NZ203473A

NZ203473A - Tenderising meat using ammonia or ammonium salts

Info

Publication number: NZ203473A
Application number: NZ203473A
Authority: NZ
Inventors: T J Staron
Original assignee: Agronomique Inst Nat Rech
Priority date: 1982-03-05
Filing date: 1983-03-04
Publication date: 1986-05-09
Also published as: FR2522476B1; EP0088693A1; FR2522476A1

Description

<div class="application article clearfix" id="description"> 2034 Priority Dote(s): . I*??}?..... Complete Specification Filed: A~,rr>.%5, Class: 03 ?S 91IQQ /. .-ft Z)££(-i lS?.j if) Pubttcaton Oat©: .. P.O. Jcarttzf. tio: J.Q.%rP /'V •• 12 v * O ,4' fr; Patents Forn. No. 5 KEV; ZEALAND PATENTS ACT 3 953 COMPLETE SPEC J F J CATI ON' PROCESS FOR THE TREATMENT OF NEAT ^'K%JSTITUT NATIONAL DE LA RECHERCHE AGRDNCMIQUE, a public national establishment of France, of 149 rue de Grenelle, 75341 PARIS CEDEX 07 FRANCE, hereby dec]are the invention, for which I/we pray that a patent ir,av be crantec to me/us, anc the method by which it is to be performed, to be particularly described in and by the following statement:- - 1 - (followed by page IA.^ - 1A - 203473 The present invention concerns a process for the treatment of meat, namely for controlling the tenderness, restraining exudation, conserving the original appearance and inhibiting microbial growth. This process is applicable to animals before slaughtering; it also permits the practice of boning warm and the abolition of maturation periods. In the present description the term "meat" means the flesh of animals which it is customary to eat. This term includes all meat products and notably the flesh of mammals, birds and sometimes fish. Moreover the term "Meat" as used in the present description designates all meat which is destined to become meat for roasting, meat for grilling, meat for boiling, meat for braising, meat for delicatessen uses and/or curing and the like, moreover in the fresh state as well as frozen or defrosted, originating from all the monogastronornic and polygastronomic animal species, vertbrates and non-vertebrates, such as the bovines, sheep, goat, horse, zebras, buffalos, poultry, game, this list not being all exhaustive. Meat is characterised by a great heterogeneity. It is principally constituted of striated skeletal muscles which also comprise other tissues in variable quantities according to the species, the race, the age, the diets and the anatomical region concerned; it is principally the tissues: connective, fatty, sometimes of the bones and of the skin. Meat possesses a very high nutritional value because it is constituted by digestible proteins, well balanced and very rich in indis-pensible amino-acids. It also constitutes a good source of iron and of water-soluble vitamins. 20347 - 2 - Meat is generally considered as a foodstuff of the prime necessity, nevertheless it involves expensive calories. In effect the yields of bio-conversion by the animals are low and are often altered by different factors. For example, it has been found that the evaluation of the bio-conversion of the proteins is 6% for beef, 9% for sheep, 15% for pork and 31?, for poultry. Moreover the production of animals and their transformation into meat require much manpower and since meat is a perishable foodstuff if may only be treated but a little outside of the refrigeration chain, the implementation of which is onerous and the energy costs of consumption which continue to escalate. Thus the substantia]/of meat is the prerogative of the developed countries, it reflects a suitable level of life, which should necessarily be compensated by a performance production. The production of meat comprises confirmed systematic procedures with technological options. The principal stages of these procedures variable according to the species, may be summarized as follows: (1) the raising, sanitary control and trade in animals, (2) the forwarding of the animals to the abbatoir (transport, stabling, rest and diet before slaughtering, health inspection), (3) the slaughtering of the animals; sacrifice by shooting, electrocution, throat cutting; bleeding in the vertical position for hygienic reasons; skinning (bovines, sheep, goats, the horse family, rabbits) or washing, scalding, depilating - 3 - 2034-73 singing, scraping (pigs) or scalding, plucking (fowls): evisceration after removal of the feet, tying of the visceral tubes and possible rinsing; splitting (bovines, horse family, pigs); possible deadening of the senses (bovines); pi'ejLLiluiT! health inspection; weighing; health -stamping official/with as an optional procedure the electrical stimulation of the carcasses and the warm boning, followed by cutting up into categories, conditioning under vacuum and freezing, (4) the cooling down of the carcasses (placed into a fast chill chamber) so that the temperatures of the carcasses are lowered as rapidly as possible to +4® C (in 24 hours for large animals), (5) the trade the carcasses after the evaluation of their quality by different standards and estimations, (6) the storage of the carcasses at +2^ C, +4^ C, with a view to the maturation of the meat and to short term conservation (generally 3 to 15 days) , (7) the cutting up in conditioned workshops: cutting up of the carcasses into quarters; partial or complete boning, and rough trimming; cutting into butchers portions according to categories, or with a view to the preparation of preserved foods, or for the delicatessen, curing, smoking, drying etc...; trimming of whole pieces, degreasing, removal of the aponeuroses and of the tendons, possible barding and tying up; retailing, weighing and packaging with a view to sale in free trade, (8) the presentation to the state and the sale to caterers and the consumers (sale of whole butchers pieces for 20347 - 4 - restaurants and collectives: the cutting up of pieces required by the consumers; possible trimming; weighing; packaging). As well as the nutritional contribution, people demand of meat that it be tender and succulent. In the course of time the observations whichplease palatal impressions have been empirically collected and they have permitted the progressive institution of technologies compatible with nutrition,hygiene and pleasure. Muscles still warm are relatively tender but their flavour is tasteless or aggressive. The muscles harden in the course of cooling, lose their