Dough-like products exhibiting reduced water activity containing derived protein-containing compositions

Products of dough-like consistency exhibiting reduced water activity are disclosed comprising a mixture of a derived protein-containing composition and particularly a deproteinized mineral-containing whey byproduct and starch at a moisture content of from about 20% to about 50% by weight. The products are effective as base materials for intermediate moisture foods.

BACKGROUND OF THE PRESENT INVENTION 
This invention relates to products of dough-like consistency exhibiting 
reduced water activity containing derived protein-containing compositions 
and particularly byproducts obtained from concentrating whey protein by 
means of ultrafiltration or gel filtration. 
It is well known that foods can be preserved by drying. It is also known 
that some foods having a moisture level between fresh and dried are stable 
and do not contain sufficient moisture to support bacteriological growth, 
i.e., cheese. Because of the recognition of this factor, a class of foods 
called "intermediate moisture foods" has arisen. One of the more important 
commercial examples of this class is semi-moist pet foods. 
In order to determine if the semi-moist food will be stable, it is 
necessary to determine the water activity, a.sub.w, of the product. Water 
activity is defined as the ratio of the materials' water vapor pressure to 
the vapor pressure of pure water at saturation in air at the temperature 
of the material. 
This can be represented mathematically by the formula: 
##EQU1## 
wherein the water activity is a.sub.w, P.sub.s is the vapor pressure of 
water vapor in the food, P.sub.o is the vapor pressure of pure water at 
the same temperature, N.sub.w is moles of water and N.sub.s is moles of 
solute (Commercial Development of Intermediate Moisture and Food, M. 
Kaplow, Food Technology, Volume 28, page 889, August 1970). 
One method of determining water activity involves humidifying samples in 
desiccators at 37.degree. C. to the desired water activity by using 
reference saturated salt solutions. The procedure involves placing the 
sample uncovered in the desiccator and leaving the sample in the 
desiccator to equilibrate. Moisture isotherms are prepared by determining 
gravimetrically the weight increase of the samples. Illustrative reference 
saturated salt solutions are as follows: 
TABLE I 
______________________________________ 
Salt a.sub.w at 25.degree. C. 
a.sub.w at 30.degree. C. 
______________________________________ 
Magnesium Chloride 
MgCl.sub.2 
0.328 0.324 
Potassium Carbonate 
K.sub.2 CO.sub.3 
0.432 0.432 
Magnesium Nitrate 
MgNO.sub.3 
0.529 0.514 
Sodium Bromide 
NaBr 0.576 0.560 
Cobalt Chloride 
CoCl.sub.2 
0.649 0.618 
Strontium Chloride 
SrCl.sub.2 
0.709 0.691 
Sodium Nitrate 
NaNO.sub.3 
0.743 0.731 
Sodium Chloride 
NaCl 0.753 0.751 
Potassium Bromide 
KBr 0.809 0.803 
Ammonium Sulfate 
(NO.sub.4).sub.2 SO.sub.4 
0.810 0.806 
Potassium Chloride 
KCl 0.843 0.836 
Strontium Nitrate 
Sr(NO.sub.3).sub.2 
0.851 
Barium Chloride 
BaCl.sub.2 
0.902 
Potassium Nitrate 
KNO.sub.3 0.936 0.923 
Potassium Sulfate 
K.sub.2 SO.sub.4 
0.973 0.970 
______________________________________ 
It has been reported that typical intermediate moisture foods have water 
contents of from 15% to 30% on a dry solids basis and water activities 
lower than 0.85. Fresh foods generally have more than 60% moisture and an 
a.sub.w of greater than 0.90. Dry foods have a moisture content of less 
than 15% and an a.sub.w of less than 0.20. 
Three problems are connected with the stability of intermediate moisture 
foods, i.e., microorganisms, browning and lipid oxidation. Depressing the 
water activity has an inhibiting effect on the growth of microorganisms 
and, apparently, an antioxidant effect on lipid oxidation. 
Stille (1948) has suggested an a.sub.w of 0.75 as an overall limit for most 
foods stored in cool environments. Mossel and Ingram (1955) have suggested 
an a.sub.w of 0.70 for long term storage in tropical climates. Mossel and 
Sand (1968) suggest inhibition of all microorganisms occurs only below 
a.sub.w of 0.60. It is noted that these are guidelines. Moisture isotherms 
shift with temperatures such that storage at a higher temperature with the 
same moisture content gives a higher a.sub.w than storage of the same 
product at lower temperature. 
Water activity below which microorganism growth if inhibited is illustrated 
by the following though these amounts can vary: 
TABLE II 
______________________________________ 
Organism Water Activity a.sub.w 
______________________________________ 
Bacteria 0.91 
Yeasts 0.88 
Molds 0.80 
______________________________________ 
(NASA CONTRACTOR REPORT, NASA CR 114,861, June 1972, Table 1, page 77). 
