TOTALLY VEGETABLE MEAT SUBSTITUTES AND PROCESS FOR PREPARING THEM

Abstract: The invention relates to totally vegetable meat substitutes containing soya proteins, wheat gluten and other ingredients. The invention also relates to a process for the production of said products comprising the following steps: preparing a gel by mixing soya protein concentrate and/or isolated soya protein with wheat gluten and water; partially hydrating texturized soya protein and/or texturized soya protein concentrate; cooking the dough obtained by mixing the gel with the partially hydrated soya protein and with the other ingredients. Alternatively, it is possible to simply cook the dough made by directly mixing the soya proteins, the water, the wheat gluten and the other ingredients.

Description: Description Totally vegetable meat substitutes and process for preparing them Technical Field The present invention relates to food products used as substitutes of meat for human consumption containing only vegetable proteins, especially those obtained by refining soya and wheat, and containing no animal proteins and/or lipids at all. The present invention also concerns a process for preparing said food product, comprising a number of steps that can be easily applied on an industrial scale and that are capable of providing a meat substitute with optimal organoleptic properties. Background Art The dietary and nutritional properties of foods based on vegetable proteins have been known for some time. These properties are due to the absence of saturated fatty acids and cholesterol and to the high content of essential components m their ammo acid composition. Food products with these properties are of special importance for complete, balanced diets with a low metabolic impact. In this context, soya is a protein source of primary importance. It is available abundant supply since soya beans are extensively cultivated. In addition, the protein component exceeds 50- of the dry weight of soya beans and, besides, the ammo acid composition of soya protein has a very high nutritional value since the essential ammo acids are present m high concentration. It has been proposed to use vegetable proteins, especially soya proteins, to prepare food products to substitute meat and the food processing industry has been especially concerned with the solution of problems relating to the industrial workability of the soya proteins and with improving the consistency and taste of the end products obtained. The soya protein is subjected to several different refining and working processes designed to confer different properties on it depending on the use required. At present, soya protein is commercially available as soya protein concentrate (SPC) or as texturized soya protein (TSP) and/or texturized soya protein concentrate. The latter is obtained by a thermoplastic extrusion process and has chemico-physical properties that confer the right firmness to the bite. In their original form, TSP and SPC contain 70-75% of protein on dry weight. The remainder is made up of water, fibres, fats and carbohydrates. The more the soya protein is refined the higher is the protein content of the end product, such as isolated soya protein, which contains mainly protein m proportions of between 92 and 97% by weight, while the remainder consists of residual water and possibly of salts (expressed as ash) . Soya proteins, although they possess quite a high capacity to retain water, are not able to confer viscoelasticity and compactness on the doughs prepared using them. To obtain a meat substitute to be cooked that overcomes this drawback, other proteins such as egg albumen or milk derivatives such as calcium and/or sodium casemate are added to improve the firmness of the product during cooking. Conventional procedures envisage cooling of the dough and forming of the product under semi-frozen conditions to prevent it from breaking up. Dimensional stabilization therefore occurs during cooking. However, products made m this way cannot claim to make the totally vegetable composition that marketing slogans would make us believe. Alternatively, other known formulations use hydrocolloidal stabilizers derived from cellulose such as methylcellulose, hydroxypropyl-methylcellulose and similar products. However, these products have the disadvantage of conferring an unpleasant consistency to the bite, stickiness and a gelatinous sensation the mouth. Patent application EP-A-0 459 787 reports the combined use of albumin and wheat gluten for the preparation of a pre- ix consisting also of soya proteins, flavourings, spices and vitamins. A product of this kind cannot claim to be totally vegetable because of the presence of