Method and device for debittering legumes

Abstract

The invention relates to a method for debittering peeled or unpeeled, whole or broken legumes, wherein the legumes are debittered or the bitterness of the legumes is significantly reduced in a debittering zone by bringing the legumes into contact with at least one hot or heating medium, such as hot air, saturated steam, superheated steam, hot water, or electromagnetic waves; at the same time, during the step of debittering the legumes in the debittering zone, energy in the form of hot air, saturated steam, superheated steam, hot water, or electromagnetic waves, is continuously input; and, at the same time, the legumes are moved constantly or periodically so that the legumes are optimally brought into contact with the hot medium or the hot media. The invention further relates to a device for carrying out said method.

Description

[0001] Method and apparatus for debittering pulses

[0002] Description

[0003] The present invention relates to a method and an apparatus for debittering pulses. In particular, but not limited thereto, the present invention relates to a method and an apparatus for producing debittered protein and starch concentrates, especially from pulses. In exemplary embodiments, the invention, and as is evident from the present documents, also relates to a method for producing debittered protein and starch concentrates, especially from pulses, as well as the use of a heat treatment for producing debittered protein and starch concentrates, especially from pulses.

[0004] Pulses, also called grain legumes, consist of a pod or husk containing the fruit or fruits. A wide variety of pulses exist. For human consumption, only a few specific varieties are used, which are cultivated in various countries. These include peas, beans (including broad beans), chickpeas, lentils, peanuts, grass peas, mung beans, and lupins. Soybeans, which are also pulses, are not covered by the present invention, as they are subject to fundamentally different processing requirements. Peas, beans, and lentils, for example, are characterized by a comparatively high protein content (18-32%) compared to cereals (wheat, spelt, etc.), while the other main component is starch, along with smaller amounts of fat, fiber, minerals, enzymes, and acids.

[0005] There are many ways to prepare and process chickpeas for human consumption. Most often, the fruit is removed from the pod, but sometimes the pod is used in the preparation, especially in the case of chickpeas.

[0006] For households, restaurants, or mass-produced ready meals, the fruit is soaked in water for a specific period of time before being cooked or otherwise processed into food. However, the fruit is not processed to separate the protein and starch; it is simply peeled before heating.

[0007] In industrial processing, it is of particular importance to extract the protein or starch contained in the aforementioned pulses, both for food and for technical applications.

[0008] For many years, starch has been produced industrially, a process that continued to evolve throughout the last century, ultimately leading to the isolation of protein and starch fractions. This isolation saw a surge in demand in the 1950s due to the post-World War II economic boom in the Western world, as starch was initially sought primarily for technical applications, especially in the booming paper and corrugated board industries.

[0009] The protein fraction was mostly used as animal feed. However, this began to change in the 1970s with the fitness boom. The demand for protein has been further boosted by the increasing interest in vegetarian and vegan diets, particularly in the last 10 years.

[0010] To separate protein and starch from legumes, an industrial process has been established since the 1970s: concentration. First, the pod is separated from the fruit, and then the fruit is peeled, leaving only the pulp.

[0011] The pulses are then crushed. This is usually done using rotor impact mills or classifier mills. By grinding to a specific particle size, pulses are prepared for dynamic classification. The fractions are then separated / classified into protein-enriched and starch-enriched fractions. This process utilizes the property that protein and starch particles are of different sizes after grinding.

[0012] Complete separation is not yet practically possible; an enriched protein fraction and an enriched starch fraction are produced. These two products are often used as raw materials in the production of other foods or as animal feed. Due to the antinutritional components, these products generally do not have a neutral taste, but rather taste more or less bitter to humans.

[0013] Currently, the following protein levels are usually achieved, also for economic reasons:

[0014] Pea approximately 55%

[0015] Broad bean approximately 65%

[0016] Chickpea approximately 45%

[0017] Lentils make up approximately 55% of the total fat content. The remaining components consist of starch, fat, fiber, minerals, acids, and enzymes.

[0018] However, it can be expected that process optimizations in concentrate production will allow for protein levels to be increased by approximately 10-15% in the future. Furthermore, an increasing number of seed varieties with a higher protein content are being developed, which ultimately leads to a higher protein content in the protein fraction.

[0019] Concentrated protein and starch / flour fractions are used in food production for various applications. However, these still contain a very high proportion of antinutritional substances and have a more or less pronounced bitter taste. Antinutritional substances can cause serious illnesses, which can even lead to death, and current state-of-the-art methods do not reduce them; instead, the protein and starch concentrates used must be heated again.

[0020] As a rule, most concentrate manufacturers do not perform any prior or subsequent processing of the fractions.

[0021] The proteins were initially used mainly as feed in salmon farms in Europe, while the starches were used in livestock feed or pet food.