Because the stability is dependent on available moisture and not total 
moisture, much research has been done in the area of humectants. In 
descending order of effectiveness as humectants are sodium chloride, 
potassium chloride, propylene glycol, glycerol 1-3-butylene glycol, 
sorbitol, fructose, polyethylene glycol 400, glucose, sucrose, 42 D.E. 
corn syrup solids and lactose. It has also been suggested that dried whey, 
delactosed whey and whey protein concentrate may find utility as 
humectants. While sodium and potassium chloride are 2-2.5 times more 
effective than propylene glycol, they have not been used for humectants 
due to flavor problems. While propylene glycol and glycerol are highly 
effective as humectants, they are detectable by pets who dislike the 
taste. Compositions which provide effective water activity and good taste 
are needed to overcome the problems incurred in using prior art materials 
in preparing intermediate moisture foods. 
It is also known that, because of the increasing requirement for protein 
sources throughout the world, various processes have been recently 
developed to extract protein from whey. Particular reference is made to 
the Dienst Attebery patent, U.S. Pat. No. Re. 27,806, which discloses a 
method of separating protein from cheese whey by means of molecular sieve 
resin, more commonly known as gel filtration. Also in active use is the 
technique of ultrafiltration to separate and concentrate the protein from 
the whey. The development of the separation techniques has also raised 
further processing problems. The byproducts from these processes are not 
easily adaptable to present known techniques of material handling. 
In the processing of cheese whey by molecular sieve resin, a low molecular 
weight fraction (about 5-10% solids) is obtained which has a solids 
composition of mainly lactose and minerals with residual protein. The 
solids in this low molecular weight fraction can be described more 
particularly by the following typical chemical analysis. 
______________________________________ 
Lactose, % 40-50 
Minerals, % 25-35 
Protein (N .times. 6.38), % 
15-20 
Lactic Acid, % 7-10 
Citric Acid, % 3-6 
Fat, % less than 1 
Moisture less than 5 
pH 6.6-7.2 
______________________________________ 
Similarly, the use of ultrafiltration provides a permeate which is high in 
minerals and lactose. The solids in the permeate can be described more 
particularly by the following typical chemical analysis. 
______________________________________ 
Lactose, % 70-80 
Minerals, % 10-15 
Protein, (N .times. 6.38), % 
4-8 
Fat, % less than 1 
Moisture less than 5 
pH 6-7 
______________________________________ 
After removing the lactose by normal lactose crystallization procedures, 
the now delactosed permeate contains from about 40% to about 45% lactose, 
from about 25% to about 35% ash and from about 8% to about 12% protein 
(TKN.times.6.38). However, the total Kjeldahl nitrogen (TKN) is a measure 
of all the nitrogen in the system (protein as well as non-protein 
nitrogen), and this is an approximation of the total protein present. 
While the delactosed permeate is indicated to have 8-12% protein 
(TKN.times.6.38), more than 60% of this protein is based on non-protein 
nitrogen, i.e., derived protein and amino acids. Derived protein is 
defined as a decomposition product of proteins that is intermediate in 
complexity of structure between proteins and amino acids (Hackh's Chemical 
Dictionary, 3rd Edition). 
Two primary problems have been associated with the low molecular weight 
fraction and the permeate. First of all, conventional drying techniques 
cannot be utilized due to undesirable particle adherence to the walls. The 
second problem associated with these products is the undesirably high 
level of hygroscopicity exhibited by these products. The products, 
particularly delactosed permeate, rapidly pick up moisture from the air. 
Also, the undesirable level of hygroscopicity tends to detract from the 
potential use of this product in food applications. Once the package is 
opened, the dried particles immediately absorb moisture and cake. 
It is also known to utilize the permeate and delactosed permeate in the 
formation of an egg albumen extender. In assignee's copending application 
Ser. No. 970,688, now U.S. Pat. No. 4,238,519, issued Dec. 9, 1980, the 
disclosure of which is incorporated herein by reference, there are 
disclosed egg albumen extenders comprising at least 65% by weight on a dry 
solids basis of a derived protein-containing composition from plant or 
animal sources wherein said derived protein-containing composition has a 
molecular weight of less than 20,000, a total Kjeldahl nitrogen content of 
from about 0.45% to about 2.1% of which at least 60% of the nitrogen is 
non-protein nitrogen, and from 0% to about 30% of a whipping aid, in 
combination with a member selected from the group consisting of gelatin, 
gelatin and a water soluble polyphosphate, a gum, and mixtures thereof. It 
has been found that these products are also difficult to dry when prepared 
from the liquid byproduct solution. Dry blending cannot be accomplished 
due to the difficulties in drying the byproduct solution before blending. 