egg proteins. Moreover, the example given m said patent application uses texturized soya proteins and the ingredients of the pre-mix constitutes 24.85% by weight which, added to the amount of water required, indicated as 24% by weight, makes a total of 48.85% by weight, so that the content of soya protein concentrate is 51.15% by weight. Therefore, the ratio between the total quantity of water used (24% by weight) and the quantity of soya protein (51.5% by weight) is 0.46:1. The total quantity of water used (24 s - by weight) is therefore much smaller (1/5 of the theoretical value, bearing m mind that commercially available soya protein has a water absorption capacity of 1:2 to 1:4) than the quantity of water required to rehydrate soya proteins, as found experiments carried out by the Applicant. An aim of the present invention is therefore to provide a meat substitute based on soya proteins that has excellent firmness and organoleptic properties and that is prepared using only vegetable proteins not only as the basic ingredients but also as binders during the stages that precede cooking. The Applicant has found that the above and other aims can be achieved if the soya protein dough is prepared using large quantities of water and using, as binder, only wheat gluten. Disclosure of the Invention The present invention therefore has for an ob ect to provide a food product used as a substitute of meat for human consumption made from totally vegetable protein sources, said product comprising: l) soya protein concentrate and/or isolated soya protein; ii ) texturized soya protein and/or texturized soya protein concentrate; in) wheat gluten; IV) water; v) one or more ingredients selected from food flavourings, taste enhancers, vitamin mixes, spices and ground vegetables. Said product is obtainable by a process comprising forming and cooking a dough, which comprises said components I) to v) with a ratio between the weight of water and the total weight of soya proteins of at least 1.80:1 and a wheat gluten content form Is to 7% by weight of the total weight of the dough. In particular, as ingredient (l) , consisting of soya protein concentrate and/or isolated soya protein, a functional soya protein concentrate can be used. Another object of the present invention is a process for the preparation of said meat substitute. This process comprises the steps of forming, cooking, cooling and freezing a dough containing: I) soya protein concentrate and/or isolated soya protein; ii ) texturized soya protein and/or texturized soya protein concentrate; in) wheat gluten; IV) water; v) one or more other ingredients selected from food flavourings, taste enhancers, vitamin mixes, spices and ground vegetables, in which process the ratio between the weight of the water and the total weight of the soya proteins in the dough before forming is at least 1.80:1 and the content of gluten is from 1% to 7% by weight of the total weight of the dough. The wheat gluten used m the food product and process of the present invention is preferably a vital wheat gluten, that is a wheat gluten constituted by the insoluble protein fraction obtained from wheat and containing a high protein content, preferably of at least 75° by weight (for instance 75-80% by weight), more preferably of at least 77- by weight (for instance 77-79- by weight) . In the process according to the present invention, the wheat gluten can be mixed with soya protein concentrate and/or isolated soya protein and water to make a pre-mix gel to which the other ingredients (ii), (iv) and (v) are then added. Alternatively, the wheat gluten can be mixed directly with all the other ingredients (l), (ii), (iv) and (v) . Therefore, m a first embodiment, the process disclosed by the present invention comprises the following steps: a) preparing a protein gel by mixing soya protein concentrate and/or isolated soya protein (I) with wheat gluten (m) and water (iv) ; b) partially hydrating texturized soya protein and/or texturized soya protein concentrate (ii) with water (iv) ; c) mixing the gel obtained from step (a) with the partially hydrated protein obtained from step (b) ; d) adding the ingredients (v) to the dough obtained from step (c) and mixing; e) forming the dough obtained from step (d) ; f ) cooking the formed dough obtained from step (e) ; g) cooling and freezing and/or deep-freezing the cooked food product obtained from step (f) . In this first embodiment of the process according to the present invention, the ratio of the weight of the water to the total weight of the soya protein before forming is preferably at least 1.90:1 and the wheat gluten content is preferably from 2- to 4 by weight of the total weight of