elasticity and decrease in volume due to contraction of the sarcomeres, when rigor mortis sets in, then they will tenderize progressively and their flavour increases after periods of hanging of the carcasses, the periods being variable according to the animal species and the ages of the animals. It will be noted that the muscles are more or less rich in connective covering tissue (endomysium, perimysium, epimysium) and that their extremities, where catching cmtothe osseous planes, require ligaments and tendons of occasionally great quantity The connective fibres do not develop in the course of rapidly maturation, but they are quite/dissolved by cooking, in the meat of young animals, although in the muscles of older animals, the stable bridges connecting the collagenous 203473 - 5 - fibres are only slowly influenced by cooking and, due to this fact the collagen probably interferes to increase the toughness of the meat in which it is present in substantial quantity, despite maturation of the muscles. After slaughtering the muscles are warm and extensible (they may be reversibly elongated by 3(H to 4 0% above their initial length) : they require energy resources UcdbLi (glycogens, ATP, CP) and their pH operaLes between 6.7 and 7.2. Progressively, with the fall in temperature, a more or less pronounced muscular acidification is observed, accompanied by contraction with loss of elasticity. It is the level of ATP initially present, the speed of its hydrolysis being catalysed by the myosin which, influenced by the temperature, determines the speed and the level of acidification as well as the degree of muscular contraction. When this becomes irreversible it has the consequence unfortunately of increasing the toughness of the meat. The ATP-ase acitivity of the myosin is activated by heat (of +25® C to +45° C), by the cold (below +10® C), by electrical stimulation and it is inhibited by acidification (pH below 6). In order to reduce the frequency and the volume of microbial invasions, the actual regulations oblige one to lower the i temperature of the carcasses to about +4° C rapidly (within i j 24 hours for large animals). But, when the temperature of •. *■■*> J 0 • [ the carcasses attains +10 C then the muscular acidity is - 6 - 203473 insufficient (pH above 6), the myosin activated by the cold, catalyses the hydrolysis of the ATP, which has the consequence of activating the muscles, which reside in the contracted or super-contracted state when the ATP is totally exhausted. One can lessen this problem by effecting a brief electrical stimulation of the carcasses (frequency of impulses = 15 Hz? potential in the upper peak = 600 volts; duration of the stimulation = 90 to 120 seconds for large bovines). This action effected warm, reversibly contracts the muscles and exhausts about 50% of the ATP. The consumption of ATP lowers the pH of the muscular masses by about 0.8. In these conditions of acidity the ATP-ase activity of the myosin will be inhibited and the molecules of residual ATP which then fix on the myosin heads act to detach them from the end filaments and free them. The separation of the thick filaments and ends within the sarcomeres, will permit a passive muscular relaxation. The electrical stimulation of a carcass does not provide a homogeneous reaction. The response obtained depends on the distribution of the electrical field and it also varies along the muscles: their compositions, their energy levels, the type of contraction and the functions which they effect, etc ... Despite several developments which remain to be made, the procedure of electrical stimulation of carcasses is attractive •"7"'" since its actions (inhibition of the muscular contraction and v r t •.' ■ -acceleration of the maturation of the meat) permits oneto envisage ■*£"o wirm boning (more rapidly realised and more complete) followed by ,S3S^i< 14 203473 - 7 - trimming and immediate conditioning of the muscular masses by catagories, having the effect of limiting: the number of manipulations, contaminations, loss of water, the volume of storage floors and permitting selective maturing hanging . i /the As/ transformation of tissues concerned in meat (maturation) is not instantaneous, a period of hanging of the carcasses in defined hygienicconditions, variable according to the species of the animal and the age of the animal is necessary and is used to permit the development of a certain number of indispensible physico-chemical reactions. the reactional complexity, the methods of evolution of the myofibrils in the course of maturation play a role determinant in the establishment of the level of tenderness of the meat (the tenderness of the meat is evaluated in terms of resistance of the fibres to cutting) but it is also necessary that the live colour of the meat conferred by the oxymyoglobin be conserved (this is a criteria of freshness), that the odour be appreciated at purchase, pleasing during cooking and that the flavour of the cooking can respond to palatal requirements. These four criterias (colour, odour, tenderness, flavour) when they are united define the good quality of the meat. Thus it is established that to obtain what is called a good I quality meat is complex and requires judicial choice of -4 1 conditions of cooling of the carcasses and of /maturation- "A & In effect, the muscles after slaughtering are the seat of numerous physico-chemical reaction and/or biologicial - 8 - 203473 influences, which contribute to the quality of the meat, but which are meanwhile disturbed and/or inhibited by changes, notably, the cooling and maturation conditions. The cooling and maturation of the meat necessitates the use of voluminous storage floors, the cost of which influences the cost price of the meat. As indicated above, electrical stimulation permits warm boning, which reduces as a consequence the storage floors, however the operation of the electrical stimulation is dangerours in the humid atmospheres of abattoirs and therefore practically hardly used. Moreover the consumer attaches a very great value on the colour of the meat and this rightly since it is a criteria of quality directly appreciable on purchase. In effect, the meat remains fresh as long as it keeps the capacity to regenerate its oxymyoglobin when cut, which is expressed by a develop ment at the surface of the cut of a live