An improved process for drying a mineral containing aqueous protein 
solution is disclosed in U.S. Pat. No. 3,840,996. In this patent, the low 
molecular weight byproduct fraction from the gel filtration of the whey is 
admixed with inorganic drying agents selected from the group consisting of 
tricalcium phosphate, dicalcium phosphate, kaolin, diatomaceous earth, 
silica ggel, calcium silicate hydrate, or mixtures thereof and spray 
dried. This product is useful in flavor-enhancing various foods. 
In assignee's copending application Ser. No. 6,817, it is disclosed that 
mineral containing deproteinized whey byproduct solutions can be more 
effectively dried by mixing from about 5% to about 50% casein or alkali 
metal caseinates with the solution and codrying the solution. However, the 
high cost of casein and caseinates make this process economically 
unattractive. 
It has now been found that dough-like products exhibiting reduced water 
activity and good flavor for preparing intermediate moisture foods can be 
obtained containing derived protein-containing compositions and 
particularly deproteinized mineral-containing whey byproducts of whey 
protein concentrate. 
BRIEF SUMMARY OF THE INVENTION 
In accordance with the present invention, it has been found that a product 
exhibiting reduced water activity comprising a blend of a first 
composition which comprises at least 65% of a derived-protein containing 
composition from plant or animal sources wherein the molecular weight of 
said derived protein-containing composition is less than 30,000, and 
preferably less than 20,000, said composition having a total Kjeldahl 
nitrogen content of from about 0.45% to about 2.1% of which at least 60% 
of the nitrogen is non-protein-nitrogen, from about 0% to 35% of a member 
selected from the group consisting of from about 1% to about 15% gelatin; 
from about 1% to about 15% gelatin and from about 5% to about 25% of a 
water soluble polyphosphate, the additive total of gelatin and phosphate 
not to exceed about 35%; from about 0.5% to about 5% of a gum; and 
mixtures thereof; and from about 0% to about 30% of a whipping aid, all 
percentages being by weight based on the total dry solids weight of the 
aforecited ingredients in said first composition and from about 20% to 
about 75% of a starch as defined hereinafter at a moisture content of from 
about 20% to about 50% and preferably from about 25% to about 35% by 
weight based on the total weight of the blend and moisture forms a product 
with a dough-like consistency which retains its moisture content and does 
not immediately dry when exposed to air. The dough is pliable and 
moldable. The dough can be formed into hard shapes by molding and drying 
which dough-like consistency can be recovered upon rehydration. The 
products of the invention are characterized by providing a water activity 
within the range of from about 0.5 to about 0.8 and preferably 0.55 to 
0.75 at 30% moisture at 37.degree. C. This product is useful as a base for 
foods. The water activity of the dough is such that microbiological growth 
is not favored so that the dough can be used in preparing intermediate 
moisture foods. The products of the invention are bland to slightly salty 
and thus contribute no flavor problems when used in foods even in large 
amounts. 
The amounts of starch are based on the dry solids in the final dried 
product. 
DETAILED DESCRIPTION OF THE PRESENT INVENTION 
The dough-like products of the present invention are based on certain 
derived protein-containing compositions. The molecular weight for 
substantially all matter in the derived protein-containing composition is 
less than 30,000 and preferably less than 20,000. A material which has 
been ultrafiltered through a membrane having a molecular cut-off of 20,000 
is considered less than 20,000. 
As used herein, the term "derived protein containing composition" is 
intended to include all protein decomposition products including peptides 
and amino acids. 
The nitrogen in the derived protein-containing composition is determined by 
the Kjeldahl method which determines nitrogen from all sources, and cannot 
differentiate between protein nitrogen and non-protein nitrogen. In the 
present invention, the total Kjeldahl nitrogen (TKN) content in the 
derived protein-containing composition preferably ranges from about 0.45% 
to about 2.1% and more preferably from about 1.1% to about 2.1% providing 
a total Kjeldahl protein content of from about 3% to about 13% and from 
about 7% to about 13% respectively. Of the total Kjeldahl nitrogen at 
least about 60% is non-protein nitrogen. Non-protein nitrogen is 
determined by adding trichloroacetic acid to a protein solution in an 
amount sufficient to provide about a 15% solution of trichloroacetic acid. 
Protein is precipitated and removed by centrifugation. The nitrogen 
content of the supernatant is determined by the Kjeldahl nitrogen method. 
The percent total non-protein nitrogen is determined by dividing the 
trichloroacetic acid soluble Kjeldahl nitrogen by the total Kjeldahl 
nitrogen content of the original solution on a dry solids basis. The 
non-protein nitrogen can range as high as 2.1 % (all non-protein nitrogen) 
and preferably from about 0.66% to about 1.68%. 
