CA1127446A

CA1127446A - Process for the liquefaction of meat, meat hydrolyzates thus produced, and use of same

Info

Publication number: CA1127446A
Application number: CA336,144A
Authority: CA
Inventors: Ursula Reigler-Rittner-Berger; Rolf Stute; Jean-Luc Charleux; Paul W. Muller
Original assignee: Unilever Bestfoods North America
Current assignee: Unilever Bestfoods North America
Priority date: 1978-09-21
Filing date: 1979-09-21
Publication date: 1982-07-13
Also published as: AU5034979A; DE2841043A1; AU526750B2; KR820001071B1; PH16111A; AR220577A1; MX5772E; JPH0311752B2; DE2841043C2; JPS5558081A

Abstract

ABSTRACT OF THE DISCLOSURE

A process for hydrolytic liquefaction of meat to produce a clear, instantly soluble, meat hydrolysate.
The meat is hydrolyzed in a single step with a neutral protease of microbial origin until at least 60% of the fresh meat protein has been converted. When the hydrolyzates are heated in aqueous solution, they are non-coagulating.
Undissolved residues are optionally separated from the liquid hydrolyzate. The product is a high protein raw material which can be used like meat or like a meat extract to make soups, sauces, dressings, baked goods, dietetic products, etc.

Description

7~
PROCESS FOR TH~ LIQUEFACTION O~ MEAT, MEAT
HYDROLYZATES TIIUS PRODUCED, AND USE OF SAM~

sAcKGRouND OF THE LNVENTION

Field of -the Invention -This invention relates to a process for the liquefact-ion of meat by enzymatic hydrolysis wi-th proteases, to meat hydrolyzates produced according to this process as well as to the use of said meat hydrolyzates as a basis for clear meat broths.
The Prior ~rt In U.S. Patent 3,113,030 a process has been disclosed for the enzymatic hydolysis of meat in which the meat is finely ground, blended with usually 60~ and more water and subjected to the action of proteases, which are present in the meat or are optionally added, until the mixture has been "liquefied", i.e. converted into a flowab]e dispersion of milky or creamy consistency which contains a considerable portion of the meat ln the form of fine solid particles in suspension. In this process it is essential to terminate the treatment before any major degradation of the meat to amino acids takes place as the process leads to bad-tasting products if hydrolysis is carried too far.
The purpose envisaged and achieved by this known proteolytic treatment is the conversion of meat into a meat product ("liquid meat") which is easy to handle, rich in energy and still easily digestible and assimilable, thus not unduly taxing the digestive system, and which is suitable for use as a protein bland diet or as a protein concentrate for emergency rations. However, the products obtained are unsuitable for the preparation o clear meat broths for the very reason that the predominant portion of the ~.~2'~
protein material contained in them is present in a form which is ei-ther insoluble or which coagulates upon heating in water.

As a basis for industrially pre-prepared clear broths and soups the food industry--as it did more than half a century ago--therefore still relys almost exclusively on "Liebig's extract of beef" although this classical meat broth base involves a number of disadvantages whichare linked to the produc-tion process. The quality of beef extract, for instance, today is still subject to considerable variation. A much greater handi-cap is, however, that beef extract is a co-product which, referred to the amount of meat used, is obtained in yields of merely a few percentages while the "rest" of more than 90% has to be processed into meat meal or corned beef, the latter being the only reasonable alternative today from an economic point of view.
Thequantities and prices in and at which beef extract is avail-able, therefore, obviously depend essentially on the amount of corned beef that is sold and on the price at which it is sold.
Finally, beef extract is unsatisfactory since the broths prepared from it do not taste like "home-made meat broths", which are prepared in the classical way from fresh meat, but always show a typical taste which is caused by the production process and which is referred to by the expert as "hydrolyzed-protein taste" or "Maillard taste".

It was only logical, therefore, that all leading food processors of the world have for decades been making great efforts to develop meat hydrolizates and processes for producing them which are free from the disadvantages inherent in beef extract and beef extract production. These efforts so far have failed, the majority of proposals being unsuitable simply because of the unsatisfactory taste of the resulting products. This applies, for instance, also to the dehydrated products which are obtained according to the process proposed in German oS 23 35 464 for the enzymatic hydrolysis of meat using the proteases recommended therein, especially trypsin and/or pepsin, to an average molecular weight within a specific range, since this known process not only involves disadvantages in terms of process technique but also--in spite of contentions to the contrary in this patent application--yields a product with absolutely inadequate taste properties, i.e. a hydrolyzate with a flat, atypical,metallic and distinctly bitter -taste, as -the compara-tive test described later illustrates.

The only proposal which does lead to a high yield of a meat hydrolyzate with the desired solubility and taste proper-ties is the process of hydrolysis disclosed in German Patent 1 084 557 which, however, in spite of the excellent properties of the products obtained does not constitute a practicable alterna-tive to classical extract of beef and which in the nearly two decades that have passed since its disclosure, therefore, has not found its way into practice because it does not yield products suitable for the preparation of meat broths with a taste equalling that of home-made bouillons unless 1. the meat is first gently extracted with water,

2. the meat residue left after separation of the aqueous extract is subjected, after addition of large amounts of water and pH adjustment, to a mild hydrolysis in the presence of an optional proteolytic enzyme, the enzyme is deactivated and the "enzymatic extract" is separated, and

3. the resulting residue is hydrolyzed and extracted with diluted aqueous acids in several steps while z~

care has to be -taken in each step of hydrolysis -that -the ratio of total nitrogen to amino nitrogen in each hydrolyzate is less than 10 and greater that 1, and

4. unless finally all extracts together are evaporated and dried to form a water-soluble concentrate, and because this process, consequently, is much too complicated and costly to constitute a true alternative to beef extract.

It therefore became an object of this invention to create a process which is free from the disadvantages of the state of the art and which, in particular, permits meat to be converted at comparatively low cost and without excessive equipment in a high yield of at least 60% and especially almost quantitatively, i.e. without any co-product, as well as without any or at most only a small amount of water and without any pH
adjustment into a meat hydrolyzate that is clear and instantly soluble in water, which is not subject to the quality variations observed in connection with beef extract and in terms of taste is not only egual but even superior to beef extract.

SUMMARY OF THE INVENTION
This object of the invention is realized on the basis of the finding that in the enzymatic hydrolysis of meat, even if 60~ and more of the meat protein is degraded in one step to hydrolizates that are clear and instantly soluble in water, a meat hydrolyzate neither bitter nor otherwise unsatisfactory in terms of taste is surprisingly obtained if very specific, namely neutral proteases of microbial origin are used as the enzyme.