gleaming red colour. There do exist different procedures of conserving meat k * (freezing, , drying, fumigation or smoking,Eradiation, addition of additives etc ... ). Freezing is thr neans of conservation which respects the principal original properties of fresh meat and in fact it has become the preponderant mode of conservation. The - 9 - 203473 major inconvenience of this process resides in the systematic exudation and this moreover becomes very important and develops during the course of defrosting. The exudates produce reduction in weight, loss of nutritive materials (dry matter, minerals, and amino acids, proteins). They are the origin of blemishes and on spreading, increase the surfaces favourable to microbial development. As well as modifications which interfere with the course of transformation of the muscles in the meat, some changes take place when the meat is cooked. The raw meat possesses a singular odour and a light taste of blood. In the majority of cases, the meat is consumed cooked. Very numerous reactions develop in the course of I cookingK method# applied^ i*> ul—ingredients added to the different meats, according to their catagories and to the cuts concerned. Good or bad cooking is always expressed by modifications in the colour and the development of flavours, development of tenderness and of taste and a degree of reduction in the volume of the meat. According to the origin of the meat, its original toughness, the mode and intensity of cooking practised (grilled meats, roast meats, rare meats, meats done to a turn, braised meats, boiled meats), dishes are obtained which give various - 10 - 203473 palatal sensations. When progressive cooking of meat is applied, up to +40°C few modifications are observed; between +40°C and +55°C, the pH rises by 0.2, the fibres diminish in diameter without shortening, losing a part of their free water, the connective network contracts, the grouping of the sulfhydrils and the capacity for stabilising the colouring matter diminish, the meat hardens; between +55°C and 65°C the proteins coagulate, the fibres diminish in length and fragment at the level of the bands A and I, the stria Z disintegrate then disappear, the meat becomes tender under the combined effect of the dislocations and of the enzymes [With reference to bands A and I and stria Z: when a non-contracted muscular fibre is observed with a microscope, regular striae constituted of isotropic clear bands called I bands are observed. Said I bands alternate with anisotropic dark bands called A bands. Moreover, I bands comprise in their middle part a dense thin stria called Z.]; at above 75°C; the massive aggregation of the myosifibular proteins, the establishment of hydro-geneous bridges between the denatured proteins and the loss of water produces a hardening of the meat. When one extends the period of cooking in these conditions a progressive tenderisation is observed due to dissolution of the connective tissue. Meat cooked slowly has a loose and stringy texture; it loses its capacity to retain water and much of the dry material, said dry material being that material remaining after cooking, when water and volatile products have been removed. In the course of cooking meat there is flavour development. The precursors of flavour are localised in the fats and in the muscles. The specific molecules according to species appear if anything associated with fats. About 100 flavour components belonging to more than ten chemical classes have been identified. 2 034 7 - 11 - There are at first the small molecules present in the muscles, to which are added those which are freed in the course of maturation and of cooking. There are then the hydrolyses, the syntheses, the transformations, the molecular interactions, the reactions of Maillard, which develop in the course of cooking and which give a complex assembly of volatile or non-volatile molecules (fat acids, aldehydes, cetones, alcohols ethers, esters , pyrazines, bases of Shiff,aliphatic and cyclic, sulphur components), conferring flavours to the meat customarily seductive or repugnant in the case of adulteration. All of the above considerations show that it is desirable to focus on a process of treatment of meat which satisfies the consumer on all planes and improves the methods of preparation of meat. Different procedures have already been proposed for the treatment of meats or other food products to ensure their conservation and/or to avoid the formation of undesirable products. To this effect we cite the following documents: U.S. Patent 3023109 concerns a process for the treatment of fresh red meat to stablize its colour. This process consists in submitting the fresh meat to an atmosphere containing 5% to 25% of ammonia for ten seconds to five minutes. It will be noted that the periods of treatment recommended are very 203473 - 12 - brief; they only act on the colour but do not have effect either on the tenderness nor on the exudations at defrosting. It is even indicated that the longest time of treatment confers on the meat the look of leather even if the appearance of the meat itself does not change. The tradesman therefore would find himself discouraged from treating the fresh meat during prolonged periods with an external agent such an ammonia. British Patent 1460913 concerns a process of conserving foodstuffs(meat and fish) with the'aid of comestible polyphosphates. A process is known for treating comestibles, in particular fish, meat and fowl to improve their quality and to prevent certain undesirable changes which may be produced notably during freezing or storage in the frozen state. This process consists in treating the comestibles in a manner to increase the. amount of concentration of hydrogen ions (pH) up to a degree such that the comestibles will show a tendency to distend and will retain their water during defrosting even after prolonged ■ storage. The treatment recommended is an alkaline or a neutral treatment effected with for example sodium, potassium, or ammonium salts. The pickling brines utilized in this process may moreover contain the nitride of sodium in quantity sufficient to maintain the colouring pigments of the comestibles in 203473 - 13 - their natural pink state. U.S. Patent No. 3042529 likewise concerns a process for improving meat. This process consists in injecting animals before or