[0022] Since the 2000s, these concentrates have been increasingly used in human nutrition, also as raw materials for the production of textured proteins for meatless substitute diets.

[0023] Document US4022919A (Removal of bitter flavour from Pea Flour) describes the debittering of pea flour using steam, as does the process according to W02023023046A1 (De-Flavored Legume Flours and Methods of Manufacturing). These two publications are representative of the processing / debittering of flour (not protein / starch concentrates).

[0024] Document CA000001118270A (Method of Agglomeration and Deflavoring Pea Flours and Pea Protein Concentrates and Products thereof) describes the dearomatization of pea protein / flour by soaking / washing pea flour or pea protein concentrate after dynamic air classification. In this process, a mixture of water and pea flour / protein concentrate is prepared, heated, and then dried using a roller dryer or spray dryer. Disadvantages of this method, i.e., after dynamic air classification, include high costs.

[0025] Similar to the previously described document, the disclosure in W02023023049 (De-Flavored Fava Protein Concentrates and Methods of Manufacture) involves preparing an aqueous solution after the fava bean protein has been produced and then drying it again in a reactor. Document W02019006286A1 (Deflavored Pea Composition) describes a dearomatization / debittering process by soaking the legume fruit, or its products such as pea flour, pea protein (isolates, concentrates), with drying as the next processing step. However, with both methods W02023023049 and W02019006286A1, germ counts of over 10,000 cfu / g total plate count are generally to be expected.

[0026] The process according to WO2021217265A1 (Method of producing protein products with reduced off-flavors) is similar to the two previously mentioned methods. Here, too, an aqueous solution is prepared and then subsequently dried. Documents US20230172238 and US 11503846 also describe debittering after the grinding of pulses. According to these documents, the ground pulse flour is separated into a protein-poor and a starch-rich fraction by sifting. The protein-rich fraction is then hydrogenated in a reactor and heated. This produces a dough that agglomerates and is subsequently heated to 95 to 150 degrees Celsius. Drying and sieving then follow. This process removes the debitter and improves the flavor of the processed products.

[0027] It has been known for many years that heating whole pulses, and especially soybeans, leads to debittering. Documents DE000P0012643DAZ and EP000000193633A1 describe how crushed or whole pulses can be debittered by heating with gases or steam. Document EP000000113900A1 also describes the debittering of soybeans through microwave treatment.

[0028] The present invention aims to eliminate or at least alleviate the disadvantages of the prior art.

[0029] To achieve this, the present invention provides a method for debittering peeled or unpeeled, whole or broken pulses, wherein contact of the pulses with at least one hot or heating medium, such as hot air, saturated steam, superheated steam, hot water or electromagnetic waves, results in debittering or a significant reduction of the bitterness of the pulses in a debittering zone, and wherein, simultaneously during the debittering process step, energy in the form of hot air, saturated steam, superheated steam, hot water or electromagnetic waves is continuously introduced into the debittering zone, and at the same time the pulses are constantly or periodically set in motion to bring them into optimal contact with the hot medium(s).

[0030] Crushing of pulses is defined here as reducing the particle size to approximately 1 mm. Crushing or pre-crushing can be accomplished with relatively little energy compared to grinding and leads to an efficiency gain by providing more or a larger surface area for the intended debittering.

[0031] Advantageous and preferred embodiments of the above method can be carried out individually or in any combination as follows: wherein the continuously introduced energy is added from outside or in the debittering zone, for example by using heated ambient air; wherein pulses are continuously introduced into the debittering zone, debittered there, and then discharged; wherein the temperature of the medium is 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius; wherein media are used that are capable of heating the pulses to 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius; wherein a combination of two or more hot media is used, such as hot air and steam or hot air and water, and wherein one medium has a temperature of at least 100 degrees Celsius.wherein the medium is in contact with the pulse for 3 to 60 minutes, preferably >15 to 40 minutes, particularly preferably 20 to 35 minutes, wherein the pulses are preferably moved continuously or periodically to ensure ideal contact with the hot medium or media, wherein, for example, this movement can be effected mechanically by means of an agitator, a conveyor, or any other device in the debittering zone that serves to enable movement of the pulses, or alternatively or in combination, the movement can also be effected by means of a rotating, moving, or oscillating housing of the debittering zone, or the pulses can be moved by means of a gas stream in the debittering zone, wherein the contact of the hot medium or media with the pulses is effected by means of a jet mill, a long-split mill, a classifier mill, a stirred ball mill, or any other mill.a fluidized bed dryer, a fluidized bed system, an oven, a sterilizer, a cooker, a roaster, a dryer, a kiln, a toaster, a mixer, or via another unit or device capable of contacting, steaming, mixing, wetting, or processing pulses with hot, gaseous, or liquid media, or of reacting with or diffusing into the pulses, wherein the hot medium is water or another liquid, and the pulses are dried after contact with the medium, wherein contact with the hot liquid takes place in one or more mills, and the pulses are crushed and then dried, wherein any residual moisture in the pulses is reduced before being fed to the debittering zone, wherein the processing steps of debittering, milling, and classifying are carried out immediately one after the other.wherein the grinding process step preferably takes place immediately after debittering, since the heated pulse results in more efficient grinding, wherein electromagnetic waves or so-called microwaves with a frequency of 300 MHz to 1 THz (corresponding to a wavelength of 1 m to 0.3 mm), in particular 1 to 300 GHz, are used as the heating medium, wherein electromagnetic waves in the form of infrared radiation, in particular with a wavelength of 78 nm to inm or a frequency of 300 GHz to 400 THz or a wavenumber range of 10 cm, -1 up to 12,800 cm -1as a heating medium, wherein after contact of the pulses with one or more hot or heating media in the debittering zone, they are ground and sifted in the next step to obtain a protein-rich concentrate and a starch-rich concentrate, and / or wherein the contact of the pulses with one or more hot or heating media takes place instead of in a separate debittering zone, in a mill, preferably in a classifier mill, impact mill, jet mill or long-split mill and / or in a dynamic air classifier or classifier, and the pulses are debittered there.