Accordingly, -the present invention provides a process for producin~ clear, in~tan-tly soluble, meat hydrolysa-te by hydroly-tic liquefaction of meat using a protease, wherein meat is hydrolyzed in a single step with a neutral protease of microbial origin into clear, instantly soluble hydrolyzates which are non-coagulating upon heating in aqueous solution.
A further subject of the invention are the meat hydroly-zates produced according to the process of the invention as well as their use as a basis for clear meat broths or soups with a taste equalling that of home-made houillon or clear soup.
The process of the invention is advantageous not only because it permits meat to be converted practically quantitatively into a clear, instantly soluble hydrolyzate, with an optimum devel-opment of the typical broth taste taking place at the same time, but also and in particular because this is achieved at much lower cost and with much less equipment than is possible with the only process so far known which, with reasonable reliability, permitted an essentially complete conversion of meat into hydrolyzates showing the desired properties.
Starting materials for the hydrolysis carried out in the process of the invention are native animal raw materials as they result from slaughter, i.e. all types of meat, e.g. any grade of beef ~with a high or a low fat content as well as with different tissue portions), beef bones, meat xesulting from industrial re-picking of bones, liver, pork, poultry and poultry skins as well as other raw materials known to be suitable for the preparation of meat broths. Preferred raw materials are those which are chiefly used also by the housewife in the preparation of broths, i.e. beef, beef bones, chicken meat, whole chicken with chicken skin as well as the meat resulting from . . . . . . . . . . . . A

f~
. ~

industrial re-picking of bones a~d poultry skins.
DETAILED DESCRIPTION OF THE INVENTION

As already mentioned, suitable proteolytic enzymes for the process of the invention are exclusively neutral pro-teases of microbial origin. All other commercial proteases, expecially the proteases of vegetable or animal origin so far preferred for use, have been found to be more or less useless as far as the yield and/or the taste of the hydrolyzates are concerned.

Proteases preferred for thepurpose of the invention are:
Proteases with an activity of at least 15 PUC b /g and expecially at least 30 PUC b /g as determined by the ANSON method as modified by Messrs. Rohm, Darmstadt.
Definition: 1 PU 2yO - 1 mmol tyrosine liberated from 1.65~ hemoglobin solution (SERVA according to ~NSON) in 10 minutes at 50C and pH 6Ø

In order to achieve not only a high yield but also an optimum taste in applying the process of the invention, the proteases preferred for use in the invention must additionaly show a high activity with regard to gelatin as well as a suff-iciently low specificity as far as the liberation of aromatic amino acids is concerned. As has been found, an appropriate selection of suitable enzymes may easily be made by determining not only the above-mentioned acitivity vis-a-vis hemoglobin but also the ratio of liberated aromatic amino acids and peptides (not precipitated by trichloroacetic acid) to the total number of split peptide bonds (amino nitrogen).

The liberated aromatic amino acids and peptides (cal-culated as tyrosine) are obtained from the extinction at 280 mu of the TCA supernatant of a 1.65% hemoglobin suspension incubated for 4 hours at pH 6 (phosphate buffer) and 50C with 6.5%
protease/substrate.

The number of split peptide bonds is calculated from the amino nitrogen values of the above-mentioned total batch, referred to the total amount of nitrogen, and determined accord-ing to the method of v. SLYKE (cf. D.D. v. SLYKE, J. Biol. Chem.
83 (1929) 425).

Proteases preferred for the purpose of the invention show a ratio tyrosine~ total N
~ 0.12 pre.~ 0.1 ~ . ~ . . = . .
aminO N/ total N

as well as a significant gelatase activity which is determined as follows:

Solutions of increasing protease concentration (in 0.1 M
phosphate buffer pH 6) are applied in drops onto the emulsion side of an exposed and developed black-and-white film and are incubated for 20 minutes at 50C. After the protease solution has been washed off, the gelatase activity may be judged from the more or less heavy attack on the gelatine layer. Suitable proteases are those which at a concentration of 1.01 - 0.05%
maximum markedly degrade the gelatine layer (leaving marks or producing holes) and especially those causing marked degradation at a concentration of 0.001 - 0.01% maximum.

With regard to the enzymes to be used in the invention, it has furthermore been found that the neutral proteases derived 4.~j from microorganisms of the Aspergillus and sacillus genes and especially microorganisms of the Bacillus subtilis, Aspergillus niger and Aspergillus melleus species are particularly preferred, the most preferable ones in every respect being, as experience has shown, the neutral proteases obtained from Aspergillus melleus strain IAM 2066 as well as its variants and mutants.

Prior to hydrolysis, the starting material in the process of the invention is usually chopped, preferably in a meat grinder or cutter, while colloidal grinding or the like is not required.

Enzymatic hydrolysis is performed preferably in a closed system with heating jacket and agitator, for instance in a so-called Stephan* cutter which permits chopping as well as agitation desired during hydrolysis. In such a system hydrolysis may be carried out without any addition of water, if desired, or with an addition of water in an amount up to 30% by weight, referred to the amount of fresh meat. While larger amounts of water would not be a handicap, they are not required and so are avoided for economic reasons.

Enzyme concentrations, referred to initial raw material, preferably range from 0.1 to 10, more preferably from 0.5 to 5 and most preferably from 1 to 2% by weight.

In the process of the present in~ention hydrolysis may, as a rule, be terminated after at most 24 hours and is preferably allowed to run for ~ to 16 hours. The temperature at which hydrolysis is carried out usually is 30-60C and preferably 45-55C, depending on the type of protease used. There is no adjustment of pH required. Hydrolysis therefore usually takes place at the natural pH of the meat. This means that with the exception of the enzyme there are no further additions needed for *trade mark carrying out the hydrolysis. Yields range from 60 to 100%, referred to fresh meat proteinl depending on the conditions chosen, especially on the extremely high substrate concentra-tions.

Hydrolysis is terminated perferably by hea-ting the batch to 80-120C for l to 60 minu-tes, more preferably to 100C for 10-20 minutes, deactivating the enzyme. The germ content naturally present in fresh meat, which -a further advantage of the invention--decreases already during hyrolysis, is reduced practically to zero as a result of this deactivation so that the hydrolyzate at the end of the hydrolysis is sterile.
In this preferred embodiment of the process of the invention, deactivation by heat or pasteurization simultaneously serves to produce the typical broth taste which develops when meat or, in this case, meat hydrolyzate is cooked. This taste of broth may also be obtained by previously cooking the batch for hydrolysis (Example l), but *his implies an additional process step which is not only unnecessary to optimum flavor development but also involves the risk of flavors being lost during the further steps of the process. When hydrolysis is carried out without any addition of water it is practically impossible to produce the taste of broth prior to hydrolysis.