after slaughter, with a composition containing ascorbic acid and biogenic amines..This process leads notably to prevention of stress which, with pork, is €ho origin of the depigmented soft meat and exudates. The biogenic amines are used in very weak quantities just sufficient to compensate the loss in natural products provoked by slaughtering and death. Processes of conservation of meat based on pickling brines constituted by amines, phosphates, sulphates, bisulphate, chloride of sodium, vitamin C and ammonium salts such as ammonium chloride are also known. U.S. Patent No. 4039690 describes a process for avoiding and reducing the formation of carcinogenic nitro-amines in slaughtered provisions and dried and smoked meats, prepared with the aid of nitrites. This process consists in treating such meats with primary aromatic amines. The prior art mentioned above shows the diversity of processes which have already been proposed for the treatment of comestibles, in particular of meat, to preserve and improve the quality 203473 - 14 - thereof. None of these however propose means for effecting a treatment in the mass ("at the heart") of the meat permitting during the ultimate cooking of this the improvement of the tenderness. A new process of treating non transformed meat ,which permits has now been found. the control of tenderness/ The process of the invention likewise permits the restraint of the exudation and the inhibition of microbial growth, in conserving the original appear ance . The present invention thus relates to a process of treatment of non-transformed meat, notably for controlling the tenderness thereof, which consists in placinq the meat in contact with an agent capable, within the conditions of treatment, to provide in situ ions NH^+ which prevent hardening of meat during cooking and thus permits muscular fragmentation during subsequent cooking of the meat. The treatment agent used in the process of the present invention is chosen notably from ammonia non-toxic amines, the salts or the solutionsof non-toxic salts of ammonia, or the said amines and the precursors of the compositions mentioned. By "non-transformed meat" is meant, according to the present invention, all meat in condition, that is to say a i !meat Hot having 203473 i - 15 - been subjected to any treatment provoking a change in the characteristics that the meat possesses after slaughter. Thus cooking transforms the meat whilst a frozen- , ^ /is a meat- defrosted meat/not transformed according to the definition of the present invention. well ■The prooooG of tho invontion appliec—ag/ to moat ifroclf ars—well as—to—living wuaeles which foi-m the meat after the death of the animalt Thus by "placing in contact the non transformed meat with a treatment agent" one means according to the invention external contact with the treatment agent, a gaseous atmosphere or a solution containing the vye 11 HS said agent, as /internal contact effected by injection or ingestion of the treatment agent before slaughter. The treatment agent according to the invention may be presented in the form of a gas or solutions. The treatment agent may likewise be presented thus or in a vehicle or inert support suitable for its transfer onto or into the meat. It has in effect been found that the placing in contact of the non-transformed meat with a treatment agent, such as defined above, for example, an ammonia atmosphere, restores an elastic tone to the meat and inhibits spectacularly hardening by cooking, of the treated meat according to the - 16 - 203473 invention. Furthermore the process of treatment according to the invention likewise annihilates exudation. When ammonia is used as a treatment agent for the meat according to the present invention the meat is placed in ammoniacal atmospheres containing preferably 5 to 30 g/m^ of ammonia for approximately 0.5 to 4 hours. The temperature at which the ammoniacal treatment is operated varies according to the period of preparation of the meat at which the treatment is effected. For example, if the treatment is effected immediately after slaughtering, the temperature will be. between +4°C and +30°C, when it is effected after defrosting, the temperature will be between -18°C and the ambient temperature. In the present description "preparation of the meat" meansthe' whole / period of the transformation of the muscles in the meat, including the freezing and the defrosting or the periods of conservation of the non-transformed meat by all other means. In fact, as the treatment may take place at any stage in the preparation of the meat, one operates , at the temperature at which the meat is normally found. Meanwhile, when the treatment takes place on defrosting it is preferable to operate at low temperatures to suppress exudation which is produced during defrosting. The treatment according to the present invention is particularly suitable at the moment of slaughtering; it permits warm - 17 - 2.03473 boning without electrical stimulation and achieves all the advantages of cold boning which are: rapidity, mechanisation, decrease in the loss of meat, the most easy trimming, the most uniform colouration of the meat, economy of refrigeration because the volume to be refrigerated is less and economy in manpower. Moreover uniformity is imparted to the portions of the meat, retention of total water and the discontinuance of maturation. The ammonia presents attractive physico-chemical characteristics for operation of the process of the present invention. The dielectric constant at -40°C is equal to 22 and its great reactivity due to a weak auto-ionisation confers on it ionising solvent properties for the electrolytes. Its dissociation constant at +40°C is K = /~ NH4+ J /~ NH2~ _7 = 10"29. It is capable of forming H inter molecular liaisons between the hydrogen atoms of one molecule and the nitrogen atoms of neighbouring molecules, for example of the proteins. The ammonia gas is at a minimum degree of oxidation (- 3) which confers on it reduction properties , which effect protection of the myoglobin responsible for the red colour of the meat. The NH^ gas dissolves easily in water with release of heat giving hydrates ^yand not hydroxides (those existing solely in the dissociated AR1986^tate NH4+ oh~' without the formation of an azeotropic N p /fixture). The aqueous 203473 18 solutions (weak bases) carprise