the dough before forming. In step (a) , the ratio by weight of water to soya protein concentrate and/or isolated soya protein is preferably at least 5:1. In step (b) , the partially hydrated texturized soya protein and/or texturized soya protein concentrate is made by mixing the texturized soya protein and/or texturized soya protein concentrate (ii) with water (iv) preferably a (ii) : (iv) ratio by weight that ranges from 1:1 to 1:3. In step (c), mixing may be effected at a temperature below 20°C and, this case, the ratio by weight between the protein gel obtained from step (a) and the partially hydrated protein obtained from step (b) is preferably from 1:25 to 1:9. Instead, if mixing is effected at 20°C to 30°C, the ratio by weight between the protein gel and the partially hydrated protein is preferably from 1:9 to 1:0.7. In step (d) , mixing is carried out preferably for 5 to 20 minutes. The dough obtained from step (d) is preferably allowed to stand for at least 15 minutes. The Applicant has found that the structural protein gel pre-mix can be prepared using wheat gluten preferably m a concentration from 8% to 20% by weight (more preferably from 12% to 18% by weight) , soya protein concentrate and/or isolated soya protein m a concentration from 8% to 16% by weight (more preferably from 10% to 14 s - by weight) and water for the remainder. The gel can be made by mixing the two protein ingredients with water and blending them for approximately 2-4 minutes, for example using a cutter type mixer. The Applicant has found that the gel made consists of a protein mass m which the peptide chains tend to adopt conformations of maximum stability. The negatively charged ammo acid residues having carboxyl functions, bind themselves m adjacent position to the positively charged residues, having ammo and/or mdole proton functions. The mass constituting the gel is therefore formed from protein chains bonded together strongly by ionic and Van der aals type forces where water constitutes a continuous pseudo-phase polarized by the presence of hydrogen bridges w th the dipolar centres and the ionic pairs. The special synergy of the gel is due to the similar water content of the two protein components since soya protein has a minimum protein content of 70% and wheat gluten a minimum protein content of 75%. The Applicant has found that the above mentioned protein gel pre- mix offers the advantage of creating doughs that are easy to work and highly cohesive and to which the texturized protein component is added at a later stage and the flavouring ingredients last of all. The amount of gel needed to make a dough suitable for forming is preferably between 7% and 46% by weight, more preferably between 15% and 30% by weight, of the total amount of finished product, this amount being variable accordance with the nature and quantities of the additional ingredients. A gel amount of 7% by weight corresponds to a gluten percentage of approximately 1« of the total weight of the finished product. This amount is sufficient if the dough is worked at temperatures below 10°C, but is insufficient if the temperature is higher than this. If the dough is to be worked at an ambient temperature ranging from 20°C to 30°C, the amount of gel needed to confer cohesion on the dough must be increased to approximately 20% by weight, corresponding to about 3% by weight of wheat gluten based on the total weight of the finished product. In this concentration range, the binding capacity of the wheat gluten is used to best advantage and this makes it possible to work the dough at ambient temperature, doing away with the cold blending process (at 10°C or less) envisaged m prior art. Gluten percentages below 1% by weight would have to be compensated by the addition of breadcrumbs, flour, starch or other starch-based binders of different kinds. If this is done, however, the carbohydrate content of the product would be too high, creating a nutritionally unbalanced product not comparable to meat. Greater gel amounts, for example up to 46 by weight, corresponding to a wheat gluten percentage of 7% by weight on the total weight of the finished product, provide highly elastic and cohesive doughs; however, this impairs the quality of the finished product. In fact, the excessive amount of wheat gluten provides a pseudo-plastic base which tends to shrink during forming. The shearing action created during preparation of the gel causes friction which raises the temperature of the gel: therefore, it may be useful to cool the gel down to a temperature of 0° to 2°C, for example a cold storage room. The Applicant has also found that the wheat gluten can be used to good advantage, preferably m smaller