial slurry to provide the particular flavor and aroma notes desired for any speci~ically intended ; purpose. Thus, for example, a meat, cheese or seafood note may be provided in from about 0 to 15%, ordinaril~ from about 1 to 10%~ by weight of appro-priate ~lavorant in the initlal slurry. In addition to the specifically food-` like flavorants, flavor enhancers may also be utili3ed. Thus, condiments, spices, and like seasonings may also be added to the lnitial slurry.
~0 It is also posslble to include already texturi~ed protein wlth-in the slurry. Thus, for example, actual meat, cheese, or similar protein may be included within the slurry to provide a desired flavor and render the eventual product even more similar to the compositions which they are intended to replace. From 0 to 40%, pre~erably from 10 to 30~, of such material may be included in the slurry and thereby homogeneously dispersed within the eventual p~oduct.
In incorporating the fore~oing, and such othe~ customary materials as may be desirable, within the slurry prior to texturlzation, only from about ,- . ,.

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2 to 60%, most preferably from 40 to 50~, of the total welght of the slurry should ordinarily comprise solids or solubles. Thus the slurry usually contains ;~
from 40 to 98%, ~ost preferably 50 to 60%, free wa~er dispersing those ingre-dients. This limitation prevents the slurry ~rom becoming so viscous as to impede processing. Also, it ensures that total texturization of untexturized protein will occur, while avoiding undesirably dilute concentrations.
If the eventual product is intended to contain solids in excess of the foregoing amount~ it is pre~erred that only some of those solids be incorporated into the slurry to be steam ~reated. The excess solids may there-after be added to the product of the process by simple admix-ture therewith.
This is ordinarily performed a~ter separation of the excess free water with which the products are recovered after steam treatment~
The textured protein products of this invention are directly use~ul as substitutes for the meats or other foods they imitate. They may be utilized as replacements, in whole or in part, in recipes calling for natural food. ~xemplary af such recipes are chi11ies, soups, chowders, meat loaves and the like. These co~positions may be made up using the present textured product. Then, ~or example, they ~ay be cooked7 as by retorting in cans.
Significantly such cooking does not -- as is common with prior art textured ~ateri~ls -- give rise to off-flavors or other undesirable results.
~ lternatively, these texturized protein products may simply be dried In dry form, they are very stable. Moreover, they are readily re-hydrated, for example~ by boiling them in water for a few minutes -- and thus convertible back into a meat ox other desirable form.
~ hen it is desired to provide a composite texturized protein product, i.e., one having a varièty o~ discrete physical, tactile and/or organoleptic cha~acteristics9 two or more untexturized protein slurry streams, each with its own ~ormulatlon, c~n be treated in accordance with the process , .

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of this invention and the resulting texturized streams combined to form protein products simulating the appearance, density, cohesiveness and flavor of many varieties of sausage, processed meat, meat loaf, and the like. Thus, for exa~ple, by treating two or three slurries of different pH, one can obtain a like number of texturized proteins each having its own distinctive bite and appearance. When the proteins are assembled in final product form, each `~ component protein will retain its individual character thus imparting still greater resemblance to the corresponding meat product.
Each untexturized p~otein slurry stream can be texturized in ~; 10 its own confined treatment zone and e~ected, together with the other texturized slurries, through a com~on duct into a holding tank. If desired, the com~on ~.
duct ~ay be pro~ided with one or more barriers along part of the length there-of thus providing for a brief period separation of the texturized protein streams emerging from the treatment zones. It is also within the scope of . . .
this invention to texturize two or more protein slurries in a common treatment zone, and to subject a protein slurry treated under one set of texturizing conditions to further texturization in a second confined treatment zone located downstream of the first~
Following ejection of the combined texturized protein slurries into a holding tank, the composite product can undergo such additional process-ing steps as compression, extruslon, etc., to provide a product of predeter-mined density and~configuration. The indi~idual proteins can be assembled wtthln the composite product in any number of ways. For example, each textu-rized protein can~be randomly, but substantially evenly distributed throughout the product, or can be arranged in the product in layers or strata or to provide a marbling effect.
The present method for producing edible texturized protein will be more apparent from the ~ollowing examples which are chosen from the many ~ ' .