The percentage of Kjeldahl nitrogen and non-protein nitrogen is based on a 
dry solids basis of the weight of the derived product containing 
composition. Further discussion can be found in Ser. No. 970,688, ibid. 
The derived protein-containing composition can be prepared from legumes, 
oil bearing seeds, milk or milk derived products. The derived 
protein-containing compositions are usually byproducts of a previous 
procedure used to extract an ingredient from the main source. 
The legumes include any members of the pea family such as peas, soy beans 
and peanuts and preferably soy beans. The oil bearing material seeds 
include those materials from which oil is extracted such as cottonseed, 
safflowers, corn and the like. 
The derived protein-containing compositions used in the present invention 
are prepared, for instance, by precipitating protein from an aqueous 
solution in a manner similar to cheese or soy protein isolate production. 
When preparing soy protein isolate, soy protein is extracted from defatted 
soy flour and is separated from the solution by acidifying to pH of 
approximately 4.6. The precipitated product is called soy protein isolate 
and the supernatant is termed soy whey. In the countries of the Far East, 
a similar product is prepared by precipitating a curd or tofu from soy 
milk leaving a similar soy whey. These soy wheys can be further processed 
to remove the higher molecular weight protein and provide a product usable 
in the present invention. Other such by-products can be prepared from 
other legume or oil bearing seeds. 
The derived protein-containing composition is preferably obtained from a 
dairy source, i.e., milk and milk derived products. The derived 
protein-containing composition prepared from a dairy source is generally 
the byproduct of a physical or chemical separation or fractionation of the 
various components in the milk or milk derived product. Such physical or 
chemical processes include gel permeation filtration, ultrafiltration, 
dialysis, electrodialysis, as well as protein precipitation processes such 
as cheese production, either enzyme or acid, chemical precipitation 
including acid addition for casein precipitation, polyphosphate, sodium 
lauryl sulfate or other such chemical protein precipitations. 
Preferably, the derived protein-containing composition is prepared from soy 
or dairy whey and more preferably dairy whey which has been processed to 
further reduce the protein constituent therein. For instance, whey can be 
filtered through an ultrafiltration membrane to provide a protein rich 
retentate and a deproteinized mineral-containing lactose rich permeate. 
The dried products of the present invention are preferably based on certain 
deproteinized whey byproduct solutions. As used herein, the term "whey 
byproducts" is intended to encompass the low molecular weight second 
fraction obtained from the molecular sieve fractionation of whey as 
described in U.S. Pat. No. Re. 27,806, the permeate obtained from the 
ultrafiltration concentration of protein from whey, and delactosed 
permeate. 
The low molecular weight second fraction is the material obtained by 
passing a partially delactosed cheese whey mother liquor through a bed of 
molecular sieve resin in accordance with Reissue Patent No. 27,806 and 
recovering, for the purposes of this invention, the low molecular weight 
second fraction containing mainly lactose, minerals and residual protein. 
The molecular weight cut-off of the gel is preferably 30,000. The 
partially delactosed whey mother liquor is obtained by concentrating raw 
cheese whey by conventional means to a solids concentration of about 60%, 
reducing the temperature of the concentrate to induce lactose 
crystallization and thereafter separating crystalline lactose from the 
liquid by conventional means. 
If desired, the whey can be pretreated to clarify the whey using processes 
such as illustrated by that disclosed in U.S. Pat. No. 3,560,291. In 
accordance with this patent, lipid is removed as a precipitate from whey 
by treating the whey solution with a calcium ion at approximately a 
neutral pH. 
Preferably, the whey stream used in the gel filtration fractionation of 
whey is clarified prior to delactosing. The preferred method of 
clarification is the process described in U.S. Pat. No. 3,560,219 for 
sweet whey. For acid whey, the preferred clarification method is that 
shown in U.S. Pat. No. 4,036,999, the disclosure of which is incorporated 
herein by reference. 
Also effective in the present invention is the permeate obtained from the 
ultrafiltration of cheese whey solutions. Ultrafiltration membranes are 
utilized to separate the high molecular weight protein and non-protein 
nitrogen compounds (below about 20,000 molecular weight); and ash in the 
whey solution. The protein enriched solution is retained on the membrane 
and it is called the retentate. The water and low molecular weight 
fraction passes through the membrane and is called the permeate. An 
illustrative method for ultrafiltration is described by Horton, B. S. et 
al., Food Technology, Vol. 26, page 30, 1972. 
In an illustrative method for ultrafiltering cheese whey, an acid or 
cottage cheese whey concentrate containing from about 40% to about 60% and 
preferably 50%-55% whey protein is prepared by neutralizing acid whey to a 
pH of 6.5 with caustic. After storage, the pH is then adjusted to 7.2 and 
any solids or precipitates are removed by centrifugal clarification. The 
clarified liquor is then pasteurized and fed into the ultrafiltration 
membrane unit. The retentate is condensed and spray dried. The liquid 
permeate is then used in the process of the present invention. 
