Compositions Comprising Textured Legume Proteins - Patent application

Abstract

The present invention relates to compositions comprising legume proteins that have been textured by a drying process, methods for their production, and uses thereof.

Description

[Background technology]

[0001] The present invention relates to a particular composition comprising texturized pea proteins, and to a process for the production thereof.

[0002] Protein II texturization techniques, especially by extrusion cooking, have been applied to numerous plant materials with the aim of preparing products with fibrous structures intended to produce meat and fish substitutes.

[0003] The processes of extrusion cooking of proteins can be broadly classified into two groups according to the amount of water used in the process. When the amount of water is more than 30% by weight, it is called "wet" extrusion cooking and the resulting product is more intended to produce a processed product that imitates animal meat, e.g. beef or chicken nuggets, for immediate consumption. When the amount of water is less than 30% by weight, it is called "dry" extrusion cooking and the resulting product is more intended to be used by food processing manufacturers to formulate meat substitutes by mixing with other ingredients. The field of the present invention is the field of "dry" extrusion cooking.

[0004] Historically, the first proteins used as meat substitutes were derived from soy and wheat, with soy quickly becoming the predominant source for this application.

[0005] Most of the subsequent work has explicitly concerned soy protein, but other animal and vegetable protein sources have also been texturized, such as peanut, sesame, cottonseed, sunflower, corn, wheat protein, microbial proteins, slaughterhouse or fishing by-products, etc.

[0006] Legume proteins such as those from pea and broad bean have also been the subject of investigation, both in terms of their isolation and "dry" extrusion cooking.

[0007] Pea proteins have been the subject of much research, not only because they have specific functional and nutritional properties, but also because their nature is non-genetically modified.

[0008] Despite recent research efforts and growth rates, these pea protein-based products still have very limited market penetration.

[0009] One of the reasons limiting this expansion has to do with the process needed to rehydrate the texturized pea protein before adding it to the formulation.

[0010] Indeed, since the proteins are dry, they must be rehydrated to be able to be shaped and intimately mixed with the other ingredients of the formulation in order to obtain a satisfactory final result.

[0011] For rehydration, the pea proteins textured during the drying process are brought into contact with an aqueous solution. Unfortunately, the amount of water absorbed for rehydration purposes is not sufficiently effective and, without corresponding human intervention, is only about 50% of the amount required for the further formulation steps.

[0012] This is usually accompanied by an additional step called "chopping" or "cutting", which consists in chopping the rehydrated textured fibers, so that when the fibers thus obtained are contacted with an aqueous solution, the chopped fibers can reabsorb the water required for drying.

[0013] This step is complicated because a poorly controlled cut can damage the textured pea proteins, and, in addition, it is an additional preparation step, which makes it more complicated to carry out.

[0014] The Applicant's achievement is to have solved the above-mentioned problems and to have developed a new specific composition comprising textured pea proteins obtained by dry extrusion cooking, the implementation of which does not require "chopping" or "cutting".

[0015] The present invention will be better understood in the following sections, which are intended to disclose a general description. Summary of the Invention

[0016] The present invention relates to a composition comprising legume proteins which have been textured by a drying process and which is characterized in that it has a water-holding capacity, measured by Test A, of more than 3 g water / g dry protein, preferably more than 4 g water / g dry protein, more preferably between 4 g and 5 g water.

[0017] The legume protein is preferably selected from the group consisting of broad bean and pea, with pea being particularly preferred.

[0018] Finally, the dry matter of the legume proteins textured in the drying process according to the invention is more than 80% by weight, preferably more than 90% by weight.

[0019] The present invention also relates to a process for producing a legume protein composition as described above, characterized in that the process comprises the following steps: 1) preparing a powder comprising legume protein and legume fiber, the powder having a legume protein / legume fiber dry weight ratio of 70 / 30 to 90 / 10, preferably 75 / 25 to 85 / 15; 2) producing a textured legume protein composition from the powder obtained in step 1, the textured legume protein composition having a density of 40 g / L to 120 g / L, preferably 60 g / L to 90 g / L; 3) compressing the textured pea protein composition obtained in step 2, 4) Optionally, drying the composition thus obtained.