~33~1 specific combillations possible. They a~e lntended to illustrate this invention and are not limitati~e of its scope.
EXAMPL~ 1 Steam treatment of an untexturized protein slurry was performed utilizing a treatmen~ ~one composed of a 30 centimeter length of 4 centimeter diameter pipe. The slurry exit port at one end o the pipe was adapted with a pressure valve adjustable to maintain a hack-pressure within the pipe at any desired level. ~t the other end of the pipe there were two entrance conduits, one is or the aqueous slurry of untexturized protein. The other terminates in a jet nozzle rom which steam is injected into the slurry. The temperature and pressure within the tube are maintained with a one-way valve between the boiler and treatment zone and by pumping the aqueous slurry into the treatment zone at a pressure higher than the pre~alling zone pressure. Treated slurry exited the zone through an open~end, 20 centimeter length of 4 centimeter diameter pipe and was collected in an open-air holding tank.
~ slurry of 25% by weight of soy protein isolate in water at a pH of 4.5 was thus treated at steam condit:ions of 165C and 7 kg/cm2. The slurry was pumped through the treatment zone at a rate which permitted a residence time of about 5.5 seconds.
The product colleeted in the holding tank consisted o slurried 1 to 2 cm3 chunks of dense well-texturized protein having a completely bland taste.
~X~MPLE 2 The process of Example 1 was repeated except that the steam conditions were maintained at 100C and 0.7 kg/c~2. The resultant product was more textured and chewy than thàt o~ Example 1 and was co~posed of iner particles of .03 to .3 cm3.

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~X~MP~E 3 Using the apparatus of Example l, texturization was obtained - using the for~ula:
_gredient percent by Weight . .
Soy Protein Isolate 18 Water 57 ~- Meat ~lavoring 9 ~at (M.P. 50C) 7 ~ Corn Syrup Solids 9 --~ The slurry was t~aated with steam at 165C and 8.5 ~g/cm2. The acidity of the ,~
~-- slurry was maintalned by addition o~ 4 N hydrochloric acid and product was ;~ 10 obtained at pHIs of 4.0, 4.5, 5.0 and 6,0.
The~collected texturized protein showed substantlal variation in appearance. Product o~ lower pH was composed of individual particles of from 0,5 to 1 c~3 and resembled ground beef. Product obtained at the higher pH's, however was more plastic. Further, the 1 to 2 cm3 particles exiting the treatment zone tended` to fuse prior to cooling in the holding tank. This product was ~oldable and more loaf-like, imitating soft luncheon meat.

Using~the~apparatus of Example l, texturi ation was obtained utilizing the for~ula~
~;~ 20 Ingredients Percent by Weight Soy Protein Concentrate 19 Starch 3 Watèr ~ 57 Corn Syrup Soolids ` 5 Fat (M.P. 60 C). ~ ~ 8 Chicken Meat ~ ~ ~ 8 :
The slurry was adjûsted to a pH of 4~5 and treated at 170C and 8 kg/cm .
, ~ The texturized product closely imitated the consistency and texture of natural chicken meat. It was also close in appearance to shredded meat o~ chicken.
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EX~PLE 5 Using the apparatus of Example 1, texturization was obtained using the formula:
Ingredients Percent by Weight Soy Protein Isolate 14 Water 63 Fat (M.P. 50 C) 16 Flavoring 7 The slurry was at a pH o~ 4.0 and was t~eated at 110C and 12 kg/cm .
The first hal~ of the treated slurry was simply collected in the holding tank. The partlcles, whlch were soft, adhered together into a plastic loaf-like product. The second-half, however, was collected in a tank containing ice water. The particles recovered from this tank were distinct and resembled cooked ground bee~ in appearance and texture.

Using the apparatus of Example 1, texturization was obtained u~ilizing ~he formula:
Ingredients Percent by Wei~ht Soy Protein Isolate 10 Water 0 40 Fat (M.P. 70 C) 5 White Cheddar (~pray Dried) 40 - Food Coloring (trace) Sodium Chloride 5 This slurry was treated at a pH of 4.0~ 165 C and 6.5 kg/cm .
The product closely resembled natural yellow cheddar although its flavor was ~lightly weak.
EXoMPLE 7 Using the apparatus o~ Example 1, texturization was obtained utili~ing the formula:

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Ingredients _ rcent by Weight Soy Protein Isolate 16 Water 51 Fat Beef (ground) 25 Flavoring 4 This slu~ry was treated at a pH of 4.25, 145 C,and 5.6 kg/cm .
The product resembled cooked ground beef in appearance and te~ture. The meat and vegetable proteins were not individually discernible.