The permeate can be dried as is or concentrated and/or delactosed by 
concentration and cooling to effect a precipitation of a lactose. The 
permeate is a deproteinized whey solution and the delactosed permeate is a 
delactosed deproteinized whey solution. 
The raw cheese whey source used in preparing the materials used in the 
present invention can be acid cheese whey, sweet cheese whey, or mixtures 
thereof. More particularly, the raw cheese whey can be cottage cheese 
whey, casein cheese whey, cheddar cheese whey, mozarella cheese whey, 
Swiss cheese whey or mixtures thereof. Preferably, raw cheese whey used in 
connection with the molecular sieve fractionation is a blend of cottage 
cheese whey and cheddar cheese whey. The preferred cheese whey for use in 
the ultrafiltration fractionation of whey is acid cheese whey. 
The remaining disclosure will be directed to the preferred species 
deproteinized mineral-containing whey byproducts. However, it is 
understood that this discussion applies equally to the broad generic 
concept of the invention. 
The starch, used in the present invention, can be any starch or blends 
thereof, modified or unmodified which is water-soluble (swellable). The 
starch is defined as that which will provide a viscosity above 1000 cps 
and less than 200,000 in a 10% solution at 25.degree. C. as measured on a 
Brookfield Model LVT Viscometer with a No. 3 spindle at 0.6 RPM. 
Preferably, the starch provides a viscosity within the range of from about 
80,000 and about 120,000 cps and more preferably 90,000 to about 100,000. 
The starch can be derived from any starch source such as cereal grains, 
i.e., corn, waxy corn, wheat, sorghum, rice; tubers, or roots of such 
plants as cassava (tapioca), potato or arrowroot and the pith from the 
sago palm. 
The starch can be modified or non-modified. Modification includes genetic 
modification (waxy corn or waxy sorghum), starch conversion, crosslinking, 
derivation, and physical treatment. The starch can be from any source and 
treated using any method of modification or combination thereof which 
provides the desired viscosity range. 
The maintenance of a maximum viscosity of starch without a substantial 
reduction in viscosity over an extended cook time is accomplished by 
cross-linking. Cross-linking is generally used in starches used for 
thickening and stabilizing. The starch granules are treated with di- or 
polyfunctional reagents capable of reacting with the hydroxyl groups in 
the starch molecule such as mixed anhydride of acetic and citric acid or 
adipic acid, meta phosphates, phosphorus oxychloride, epichlorohydrin and 
the like. Only a few crosslinks are necessary to toughen the starch 
granules. 
Derivation includes reacting the hydroxyl groups of the starch with various 
chemical agents to change the characteristics of the starch. Physical 
treatment includes redrying, blending with additives such as tricalcium 
phosphate as a flow control agent, precooking (pregelatinized starch), 
drum dried ground flakes (water soluble) and spray dried cooked starches. 
The type of starch utilized depends on the physical and chemical 
characteristics of the starch, the amount used, and the end use of the 
product. The preferred starch is a high viscosity, precooked, modified 
starch designed for instant dessert applications such as H-50A of National 
Starch and Chemical Corp. 
Thin-boiling starches made by controlled acid hydrolysis of starch in the 
granular state at about 52.degree. C. using sulfuric or hydrochloric acid 
as catalyst are less preferred since the use of these starches forms 
sticky dough. 
The dough containing the whey byproduct solution and the starch can be 
prepared alone or with flavors, colors, emulsifying agents, stabilizers 
and the like which can also be dissolved in the solution of the whey 
byproducts and the starch. Other proteins (up to 25%) such as dairy 
proteins including whey, delactosed whey, whey protein concentrates, whey 
precipitates prepared by the processes of U.S. Pat. Nos. 3,560,219 and 
4,036,999 and the like or vegetable proteins such as soy can also be added 
though this is not preferred. Also, functional ingredients in amounts 
ranging from about 0% to about 35% and preferably from about 0.5% to about 
35% can be added in forming a final product with specific functionality. 
For instance, from about 1% to about 15% gelatin; or from about 1% to 
about 15% gelatin and from about 5% to about 25% of a water soluble 
polyphosphate such as sodium hexametaphosphate, the additive total of 
gelatin and polyphosphate not to exceed about 35%; or from about 0.5% to 
about 5% of a gum; or mixtures thereof can be included in the dough. The 
percentages are based on the weight of the solids of the raw whey 
byproduct exclusive of the starch. 
The gelatin used in the present invention can be either of the alkaline or 
preferably the acid prepared type. Gelatins ranging in Bloom strength from 
about 100 to about 300 and preferably from about 200 to about 250 Bloom 
can be used. The gelatin can be predissolved in water to facilitate 
incorporation. Preferably, .-+.cold-water dispersible" gelatin is used. 