For producing a hydrolyzate that is clear and soluble in water, it is advisable to remove the fat, which is liberated during hydrolysis and whose amount depends chiefly on the type and quality of the raw material used, as well as optionally a protein (or bone) residue, which has not gone into solution, by using suitable processes, e.g. sifting, centrifuging, filter-ing or settling. If the product is intended for uses, e.g.
sauces or casseroles, in which a small amount of finely dispersed g _ material is not considered disturbing, such separation can of course be despensed with.

A special advantage of the hydrolyzates obtained according to the process of the invention is their high solids content which in those cases where hydrolysis is carried out without any addition of water corresponds to ~he solids content of fresh meat (Example 2) and in cases where additions of water up to 30% are used is still essentially higher than the solids content common in other enzymatic hydrolyzates.
The hydrolyzates of the invention may therefore be directly converted into a dry product, e.g. by means of spray drying, with no additional concentration (as needed, e.g., for beef extract) being required. Such a dry product may, of course, also be obtained by freeze-drying. Freeze-drying, while being more gentle a process, is also more costly and does not offer any essential advantage over spray-drying when the latter is effected under proper drying conditions (Example 3). A powder thus obtained is of light-yellow to beige color, flowable and therefore excellently suited for use in dehydrated products, especially in free-flowing products. The pasty beef extract permits such uses only after additional process steps, e.g.
admixture of carriers. Common industrial bouillon products based on beef extract, therefore, usually are pasty masses which are marketing preferably in the form of cubes or in jars. The hydrolyzates obtained according to the process of the invention by contrast, permit also a flowable bouillon to be produced in a simple way.

Another special advantage of the invention is that the hydrolyzates are directly suitable for further processing. Due to their high solids content, which is practically identical to that of meat, it is possible to directly produce from them sub-sequent or finished products in a simple way, e.g. by adding suitable ingredlents. Example ~ explains such direc-t further processing for the produc-tion of a bouillon base mixture.

The products obtained in this manner show a w values below 0.7 and thus are stable to microbiological decay In these basic masses of low water activity pieces of garnishes, such as vegetables, meat or seasonings, may also easily be incorporated and, while maintaining the low water activities, storable products are again obtained which are by far superior in quality to comparable dehydrated products and which may be converted into ready-to-eat form simply by an addition of water.

This simple, direct way of further using the hydrol-yzates in subsequent and finished products corresponds, in principle, to the processing of meat, lean minced pork, etc.
into meat pastes or the like as it is effected~ for instance, in the manufacture of sausages and similar products. It is therefore also under this aspect and because of their compo-sition which largely corresponds to meat that thP meat hydrol-yzates of the invention are to be regarded as a raw material equivalent to meat, the only exception being that their good solubility permits uses which are not possible with meat or meat pastes.

Depending on the type of meat used, distinctly different flavors are obtained. Meat cut from the shoulder (Example 3) givesa very fine taste which was preferred by part of the testers, as illustrated by the table in Example 5. Meat cut rom the breast, which is usually used for making soups, gives a taste of broth which is perceived most to be heartier and which was preferred by another, approximately equal number of testers. It cannot be said, therefore, that in the manufacture of starch hydrolyzates a specific flavor of such a hydrolyzate is .~

~z~
particularly advantageous and desira~le. Rather, the flavors correspond to those obtained when different meat qualities are processed by the housewife.

The versatile properties of meat as a raw material are thus fully retained in the process of the invention even as far as flavors are concerned and may be ~ully utilized in the products made from.

A special embodiment of the proposed process is termination of hydrolysis without final heating to produce the broth flavor. The hydrolyzates obtained in this manner exhibit the flavor and odor typical of raw meat and may be used like ra~
meat. They show low germ contents as they result from hydrolysis and, being adjusted to low water acitivities, are stable to micro-biological decay. Like raw meat the hydrolyzates may be subjected to subsequent processing steps like cooking, salting, etc. to achieve the flavors typical of cooked, salted products.

The possibility of using, for instance, soupbones, meat resultingfrom industrial re-picking of bones, etc. in the process of the invention in the same manner as beef is illustrated in Example 6. The hydrolyzates exhibit the flavor characteristics of stock made from bones. In mixing them with pure meat hydroly-zates a flavor is obtained which corresponds to that of a home-made broth including bones and meat.

The use of chicken meat, chicken skin and other raw materials resulting from poultry processing in the process of the invention is illustrated in Examples 8 and 9.

As distinct from the hydrolysis of beef, the high fat content of chicken and of the raw materials obtained there-from invariably requires separation of the fat during or after hydrolysis. This is usually done in a simple way, e.g. by centrifuging, because the chicken fat is liquid at the tempera-tures proposed for hydrolysis. Separation of the high fat portion contained in such poultry products i5 advantageous because the chicken fat itself is regarded as an important flavoring ingredient in the manufacture of chicken bouillons and soups. Where chicken bouillon products are made from chicken skins, etc., the process of the invention offers an additional advantage in that only two main fractions, i.e. an aqueous hydrolyzate and a fatty phase, result from the hydrolysis when the latter is carried out under proper conditions. The two fractions may be used either together or separately as flavor-ing ingredients in relevant products. This means a 100~ utiliza-tion of the raw material employed. There is no residue to be utilized, in other words no meat to be subjected to, e.g. an expensive drying process involving serious disadvantages. This high-degree or even complete utilization of the raw materials is particularly aavantageous when by-products of chicken proces-sing, such as chicken skin, chicken bone meat etc., are involved which normally are either not used at all or are difficult to use in the manufacture of relevant products. On the oneAhand, an aqueous hydrolyzate of high nutritional value in terms of amina acid composition is obtained (table in Example 10~. On the other hand the fat is completely liberated as the protein is solubilized and so may be separated, which is not possible with any other process avoiding chemical hydrolysis or extraction. In this respect the proposed process simultaneously represents an improved process for recovering the chicken fat to be used as flavoring ingredient.

The simultaneous production of two flavor sources, namely a water-soluble hydrolyzate and a flavor-intensive fat, as described above in connection with the hydrolysis of chicken meat or of by-products of chicken processing, constitutes a further advantageous embodiment of the process of the invention.