[0032] Furthermore, according to the invention, the throughput (kilograms / per hour) during milling is significantly higher if debittering is carried out beforehand than with native untreated pulses.

[0033] Furthermore, the invention provides a device for carrying out the inventive method according to any of the aforementioned method variants for the desired debittering as well as a heat treatment for debittering legumes.

[0034] Corresponding embodiments and variants of such a device for processing peeled or unpeeled pulses according to the following explanations are also explicitly the subject of the present invention and specifications for suitable embodiments of the device according to the invention, which the person skilled in the art can implement without further ado, knowing the process embodiments and variants, without having to be inventive himself, since he has the exact instructions for the skilled implementation here.

[0035] Preferably, the method and apparatus are designed for processing peeled or unpeeled pulses to obtain a protein-rich and a starch-rich fraction by comminution and sifting, wherein the pulses are treated before or during comminution or sifting to improve their taste or remove their bitterness.

[0036] In this context, it is important to note that not the

[0037] Products are only debittered after sifting (starch concentrate and protein concentrate). The milled flour of the legumes is already debittered. This means that for debittering itself, the following applies: debittering with subsequent or simultaneous milling and no further sifting. This process produces a debittered legume flour. This is a new product, not previously available on the market, and offers numerous new applications. Currently, there is flour made from legumes. This means that the flour has a correspondingly bitter taste and has not yet found a significant market. In addition to the protein and starch fractions, this process also produces this new product in the form of a debittered legume flour. This can be used, for example, to produce gluten-free baked goods.

[0038] Further advantageous and preferred embodiments result from the combination of individual claims and the following description of individual embodiments.

[0039] The invention is explained in more detail by way of example using the embodiments and application examples and variants described below; that is, it is not limited to these embodiments and application examples and variants. Method, use, and device features can also be derived analogously from the device, method, and use descriptions.

[0040] Individual features that are specified and / or illustrated in connection with a specific embodiment are not limited to that embodiment or its combination with the other features of that embodiment, but can be combined, within the limits of technical feasibility, with any other variants, even if they are not specifically addressed in these documents. According to one embodiment of the invention, hulled or unhulled pulses are debittered in a debittering zone, then finely ground in a comminution zone, and finally sifted in a classifying zone into a protein concentrate fraction and a starch concentrate fraction.

[0041] In a process zone where hulled or unhulled pulses are debittered, a hot medium is introduced, and the pulses are preferably fed continuously via a device. Alternatively, pulses are processed that are first dried before entering the debittering zone, thus exhibiting very low residual moisture. Treatment with a hot medium or electromagnetic waves further dries the pulses in addition to debittering them. This makes the subsequent grinding more efficient. If the pulses enter the grinding zone while still hot immediately after debittering, the grinding efficiency increases even further.

[0042] The device according to the invention and the method used with it reduce the residual moisture of the final product. An observation during trials was that the device and the method used with it not only remove the bitterness from the pulses. By treating the pulses with a hot medium, such as hot air, superheated steam, microwaves, or infrared radiation, the residual moisture content of the product, typically 7 to 15 percent, is significantly reduced. During treatment with infrared radiation in trials, the residual moisture content was reduced from over 9 percent to below 0.5 percent. This substantial reduction in residual moisture significantly improves the grindability. This allows for a significantly higher throughput (approximately [value missing in original text]) while maintaining the same fineness.50% reduction in moisture content can be achieved, or the same throughput can be achieved with significantly less specific energy per kg of product. Another major advantage of the lower residual moisture is a considerably longer shelf life compared to products with a higher residual moisture content.