The water soluble polyphosphate usable in the present invention are medium 
chain length sequestering type polyphosphate of the formula: 
##STR1## 
wherein X is hydrogen or alkali metal. Preferably, the average chain 
length (N ave.) is from 3 to 20. Representative compositions within this 
group are sodium or potassium tripolyphosphate, sodium or potassium 
tetrapolyphosphate, sodium or potassium hexametaphosphate, the more 
preferred being sodium hexametaphosphate (SHMP) with an average chain 
length of 6-18, and the most preferred 9-12. 
The gums which can be used in the present invention include any of the 
edible gums or protective colloids such as carrageenan, alginates 
including sodium or potassium alginate, cellulose gums including sodium 
carboxymethylcellulose, methyl cellulose, hydroxymethylcellulose, 
hydroxyethylcellulose, hydroxypropylcellulose, 
hydroxymethylpropylcellulose and preferably, carboxymethylcellulose, 
acacia, guar, xanthan, and mixtures thereof. 
The gum is preferably used in an amount ranging from about 0.5% to an 
amount above which the final product shows adverse properties in the area 
of use. In general, the gum is not to exceed about 5% by weight based on 
the weight of the final product (exclusive of starch), the upper limit 
varying depending on the actual gum utilized. In some cases, more can be 
used and in some cases, less. The preferred gum is carrageenan which is 
used in amounts ranging from 0.5% up to and including about 3% (exclusive 
of starch). 
The optional whipping aid is illustrated by enzyme hydrolyzed wheat or soy 
protein which can be prepared by hydrolyzing any wheat or soy protein or 
wheat protein mixture such as gluten by any proteolytic enzyme effective 
for that purpose provided the final product has a bland flavor which will 
not affect the overall flavor of the egg albumen replacer. Proteolytic 
enzymes are well known to those skilled in the art and effective 
proteolytic enzymes can be easily determined by such person. While the 
enzymatically hydrolyzed wheat or soy protein can be used alone, it is 
preferably used with a small quantity (up to and including about 20%) to 
thicken and stabilize the mixture, the percentage being by weight based on 
the total weight of the enzyme hydrolyzed wheat protein. An illustration 
of these materials is HYFOAMA 68 available from Naarden Lenderrink and 
Co., Belgium and GUNTHERS 400V available from A. E. Staley. 
The former material has 60% protein, 5% water, 6% ash, and 20% 
carbohydrate. The enzymatically hydrolyzed wheat protein is used in 
amounts of from about 5% to about 30% and preferably from about 10% to 
about 20% by weight based on the total weight of the whey byproduct 
containing composition exclusive of starch. The latter material is 
composed of enzymatically modified soy protein (55% of total), sodium 
hexametaphosphate, gelatin and sodium aluminum sulfate. 
The amount of starch used is dependent on the chemical characteristics of 
the starch. In general, the starch is used in an amount ranging from about 
20%, preferably from about 20% to about 75% and more preferably from about 
25% to about 50%, said percentages being based on the dry weight of the 
protein component and optional gelatin, polyphosphate, gum and whipping 
aid. These amounts are for the preferred high viscosity, precooked, 
modified instant dessert starches and may vary from starch to starch. 
The dough can be provided by any means adapted to effect the preparation of 
a dough with a moisture content within the ranges to be discussed 
hereinafter. Dried ingredients can be rehydrated with moisture 
specifically added or absorbed from the atmosphere. The dry powder can 
include some or all of the ingredients and can be prepared by drying each 
ingredient and blending using known techniques or codrying some or all of 
the ingredients. Ingredients can be partially dried and if desired blended 
with other dry ingredients to provide the proper moisture level. As 
illustrative, liquid delactosed permeate can be concentrated by such 
standard means as a falling film evaporator. Dry ingredients such as 
gelatin and SHMP can be added. Concentration of the liquid delactosed 
permeate can be undertaken to a point which, when combined with the solid 
ingredients, provides the final desired moisture content. Some moisture, 
up to 15%, can be lost on mixing. Preferably, the dough is prepared 
wholely or partially from liquid ingredients such as liquid delactosed 
permeate to avoid an expensive drying step. 
It is important that the moisture content of the dough be maintained 
between about 20% and about 50% and preferably from about 25% to about 35% 
by weight based on the total weight of the dough of the byproduct 
composition and the moisture. 
It has been found that the dough-like product with or without the gelatin, 
SHMP, or gum when incorporated in a food product can perform the function 
of a humectant. Thus, the product of the invention can be used in areas 
where humectants such as propylene glycol are presently in use. The 
products of the invention can be used as the sole humectant or in 
combination with other known humectants. Effective humectant activity can 
be established using a sufficient amount of the humectant to provide from 
about 2% to about 20% by weight derived protein in said food on a dry 
solids basis. 