hydrogenous liaisons (N and it is water which cedes its protons: NH3 + H + H-0) + h2° ~ NH 3 + h3o+. Ammonia is a molecule of a large reactivity which gives: (1) addition reactions (nh3 + H20 «= NH^OH ; SH2 + 2NH3 = S (NH4)2); (3) substitution reactions (R-CO-COOH + NH3 > R-CH (NH2)-COOH + h °2) ; (4) co-ordination reactions (formation of monodentic co-ordinates due to the existance of a free doublet of the nitrogen atom). Without wishing to be bound by such a theory, it is believed that as a function of the composition of the components of the meat concerned, the properties of ammonia express themselves separately or in a simulataneous fashion and confer universally an accentuation of the hydrophilic molecules which manifest themselves by the water retention , the formation of gel§ and new salts , che structural alterations and a disorganisation of the cellular anisotropy. The treatment by ammonia of the boned muscles in the warm' and of hard meats provokes an inhibition of the hardening in cooking accompanied by extinction of the sulphur flavours and of the savouriness. (2) dismutation reactions (NH-j + H20 5= v NH4+ + OH-) ; — NH3OH2 203473 The sulphur components of the meat intervene in the hardening in cooking, and the treatment provided by the invention, for example with ammonia, moreover exerts a desulphuring action. It will be recalled that sulphur, is a nucleophile much more energetic than oxygen; the thiols easily form disulphurs (2RSH + *5 02 = RSSR + H20) and fragile polysulphurs (R.SSSS.R etc....) which by decomposition free elementary sulphur; in an acid medium the action of the thiols on the aldehydes and the ketones produce thioacetals (RCH=S) and thioketones (RR'C=S) difficult to study since they are poly-merisable spontaneously. During cooking of the meat, the conjugated action of elementary sulphur and its polymers hardens the muscular structures. Given the large number of possible reactions and the multitude of transistory states which develop when cooking meat, in the course of which denaturation of protein structures occur, it is impossible to indicate with precision the reactions which take place. Meanwhile to confirm the desulphuring action of ammonia on the meat, muscular hardening . has been simulated with CS2 and their inhibitions by NH3. The cairboiv-disulphide reacts on the primary and secondary amines and NH3 to give the dithiocarbamic acids (RNH-R' + CS2^RR'N-C(S)SH) easily oxydisable into disulphurs of thiocarbamoyl known under the name of disulphurs of thinram (RR'N-C(S)-S-S-C (S) NRR') important catalysers of hardening. 203473 - 20 - The following tests have been effected: (1) the muscles and meat subjected raw to atmospheres of CS2 then cooked, hardened intensely; (2) submitted raw to successive atmospheres of CS2 and NH^, then cooked, they remained tender; (3) submitted raw to successive atmospheres of NH^ and CS2, then cooked, they remained tender. In test (1) above hardening of meat occurred during cooking and total inhibition thereof in tests (2) and (3) owing to the treatment with ammonia. Thus the treatment according to the invention in particular with ammonia inhibits the hardening of meat during cooking. It has likewise been found that it stabilises the colour of the meat, retards microbial evolution and restrains exudation. A lesser loss of nutritive material thus results. The process of treatment of meat may likewise be operated with a non-toxic amine which is notably volatile. The operation of the process is similar to that described above for ammonia. It will be within the scope of the person skilled in the art to determine for each amine the appropriate doses by routine tests, concerning notably the tenderness of the meat, the exudation, which are described in the following illustrative examples. The process of treatment of non-transformed meat of the . ^ invention may likewise be put in operation with solutions u of non-toxic salts of ammonia or of amines. 203473 - 21 - In this mode of operation the non-transformed meat is placed in contact with an aqueous solution of a non-toxic salt of ammonia or amine for about 0.5 to 4 hours at a temperature which varies as a function of the stage when the treatment is applied during the preparation of the meat. The treatment of the meat with the aid of an ammonium salt (acetate, citrate, chloride, lactate, phosphate, sulphate) likewise permits the restraint of exudation. It will be noted, however, that the treatment of the meat with the non-toxic salts in the form of aqueous solutions moistens the meat and gelifies its surface which may constitute an inconvenience when it is required that the carcases be dried out, but this is not meanwhile a requirement in all countries. 203473 - ?2 - Meanwhile it will be noted that these inconveniences may be avoided by injecting solutions of one of the salts referred to above before slaughtering the animal. The invention thus concerns a modification from the contacting of the tnuscles before preparing the meat with solutions of non-toxic salts of ammonia or of amines or other desulphuring compositions by injection or ingestion of these solutions into the animals before slaughtering. In the method of carrying out the process of the invention aqueous solutions of -"blaring nr-rrf ammonium chloride at pH 7 are advantageously used, the concentrations of which are appropriate for quick injection is = 20 to 150 ml of solution per beast. The quantity of solution to be used varies as a function of the weight of the animal. It is preferable to use solutions saturated in salt otherwise the injection would be effected by perfusion, which increases the time of treatment. Solutions of ammonium chloride may be used for example containing 8 g/100 ml of NH^+. With such solutions containing about 330 g/1 of NH4C1, it is indicated by way of example that the dose to use for one bovine of 750-800 kg, the carcass of which is approximately 360 kg, is preferably 70-100 ml of the above solution. The solutions of ammonium citrate appropriate to the objects of the invention contain advantageously about 600 g/1 of ammonium citrate (salt in diammonium form) ; when the pH of 203473 - 23 - these solutions is adjusted to pH 7 with the aid of ammonia the salt is thus in the triamrnonium form. These solutions titrate 1° g/100 ml of NH^4. The doses to be used for injection are in general 50 to 80 ml per bovine. The solutions of ammonium citrate are particularly advantageous, because the citrate itself prevents immediate coagulation. With the process of treatment according to the invention effected by injection of the solutions of ammonium citrate before slaughtering, the blood coagulates only after exriry of about 10 minutes; on the one hand it permits an increase in the tenderness of the meat and on the other hand provides powdered blood having an excellent microbiological quality. According to another modification of the operation of the process of the present invention, the process of treatment of meat can be coupled with a treatment using nor.