quantities, m a dough made by mixing the protein and flavouring components a single mixing step. Therefore, a second embodiment of the invention, the process comprises the following steps: d' ) preparing a dough by mixing all the ingredients from (1) to (v); e) forming the dough obtained from step (d' ) ; f ) cooking the formed dough obtained from step (e) ; g) cooling and freezing and/or deep-freezing the cooked food product obtained from step (f) . In this second embodiment of the process according to the present invention, the wheat gluten content is preferably from 4u to 7% by weight of the total weight of the dough before forming. In step (d' ) , the ratio of the weight of the water to the total weight of the soya protein is preferably at least 1.90:1, more preferably at least 2.0:1. In step (d' ) , mixing is carried out preferably for 5 to 20 minutes and the resulting dough is then preferably allowed to stand for at least 15 minutes. In both the embodiments described, that is to say, with preparation of gel pre-mix and direct mixing, the water used is preferably cooled to a temperature of preferably 0° to 8°C. In step (d) or step (d' ) , one or more ingredients selected from food flavourings, taste enhancers, vitamin mixes, spices and ground vegetables are added. The latter are preferably frozen. The food flavourings used preferably reproduce the flavour of meat. The spices and ground vegetables can be chosen according to local tastes and culinary traditions. For example, ground onion or garlic or concentrated essence of onion or garlic might be added. The raw doughs obtained from step (d) or step (d' ) are formed for example by moulding and then cooked, for example by frying, preferably vegetable oil, preferably at a temperature of not less than 170°C, more preferably around 180°C, and preferably for 45 to 60 seconds depending on the size of the chunks. Cooking m this way causes a thin crust to form rapidly on the surface of the product, due to the transformation of the starches into dextrms, to the coagulation of the proteins, and to the reaction known as Ma llard' s reaction. The compactness of the crust also helps keep the product light and digestible by preventing the cooking oil from penetrating inside it. Moreover, the internal temperature of the product during cooking should preferably exceed 72°C so as to guarantee adequate pasteurization and thus improve shelf life. Alternatively, the dough can be baked an oven after spraying its surface with vegetable oil or it can be cooked m two stages, of which the first m an oven or fryer and the second during the pasteurization and/or sterilization steps, if envisaged by the process . The cooling of the product can be effected by simply allowing it to stand or it can be accelerated by forced circulation of air at a temperature of not more than 25 °C. Lastly, the product can be stored by refrigeration at 0°C or by freezmg/deep-freezmg at temperatures below -18°C. If stored by refrigeration, the product should be packed m a conditioned atmosphere, for example using a mixture of inert gases, for example nitrogen and carbon dioxide m proportions from 5:1 to 1:1, preferably around 3.5:1, and vacuum packed using plastic films impermeable to oxygen. For packaging the food product, polymer films that are vacuum resistant and impermeable to oxygen are preferable. The product is preferably packaged m a vacuum and/or in an inert atmosphere consisting for example of mixtures of nitrogen and carbon dioxide (for example, proportions from 3:1 to 5:1, especially around 3.5:1) . When the product is packaged in airtight films, it can be pasteurized at atmospheric pressure at temperatures above 63°C for 1 to 30 minutes or sterilized, for example by gamma irradiation at 2 kilograys . The examples below are intended to further clarify the invention and must not any way be construed as restricting the scope of the invention. Example 1 Product made by preparing a soya and wheat protein gel and then blending m the texturized soya protein and other ingredients A protein gel is made by mixing soya protein with wheat gluten and water m the following proportions: a) 0.84 kg of functional soya protein concentrate; b) 1.1 kg of wheat gluten, having a protein content of about 78% by wheight; c) 5.57 litres of cold water (6°C). The ingredients are mixed for approximately 2 minutes m a "cutter" type mixer at a high speed at ambient temperature. The mixture is then cooled for a few hours until it reaches a temperature of 2°C to 0°C. Separately, the texturized soya protein is rehydrated by mixing with water and flavourings m the following proportions. d) 8.0 kg of texturized soya protein (TSP) ; e) 0.75 kg of flavouring