The dough-like product of the invention can be used in food products as 
flavor enhancing agents, flavor agents or binding agents. More 
specifically, the dough-like products of the invention can be used in meat 
products, for example, soups, stews, gravies, breadings, batters, beef 
patties and imitation sausages. Also, the product can be used in chip 
dips, cheese products such as cheese spreads, process cheese foods, spray 
dried cheeses, and imitations thereof and the like. The dough can also be 
used in non-food areas such as cosmetics and moldable dough for playing. 
Of particular importance is the use of the products of the present 
invention as a base and humectant in intermediate moisture foods such as 
semi-dry pet foods. The semi-dry pet food can be prepared by blending the 
food ingredients with the liquid whey byproduct and starch at a moisture 
content sufficient to provide a dough. Also, the whey byproduct/starch 
blend can be dried and added to the ingredients of the food under such 
conditions that the blend is rehydrated to the desired level. The dough, 
because of its bland taste, is compatible with most ingredients of a food 
product. The products of the invention can be used as the sole base and/or 
humectant or in combination with other known base materials and/or 
humectants. The products can be incorporated in place of existing 
humectants in standard recipes. The products of the invention are 
preferably used in such amounts as to provide a water activity for the 
food of between about 0.5 and about 0.8 when measured at 30% moisture at 
37.degree. C. 
The present invention is further illustrated in the examples which follow. 
The starch as used herein as identified as a pudding grade starch, H-50A 
from National Starch and Chemical Corp., is a finely ground, high 
viscosity (about 90,000-95,000 cps in a 10% solution at 25.degree. C.) 
precooked modified starch primarily designed for instant dessert 
applications.

EXAMPLE 1 
11 grams of SHMP, 2.3 grams gelatin and 66.7 grams of a pudding grade 
starch (H-50A, National Starch and Chemical Corp.) are dry blended. The 
dry blend is blended slowly into 140 grams delactosed permeate (31% to 34% 
TS). The dough is kneaded until the dry ingredients are well dispersed. 
Sample is then placed in a laboratory vacuum oven set at 54.4.degree. C. 
and 63.5 centimeters of mercury vacuum. The rate of moisture loss is shown 
in Table I below: 
TABLE I 
______________________________________ 
SAMPLE % 
WEIGHT % TOTAL 
TIME (Hours) (GRAMS) LOSS SOLIDS 
______________________________________ 
0 105.5 0 56.15 
1 101.8 3.7 58.19 
2 92.6 9.2 63.97 
2.5 89.2 3.4 66.41 
9.0 Room Temp. 86.9 2.3 68.17 
7.2 Ambient 77.3 9.6 76.63 
Hum. 
______________________________________ 
EXAMPLE 2 
A similar sample prepared in accordance with the procedure of Example 1 and 
oven tested at 65.5.degree. C. and 73.66 centimeters of mercury vacuum 
provides the following results: 
TABLE II 
______________________________________ 
SAMPLE % 
TIME WEIGHT % TOTAL 
(HOURS) (GRAMS) LOSS SOLIDS 
______________________________________ 
0 118.1 00 56.15 
1 105.8 12.3 62.66 
2 96.3 9.5 68.86 
3 90.8 5.5 73.03 
4 87.0 3.8 76.22 
5 84.3 2.7 78.66 
6 82.7 1.6 80.19 
______________________________________ 
EXAMPLE 3 
300 milliliters of delactosed permeate is evaporated to 40.degree. 
Brix.sup.+ using a rotating flask vacuum evaporator set at 62.degree. C., 
63.5 centimeters mercury and a Varispeed.TM. setting at 100 for 3 hours. 
5.5 grams sodium hexametaphosphate, 1.1 grams gelatin and 33.3 grams 
pudding type starch (H-50A, National Starch and Chemical Corp.) are dry 
blended and added to 43 grams of concentrated DLP. Small dough balls are 
formed when the ingredients are mixed by hand with a spatula. 
EXAMPLE 4 
Delactosed permeate from the ultrafiltration concentration of whey is 
concentrated to 47% solids on a falling film evaporator. 1.3 liters of 
this concentrated DLP is added to a stainless steel container and heated 
to 60.degree. C. in a water bath. 7 milliliters of catalase is added to 
destroy any residual hydrogen peroxide which may be present from a 
preservation system. 0.804 grams of OROLINE yellow dye is then dissolved 
in the DLP. 42.25 grams of gelatin is also dissolved into the hot DLP. The 
DLP/gelatin/dye mixture is added to a Hobart.TM. Mixing Bowl using a 
paddle and low speed. Incrementally blended into said liquid is a dry mix 
of 663 grams of pudding starch (H-50A National Starch and Chemical Corp.) 
and 189 grams of sodium hexametaphosphate. The dried powder is added 
slowly over a period of about 50 minutes. Upon completion of the powder 
addition, the mixing paddle is detached and a dough hook is attached and 
mixing continued. Mixing is stopped approximately 1 hour and 20 minutes 
after mixing was initially started. The product is an orange dough-like 
mass of approximately 1.9 kilograms having a total solids within the range 
of 71-75%. 