[0020] The powder containing legume proteins and legume fibers used in step 1 can be prepared by mixing the proteins and fibers. The powder can consist essentially of legume proteins and legume fibers. The term "consist essentially of" means that the powder may contain impurities related to the process of preparing the proteins and fibers, such as traces of starch. The legume proteins and fibers are preferably selected from the group consisting of broad beans and peas. Peas are particularly preferred.

[0021] Preferably, step 2 is carried out by extrusion cooking the mixture in a twin-screw extruder by applying a specific energy of 20 kWh / kg to 30 kWh / kg and adjusting the outlet pressure in the range of 70 bar to 90 bar. Even more preferably, the twin-screw extruder is characterized by having an outlet die with a diameter of 27 mm and a length / diameter ratio of 60.

[0022] Preferably, the temperature of the textured pea protein composition during the compression of step 3 should be between 30°C and 50°C, preferably 40°C.

[0023] Preferably, the compression in step 3 is characterized in that the textured protein after compression has a density between 100 g / L and 170 g / L, preferably between 130 g / L and 150 g / L.

[0024] Preferably, the compression carried out in step 3 is carried out in a drum dryer, which in particular has a diameter of 300 mm, rotates at a speed of 10 rpm to 20 rpm, preferably 16 rpm, and is equipped with four satellite cylinders of 75 mm, with a gap between the satellite cylinders and the main cylinder in the range of 0.5 mm to 1.5 mm, preferably 1 mm.

[0025] Finally, the present invention relates to the use of a legume protein composition textured by a drying process as described above in industrial applications, such as the human and animal food industry, industrial pharmaceuticals or cosmetics.

[0026] The invention will be better understood upon reading the following detailed description. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention relates to a composition comprising legume proteins which have been textured by a drying process and which is characterized in that it has a water-holding capacity, measured by Test A, of more than 3 g water / g dry protein, preferably more than 4 g water / g dry protein, more preferably between 4 g and 5 g water.

[0028] The legume protein is preferably selected from the group consisting of broad bean protein and pea protein, with pea protein being particularly preferred.

[0029] The term "legume" or "legume" is herein intended to mean the family of dicotyledonous plants of the order Fabaceae. Fabaceae is the third most numerous flowering plant family after Orchidaceae and Asteraceae in number of species. Fabaceae includes about 765 genera and more than 19,500 species. Some legumes are important crop plants such as soybean, pod bean, pea, broad bean, chickpea, peanut, cultivated lentil, cultivated alfalfa, various clovers, vetch, carob, and liquorice.

[0030] The term "pea" is considered herein in its most widely accepted usage and in particular includes all varieties of "round pea" and "wrinkled pea", as well as all variants of "round pea" and "wrinkled pea", regardless of the usual purpose of the variety (human food, animal feed and / or other uses).

[0031] In the present application, the term "pea" includes pea cultivars belonging to the genus Pisum sativum and more particularly to the species aestivum, in particular those designated "mutant r", "mutant rb", "mutant rug3", "mutant rug4", "mutant rug5" and "mutant lam", as described in the article by CL HEYDLEY et al., entitled "Developing novel pea starches", Proceedings of the Symposium of the Industrial Biochemistry and Biotechnology Group of the Biochemical Society, 1996, pp. 77-87.

[0032] "Texturized" or "texturizing" is intended in this application to mean any physical and / or chemical processing aimed at modifying a composition comprising a protein to give it a particular ordered structure. In the context of the present invention, protein texturization aims at giving it a fibrous appearance as exhibited in animal meats.

[0033] To measure the water retention capacity, the use consists of test A, the protocol of which is described below. a. Weigh 20 g of the sample to be analyzed into a beaker. b. Add potable water at ambient temperature (20°C ± 1°C) until the specimen is completely immersed. c. Leave in static contact for 30 minutes. d. Use a sieve to separate the remaining water from the sample. d. Weigh the final weight P of the rehydrated sample.

[0034] The water holding capacity, expressed as the weight of water (g) per gram of protein analyzed, is calculated as follows: Water retention capacity=(P-20) / 20

[0035] By "drinking water" is intended in the present invention to mean water that is drinkable or that can be used for domestic and industrial purposes without creating health risks. It will be understood that preferably this water has a sulfate content of less than 250 mg / L, a chloride content of less than 200 mg / L, a potassium content of less than 12 mg / L, a pH of 6.5 to 9, and a total hardness (TH, a measure of the calcium and magnesium ion content of water that corresponds to a French hardness of greater than 15). In other words, drinking water must contain less than 60 mg / L calcium or less than 36 mg / L magnesium.