-toxic acid, such as citric acid at a pH of gelification of the meat, which is between 2.97 and 3.08. Citric acid is used advantageously at the rate of 4 g/kg of meat This modification is particularly suitable for frozen meats which are to be subjected to an acid treatment using citric acid (4 g/kg of meat), after having defrosted in saline solutions CI for example) or atmospheres containing a treatment agent (for example NH-j gas at a level of 5 to 30 g/m^) for 0.5 to 4 hours approximately and at temperatures of + 4°C to + 30°C. 203473 24 The acid treatment (citric acid) provides an aqueous and aminated loss of 0.5 to 2% (wherein said aminated loss refers to a lessening in concentration of ammonium salt); it discolours the meat which becomes grey but it diminishes the microbial populations. Moreover it increases the duration of conservation of cooked foodstuffs, whereas the acidity remains lightly perceptible after cooking. The acid used for acid treatment may be used in a pickling brine comprising a salt and a sugar, for example a saccharose. It has been confirmed that at a pH of gelification of the meat (pH = 2. 97-3.08) it produces migration phenomena; the products contained in the pickling brine penetrate into the interior of the meat; it produces a most rapid lactic fermentation which has the effect of anulling adulterations which may be produced in sausages. According to another modification of the process of the invention, the process of treatment (for example ammoniacal or with ammonium salts) is combined with a treatment using vaporised diacetyl. Fresh and warm meat possesses a good resistance to microbial invaders which progressively diminishes; as has been previously indicated the treatment according to the inventiont for example ammoniacal or with the aid of an ammonium salt inhibits the microbial growth. It has been found that this inhibition is reinforced by treatment of the meat after slaughtering with the aid of vaporised diacetyl at doses from 0.5 °/00 (by weight). This diacetyl treatment 203473 - 25 - ensures attractive protection of the surfaces of the meat. It will be noted that fresh meat treated with diacetyl acquires flavours which dissipate in the cured and smoked products. This treatment is thus particularly appropriate for meats - t destined for curing ' and smoking. The advantages of the process according to the present invention will be demonstrated by the following tests effected on beef meat and with reference to the attached drawings (figures la to 9) as The adult bovine meat, which/is universally appreciated is such that its tenderness is the most difficult to master. The following tests have been effected on the warm-boned muscles and (thigh - rump steak of beef)/on prime meats; secondary and third categories, parts from carcases having been subjected to periods of maturation at + 2°C for variable times (3 to 10 days). The pieces of meat perfectly dressed (with bone, fat, aponeuroses and tendons removed) have been directly analysed and treated or even, cut up (pieces of 0.6 to 1 kg) , conditioned and frozen at -30°C according to requirements. These pieces of meat have been treated according to the process of the invention with ammonia at a rate of 5 to 30 g/m^ for 30 minutes to 4 hours. The process has been applied fresh meat (just after slaughtering) and matured meat (3 to 10 hours +2°C) . nwE - 26 - 203473 Test No. 1 The beef meat has been cooked 20 hours after slaughtering, and the development of tenderness has been followed in the course of cooking, on the one hand according to the temperature at the heart of the portion (Figures la and lb) and on the other hand according to the time of cooking in a boiling bian-marie (figures 2a and 2b). In this case treatment with ammonia has been effected after slaughtering and by way of comparison identical meat which has not been treated with ammonia has been used. The results obtained are shown graphically in figures la, lb and 2a-2b. The notation of tenderness has been effected according to the following scale: 9 = very tender; 7 = tender; 5 = tender enough 3-4 = hard; 1-2 = very hard. The notation has been shown in ordinates on each of the figures and in the abscissae are indicated: the temperature at the heart in centrigrades (figures la and lb) and the time of cooking in minutes (figures 2a and 2b). In the figures the curves (1) relate to the meat of prime category (rump steak, round of beef) and curve (2), (3) relate to meat of secondary category (gravy beef) and third category (neck) . J 27 203473 The■curves of figures la and lb, 2a and 2b show that the tenderness diminishes considerably as a function of the temperature at the heart (figure la) and of the cooking temperature (figure 2a) and the treatment with ammonia permits the diminishing of this stages of tenderness since"in all cases the tenderness of the meat treated with NH^ is greater or egual to 5. Test No. 2 In this test the development of the tenderness of the adult bovine meat has been evaluated by dynamometric means, , and these results have been compared with the odontologic impressions according to the notation indicated in the above test. The behaviour of 89 samples of muscle "quadriceps femoris" boned warm or in a traditional manner, raw, treated with ammonia and sampled at different stages of cooking have been analysed. The dynamometric tests have been effected with .an INSTROM 1122 dynamometer. Characteristics of test pieces of meat; thickness = 3 mm, size = 1 inch (25.4 mm); length between the jaws equals 30 mm. The elongation was measured, the resistance to rupture was calculated in kg/cm2 with the formula R = F/S (R = resistance • to