Using the apparatus oF Example 1, te~turization was obtained utilizing the formula:
In~redients Percent by Weight Soy Protein Isolate 11 Water 59 Fat 7 Fish (ground) 23 This slurry was treated at a pH of 4.5, 154 C and 7.7 kg/cm .
Nicely textured ~hunks were recovered. They were similar in texture to fish.
EX~MPLE 9 Using the apparatus of Example 1, texturization was obtained utilizing the formula:
Ingredients ~ y_Weight Soy Protein Isolate 13 Water 54 Fat 7 Shrimp (ground) 26 This slurry was treated at a pH of 4.79, 160C and 7.7 kglcm .
The texture and flavor of final product was s~milar to that of shrimp.

230 grams of the texturized soy product produced at a pH of 4.0 in Example 3 was incorporated into a chili also containing ~ kg of kidney beans, 310 grams of tomato paste5 1.5 kg oP ~omato sauce, and 160 grams of commercially packaged chili spices.

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The texturized p~otein ~as boiled in 400 gr~ms of water for lO minutes. It was then drained, added to the chili base and canned. The cans were retorted at 120C for 45 minutes and stored.
After two months at room temperature, the cans were opened and the chili examined. None of the off-flavors or aromas often associated wlth soy products was detected. Moreover, the textured protein had remained firm and chewy with the result that the chili was substantially iden~ical to true meat-based products.
E~AMPLE 11 ~n aqueous slurry o~ defatted soy flour (40% by total weight) was treated in the apparatus of Example 1. The slurry was at a pH of 4.5 and the steam was at 138C and 3.5 kg/cm2. The ~lour was reco~ered as large ~1 to 2 cm3) chucks of well texturi~ed, firm product.
These chunks - which were similar iII appearance to fresh ground beef - were then separated from the water with which they exited the apparatus.
The solids were then drled in an oven at 125C ~or 25 minutes. This dried product was stored~for two months. It was then reconstituted by addition of hot water and then added to an equal amount of ground beef. Hamburger patties made from this mixture were broiled and Judged to be of accep~able flavor and mouth feel.
EXA~PLE 12 A two component composite texturized protein product was prepared ~rom the~fo1lowing untexturized protein formulations~

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~or~ulation (Percent by ~eight) _, . . . . . . .
Ingredient A B
(brown color)~natural white color~
Soy Protein Isolate18.06 18.06 Soy Flour 7.23 7.23 Water 69.71 69.36 Fat (M.P. 50 C) 4,00 4,00 Calcium Cllloride .25 .25 Caramel Color .60 .60 Imitation Beef Broth ~lavor .15 ; Imitation Bee~ Enhancer~ .50 Total 100.00% 100.00%

Untexturized protein slurry formulation A was adjusted to pH
10 6,0 and processed in apparatus identical to that of Example 1 at 150C and 7~0 kglcm2, Untexturized protein slurry formulation B was adjusted to pH 4.5 and processed in identical apparatus at 135 C and 4.2 kg/cm .
; Each of formulatiorls A and B, following texturization, weresimultaneously brought together in a common duct as the texturized protein streams emerged from the1r respective treatment zones. The resulting composite :~ texturized protein product which was discharged from the duct possessed an acceptable texture and flavor. The product sliced well and demonstrated an ~; excellent texture upon frying.

A three component composite texturized protein product was prepared from the folloving un~exturized protein formu1ations:

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~o~mulation (percent by weight) A B C
(b20wn (natural (yellow Ingredient color) white color) color) Soy Protein Isolate 18.06 18.06 18.06 Soy ~lour 7.23 7,23 7.23 Water 66.96 67.46 67.21 Fat (M.P. 50 C) 6.00 6,00 6.00 Calclum Chloride .25 .25 .25 Caramel Color .50 Beef ~lavor .50 .50 .S0 Wheat Gluten .~5 .25 .25 Egg White .25 .25 .25 ~D & C Yellow No. 5 ~ ---- .25 Alum Lake Total lO0.00 lO0.00 100.00 Each of Pormulations A, B and C were adjusted to a pH of 6Ø
~ ormulations A and ~ were processed in apparatus iden-tical to that of Exa~ple 1 at 150C and 5.0 kg/cm .
~ ormulation C was processed in identical apparatus at 150C
and 5,o kg/c~2 The texturi~ed protein streams emerging from each treatment zone were simultaneously brought together and ejected from a common duct into an open air holding tank. The composite texturized protein product had acceptable color distribution, texture and flavor.