[0036] As mentioned above, prior art textured pea protein compositions are already known and used in the food industry, especially in meat substitutes. It is known that the moisture content required for the use of these compositions in recipes is at least 3 g, preferably 4 g, per gram of protein. This rehydration makes it possible to prepare the fibers contained in the formulation that best mimic the functional properties of meat fibers, as well as to cause a perception of hardness during final consumption, while avoiding an overly prominent presence of insufficiently rehydrated portions. It is also known that this rehydration cannot be carried out in a single step.

[0037] A person skilled in the art will first carry out an initial rehydration by combining the textured pea protein with an aqueous solvent to reach about 2 g of water per gram of protein. The rehydrated protein fibers are then chopped. Without being bound to a particular theory, this chopping breaks the fibers, exposing their internal parts and allowing their hydration. It is therefore sufficient to contact the rehydrated and broken protein fibers with an aqueous solvent, the water holding capacity being at least 4 g per gram of protein.

[0038] This protocol is described, for example, in the technical documentation for NUTRALYS® T70S, manufactured and sold by the Applicant.

[0039] Shredding of proteins is a known solution, but it adds steps that make the final formulation process more complex and costly. Furthermore, poorly controlled shredding can result in excessive fiber destruction, resulting in loss of the desired functional benefits. Plant fibers are short and do not mimic meat fibers well.

[0040] Finally, the dry matter of the legume proteins textured in the drying process according to the invention is more than 80% by weight, preferably more than 90% by weight.

[0041] Dry matter is measured by any technique known to those skilled in the art. Preferably, the "dehydration" method is used, which involves heating a sample of known weight in a known amount to determine the amount of water that evaporates.

[0042] The protein content of the composition according to the invention is advantageously between 60% and 80% by weight, preferably between 70% and 80% by weight, based on the total dry matter. Any method known to those skilled in the art can be used to analyze this protein content. Preferably, the total nitrogen content is analyzed and this content is multiplied by the factor 6.25. This method is particularly known and used for vegetable proteins.

[0043] The present invention also relates to a process for producing a legume protein composition as defined above, characterized in that it comprises the following steps: 1. Preparing a powder comprising legume proteins and legume fibre, the powder having a legume protein / legume fibre dry weight ratio of 70 / 30 to 90 / 10, preferably 75 / 25 to 85 / 15; 2. producing a textured pea protein composition having a density between 40 g / l and 120 g / l, preferably between 60 g / l and 90 g / l, from the powder obtained in step 1, 3. compressing the textured pea protein composition obtained in step 2, 4. Optionally, drying the composition thus obtained.

[0044] The legume proteins and fibres of step 1 are preferably selected from the group consisting of broad bean protein and pea protein, with pea protein being particularly preferred.

[0045] The powder containing legume protein and legume fiber used in step 1 can be prepared by mixing the protein and fiber. The powder can consist essentially of legume protein and legume fiber. The term "consist essentially of" means that the powder may contain impurities related to the process of preparing the protein and fiber, such as traces of starch. Mixing involves obtaining a dry mix of the various ingredients required to synthesize the plant fiber during step 2.

[0046] By "legume fiber" is intended to mean any composition containing polysaccharides extracted from a legume plant that are relatively indigestible or indigestible in the human digestive system. Such fibers are extracted by any process known to those skilled in the art. A commercial example of such fibers is, for example, the fiber Pea Fober I50 from the company ROQUETTE.

[0047] The mixing may be carried out upstream of step 2 or directly at the feed. During this mixing, additives known to those skilled in the art, such as flavors or dyes, can be added.

[0048] In an alternative embodiment, the fiber / protein mixture is obtained naturally by turboseparatation of legume flour. Legume seeds are washed, their outer fibers are removed and ground into flour. The powder is then centrifugal classified by an upward flow of air, which allows the different particles to be separated on the basis of density. This makes it possible to concentrate the protein content in the legume flour from about 20% to more than 60%. Such powders are called "concentrates". These concentrates also contain 10% to 20% legume flour.

[0049] The dry weight ratio of protein to fibre is advantageously between 70 / 30 and 90 / 10, preferably between 75 / 25 and 85 / 15.