The fact that fats are ln large measure a source of flavors has been known not only for chlcken fat but also for other animal fats since the flavors specific to the species are present preferably ln the fat portlon of meat. Moreover, fats are known to be solvents for fat-soluble flavors as present, e.g., in spices or as developed during roasting, frying, baking, etc.

By utilizing this solvent property it is possible in the special embodiments of the process of the invention described below to produce flavor-intensive fats which may be used as flavoring fats:
(a) By direct enrichment of the flavors, which are typical of the kind of meat or specific to the species, in the fat anyhow contained in the meat and liberated during hydrolysis.

(b) By concentration of the flavors specific to the meat and liberated during hydrolysis in added vegetable and/or animal fats of neutral taste. The fat in this case may be added either during hydrolysis or else after hydrol-ysis extracting the flavors. Such an addition of fat is advantageous especially in low-fat starting materials.

(c) By the simultaneous extraction of flavors from different raw materials, especially from spices, vegetables or relevant extracts added during or after hydrolysis, this simultaneous extraction being effected, in the case of high-fat starting materials, by the fat liberated anyhow. Extrac-tion and separation of the fat after hydrolysis in this case does not even constitute an additional process step.

It is thus possible to produce a wide range of flavoring fats with a flavor spectrum typical especially of meat broths. This applies especially to the hydrolyzates prepared with the vegetables commonly used in broths, e.g.
celeriac, leek, carrots etc.

A meat hydrolysis carried out in the presence of fat and optionally further flavoring components such as vegetables, spices, etc., therefore, constitutes a particularly advantageous embodiment of the invention which is suitable not ~ust for by-products of chicken processing and which permits complete utilizationof the raw materials. This is illustrated by Examples 9 and 10 in which apart from the flavoring fat a hydrolyzate is obtained which contains the protein of high nutritional value and which may be used as is or as a flavoring substance, too. The simultaneous recovery of a flavoring fat also offers an opportunity for stabilizing flavoring substances which,per se, are unstable because, on the one hand, the steam pressure of flavors dissolved in fat is substantially reduced and because on the other hand unstable flavors may be stabilized by the presence of stabilizing spices during hydrolysis.

Besides beef and chicken broths, broths prepared from other types of meat are hardly of any importance in the traditional kitchen. Well-known exceptions which, however, are insignificant volumewise are some specialties, e.g. turtle soup, game soup and fish soup. Examples 11 and 12 illustrate that the process of the invention may nevertheless be used successfully also for these types of broth.

Other types of meat of great importance in human diets, e.g. pork, mutton or liver, are less customarily used in the preparation of broths even though these types of meat themselves are used in a number of dishes containing meat broths. Genuine :~ ~ 2~
Hungarian goulash, for instance, contains pork, although usually in combination with meat broth. The reason why these types of meat are less commonly used in the preparation of broths in Central Europe is that the taste of these broths is considered undesirable. The taste either is no~ very specific (see pork, Example 13) or it is very characteristic, as e.g.
with lamb.

Broths made from pork, for instance, while imparting a pleasant basic taste, do not add a characteristic touch to a dish. Such broths, therefore, when obtained in the kitchen, are preferably added to other dishes to produce a basic taste.

The possibility of nevertheless using these types of meat, which are less commonly employed in the preparation of broths, in the process of the invention is illustrated by Examples 11 to 13.

From the taste ratings of the hydrolyzates it becomes apparent again why these types of meat are less commonly employed in the preparation of broths. The hydrolyzate derived from pork exhibits a pleasant, powerful taste, is not bitter either but on the whole is atypical. Hydrolyzates made from pork, just like meat broths prepared from pork, therefore are suited prefer-ably for use as flavoring substances imparting a basic taste, the lack of a specific taste in some cases being even considered a particular advantage.

An interesting aspect from the economic point of view in the production of this latter type of basic flavoring sub-stance is that the raw material need not necessarily be meat but may also be slaughtering offals r as Examples 14 and 15 show for pig's tails and rinds. The hydrolyzates obtained in this way are practically identical to those obtained from pork.

Their amino acid composition must also be regarded as of very high nutritional value, even though the elevated hydroxproline content clearly points to the elevated collagen portion of such raw materials.
The examples and comparative tests described below will more clearly illustrate the invention and the advantages obtained over the state of the art.
The tests were carried out with the commercial enzyme preparations listed in Table I below.

TABLE I
ENZYME
S~ol * Txade Mark or Origin, Activity, etc.
Trade Name _ _ _ ... __ . .. _ _ ............ .. . __ A 1 CGA*56740 Protease from Asp. melleus s-train CGA*20391 JAM2066 of Ciba-Geigy, Switzerland;
activity: 33.6 and 94.4 PU/g _ respectively _ _ B Bakterien- Protease from Bac. of Rohm proteinase N
... _.__ ..___ C Corolase*S50 Protease from Papaya latex of Rohm, activity: 84.8 PU/g , .... ._ . :

D HT~Proteo- Protease from Bac. of Miles-Kali lytic .. _ __ . .~
E Sumyzyme*LP Protease from Asp.oryzae of Shin Nihon;activity: 17,3 PU/g _ _ . _ ._ F Orientase* Protease from Bac of Hankyu 100 Kyoei;activity: 15 PU/g _ . __ G 1 Prolisin*200 Protease from Bac.~ub. of Ueda G 2 Prolisin*400 activity: 25,1 and 91,2 PU/g __ .~ .. __ _.... _ ......... _ _ . __ H Pilzprotease* Protease from Asp. of Rohm activity: 24,8 PU/g . .. _ . _ I Optimase 300* Protease from Bac of Miles-Kali aë
-Example 1 (a) 1 kg fresh beef from the shoulder is cut into cubes, about 2-3 cm long, and is cooked in 300 g water for 60 minutes, with evaporated water being replaced as necessary. After the fat has been skimmed off, the meat cubes are ground in a meat grinder and are hydrolyzed for 4 hours at 50C in a closed vessel with vigorous agitation together with the water in which they have been cooked and with an addi-tion of 13 g of protease A 2. For deactivating the enzyme the batch is then heated for 10 minutes to 100C, liberated fat and nonhydrolyzed protein are separated by centrifugation and the clear hydrolyzate (yield: 81% soluble protein) is freeze-dried. The taste of the freeze dried product dissolved in water or bouillon base corresponds to that of a freshly prepared meat broth, without any bitter or other off-taste.

(b) Comparable or even better results in terms of yield and taste are achieved if, circumventing the cooking process (optionally after 10-minute pasteurization at 80C), the fresh meat is directly ground in the meat grinder and is hydrolyzed with enzyme and water.