mix; f) 12 litres of water. The two mixtures (a)+(b)+(c) and (d)+(e)+(f) are then mixed in an open mixer for 2 to 3 minutes at ambient temperature to make the protein mass (A) . The other components, ingredients and flavourings are then added to the mass made this way the following proportions: 28.26 kg of protein mass (A); g) 5 kg of frozen ground onion; h) 0.2 kg of frozen ground garlic; ) 2. kg of rusk type breadcrumbs; k) 0.4 kg of table salt; ) 0.35 kg powdered tomato; 1) 2 g of vitamin premix. This makes 36.6 kg of dough with a gluten content of 3.0% by weight and a ratio between the weight of water and the total weight of soya proteins of about 1.99:1. This dough is mixed to a smooth consistency for 10 minutes and allowed to stand for 15 minutes. It is then formed into chunks of the required size and then fried or baked at a temperature of 180°C for 45 to 60 seconds depending on the size of the chunks. At the end of the operation, the product has a typical golden brown colour. It is then cooled by forced ventilation with air at a temperature below 25 °C and then placed a deep-freezing tunnel at temperatures below -18°C. Example 2 Product made by direct mixing of soya and wheat protein with the other ingredients A mixture containing soya protein and wheat gluten is made by mixing the ingredients m the following proportions: a) 12 kg of functional soya protein concentrate; b) 109 kg of texturized soya protein (TSP) ; c) 35 kg of wheat gluten with a protein content of about 78% by weight; d) 15 kg of flavouring mix; e) 45 kg of rusk type breadcrumbs; f) 4.5 kg of table salt; g) 7 kg of powdered tomato; h) 40 g of vitamin premix. The mixture, approximately 227.5 kg, is placed m a mixer where water at 6°C and ground vegetables are added m the following proportions: l) 245 litres of water j ) 50 kg of frozen ground onion; k) 4 kg of frozen ground garlic. After mixing for 15 minutes, approximately 526.5 kg of dough is obtained with a gluten content of 6.6% by weight and a ratio between the weight of water and the total weight of soya proteins of about 2.02:1. The dough is allowed to stand for another 15 minutes. It is then formed and fried at a temperature of 180°C for 45 to 60 seconds depending on the size of the chunks to give it a typical golden brown colour. The product is then allowed to cool by forced ventilation with air at a temperature below 25 °C and then placed a deep-freezing tunnel at temperatures below -18°C. Example 3 (comparative) A premix containing soya protein and wheat gluten is made by mixing the ingredients m the following proportions: a) 0.84 kg of functional soya protein concentrate; b) 8.0 kg of texturized soya protein (TSP); c) 1.1 kg of wheat gluten; d) 0.75 kg of flavouring mix; e) 2.4 kg of rusk type breadcrumbs; f) 0.4 kg of table salt; g) 0.35 kg of powdered tomato; h) 2 g of vitamin premix. The mixture, approximately 13.84 kg, is placed n a mixer where water at 6°C and ground vegetables are added m the following proportions: 1) 15.27 litres of water j ) 5.0 kg of frozen ground onion; k) 0.2 kg of frozen ground garlic. After mixing for 15 minutes, approximately 34.3 kg of dough is obtained, wherein the ration between the weight of water and the total weight of soya proteins is about 1.73:1. This dough is allowed to stand for another 15 minutes. Forming is difficult because the dough is dry and tends to crumble. It is nevertheless fried or baked at a temperature of 180°C for 45 to 60 seconds to obtain a loose, not cohesive product.

Claims: Claims 1. A food product used as a substitute of meat for human consumption made from totally vegetable protein sources, said product comprising: I) soya protein concentrate and/or isolated soya protein; ii) texturized soya protein and/or texturized soya protein concentrate; m) wheat gluten; iv) water; v) one or more other ingredients selected from food flavourings, taste enhancers, vitamin mixes, spices and ground vegetables, said product being obtainable by a process comprising forming and cooking a dough, which comprises said components I) to v) with a ratio between the weight of water and the total weight of soya proteins of at least 1.80:1 and vital gluten content from 1-ε to 7- by weight of the total weight of the dough. 2) A process for the preparation of the product according to claim 1 comprising the steps of forming, cooking, cooling and freezing and/or deep-freezing a dough containing: l) soya protein concentrate and/or isolated soya protein; ii ) texturized soya protein and/or texturized soya protein concentrate; m) wheat gluten; iv) water; v) one or more other ingredients selected from food flavourings, taste enhancers, vitamin mixes, spices and ground vegetables, which process the ratio between the weight of the water and the total weight of the soya proteins m the dough before forming is at least 1.80:1 and the content of wheat gluten is from 1% to 7% by weight of the total weight of the dough. 