[0050] Then, during step 2, this powder mixture is textured. Texturing is synonymous with the pyrolysis and reorganization of the proteins and fibers to mimic the fibers present in meat by forming fibers that run continuously in straight parallel lines. All processes known to those skilled in the art, especially those used in extrusion, are suitable.

[0051] Extrusion involves forcing the product through small holes in a die under the action of high pressure and shear forces, using the rotation of one or two Archimedes screws. Extrusion is sometimes called "extrusion cooking" since the resulting heat causes cooking and / or denaturation of the product, which then expands due to the evaporation of water at the die exit. This technique makes it possible to develop products with a wide variation in composition, structure (expansion and foam-like morphology of the product), as well as functional and nutritional properties (e.g. denaturation of antinutritional or toxic factors, sterilization of foods). Protein processing often results in structural modifications reflected by obtaining products with a fibrous appearance, thus mimicking animal-derived meat fibers.

[0052] A person skilled in the art will carry out this texturization through his knowledge and choice of equipment to obtain textured vegetable protein with a density between 40 g / L and 120 g / L, preferably between 60 g / L and 90 g / L.

[0053] To measure this density, the following protocol, referred to as Test B, is applied. Tare a 2 liter graduated cylinder. Fill the cylinder with the product to be analyzed. It may be necessary to fill it tightly by finely tapping the walls of the cylinder to ensure that the product fills the 2 liter volume. Weight of the product (Weight P (grams)). Density=(P(g) / 2(L))

[0054] Preferably, step 2 is carried out by extrusion cooking the mixture in a twin-screw extruder by applying a specific energy of 20 kWh / kg to 30 kWh / kg and adjusting the outlet pressure in the range of 70 bar to 90 bar. Even more preferably, the twin-screw extruder has a die diameter of 27 mm and is characterized by a length / diameter ratio of 60.

[0055] Under these conditions, for a material flow rate of about 35 kg / h, water is also added at a rate of 5 kg / h to 7 kg / h, preferably 5.5 kg / h to 6.5 kg / h. The preferred screw profile used has the following element distribution: 80%~95% supply factor, 2.5% to 10% kneading elements, 2.5% to 10% reverse thread factor.

[0056] A person skilled in the art would know through basic knowledge of this technology how to know the perfect settings to obtain the desired density.

[0057] These procedural conditions can easily yield textured proteins with a density suitable for most commercial extrusion cookers, and one of ordinary skill in the art would know how to easily adjust these conditions as needed.

[0058] Preferably, the temperature of the textured pea protein composition during step 3 of the compression should be between 30°C and 50°C, preferably 40°C.

[0059] If the density of the protein to be extrusion cooked is below the above range, the following step 3 may not be performed effectively.

[0060] Preferably, the compression in step 3 is characterized in that the textured protein has a density after compression of between 100 g / L and 170 g / L, preferably between 130 g / L and 150 g / L.

[0061] Step 3 aims at compressing the protein extruded in step 2 by applying mechanical pressure. Surprisingly, this compression is carried out on a textured protein having a density between 40 g / L and 120 g / L, preferably between 60 g / L and 90 g / L, thereby obtaining a textured protein with an optimal final water-holding capacity without shredding. In fact, a person skilled in the art would have expected that after compression, the textured protein would be completely destroyed by this mechanical compression, losing its functionality. The Applicant has in fact demonstrated that the opposite of this expectation is true, as long as the protocol described in this application is followed.

[0062] Any type of device is suitable that makes it possible to mechanically compress the textured protein in order to increase the density to a value between 100 g / L and 170 g / L, preferably between 130 g / L and 150 g / L.

[0063] Preferably, the compression carried out in step 3 is carried out in a drum dryer, in particular having a diameter of 300 mm, rotating at a speed of 10 rpm to 20 rpm, preferably 16 rpm, equipped with four satellite cylinders of 75 mm, with a gap between the satellite cylinders and the main cylinder in the range of 0.5 mm to 1.5 mm, preferably 1 mm. A particularly preferred device is the type 350323 manufactured by Tummers Machinebrouw BV.

[0064] Finally, the present invention relates to the use of legume protein compositions textured by a drying process as described above in industrial applications, such as in the human and animal food industry, in industrial pharmaceuticals or cosmetics. A particular application relates to the use of the compositions according to the invention for the production of meat substitutes, in particular ground meat.