rupture; F = force applied in kg; S = section of the test pieces which equals thickness x size). fall in tenderness and produces meat having controlled \ The conversion of kg/cm may be effected into newton/mm - 28 - 203473 or megapascal: 1 kg/cm2 = 9.8/100N/mm2 = MPA. The work (T) may be calculated by the formula: T = F.A/S (A = elongation in cm). The recorded peak surface is proportional to the work provided. The results are shown in figures 3a and 3b in which are indicated in the abscissa the temperatures of cooking in degrees centrigrade and in the ordinates the resistance to the traction in kg/cm2, the speed of traction being 5 cm/min (figure 3a) and 1 cm/min (figure 3b) and the notation of the tenderness (figure 3b). The different curves of figures 3a and 3b are respectively relative to: (1) round of beef boned warm, not mature, not treated, (2) round of beef boned warm, not mature, treated (NH3), (3) round of beef boned after four days of maturation at +2°C and treated (NH^), (4) round of beef boned after 4 days at +2°C and treated (NH3), (5) round of beef boned after 4 days of maturation at +2°C and treated (citric acid), (6) gustatory appreciation of the tenderness of the samples 2, 4, 5. The results of figures 3a and 3b show that a remarkable correspondence exists between the two methods .of evaluation of the tenderness, the gustatory notation being more severe with respect to several samples. 203^73 - 29 - The,same tests have been effected using meat in which the animal muscles were treated before slaughter either with a solution of ammonium chloride at 330 g/1, or with a solution of ammonium citrate at 600 g/1-. Two hundred bovines were thus treated before slaughtering. On cooking the meat obtained from these animals thus treated,results were obtained analogous to those mentioned above. Test No. 3 Electometric titrations were effected of the exudates of defrosted matured meat and of warm meats with the aid of hydrochloric acid 0.IN and sodium hydroxide 0.1N. The titrations were effected on 2 ml of the exudates of defrosting. The electometric behaviours of extracts KC1 0.5 M pH = 7 of warm muscle and matured meat, treated or not treated with ammonia were likewise studied. The titrations were effected on 2 ml of the extract KC1 0.5 M pH = 7. The results obtained were entered on figures 4 and 5 on which the pH is indicated in the ordinates and the quantities of HC1 and NaOH in the abscissae. Figure 4 gives the curve by adding the electrcnetric titrations of the exudates of defrosting of the beef; the curves of this figure relate respectively: Curves (1): rounds boned warm and frozen 6 hours after boning. Curve (2) : matured rounds (3 to 10 days at +2°C) then frozen. 203473 -30- Figure 5 represents the curves of electrometric titrations of extracts KCl 0.5M pH = 7.0 of rounds of beef; the curves of this figure are respectively: Curve (1): rounds warm and mature references Curve (2): rounds warm and mature treated (NH3). The above titrations of the exudates of defrosting show that the juice which«xises from the mature meat is stopped better than those of warm meat. In the two cases free and massive gelification is observed at pH 3 and a viscosimetric densification above pH = 8 . 6 . On the other hand the electro-metric behaviour of the extracts KCl 0.5 M pH 7 of the warm muscles and of the mature meat are identical and influenced in a similar manner by the treatment with ammonia. Test No. A The variation in the mean percentages of spontaneous loss of weight by exudation during , defrosting at + 4°C as a function of the peripheral pH ( 2.5 to 5) or and pH central/peripheral/ (from 5 to 8.5) of pieces of meat subjected to different processes of the invention were studied. The results obtained are shown in figure 6 in which the ordjnates indicate the weight exuded .. as percentage of initial fresh weight and the abscissae the pH of the meat. The roman numbers I to V shown. under the abscissate. relate to meat having been subjected to the following treatment: - 203473 - 31 - I I - meat treated by pickling brine acids (citric acid), then frozen, II - fresh meat of all categories, frozen, III - fresh meat of third category frozen, IV - fresh meat frozen and treated at defrosting (NH^)» . V - fresh meat frozen and treated at defrosting (NH3), The results indicated on figure 6 show that the exudation may be contained by treatment of the meat with pickling brines containing citric acid or by treatment with ammonia. Moreover the centesimal composition of the exudates of defrosting of beef meat of prime category, frozen warm and matured has been determined. The results obtained are shown in the following table I. The centesimal composition of beef meat of prime quality has also been determined and the extracts of these by KCl 0.5 M pH = 7 (100 ml/20 g) and the quantities of dried materials and solubilised proteins have been determined. The results obtained are shown in the following table II. Furthermore the precipitates obtained at different concentrations of (NH^^SO from the exudates of defrosting and the extracts of meat of prime category matured or warm and treated or not with ammonia have been analysed. The results obtained are shown in the following table III. As well as those of table I and II they show that treatment with iammonia influences the exudates little. .1 It follows from the experiments effected on this occasion that the exudates of the warm-boned muscles are very voluminous, ■. 