This example was repeated using all other enzyme preparations listed in Table I. The conditions chosen and the results achieved may be seen from Table II below.

TABLE II

EnzymeWater Time of Yield Properties of Hydroly-(ml) Hydrolysis (% initial zate (hr) N) A 1 16 _ typical taste of fresh _ . meat`broth 300 __ 66 pleasant taste of cooked meat, slight , , off-taste . _ .. ___ C 300 4 69 meaty 300 4 55 __ _ _ pleasantly meaty O 16 56 pl asantly meaty 300 . 55 meaty O 16 79 meaty with a roasty ,,,. . tou~h`,.
300 66 heartily meaty, pure , , . without'off-taste Gl 62 meaty G2 300 4 , 74 , , .
. . _ .
H 300 4 64 , pleasantly,meaty, I 300 4 63 pleasant, weakly meaty . . . . . . . ' ` ' _ ..

:

:~1 Exam~
1 kg fresh beef from the shoulder is ground in a meat grinder, blended with 13 g oE protease A 2 and hydrolyzed in a closed vessel under vigorous stirring for 16 hours at 50C. At the end of hydrolysis the then liquid batch is treated further as describedin Example 1. As dis~inct from Example 1, the solids content of the hydrolyzate batch practically corresponds to that of the meat, as obvious from Table III, which indicates a true liquefaction of the meat. The yield of soluble meat protein is 90%.

TABLE III

_.
Solids content (~) Fresh meat used 30.5 Hydrolyzate acc. to Example 2 29.6*
Hydrolyzate acc. to Example 1 19.5*

*after separation of fat and undissolved residue.

The product thus obtained shows the same typical taste of fresh meat broths as the products obtained according to Example 1.

Example 3 Of a meat hydrolyzate prepared according to Example 2, one half is freeze-dried and the other half spray-dried. No difference is noted between the freeze-dried and the spray-dried product. A hydrolysis carried out without any addition of water and resulting, consequently, in a high solids content of the hyrolyzate, therefore, has not only made i~ possible at all to use the spray-drying process, which is much more economical than freeze-dryiny, but has permitted the spray-drying process to be realized without any noticeable affect on the ~uality of taste of the end product.

Example 4 To 42.3 kg of a hydrolyzate prepared as described in Example 2, 84 kg. salt, ~0 kg sodium glutamate, 45 kg lactose and 45 kg potato starch each are added (a) directly (b) after centrifugation to obtain a clear liquid.

Following thorough mixing with a kneadera pasty massis obtain which, when dissolved in water, shows a pleasant ~ .
taste of fresh meat broth and may be used as a bouillon base mix.
The paste features an a value of 0~67, is therefore storage-stable and may directly be used for products to be filled in tubes or jars.

Example 5 From 1 kg beef each cut from shoulder and breast hydrolyzates are prepared as set forth in Example lb and are degustated in a bouillon base ~2 g/l) by 5 experienced testers.
The results of this taste rating are given in Table IV.

TABLE IV

Hydrolizate From Shoulder From Breast _ _ Taste rating fine, pure taste full, hearty of meat broth taste of meat broth Preference 3 2 (number of testers) Exa,mple 6 Meat soup bones are ground to pieces, about 0.5-1 cm large, in a Conclux* mill. To 1 kg of these ground bones 13 g protease A 2 and water (approx. 400 ml) to cover the bones are added. After 4 hours of hydrolysis at 50C the batch is heated for 10 minutes to 100C, is freed from undissolved matter, preferably pieces of bones, by sifting and subsequent centrifugation, and is freeze-dried. The yield is 70% soluble protein, referred to starting protein.
The dry hydrolyzate, when added to a bouillon base mix in an amount of 2 g/l, shows a pleasant intensive and typical taste of a broth freshly prepared from bones.
A product of comparable taste is obtained when meat resulting from industrial re-picking of bones is used instead of soup bones. The yield in that case is 86~ soluble protein.
*trade mark Example 7 A meat and a bone hydrolyzate prepared as described in Examples 2 and 9 as well as a mixture of the two products at a ratio of 1:1 are degustated in a bouillon base in a concentra-tion of 2 g/l each. The results of this degustation are presented in Table V.
TABLE V

Hyrolyzate made from ~ Taste ~ . , Meat - intensive and typical of fresh meat broth Soupbones intensive and typical of fresh bone-based broth Meat/soupbones intensive and typical of (1:1) a home-made broth based on meat and bones This example shows that, as in the preparation of home-made broths, the optional use of meat or bones, or of meat in combination with bones, yives -the flavoxs which are typical of these home-made broths.

Example 8 200 g of chicken meat freed from adhering fat and skins is hydrolyzed and further processed according to Example 1. The freeze-dried hydrolyzate (yield: 80~ of the initial protein), when dissolved in water, or a chicken bouillon base, tastes pure, not bitter and of home-made chicken broth. More-over, about 10 g chicken fat is obtained which, following hydrolysis, may be separated, e.g. by centrifuging and which shows a typical taste of chicken fat.

Example 9 200 g raw chicken skin is hydrolyzed and further processed as described in Example 1. Protease A 2 causes practically 100% of the skin protein to be converted into a clear-water-soluble form. Moreover, approximately 70 y chicken fat is obtained. When chicken meat picked from the bones is employed, 90% of the protein in soluble form and about 30 g fat are obtained under the same conditions.

Example 10 The amino acid composition of chicken meat, a hydrolyzate made from it according to Example 8 as well as of a hydrolyzate derived from chicken skin (Example 9) in compari-son with the RAO/WHO recommendations for essential amino acid levels is shown in Table VI below. It is evident from the fig-ures that not only chicken meat but also the hydrolyzate derived from it and even a hydrolyzate based on chicken skin constitute nutriophysiologically valuable sources of protein.