[0065] The invention will be better understood on reading the following non-limiting examples. EXAMPLES

[0066] Example 1A: Production of a legume protein composition textured by a drying process according to the present invention

[0067] A powder mixture is produced consisting of 87% NUTRALYS® F85M from the company ROQUETTE and 13% 150M pea fibre.

[0068] The mixture is fed by gravity into a LEISTRITZ ZSE 27 MAXX extruder.

[0069] The mixture is added at a controlled rate of 35 kg / h. Water is also added at a rate of 5.5 kg / h.

[0070] An extrusion screw consisting of 85% feeding elements, 5% kneading elements, and 10% reverse pitch elements rotates at a speed of 1100 rpm to 1200 rpm to deliver the mixture to the die.

[0071] This particular procedure produces a mechanical torque of 42% at an outlet pressure of 91 bar. The specific energy of the system is approximately 24 kWh / kg.

[0072] The product passes to an outlet towards a die consisting of a 3 mm cylindrical hole through which the textured protein is expelled and then cut into approximately 1 mm pieces by a cutting blade.

[0073] The measured density of the protein extruded using Test B is 59 g / L.

[0074] The extruded protein thus produced is then deposited on the main cylinder (300 mm diameter) of a Tummers Machinebouw BV type 3500323 drum dryer.

[0075] This cylinder is rotated at a speed of 16 rpm. It also drives four peripheral cylinders (75 mm diameter). The gap or distance between the main and peripheral cylinders is 1 mm.

[0076] The protein is piled at a temperature of about 40°C, compressed between different cylinders and then enters a container at the bottom of the drum dryer.

[0077] Example 1B: Production of a legume protein composition textured by a drying process according to the present invention

[0078] A powder mix is ​​produced consisting of 100% VESTKORN "Faba Protein" fava bean concentrate, containing 65% protein and 15% fiber.

[0079] The mixture is fed by gravity into a COPERION ZSK 54 MV extruder manufactured by COPERION.

[0080] The mixture is added at a controlled rate of 350 kg / h. Water is also added at a rate of 65 kg / h.

[0081] An extrusion screw consisting of 85% feeding elements, 5% kneading elements, and 10% reverse pitch elements rotates at speeds between 950 rpm and 1100 rpm to deliver the mixture to the die.

[0082] This particular procedure produces a mechanical torque of 50±2% with an outlet pressure of 82±2 bar. The specific energy of the system is approximately 24 kWh / kg.

[0083] The product passes to an outlet towards a die consisting of a 5 mm cylindrical hole through which the textured protein is expelled and then cut into approximately 3 cm pieces by cutting blades.

[0084] The measured density of the protein extruded using Test B is 84 g / L.

[0085] The extruded protein thus produced is then deposited on the main cylinder (300 mm diameter) of a Tummers Machinebouw BV type 3500323 drum dryer.

[0086] This cylinder is rotated at a speed of 16 rpm. It also drives four peripheral cylinders (75 mm diameter). The gap or distance between the main and peripheral cylinders is 1 mm.

[0087] The protein is piled at a temperature of about 40° C., compressed between different cylinders and then enters a container at the bottom of the drum dryer.

[0088] Example 2: Production of a legume protein composition textured by a prior art drying process

[0089] A powder mixture consisting of 87% by weight of NUTRALYS® F85M from the company ROQUETTE and 13% by weight of 150M pea fibre is produced.

[0090] The mixture is fed by gravity into a LEISTRITZ ZSE 27 MAXX extruder.

[0091] The mixture is added at a controlled rate of 35 kg / h. Water is also added at a rate of 6.5 kg / h.

[0092] An extrusion screw consisting of 85% feeding elements, 5% kneading elements, and 10% reverse pitch elements rotates at a speed of 1100 rpm to 1200 rpm to deliver the mixture to the die.

[0093] This particular procedure produces a mechanical torque of 41% at an outlet pressure of 70 bar. The specific energy of the system is approximately 220 kWh / kg.

[0094] The product passes to an outlet towards a die consisting of two 3mm cylindrical holes through which the textured protein is expelled and then cut into approximately 1mm pieces by a cutting blade.

[0095] The density measurement of the extruded protein gives a value of 100 g / L.