2 034 73 very rich in dry materials and proteins, of a very high molecular weight; the level of the proteins of the exudates issuing from the mature meat has been reduced by enzymatic action (factors Ca++, cathepsins, etc....). The extraction of muscular proteins by gentle methods (KCl, 0.5 M) principally concerns soluble sarcoplasmic proteins, which constitute approximately 30% of the total muscular proteins. The -degree of extraction and the compositions are little influenced by the maturation and the treatments, only certain physi-cochemical properties distinguish the muscles of the meat. The compositions of the cooking juice, which arise from the muscles of the meat differ little. The ' constant behaviour of the greater part of the soluble lumps studied show that the fundamental change in the transformation of the muscles in meat operates necessarily in the organic region , that is to say at the level of the fibres, which has been confirmed by observations effected by photonic microscope. Test No. 5 The evolution of microbial populations as a function of the rate of initial pollution and of treatments. applied on the then one hand tothe beef meat frozen and/defrosted and stored at +4°C and on the other hand, to raw and cooked beef meat stored at +4°C has been studied. Figures 7a and 7b relate to beef meat frozen then defrosted and stored at +4°C; the curves of the figures (number of days in the abscissa^and microbial populations in the ordinates) are related respectively to: curves (1) and (3):reference meat -33- 203473 noti being subjected to any treatment according to the invention. Curves (2) and (4): meat treated with ammonia before freezing (figure 7a). Curves (5) and (6): meat treated with a pickling brine of citric acid base (4 g/kg) (figure 7 b). Figures 8a and 8b relate to raw and cooked beef meats stored at 4°C. Figure 8a concerns cooked meat, curve (1) relating to reference cooked meat and curve (2) to cooked pickled meat (citric acid). In figure 8b, the different curves are related respectively to: curves (1) and (2) curve (3) curve (4) raw reference meat raw meat treated with diacetyl at 0.5°/ raw meat treated with diacetyl at 2.0°/ oo oo curve (5) : raw meat treated with diacetyl at 5°/ oo- The results of this test show that the treatment with citric immediately acid (pickling) diminishes then subsequently slows down the microbial development. This action subsists after cooking. The warm and fresh meat possesses a good resistance to microbial invadere» the growth of which progressively attenuates; the ammoniacal treatments, with diacetyl as well as with citric-racid. reduce / ' I- ? A ' \ the microbial growth. i /a if * i\ K • 4. \\<* Test No. 6 v.^ v, rise V fr q The curves of / in temperature at the heart of "the-pieces of meat of 600 to lOOOg cooked in three parts of boiling water 34 203473 have been determined. In this test fresh meat mature meat \ (maturation) and meat treated with ammonia after slaughter were used. The results obtained are shown in graphic form in figure 9 in which the ordinates show the temperature registered at the heart of the piece of meat in degrees centigrade and the abscissacthe period of cooking in minutes. Curve (1) relates to fresh meat, whereas curve (2) relates to mature meat and meat treated with ammonia. This test shows that with treatment with ammonia one obtains instaneously that which took about 14 days to obtain in the traditional manner of maturation. This test thus gives evidence of the fact that the treatment with ammonia enables need for one to avoid/maturation. TABLE I Centesimal comppgitlon of exudates of defrosting of beef meat of premier category, frozen warm and mature Warm Mature meat meat D.M. : 14.0 : 12.0 Nt D.M. : 12.4 : 11.2 NnD/Nt : 80.4 : 68.7 N.TCA| /Nt : 90.0 : 81.1 Ashes (remains) : 9.0 : 9.2 Legend D.M. = dry material Nt = total nitrogen NnD = non-dialisable nittogeri - " NTCA^= nitro^^recipitable by trichloreacetic acid Treatment = NH3 TABLE II Centesimal composition of beef meat of prime category; Extraction of this by KCl 0.5 M pH = 7(100 ml/20 g) and balance of extractions % Mean composition of samples Quantities of dry material and of solubilised proteins, in- % Warm meat Mature meat Warm meat 1 Mature meat Reference 1 Treated Re fer-ence Treated D.M. 25.5 25.0 27.0 33.5 26 .5 D.M. extract % 31.0 of the total D.M. Proteins/D.M. 80.5 81.0 Extract proteins % 35 .0 36 . 0 35.5 37.0 of total proteins NnD/Nt 94. 9 66 . 2 87 . 3 95 . 9 NTCA 4, /NT 86.6 72.0 72.7 75 . 7 Ashes (remains) 4.5 4.1 Legend: NnD = non-dialysiable nitrogen D.M. = dried material NTCA-t = nitrogen precipi table by trichloreacet ic acid ^ Nt = total nitrogen Treatment = NH3 k* -F 1 t -37- 203473 w ■j CC i < u c B c u a O 4J c E <*~ CI r. £ V) u T U X C C? X T> C CT> C Cfl <| O < W 4 W- C T3 U o cr u? o it x c a> o X z O to >! ,Q W c o • H JJ c o o ro U-l 0 to •P r-H 3 if) V (X U F. O W-. 0 c 3 r tr o o o r* t X a u X, IT. 4J <J K U -i- X u: w 0 3 er cn c ir —. 0 ^ E vw a, o »o m *H 0 10 a.1 +j w U-< c O O if) -H CO -P 4-> U) 3 fC 4-> C t E L T * C 5 E c w 3 rr c c t. Treated Reference Treated Reference a ur. Treated o 0. Reference E u ic r c :< £ 0 v- 3 4-» 4J ft to t r e E ^ u * c c» :« £ 0) U 4J 3 <C * I 3 -H V "3 £83 o» in c- r-> 0 rc> U-^ JJ 2 *j O C O o v c c > 21 l~. c 0 4J g •H 4-1 C W c 3 -p -P o Hd)3 m M'p O 4-1 U poa M-l o (0 & tJ-S 3 in y m e It c> S E Treated cr-a Reference r- r—i Treated o o Reference o Treated o Reference Treated Reference in o Treated in c in ro -cL Reference m o Mature meat CD m Warm meat r-o Mature meat o m o a> (N in Warm meat o 5T O 5T fN Mature meat u o Warm meat Mature meat ro »—l O o Warm meat o fN o o» in d Precipitates obtained at different concentrations of S0^(NH^)2 added to the exudate '(P/V) % o m in ro o o m in in o tn \D cr c\ m (N O rH ^ rT r- fN r- r—I CO r- in o to 4J o K- r'\) . / / </div>

Claims

<div class="application article clearfix printTableText" id="claims"> - 38 - 203473 WHAT WE CLAIM IS:

1. Process for treatment of untreated raw meat, notably for controlling the tenderness thereof, characterized in that the meat is contacted with a treatment agent capable, within the conditions of treatment of furnishing in situ ammonium ions which hinder hardening of meat during cooking and thus permit muscular fragmentation during subsequent cooking of the meat, said treatment agent being chosen from ammonia gas and a composition comprising a non-toxic ammonium salt, 3 the ammonia gas being used at a rate of 5 to 30g/m of the surrounding atmosphere during a treatment time between 30 minutes and 4 hours at a temperature between -18°C to 30°C while the non-toxic ammonium salt is used as a solution having a pH 7 quickly injected into the animal just before or during slaughter and comprising 300 to 600g/l of said non-toxic ammonium salt.

2. Process according to claim 1, characterized in that the non-toxic ammonium salt is ammonium chloride.

3. Process according to claim 1, characterized in that the non-toxic ammonium salt is ammonium citrate.

4. Process according to any one of claims 1 to 3, characterized in that the non-toxic ammonium salt is injected in a quantity of 50 to 80 ml.

5. Process for treatment of untreated raw meat as claimed </div>