[0043] Depending on the specific product, process, and / or desired end product, it is neither strictly necessary nor generally desirable or advantageous to dry the pulses additionally before introducing them into the debittering zone, as drying can already occur during the existing debittering step. Therefore, the option of "pre-drying" or residual moisture reduction during debittering is optional.

[0044] Furthermore, if the product is fed into the mill while hot (directly from the debittering process), this results in an even higher grinding capacity or, alternatively, a lower specific energy requirement per kg. This has been proven through experiments, which showed an approximately 20% higher performance with hot product compared to cold product. The reason for this efficiency gain is that the energy present in the product in the form of heat can be used for grinding, thus requiring less additional energy input.

[0045] After grinding, the product may be separated into fractions. Because the product has a lower residual moisture content, the protein concentrate has a significantly higher protein content, approximately 5-10% higher. This is a considerable advantage, as customers desire the highest possible protein content in the concentrate. This is due to the reduced water content in the product. The product, which has been pretreated with a hot medium, therefore lacks water in its mass balance. The remaining product has a higher protein content. The hot medium, which can be, for example, hot air, saturated steam, superheated steam, or water, comes into contact with the legumes. Alternatively, several media can be used, at least one of which must be above 100 degrees Celsius. For example, hot air can be combined with water or hot air with steam.

[0046] The hot media should preferably have a temperature of 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius, when they enter the process chamber, which contains at least the debittering zone. Alternatively, one or more media can be introduced into the process chamber and heated to the aforementioned temperature within the chamber. Another criterion is that media capable of heating the pulses to 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius, without themselves being at the corresponding temperature, such as suitable radiation, can be used.

[0047] Simultaneously with the hot or heating medium, the pulses are fed into the process chamber, which contains at least the debittering zone. These pulses can be cold, warm, and / or pre-dried. They are fed into the debittering zone preferably continuously, come into contact with the hot or heating medium during or within the process chamber, pass through the chamber, and then preferably exit the chamber continuously. Crucially, the pulses must be kept in constant motion to ensure optimal contact with the hot or heating medium. The exposure time to the hot or heating medium(s) is 3 to 60 minutes, preferably 10 to 40 minutes, particularly longer than 15 to 40 minutes, and most preferably 20 to 35 minutes.This contact can occur in the form of the hot medium wetting, splashing, steaming, mixing, blending, irradiating, or reacting with or diffusing into the pulses. During this process, the pulses undergo a debittering process or their bitterness is significantly reduced.

[0048] For the debittering process, it is of particular importance that the pulses are kept in constant or periodic motion, as this is the only way to ensure optimal contact between the pulses and the hot or heating medium(s). This motion can be achieved mechanically via an agitator, conveyor, or any other device within the debittering zone. Alternatively, the motion can be achieved via a rotating, moving, or oscillating housing within the debittering zone, or the pulses can be moved by a gas stream within the zone.

[0049] When the hot or heating medium(s) come into contact with the pulses, these media may transfer heat to the pulses, thus lowering the temperature of the hot medium accordingly. The hot or heating medium may also escape at the point where the pulses are fed into or discharged from the debittering zone. Simultaneously, the hot or heating medium(s) transfer energy as heat to the walls of the process chamber or to internal components such as agitator components. All of this necessitates the continuous replacement of the energy transferred to the pulses or the process chamber as heat, or lost through input and output.This can be done by continuing to introduce or supply hot or heating media into the debittering zone, or by heating the media in the debittering zone to ensure the preferred or required temperature for the process.

[0050] Various machines, apparatuses, or devices can be used to bring pulses into contact with a hot or heating medium. They all have in common that the pulses are exposed to, steamed, mixed, wetted, irradiated, processed, or otherwise come into contact with the hot medium. Suitable devices for this purpose include jet mills, long-slit mills, classifier mills, stirred ball mills, other mills, fluidized bed dryers, fluidized bed systems, ovens, sterilizers, cookers, roasters, dryers, mixers, or any other unit, machine, or device capable of exposing, steaming, mixing, wetting, irradiating, processing, or bringing a solid into contact with hot, gaseous, or liquid media.

[0051] If a liquid such as water is used as the hot medium, the legume must be dried in the debittering zone, the milling zone, or the sifting zone. Alternatively or additionally, separate drying in a dedicated drying zone can take place after wetting with the liquid.

[0052] Preferably, in specific exemplary embodiments, the process steps of debittering, grinding or comminution, and sifting are carried out immediately one after the other. Particularly preferably, the grinding step is performed immediately after debittering, since the heated pulses allow for more efficient grinding. The energy available in the form of the pulses' temperature can be used for grinding. This leads to more energy-efficient grinding and simultaneously to better deagglomeration of the protein particles from the starch particles.