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Claims (20)

1. THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
   OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
   
   l. A process for producing a texturized vegetable pro-tein product comprising introducing a slurry of untexturized vegetable protein in an aqueous dispersant having a pH of from 4 to 6.7 into a confined treatment zone, injecting steam into said zone at a temperature of 100 to 200°C and a pressure of 0.5 to 15 kg/cm for a time sufficient to texturize said vegetable pro tein and removing the texturized vegetable protein from said zone . and cooling said texturized vegetable protein.
2. 2. The process of claim l, wherein the steam is injected into the aqueous slurry in the treatment zone.
3. 3. The process of claim l, wherein the texturized protein is recovered from the zone at a temperature below about 100°C.
4. 4. The process of claim l, 2 or 3, wherein the slurry introduced into the zone is at a temperature between about O and 90°C.
5. 5. A process according to claim 1, 2 or 3, wherein the aqueous dispersant of the slurry introduced into the zone comprises from about 40 to 98% by weight of said slurry.
6. 6. The process of claim 1, 2 or 3, wherein the slurry introduced into the zone is at a temperature between about 15 and 60°C.
7. 7. A process according to claim l, 2 or 3, wherein the slurry is treated with the steam for from l to 60 seconds.
8. 8. A process according to claim 3, wherein the slurry introduced into the zone has a pH of from 4.0 to 5.8 and the steam in said zone is at a temperature and pressure sufficient to texturize the vegetable protein of said slurry into discrete chunks of texturized vegetable protein.
9. 9. A process according to claim 1, 2 or 3, wherein the slurry introduced into the zone has a pH of from 5.0 to 6.7 and the steam in said zone is at a temperature and pressure sufficient to texturize the vegetable protein of said slurry into a plastic solid of texturized vegetable protein.
10. 10. A process according to claim 3, wherein the aqueous slurry introduced into the treatment zone comprises:
    (a) from 2 to 35% of texturizable vegetable protein;
    (b) from 0 to 25% of fat;
    (c) from 0 to 25% of carbohydrate;
    (d) from 0 to 40% of texturized vegetable protein;
    and (e) from 0 to 15% of flavorant by total weight, and has a total solids content of from 2 to 60%.
11. 11. The process of claim 10, wherein the aqueous slurry contains from 4 to 10% of fat.
12. 12. The process of claim 10, wherein the aqueous slurry contains from 1 to 10% of carbohydrate.
13. 13. The process of claim 10, wherein the aqueous slurry contains from 10 to 30% of texturized protein.
14. 14. The process of claim 10, wherein the aqueous slurry contains from 1 to 10% of flavorant.
15. 15. A process according to claim 1, 8 or 10, wherein the untexturized vegetable protein comprises vegetable protein concentrate.
16. 16. A process according to claim 1, 8 or 10, wherein the untexturized vegetable protein comprises vegetable protein isolate.
17. 17. A process according to claim l for producing a com-posite texturized vegetable protein product comprising introducing a plurality of slurries of untexturized vegetable protein into at least one confined treatment zone, each of said slurries containing the untexturized vegetable protein in an aqueous dispersant having a pH of from 4 to 6.7, injecting steam into each treatment zone at a temperature of 100 to 200°C and a pressure of 0.5 to 15 kg/cm2 for a time sufficient to texturize each of said vegetable proteins, removing the texturized vegetable proteins from each treatment zone, and discharging each texturized vegetable protein through a common duct to provide the composite texturized vegetable protein product and cooling said product.
18. 18. The process of claim 17, wherein at least two slurries having a different pH are treated.
19. 19. A process according to claim 10 for producing a composite texturized vegetable protein product comprising intro-ducing a plurality of slurries of untexturized vegetable protein into at least one confined treatment zone, each of said slurries containing the untexturized vegetable protein in an aqueous dis-persant having a pH of from 4 to 5.8, injecting steam into each treatment zone at a temperature of 100 to 200°C and a pressure of 0.5 to 15 kg/cm for a time sufficient to texturize each of said vegetable proteins, removing the texturized vegetable proteins from each treatment zone, and discharging each texturized vege-table protein through a common duct to-provide the composite texturized vegetable protein product, and cooling said product.
20. 20. The process of claim 19, wherein at least two slurries having a different pH are treated.