~'7~

TABLE VI
_ Amino Chicken Hydrolyzate Hydrolyzate FAO/
acid meat from chicken from chicken WHO
mea-t skin ._ Alanine 6,2* 5,6 7,2 _ Arginine 4,0 6,5 7,6 Aspartic acid 10,0 9,5 8,1 Cystine + 0,6 0,1 0,1 2,0 Cysteic acid Glutamic acid 16,7 16,4 11,8 Glycine 4,6 5,4 16,0 Histidine 3,6 3,7 1,9 Isoleucine 5,1 4,9 2,9 4,2 Leucine 9,1 8,1 5,0 4,8 Lysine 7,2 10,1 6,1 4,2 Metnionine 2,3 2,2 0,9 2,2 Phenylalanine 4,2 3,8 2,9 2,8 Proline 3,7 3,9 8,7 _ Hydroxyproline _ 1,0 ~7,1 Serine 4,0 4,0 3,6 Taurine: 0,6 0,5 0,3 Threonine 4,6 4,6 3,0 2,8 Tyrosine 3,4 3,4 2,1 2,8 Valine 5,4 - _ _ _ _ 4,2 * Figures in % amino acid/total amino acids Example 11 200 g venison from the shoulder is hydrolyzed and further processed as described in Example lb. In this manner 82% of the meat protein is obtained in clear-water-soluble form. The freeze-dried product dissolved in hot water or bouillon base shows a fine flavor of game broth.
Example 12 200 g fillet of codfish is treated as described in ,~* - 24 -Example lb. 92% of tile protein is obtained in clear-water-soluble form. The freeze-dried hydrolyzate shows a very intensive typical and pleasant taste of fish bouillon.

Example 13 200 g pork is treated as described in Example lb.
The yield of soluble protein corresponds to that of a beef hydrolysis. The hydrolyzate dissolved in bouillon base gives a pleasant but not very typical taste of broth.

Example 14 200 g pig tails is cut in a cutter and treated as described in Example 1. 64~ of the protein is obtained as clear-water-soluble hydrolyzate which in a bouillon base shows a pleasant but not typical taste of broth.

Example 15 200 g pig rind is treated as described in Example 1.
78% soluble protein and additionally approximately 80 g fat are obtained. In a treatment according to Example 2 the protein contained in the rinds is completely broughtinto solution. In bouillon base the hydrolyzates exhibit a mild, pleasant but atypical taste of broth.

Example 16 A beef hydrolysis is carried out as described in Example 1 in which 1% ribose, referred to the protein content (N x 6.25) of the meat, is added together with the enzyme.
Further processing of the hydrolyzate, the yield of soluble protein etc. correspond to that of a normal meat hydrolysis.
The resulting hydrolyzate exhibits an intensive, pleasant and lasting roast flavor. The same result is obtained when ribose-5-- 2~ -. . ~
~,.,.`

phosphate is used instead of ribose.

Example 17 200 g each of the same kind of beef was hydrolyzed and further processed in parallel as described in Example 1:
Batch A without addition Batch B with an addition of 1~ thiamine x ~Cl, referred to protein or together with the addition of enzyme Batch C with an addition of thiamine amount corresponding to batch B
immediately before the bouillon is prepared The three hydrolyzates were degustated in bouillon base.
Ratings are given in Table VII below:

TABLE VII

__ Batch Taste . . .. .. ._____ _ A tastes of fresh meat broth B tastes must more distinctly of fresh meat broth C as A

_ .............. __ Comparative Test 1 1. Manufacture oE a hydrolyzate As described in Example 1 of the above-mentloned German OS application 23 35 464, 250 g beef with a low fat content and a low sinew portion was ground in a meat grinder, mixed with 250 g ice wa~er and comminuted -to a very finely divided state. After an addition of another 500 g water the mixture was proteolyzed with 250 g crystalline trypsin for 8 hours at 40C and a pH from 6.5 to 7, then acidulated to pH 1.8 and proteolyzed with 250 mg crystalline pepsin for another 16 hours. At the end of the reaction the fat was removed, the pH
adjusted to 5.0 and the enzyme deactivated by heating (7 minutes at 90C). The concentration of soluble meat protein in the suspension was only 5.5%, the proportion of solublized meat protein 90~ (instead of 99~ as indicated) of the starting material.

2. Taste rating Of the freeze-dried substance of the meat hydrolyzate prepared as described above, 4 g was dissolved in 1 liter of hot water and another 2 g in 1 liter of a hot bouillon base mix and degustated by experienced testers. Both in water and in the bouillon base the hydrol~zate hardly tasted of meat but rather exhibited a fairly strongly bitter, metallic and unpleasant taste.

Comparative Test 2 .. . ..
2.94 g protein of a beef hydrolyzate produced as described in Example 1 was refluxed according to German OS
applications 24 13 138 and 23 55 868 with the same amount of thiamine x HCl in 150 ml water for 4 hours, and was then freeze dried.

The resulting dry product, while strongly smelling of meat broth, har(~ly tastes of meat broth any longer when dissolved in bouillon base but exhibits a s-trongly acidic, atypical and "fruity" flavor so that no flavorable substance comparable to the process of the invention can be obtained when proceeding according to the conditions specified in the above-mentioned patent applications.
With regard to their nutriophysiological composition, the products obtained according to the process of the invention are of high quality and are at least equivalent to other conventionally prepared meat or meat products. This is evident, for instance, from the content of vitamin Bl (thiamine) which drops by no more than about 20% during hydrolysis while losses of 20-25~ and 80% respectively are known to occur in preparation by the housewife and in the manufacture of sterilized ready-to-serve meals. Another advantage in terms of the nutriophysiological value is the fact that the fat portion, whieh usually is quite considerable in some types of meat, may readily be separated following hydrolysis and prior to the further use of the hydroly-zates, which may be of great importance especially in dietetic products.
The embodiments of the invention described last illustrate that the process may be used successfully also where liquefaction of the raw material to a pleasant or neutral-tasting hydrolyzate is envisaged but a characteristic flavor is neither required nor desired.
This possibility of optionally producing hydrolyzates of less intensive a~d typical taste does not alter the fact that a special advantage of the process of the invention is seen in the development and retention of characteristic flavors. The latter, in a broader sense, also applies to the enhancement and modification of such a characteristic flavor, whieh may be achieved by means of per se known processes. In the simplest case such processes involve an admixing of suitable components for the purpose of seasoning (salt, spices), an enhancement of the taste, e.g. with MSG and/or IG, or a rounding off or modification of the taste, e.g. by means of vegetable(s).
Moreover, meat hydrolyzates of the invention due to their good solubility are particularly suitable for reactions in which flavors are produced by the use of temperatures and pressures, optionally also by an addition of suitable reactants.
In this context it is particularly advantageous to utilize reactants which are naturally present in meat and meat hydrolyzates and which contribute to flavor formation because in this manner the natural flavor development which takes place is supported and it is not necessary for flavor development to rely on other reactions which usually do not occur in this type of food.
Reactions which occur under very drastic conditions, compared to the cooking process, or which require the presence of relatively large amounts of suitable additives, therefore, will not be discussed here even though they can equally be carried out with the hydrolyzates of the invention. This seems even less required as the development of such flavor variants, produced chiefly by Maillard reactions, and the resulting aromas are well-known to the expert from the literature (cf., for instance, Swiss patent 481,588 and German OS applications 24 13 138 and 23 55 868).
The surprising advantage derived from an addition of compounds occuring in meat is seen in the fact that amounts of 0.1-1% by weight of these components, referred to meat hydrolyzate protein, are already sufficient to significantly G