[0053] As an alternative to using a hot medium, electromagnetic waves, such as microwaves, can also be used as the heating medium. These microwaves, preferably operating at a frequency of 300 MHz to 1 THz (corresponding to a wavelength of 1 m to 0.3 mm), and in particular 1 to 300 GHz, cause the matter of the legumes to vibrate and heat them. This process reduces the bitter substances or, in particular, completely removes the bitterness from the fruit. Subsequently, the product is milled and sifted to obtain a protein-rich and a starch-rich concentrate.

[0054] Electromagnetic waves can also be in the form of infrared radiation, especially with wavelengths from 78 nm to inm or frequencies from 300 GHz to 400 THZ or a wavenumber range of 10 cm. -1 up to 12,800 cm -1Infrared radiation can be used as a heating medium. Trials with infrared dryers / roasters have shown that this is a particularly promising technology for debittering. The electromagnetic radiation not only heats the surface of the pulses, but also penetrates directly into the fruit. This makes the debittering process more efficient than heating solely via the surface of the pulse, such as with air, steam, or a liquid. This more efficient method using infrared radiation to heat the pulses is also more economical.

[0055] The contact of the pulses with one or more hot or heating media is particularly preferred in the debittering zone. In a subsequent step, the debittered pulses are ground in the comminution zone and separated into two fractions in the classifying zone to obtain a protein-rich concentrate and a starch-rich concentrate.

[0056] Preferably, comminution follows debittering. Suitable milling machines include rotor impact mills, classifier mills, long-split mills, and jet mills. A classifier mill is preferred. This mill integrates a rotor with a grinding disc and impact tools, as well as a grinding track. The material is comminuted between the impact tools and the grinding track in the grinding zone. In the case of pulses, this step primarily serves to deagglomerate the fruit, separating and isolating the small protein particles from the larger surrounding starch particles. Comminution of the primary particles is not the objective. An airflow carries the separated particles to a dynamic classifier wheel integrated into the mill.If the particles are too large (because they are still agglomerates and not individual particles), they are rejected due to their higher specific gravity and re-enter the grinding or comminution zone. If they are small enough, they pass through the classifier wheel and exit the mill as finely ground flour. This flour consists essentially of individual starch and protein particles.

[0057] A dynamic air classifier is then typically used. This is a separation process in which particles are separated based on their ratio of inertial force to flow resistance in a gas stream due to gravity and centrifugal force. In simplified terms, heavier particles with high density (starch particles) are separated from lighter particles with lower density (protein particles). While this process does not achieve complete separation, it yields a very high proportion of each particle type in the corresponding fraction, hence the term concentrate. Thus, at the end of the process, a protein-rich concentrate and a starch-rich concentrate are obtained. Both concentrates are debittered after the process, or at least exhibit significantly less bitterness compared to concentrates produced without a debittering process.

[0058] As an alternative to debittering in a dedicated debittering zone, the pulses can be contacted with one or more hot or heating media in a mill or classifier instead of in a dedicated debittering zone. A classifier mill, impact mill, jet mill, or long-split mill is preferably used, and a dynamic air classifier is preferred. Alternatively, debittering can be carried out in several steps. For example, it can be partially carried out in a debittering zone and then further debittered in the mill and / or classifier. Or, debittering can be partially carried out in the mill and further debittered in the classifier to achieve the desired result.Regardless of the combination used for debittering, the legume, flour, or concentrate must be in contact with the hot or heating medium for a sufficient length of time and must be continuously agitated to achieve adequate debittering. The smaller the particles, or the more isolated the protein and / or starch, the shorter the contact time with the hot or heating medium, as the heating efficiency increases.

[0059] The device and method according to the invention are used to optimize the taste of bitter legumes (e.g., peas, broad beans, lentils, chickpeas) and reduce their antinutritional components, since the bitter taste of legumes significantly reduces consumer acceptance in many foods. This reduction and / or elimination of bitter substances opens up new applications for consumers, especially in vegan diets. A vegan diet is more sustainable than one based on animal products, particularly with regard to:

[0060] Egg substitute

[0061] Vegan sausage and meat products

[0062] Vegan cake

[0063] Vegan ready meals

[0064] Vegan cheese products and milk substitute drinks

[0065] And much more

[0066] Debittering is what makes some applications more readily accepted by consumers.

[0067] Legumes contain antinutritional substances, such as bitter compounds (e.g., glycosides, saponins). These serve to protect the plant from predators, but are often unsuitable for human consumption.