Samples show no growth when exposed to air for one week and in some cases, 
a reduction in growth. 
EXAMPLE 5 
100 grams of pudding type starch (H-50A, National Starch and Chemical 
Corp.) is blended with 429 grams of liquid DLP having 35% solids at a 
ratio of about 1:1.5 on a solids basis. The blend is pasty and viscous and 
is freeze-dried. After milling, the freeze-dried blend is a fine powder. 
The freeze-dried powder is placed inside a humid chamber at 75% relative 
humidity at 37.degree. C. which is equilibrated with a saturated NaCl 
solution. After reaching equilibrium (about three days), a dough of a 
moisture content of about 30% is formed. The time period for forming the 
dough can be shortened by the use of a higher relative humidity in the 
chamber. The dough remains moist and unspoiled in a moist air environment 
for several months. 
In comparison to the dough formed in Example 4, the consistency of the 
dough of the present example is softer and more pliable. The doughs made 
by both examples are cohesive and non-sticking. 
A dough made with starch and water (30% moisture) without DLP cannot 
maintain a soft dough-like consistency and becomes hard after a short 
period of storage even under humid conditions (75% relative humidity). 
Samples from the preceding examples showed no microbiological growth when 
exposed to air for one week and in some cases a reduction in growth is 
shown. 
EXAMPLE 6 
Three intermediate moisture pet foods are prepared to show the 
effectiveness of the products of the invention as humectants. The 
formulation used is as follows: 
TABLE II 
______________________________________ 
INGREDIENT % 
______________________________________ 
Chicken Junior Baby Food 
30.1 
Dextrose 28.6 
Soy Flour 27.6 
Water 4.8 
Fat 2.4 
Emulsifier (Mono and di- 
glycerides-Atmul 80) 1.0 
Potassium Sorbate 0.5 
Sample A-Propylene Glycol 
(Control) 5.0 
Sample B-Liquid DLP 4.8 
Sample C-DLP/Starch (Tapioca 
Dextrin)-2:1 ratio 2.9 
______________________________________ 
The baby food, a retorted blend of chicken, chicken broth and cooked 
chicken and the water is weighed into a stainless steel mixing bowl. The 
mixture is heated to 70.degree. C. The emulsifier, fat, potassium sorbate 
and the liquid DLP or the propylene glycol are then added. Heating is 
continued until the ingredients are dissolved. The dextrose and soy flour 
and, if present, the DLP/Starch product are dry blended and the liquid 
system is then added to the dry system. The resultant blend is kneaded 
into dough and shaped into pellets having a diameter of 1.9 centimeters 
and a height of 1.27 centimeters. The pellets are stored in water 
impermeable containers. 
The water activity of the Samples is determined with the following results: 
______________________________________ 
SAMPLE WATER ACTIVITY % MOISTURE 
______________________________________ 
A (Control) 0.80 29.3% 
B (L. DLP) 0.83 27.1% 
C (DLP/Starch) 
0.825 24.7% 
______________________________________ 
EXAMPLE 7 
Three dough-like products were prepared, the first in accordance with the 
invention and the second and third using propylene glycol and glycerol 
respectively as humectants. The doughs were prepared by dissolving 1.7 
grams of gelatin and 8 grams SHMP in 30 grams of water. The water was 
heated to 50.degree. C. to dissolve the gelatin after which the solution 
was cooled to 25.degree. C. 32.3 grams of DLP or propylene glycol or 
glycerol were mixed with the gelatin/SHMP solution. 28 grams of pudding 
starch (H-50A) was added slowly to the gelatin/SHMP solution blending to a 
smooth consistency. The resultant dough was kneaded 15 minutes to evenly 
disperse all ingredients. The following results were obtained: 
______________________________________ 
WATER 
SAMPLE ACTIVITY PHYSICAL PROPERTIES 
______________________________________ 
DLP Aw = .69 Firm, pliable, dry to 
the touch 
Propylene Glycol 
Aw = .55 Very soft, very 
sticky 
Glycerol Aw = .51 Very wet, not sticky 
______________________________________ 
While propylene glycol and glycerol will form a dough, the handling 
properties are quite different from a DLP-based dough. The DLP-based dough 
is firm, pliable and dry to the touch and more similar to a cheese analog 
product than the other two.