enhance flavor and aroma. An addition of ribose or ribose phosphate, for instance, in amounts from 0.1 to 1% gives an aroma of roastedor fried foods(Example 16). A substance particularly suited for producing a taste typical of home-made broths is thiamine (hydrochloride). Here the required additions, i.e. 0.5-1%, referred to the amount of hydrolyzate, are much lower than in ]~nown processes providing for the use of thiamine (cf., for instance, German OS applications 24 13 138 and 23 55 868).
The fact that thiamine is a reactant which, at least in the process of the invention, during hydrolysis intervenes in the aroma precursors is illustrated by the circumstance that additions of thiamine suprisingly do not enhance the flavor unless they are added prior to or during hydrolysis.
(Example 17). The use of thiamine in meat hydrolyzates of the invention, therefore, in this respect also differs from the processes so far described using thiamine in high concentrations, in which aroma development is achieved only by a subsequent reaction, e.g. a Maillard reaction (cf., for instance, German OS
applications 24 13 138 and 23 55 868).
Such a subsequent reaction does not only constitute an additional and, consequently, disadvantageous process step but, as has been found, is disadvantageous also because such a subsequent reaction using high thiamine concentrations, while producing an intensive smell of meat, drastically deteriorates the broth flavor of such hydrolyzates reacted with thiamine (Comparative Test 2).
Additions of thiamine in the concentration specified for the hydrolyzates of the invention are advantageous also under nutriophysiological aspects (cf., for instance, K. Hofmann "Die Beeinflussung des Nahrstoffgehaltes von Fleisch durch verschiedene Zuhereitungsarten", Hippokrates 40 12, 41-47 (1969~.

As in beef hydrolyzates, the flavor of poultry meat and poultry meat hydrolyzates may be enhanced by an addition of compounds occurring in poultry. Particularly suitable substan-ces for such flavor enhancement are: thiamine, cysteine and methionine.
As the remarks above have shown, the meat hydrolyzates of the invention are generally suitable for all aroma-develop-ing and/or aroma-enhancing reactions known to oecur in hydrolyzates of this type, i.e. for Maillard reaetions just as well as for other aroma-producing reactions. It is noted, however, that in connection with themeat hydrolyzates of the invention sueh reaetions, which ultimately also cause a change in flavor and aroma, as a rule are neither required nor desired and that especially Maillard reactions,which almost inevitably occur in beef extract production, according to the invention may be avoided and, as a rule, are actually avoided. As has been outlined above, the flavor and aroma enhancement desired in meat hydrolyzates, therefore, refers preferably to the taste of broth typical of the individual products. This flavor may be enhanced by an addition of small amounts of substances naturally contained in meat, whieh merely intensifies the re-aetions oeeurring, e.g., during cooking, while other reactions which are considered disturbing and which cause a change in flavor like, e.g., the Maillard reaction are practically excluded.
The flavor intensity of such meat hydrolyzates of the invention made with additives is several times that of meat hydrolyzates not containing any additive. In the series of meat in pieces, fine]:yground meat, meat hydrolyzate of the invention without any additive, meat hydrolyzate of the invention with an additive it is thus possible to bring about an appro~imately 2- to 100-fold flavor increase, which is of decisive importance for the economic efficiency of the use of such hydrolyzates in foods. An intensive taste is of great advantage also under nutriophysiological aspects since flavor-intensive dishes are known to require less seasoning with salt, glutamate etc.
~ leat hydrolyza-tes of the inven-tion made ~ith or without additives are distinguished by their flavor or odor which is ~ypical of the raw material used. They may, therefore, be used primarily in all foods and products in which this characteristic flavor and odor, e.g. the broth flavor, is considered to be of importance. Examples of such uses are dehydrated soups and sauces, ready-to-serve meals, soups and sauces either in canned form or frozen, meat and meat products, all kinds of meat-containing dishes, e.g. ragouts, fricassees, fillings, as well as condiments, barbecue sauces and salad dressings etc., snack items, pasta products and baked goods.
Also included are special uses in dietetic products, in baby foods, bland diets or even in animal food, e.g. dog, cat or fish food. Finally included are the uses of protein hydrolyzates known for the pharmaceutical sector. The examples given illus-trate a number of such uses. The advantage that the meat hydrolyzates of the invention, unlike the products obtained according to the "liquefaction process" outlined at the beginning, are clear-instant-soluble is fully felt, of course, only where clear broths are to be produced.
The meat hydrolyzates of the invention, therefore, constitute an entirely novel raw material which on the one hand may be used like meat and on the other hand may be used like beef extract. The meat hydrolyzates of the invention in this respect combine the advantage of meat (taste, nutritional value) with those of beef extract ~solubility~. The individual advantages may be described as follows:

1. Like beef extract the meat hydrolyzates of the invention are practically completely soluble. Unlike beef extract, however, their composition, flavor and odor correspond to that of the meat used or of the meat broth prepared in the traditional way from said meat, which makes these meat hydroly-zates an ideal raw material for bouillons, soups, sauces etc., i.e. for all products in which mea~ or meat broths are used because of the typical flavor of the latter.

2. Unlike conventionally prepared broths or unlike beef extract, the meat hydrolyzates of the invention contain practically all of the meat protein as well as all other ingredients of the starting material determining the nutritional ~alue, e.g. thiamine and creatinine.

3. Since hydrolysis may be carried out after addition of the enzyme without any pH adjustment or control thus dispensing with an addition of acids, lyes or butter substances normally required in enyzmatic hydrolysis, meat hydrolyzates produced according to the process of the invention need not subsequently be purified to remove such agents.

4. The meat hydrolyzates of the invention taste as pleasant and are as appetizing and stimulating as conventional meat broths but unlike the latter also contain all other nutriophysiologically important components of meat.

5. As hydrolysis is carried out under very mild conditions, losses of ingredients determining the nutriophysio-logical value are substantially lower than in many other processes employed in meat processing; degradation of lysine and thiamine (vitamin Bl), for instance, occurs to a smaller extent than in the manufacture of canned meat. Losses of creatinine are also smaller than those observed whenmeat products are sterilized.