[0068] By using thermal processes according to the present invention, these antinutritional components, as well as factors that cause flatulence (e.g., stachyosis), are reduced. This not only improves the taste of the protein or starch concentrate, but also reduces the antinutritional components. These two effects go hand in hand.

[0069] This reduction of antinutritional properties and bitter substances through thermal processes is described in principle, among other places, in:

[0070] 1. "Dry beans processing, quality evaluation and nutrition" (Howard et al., 2018)

[0071] 2. "Flavour aspects of pulse ingredients" (Roland et al., 3 . " Increase of the nutritional quality in fava bean flour and concentrate by reduction of antinutritives" (Mittermaier , Stephanie )

[0072] 4 . Changes in levels of phytic acid, lectins and oxalates during soaking and cooking of Canadian pulses" ( Shi L, et al . , 2018 )

[0073] The thermal process or thermal treatment can therefore be used, in particular, before milling / sifting. First, the pulses can be separated from their pods or shells, or in other words, the pods from the pulses. Subsequently, the pulses are usually peeled as before. The inventive process then means that, in the next step, the peeled whole pulses are subjected to a treatment that results in extensive debittering of the pulses. Afterwards, the debittered pulses are ground. This is followed by sifting or separation into a fraction containing protein concentrates and a fraction containing starch concentrates. Various methods can be used for the thermal treatment.The product can be exposed to dry heat and / or a combination of steam and dry heat and / or moist heat after soaking. Alternatively, the treatment can also take place during milling and / or sifting.

[0074] In this context, it is important to note that the products are not only debittered after sifting (starch concentrate and protein concentrate). The milled flour of the legumes is already debittered. This means that for debittering itself, the following applies: debittering -> milling (without sifting) or debittering during milling without further sifting. This process produces a debittered legume flour. This is a new product, not previously available on the market, and offers numerous new applications. Until now, there has been non-debittered flour made from legumes. This means that the flour has a correspondingly bitter taste and has not yet found a significant market. In addition to the protein and starch fractions, this process also produces this new product in the form of a debittered legume flour. This can be used, for example, to produce gluten-free baked goods.

[0075] The bitter taste is significantly reduced or, in particular, almost or completely eliminated by the invention. This results in considerable added value for the food and broader consumer acceptance.

[0076] This was determined using a sensory testing procedure according to DIN 10967-1, profile testing. Eight test subjects, trained according to ISO 8586-1 and -2, were used to identify defined characteristic properties (e.g., bitterness).

[0077] The bitter note was first trained several times using roasted coffee beans and then further developed using roasted legumes. The test was conducted in a test chamber according to DIN 10962. Eight test subjects participated in the example described below.

[0078] Test for roasted chickpea protein (as an example of the process mentioned below in Example 1), single protocol after the 1st reduction, for bitterness: intensity scale: 0 not detectable

[0079] 1 very faintly visible

[0080] 2 faintly visible

[0081] 3 clearly recognizable

[0082] 4 clearly recognizable

[0083] 5 very clearly recognizable

[0084] As a blind sample, unroasted chickpea protein was used. Further sensory results are available for other pulses using the methods applied for here for patent.

[0085] Three test series were conducted with periodic sampling and analysis of the samples. The test panel consisted of 15 participants to assess the bitterness, color, and taste of anonymous samples. This demonstrated that exposure to 150 degrees Celsius resulted in the least bitter taste, while the color darkened more significantly than exposure to 140 degrees.

[0086] Particularly in many applications, such as vegan milk alternatives, the bitter taste permeates added flavorings and results in an unpleasant taste. This new process avoids this. Furthermore, the antinutritional components are reduced.

[0087] The advantage of the process is the optimization of taste and also the reduction of saponins and lectins, so that the raw materials can be used more broadly and thus make a greater contribution to supplying the world's growing population.

[0088] Defatting legumes after peeling can also be beneficial. This results in an even higher protein and starch yield and facilitates mechanical processing, especially for chickpeas, which have a higher fat content than peas or broad beans.

[0089] This can usually be achieved through extraction using an extraction agent, e.g., CO2, or a more economical method using hexane. Mechanical presses have their limitations because the fat content is very low, but it would be possible to use this method in the future.

[0090] Another advantage of defatting lies in the longer shelf life achieved by reducing fat oxidation. Fat oxidation can cause legumes to become rancid and ultimately inedible for consumers, and oxidation products are also nutritionally undesirable.

[0091] Furthermore, applications in the cosmetics sector are opening up, as debittering results in a significant reduction of germs. The cosmetics market is trending away from chemicals and microplastics. Therefore, the demand for natural ingredients is high.