[0096] Example 3: Comparison of legume protein compositions textured by the drying process obtained in the above examples with compositions originating from the prior art

[0097] The protocols described herein above are carried out to measure density according to test B and water retention according to test A.

[0098] Water retention "with shredding" is also measured by modifying Test A as shown below. a. Weigh 40 g of the sample to be analyzed into a beaker. b. Add potable water at ambient temperature (20°C ± 1°C) until the specimen is completely immersed. c. Leave in static contact for 30 minutes. d. Pour water + textured protein into a KENWOOD blender fitted with a pasteurizer attachment (not cutting) and blend on Variable 1 for 45 seconds. e. Use a sieve to separate the remaining water and the sample. f. Weigh the final weight P of the rehydrated sample.

[0099] The water holding capacity, expressed as the weight of water (g) per gram of protein analyzed, is calculated as follows: Water retention capacity (g) = (P-40) / 40

[0100] [Table 1]

[0101] Thus, only products according to invention 1A and 1B are capable of obtaining compositions, the water retention capacity according to test A (without shredding) being greater than 3 g water per gram of composition containing textured protein.

[0102] To achieve this performance level, prior art compositions require a chopping or cutting step.

[0103] Example 4: Use of legume protein compositions textured by a drying process according to the present invention in meat substitutes

[0104] The compositions shown in Example 1A and Example 2 are used to prepare hamburgers or burger patties.

[0105] The ingredients used are as follows (the amounts given in the table below are in grams per 100g of finished burger):

[0106] [Table 2]

[0107] The manufacturing procedure is as follows. 1. Hydrate the textured protein in drinking water for 30 minutes. 2. For Burgers 2 and 3 (not of the invention) only, the textured protein / water mixture is milled using the KENWOOD automatic mixer for 45 seconds and then allowed to contact for an additional 30 minutes. 3. Mix methylcellulose and crushed ice in a container and then place in the refrigerator for 5 minutes. 4. Mix all other ingredients in another container. 5. Combine the mixtures from steps 1 (or 2), 3, and 4 in the same container and mix to obtain a homogenous composition. 6. Form the final mixture, amounting to approximately 150 g, into burger patties by hand.

[0108] After tasting by a panel of 10 people, Burger #1 was noted to be closest to the animal-based burger, with the fiber being more clearly perceived during tasting.

Claims

1. Test A given in the following protocols a. to e. a. Weigh 20 g of sample into a beaker. b. Add potable water at ambient temperature (20° C.±1° C.) until the sample is completely immersed. c) Leave in static contact for 30 minutes. d. Separate the remaining water from the sample using a sieve. e. Weigh the final weight P of the rehydrated sample.

1. A method for producing a composition comprising legume protein textured by a drying process, the composition having a water-holding capacity calculated by the formula: [=(P-20) / 20] of more than 4 g water per gram dry protein, comprising:

1. Providing a powder containing legume proteins and legume fibers, the powder having a legume protein / legume fiber dry weight ratio of 70 / 30 to 90 / 10; 2. Extruding the powder to produce a textured legume protein composition having a density of 40 g / L to 120 g / L; 3. compressing the textured legume protein composition obtained in step 2; 4. Optionally, drying the compressed composition.

2. 2. The method according to claim 1, wherein the powder in step 1 is a powder having a legume protein / legume fiber dry weight ratio of 75 / 25 to 85 / 15.

3. The method according to claim 1 or 2, wherein the legume protein composition obtained in step 2. has a density of 60 g / L to 90 g / L.

4. 2. The method according to claim 1, wherein step 2. is carried out by extrusion cooking the powder in a twin screw extruder by applying a specific energy of 20 kWh / kg to 30 kWh / kg and adjusting the outlet pressure in the range of 70 bar to 90 bar.

5. 2. The method of claim 1, wherein the temperature of the legume protein composition obtained in step 2. is between 30°C and 50°C during step 3.

6. 6. The method of claim 5, wherein the temperature of the legume protein composition obtained in step 2 is 40° C. during step 3.

7. 7. The method according to any one of claims 1 to 6, wherein the compression carried out in step 3 is carried out in a drum dryer having a diameter of 300 mm, rotating at a speed of 10 to 20 rpm, and equipped with four satellite cylinders of 75 mm, the gap between the satellite cylinders and the main cylinder being in the range of 0.5 mm to 1.5 mm.

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