6. The use of mea-t hydrolyzates of the invention instead of meat broths or beef extract, therefore, means a nutriophysiological upgrading of all products based on meat broths or other broths as well as on beef extract and its respective substitutes.

7. In terms of flavor, nutriophysiological and processing properties the meat hydrolyzates of the invention are equivalent to or essentially better -than beef extract.
They are thus capable of replacing beef extract in all its uses.

8. The meat hydrolyzates of the invention constitute an inexpensive new raw material which may largely replace broth preparation in the kitchen as well as industrial production and use of beef extract.

9. The meat hydrolyzates of the invention may be produced not only in pasty but also in dry flowable form; they are also of a much lighter color than beef extract and are therefore better suited for use in light-color products or in higher concentrations.

10. The meat hydrolyzates of the invention exhibit a pleasant taste characteristic of the meat used. They may, therefore, be freely used in products in which a flavor tvpical of a certin type of meat is required and in this respect they also differ advantageously from beef extracts in which the flavor produced by a Maillard reaction is noted as disturbing, especially in higher concentrations.

11. Like beef extract manufacture, the manufacture of meat hydrolyzates of the invention in principle, is a preserving process for fresh meat, which, however, offer the advantages of:

(a) a solids content comparable to meat thus making it possible to convert said meat directly and in a simple way into a durable and storable en~ product.

(b) being largely independent of a by- or co-product and (c) flavor properties more typical of bouillons as well as better nutriophysiological properties.

12. The manufacture of meat hydrolyzates of the inven-tion may be used as a technologically and commercially independent process supplying the basic raw material for the broth product producing industry side by side with the freezing process preva-lently employed today in the preservation of fresh meat.

13. Unlike beef extract production, the manufacture of meat hydrolyzates of the invention is not limited essentially to beef but may equally be used for other types of meat, e~pecially poultry and slaughtering offals.

14. As the fat may be separated relatively easily, the quality of the hydrolyzates is largely independent of the fat content, i.e. of the ~uality of the meat used. This is important especially in dietetic products where a high fat content, especially a content of animal fats, may be considered disturbing.

15. By an addition of and/or reaction with suitable substances, the meat hydrolyzates of the invention, optionally while retaining their typical flavor note, may be enhanced in flavor or, in the manner known per se for aroma production from protein hydrolyzates, may be used for producing new flavors and aromas.

16. In the process of the invention, although being simple, a proper quality oE the hydrolyzate also under micro-biological aspects is ensured, even if -the product is not subjected to any special subsequent treatment for the purpose of sterilization.

17. The meat hydrolyzates of the invention are "natural" products since no drastic process steps are involved and no large amounts of additives are needed in flavor develop-ment, as distinct from the manufacture of beef extract or artificial flavors, and in this respect they are certainly advantageous also under health and food law aspects.

having set forth the general nature and some specific embodiments of the present invention, the scope of the invention is now particularly set forth in the following claims.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for producing clear, instantly soluble, meat hydrolysate by hydrolytic liquefaction of meat using a protease, wherein meat is hydrolyzed in a single step with a neutral pro-tease of microbial origin into clear, instantly soluble hydrolyzates which are non-coagulating upon heating in aqueous solution.

2. The process of claim 1 wherein undissolved residues are separated from the liquid hydrolyzate in a final step.

3. The process of claims 1 or 2 wherein the meat is hydrolyzed until at least 75% by weight of the fresh meat protein has been converted into clear, instantly soluble hydrolyzates.

4. The process of claims 1 or 2 wherein the meat is hydro-lyzed until at least 94% by weight of the fresh meat protein has been converted into clear, instantly soluble hydrolysates.

5. The process of claims 1 or 2, wherein a protease is used at a pH from 5.5 to 7.0 and has a proteolytic activity of at least 15 units, measured according to the modified Anson method.

6. The process of claim 1, wherein a protease is used which has a significant gelatase activity in a concentration of 0.001 to 0.05% by weight maximum.

7. The process of claim 6 wherein the protease is derived from a microorganism of the Aspergillus or Bacillus genus.

8. The process of claim 6 wherein the protease is derived from Bacillus subtilis, Aspergillus niger or Aspergillus melleus.

9. The process of claim 8 wherein the protease is derived from Aspergillus melleus strain IAM 2066 as well as variants and mutants thereof.

10. The process of claims 1 or 2, wherein 0.1 to 10% by weight of the meat of protease is used.

11. The process of claims 1 or 2, wherein the meat is hydro-lyzed for a period not over 24 hours.

12. The process of claims 1 or 2, wherein hydrolysis is performed at temperatures from 30 to 60°C.

13. The process of claims 1 or 2, wherein hydrolysis is initiated without previously adjusting the pH by an addition of acids, bases or buffer salts, and no pH adjustment is made during the hydrolysis.

14. The process of claim 1, wherein hydrolysis is stopped by deactivating the enzyme with heat.

15. The process of claim 14 wherein the hydrolyzate mixture is heated for 1 to 60 minutes to temperatures from 80 to 120°C.

16. The process of claims 1 or 2, wherein fat and other undissolved residues are separated from the hydrolyzate mixture.

17. The process of claims 1 or 2, wherein the hydrolyzate mixture is blended with salt, spices and other common additives to form a stabilized end product, the concentration of the additives being selected so that the water activity in the end product is not over 0.75.

18. The process of claim 1, wherein the hydrolyzate mixture is concentrated to a dry product by evaporating water.

19. The process of claim 18 wherein the hydrolyzate mixture is spray-dried.

20. The process of claims 18 or 19 wherein salt, spices, fat, thickeners and other common additives are incorporated in the hydrolyzate mixture.

21. The process of claims 1 or 2, wherein prior to chopping the meat to the particle size in which it is used in liquefaction, the meat is heated and cooked for flavor development in the presence of added water.

22. The process of claims 1 or 2, wherein prior to hydroly-sis the fat is partially separated from the meat.

23. The process as claimed in claim 1, including an addition of water in an amount of up to about 30% by weight of the fresh meat.

24. The process as claimed in claim 1, wherein hydrolysis proceeds until at least 60% of the fresh meat protein has been converted into clear, instantly soluble hydrolyzates which are non-coagulating upon heating in aqueous solution.

25. Meat hydrolyzates produced according to the process of claim 1.

26. A meat hydrolyzate as claimed in claim 25 in combination with meat extract as a food component for flavoring foods and as a basic component in clear meat broths, soups, sauces and the like.