[0092] Furthermore, in a production plant operating continuously, it is advantageous to incorporate heat recovery to reduce the system's energy consumption. This is achieved primarily by allowing warm / hot air or steam to escape from the system through product discharge or venting. This gas can be captured and used to preheat the pulses before they enter the debittering zone. This has the advantage that the pulses reach the target temperature more quickly in the debittering zone, thus reducing the amount of energy required in the form of heating media. Simultaneously, the product's residence time in the debittering zone is reduced accordingly. Alternatively, the hot air or steam can simply be recirculated back into the debittering zone.If necessary, the hot air or steam can be filtered to prevent dust or other particles from being recirculated. This reduces the energy required to expose the pulses to a hot or heating medium to reach the target product temperature for debittering.

[0093] In the continuous debittering process, it is crucial that material is constantly fed into and discharged from the debittering zone. The system control defines how long the pulses should remain in the debittering zone and what temperature they should reach during this time due to the heating medium. In this continuous process, new material is constantly being fed in, remains in the debittering zone for a defined time at a defined temperature, and is then discharged from the zone.

[0094] To enable this process, it must be continuously monitored and controlled. Firstly, it must be ensured that product continuously enters the debittering zone, and secondly, it must be ensured that the material passes through the debittering zone and is ultimately discharged.

[0095] A key component here is monitoring the process within the debittering zone itself, which is done via the plant control system. It must therefore be ensured that the desired temperature is maintained in the debittering zone or introduced into the pulses. This can be achieved using sensors that measure the temperature in the zone (the temperature in the debittering zone can also be considered representative or convertible to the temperature in the pulses). If this temperature is too low or too high relative to certain thresholds, more or less heat must be introduced via the heating medium.Alternatively, the temperature can be regulated via the control system by continuously adding as much additional energy to the debittering zone as is simultaneously supplied to the product and lost through processes such as heating of the debittering zone itself, exhaust air, or material discharge. This must be ensured by appropriately defined parameters within the process control system.

[0096] Various devices can be used to feed material into the debittering zone, such as volumetric feeders, screw conveyors, belt conveyors, pneumatic conveying systems, vibratory feeders, trough feeders, bulk material feeders in the form of a container or hopper with dosing flaps, - TI -

[0097] Metering valves or rotary valves, bucket elevators, bulk material or powder pumps, twin-screw feeders, differential carriage feeders, or flow meters. All these systems have one thing in common: they serve to feed pulses into the debittering zone in a targeted and defined manner. A control system monitors the process, for example, by controlling the speed of the metering screw or conveyor, or the settings of the valves or flaps, in order to control how much, in terms of volume or weight, is fed into the debittering zone.

[0098] When particularly precise dosing is required, so-called "loss-in-weight" systems can be used. In these systems, the weight of the material to be dosed is continuously monitored and controlled. The material is first placed in a container mounted on a load cell. During the dosing process, the material is removed from the container and fed into the debittering zone (for example, via a screw conveyor), and the load cell measures the weight being added in real time. The system calculates the quantity of material dispensed by detecting the weight difference. This information is used to adjust the dosing speed and ensure that the desired quantity is dispensed accurately and consistently.

[0099] An alternative to these systems is to mount the entire debittering zone on one or more load cells. By measuring the weight difference compared to the empty debittering zone, the amount of material in the zone can be determined. Material is initially added until a defined value for the process is reached. When material is then discharged, the control system can calculate how much new material must be added to maintain a defined weight in the process zone. If the material passes through the process chamber mechanically or pneumatically, the residence time can be determined by the control system. It is crucial to monitor the temperature so that the pulses are heated appropriately by the heating medium over the defined period.

[0100] All dosing and control systems for monitoring debittering must take into account that the accompanying drying process reduces the residual moisture content of the pulses or flour, causing water to escape in the form of steam. This must be factored into the control system's mass balance, as the weight of the product being fed in is higher than the weight of the product being discharged.

[0101] In the process according to the invention, in specific embodiments, pulses are treated after peeling and before or during grinding / sifting to improve flavor and reduce bitterness. This results in a significant reduction of antinutritional components in the production of protein and starch concentrates from pulses, and consequently, a reduction of the bitter substances responsible for the bitter taste. The shelf life of these products is also increased by further microbial reduction. The present process can increase consumer acceptance among a considerable portion of the population, as the protein and starch products produced using this method have no or only a barely perceptible bitter taste.

[0102] The invention is presented by way of example in the description and is not limited to these examples, but encompasses all variations, modifications, substitutions and combinations that the person skilled in the art can derive from the present documents, in particular within the scope of the claims and the general descriptions in the introduction to this description as well as the description of the exemplary embodiments, and which they can combine with their expert knowledge and the prior art. In particular, all individual features and embodiments of the invention are combinable.