3) The process according to claim 2 comprising the following steps: a) preparing a protein gel by mixing soya protein concentrate and/or isolated soya protein (I) with wheat gluten (m) and water (iv) ; b) partially hydrating texturized soya protein and/or texturized soya protein concentrate (ii) with water (iv) ; c) mixing the gel obtained from step (a) with the partially hydrated protein obtained from step (b) ; d) adding the ingredients (v) to the dough obtained from step (c) and mixing; e) forming the dough obtained from step (d) ; f ) cooking the formed dough obtained from step (e) ; g) cooling and freezing and/or deep-freezing the cooked food product obtained from step (f ) . 4) The process according to claim 3 where in step (a), the protein gel is obtained by mixing the following components: - 8-g to 16% by weight of soya protein concentrate and/or isolated soya protein (l) ; - 8% to 20% by weight of wheat gluten (m) ; - 7 Of to 78% water (iv) . 5) The process according to claim 3 or 4, where m step (a) the protein gel is made by mixing m a mixer at high speed for 1 to 5 minutes . 6) The process according to one or more of claims 3 to 5, wherein the protein gel obtained from step (a) is allowed to stand m a refrigerated environment until it reaches a temperature of 0° to 2°C. 7) The process according to one or more of claims 3 to 6 where step (b) the partially hydrated texturized soya protein and/or texturized soya protein concentrate is made by mixing the texturized soya protein and/or texturized soya protein concentrate (n) with water (iv) m a (ii) : (iv) ratio by weight ranging from 1:1 to 1:3. 8) The process according to one or more of claims 3 to 7 where in step (c) mixing is effected at a temperature below 20°C and the ratio by weight between the protein gel obtained from step (a) and the partially hydrated protein obtained from step (b) is from 1:25 to 1:9. 9) The process according to one or more of claims 3 to 7 where step (c) mixing is effected at a temperature from 20°C to 30°C and the ratio by weight between the protein gel obtained from step (a) and the partially hydrated protein obtained from step (b) is from 1:9 to 1:0.7. 10) The process according to one or more of claims 3 to 9 wherein the mixing step (d) is carried on for 5 to 20 minutes. 11) The process according to one or more of claims 3 to 10 wherein the dough obtained from step (d) is allowed to stand for at least 15 minutes . 12) The process according to one or more of claims 3 to 11 wherein the wheat gluten content of the dough obtained from step (d) is from 2% to 4% by weight of the total weight of the dough. 13) The process according to one or more of claims 3 to 11 wherein the water used has a temperature of 0°C to 8°C. 14) The process according to claim 2 comprising the following steps: d' ) preparing a dough by mixing all the ingredients from (l) to (v) ; e) forming the dough obtained from step (d' ) ; f ) cooking the formed dough obtained from step (e) ; g) cooling and freezing and/or deep-freezing the cooked food product obtained from step (f) . 15) The process according to claim 14, wherein the mixing step (d' ) is carried on for 5 to 20 minutes. 16) The process according to claim 14 or 15, wherein the dough obtained from step (d' ) is allowed to stand for at least 15 minutes. 17) The process according to one or more of claims 14 to 16 wherein the wheat gluten content of the dough obtained from step (d' ) is from 4u to 7% by weight of the total weight of the dough. 18) The process according to one or more of claims 14 to 17 wherein the water used has a temperature of 2°C to 8°C. 191 The process according to one or more of claims 3 to 13 or 14 to 18, where in step (f) cooking is effected n vegetable oil at a temperature not less than 170°C for 45 to 60 seconds. 20) The process according to one or more of claims 3 to 13 or 14 to 18, where m step (g) the cooling of the cooked food product is effected by simply allowing the product to stand or an accelerated way by forced circulation of air at a temperature of not more than 25°C. 21) The process according to one or more of claims 3 to 13 or 14 to 18, where step (g) the freezing and/or deep-freezmg of the cooked food product is effected at temperatures under -18°C.

Inventors: TONAZZO ALBINO, TONAZZO, ALBINO
Applicants: HIT INVESTMENT S A, TONAZZO ALBINO, HIT INVESTMENT S.A., TONAZZO, ALBINO
Application year: 1998
Main classification: A23J3
IPC codes: A23J3