Claims

Method and apparatus for debittering pulses Claims 1. A method for debittering hulled or unhulled, whole or broken pulses, wherein contact of the pulses with at least one hot or heating medium, such as hot air, saturated steam, superheated steam, hot water or electromagnetic waves, results in debittering or a significant reduction of the bitterness of the pulses in a debittering zone, and wherein, simultaneously during the debittering process step, energy in the form of hot air, saturated steam, superheated steam, hot water or electromagnetic waves is continuously introduced into the debittering zone, and the pulses are simultaneously set in constant or periodic motion to bring them into optimal contact with the hot medium(s).

2. Method according to claim 1, wherein the continuously introduced energy is added from outside or in the debittering zone, for example by heating air from the environment.

3. Method according to claim 1 or 2, wherein pulses are continuously introduced into the debittering zone, debittered there and subsequently discharged again, wherein the debittering process is continuously monitored and controlled with appropriately designed and suitable equipment, and in particular in the debittering zone, in order to preferably at least control that product continuously enters the debittering zone, passes through the debittering zone and is finally discharged again as desired.

4. Method according to one of the preceding claims, wherein the temperature of the medium is 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius, or that media are used which are capable of heating the pulses to 70 to 150 degrees Celsius, preferably 100 to 145 degrees Celsius.

5. Method according to one of the preceding claims, wherein a combination of two or more hot media or heating media is used, such as hot air and steam or hot air and water, and wherein one medium has a temperature of at least 100 degrees Celsius.

6. Method according to any of the preceding claims, wherein the medium or media come into contact with the pulses for 3 to 60 minutes, preferably >15 to 40 minutes, particularly preferably 20 to 35 minutes.

7. A method according to any of the preceding claims, wherein the pulses are preferably set in motion continuously or periodically in order to ensure ideal contact with the hot medium or heating medium(s), wherein, for example, this movement can be effected mechanically by means of an agitator, a conveyor, or any other device in the debittering zone which serves to move the To enable pulses to be moved, or alternatively or in combination, the movement can also be carried out via a rotating, moving or oscillating housing of the debittering zone, or the pulses can be moved via a gas stream in the debittering zone.

8. A method according to any of the preceding claims, wherein the contact of the hot or heating medium(s) with the pulses is effected via a jet mill, a long-split mill, a classifier mill, a stirred ball mill, another mill, a fluidized bed dryer, a fluidized bed system, an oven, a sterilizer, a cooker, a roaster, a dryer, a kiln, a toaster, a mixer or via another unit or device which is capable of applying, steaming, mixing, wetting, irradiating or processing pulses with hot, gaseous or liquid media or of reacting with or diffusing into the pulse.

9. Method according to any of the preceding claims, wherein the hot medium is water or another liquid and the pulses are dried after contact with the medium.

10. Method according to one of the preceding claims, wherein the contact with the hot or heating liquid for debittering takes place in or before the feeding into one or more mills and the pulses are crushed and then dried.

11. Method according to any of the preceding claims, wherein any residual moisture present in the pulses is reduced before being fed to the debittering zone, and / or where debittering is accompanied by a reduction in the residual moisture of the product in the debittering zone.

12. Method according to one of the preceding claims, wherein electromagnetic waves or so-called microwaves with a frequency of 300 MHz to 1 THz, in particular 1 to 300 GHz, are used as the heating medium, or wherein electromagnetic waves are also used in the form of infrared radiation, in particular with a wavelength of 78 nm to inm or a frequency of 300 GHz to 400 THz or a wavenumber range of 10 cm -1 up to 12,800 cm -1 can be used as a heating medium.

13. A method according to any of the preceding claims, wherein, after contact of the pulses with one or more hot or heating media in the debittering zone, they are ground and sifted in the next step to obtain a protein-rich concentrate and a starch-rich concentrate, and / or wherein, in the processing after debittering, the process steps of grinding and sifting are carried out immediately one after the other, wherein preferably the process step of grinding is carried out immediately after debittering, since the heated pulse provides more efficient grinding, and / or wherein, instead of in a separate debittering zone, the contact of the pulses with one or more hot or heating media takes place in a mill, preferably in a sifter mill, impact mill, jet mill or long-split mill and / or in a dynamic air classifier or classifier, and the pulses are debittered there.

14. Method according to one of the preceding claims, wherein, after or simultaneously with the debittering of hulled or unhulled pulses, the pulses are crushed in a crushing zone which is downstream of or combined with the debittering zone, so that a debittered pulse flour is obtained.

15. Device for debittering hulled or unhulled pulses comprising a debittering zone, a crushing zone and a classifying zone, designed for carrying out the method according to one of the preceding claims.

16. Device according to claim 15, comprising a debittering zone, a comminution zone and a classifier zone for obtaining a protein-rich and a starch-rich fraction by comminution and classification, wherein the debittering zone is upstream of the comminution zone or combined with the comminution zone or integrated in the classifier zone.

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