Improved methods for couscous production using enzymes

Abstract

The present invention relates to the field of food production, in particular to the production of couscous. The invention discloses different methods for preparing couscous from ground cereal grain, wherein some of these methods comprise a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase or any combination thereof. The invention further relates to the use of any of the above-mentioned enzymes for preparing couscous from ground cereal grain and for improving the processability of ground cereal grain during couscous production and / or increasing the ability of the produced couscous to absorb water. Additionally, methods of preparing couscous comprising mixing with a colouring agent and / or a flavouring substance are disclosed. The present invention further relates to couscous obtainable by the methods disclosed herein as well as to kits suitable for couscous production.

Description

[0001] Improved methods for couscous production using enzymes

[0002] The present invention relates to the field of food production, in particular to the production of couscous. The invention discloses different methods for preparing couscous from ground cereal grain, wherein some of these methods comprise a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase or any combination thereof. The invention further relates to the use of any of the above-mentioned enzymes for preparing couscous from ground cereal grain and for improving the processability of ground cereal grain during couscous production and / or increasing the ability of the produced couscous to absorb water. Additionally, methods of preparing couscous comprising mixing with a colouring agent and / or a flavouring substance are disclosed. The present invention further relates to couscous obtainable by the methods disclosed herein as well as to kits suitable for couscous production.

[0003] Couscous is the name of a dish based on a granular ground grain product that is a staple food in the Mediterranean region and especially in the Middle East and northern Africa (MENA). When prepared at home, the ground grain product is first agglomerated into lumps of approx. 1 to 2 mm in diameter while adding water and then cooked over steam. For traditional couscous dishes, the cooked ground product is then seasoned and served with vegetables and / or meat.

[0004] When producing couscous on a kitchen scale, the non-standardised conditions and varying raw material qualities lead to major deviations, particularly with regard to grain size, water absorption and cooking status. The process of preparing couscous is also comparatively tedious and timeconsuming because the semolina-like ground material must first be manually agglomerated before it can be cooked.

[0005] Due to changing family structures and lifestyles, there has long been a global trend towards simpler and quicker food preparation, which has also manifested itself in MENA. For this reason, industrially pre-agglomerated, pre-cooked and dried couscous has become a major market that is expected to continue to grow disproportionately by 3.5 % annually, from USD 34 billion in 2024 to USD 45 billion in 2032 (https: / / www.expertmarketresearch.com / reports / couscous-market).

[0006] The most important ground grain product used in the preparation of couscous is semolina made from durum wheat (Triticum durum). However, the vast majority of the durum wheat grown worldwide is used for the production of pasta, including in the Middle East and northern Africa, where around half of the world's durum wheat production is consumed. According to estimates, only around 10 % of this share, i.e. 2 million tonnes of durum wheat, is annually processed into couscous. i As the pasta market is also growing (compound annual growth rate = 6.9 % until 2029, Statista 13.12.23), the already scarce supply of durum wheat will continue to decrease, resulting in price increases. Fluctuations in availability, e.g. due to weather events or disruptions to global trade, have a particularly negative impact on durum wheat supply and durum wheat prices. (Futures on 2 February 2024: milling wheat (mostly bread wheat) EUR 213 / t; durum wheat EUR 376 / t). It can be assumed that this problem will be further exacerbated in the future due to man-made climate change.

[0007] The high price of durum wheat is prompting processors to accept batches of lower quality - and therefore at a lower price - or to use cheaper alternatives, in particular bread wheat (Triticum aestivum), which is by far the most widely cultivated type of wheat in the world, as well as various types of millet or maize. However, it is difficult to obtain a sufficiently high yield of semolina from, e.g., bread wheat. Indeed, bread wheat is typically used in the form of flour with a smaller particle size than semolina.

[0008] However, the use of low-quality durum wheat or flour from alternative wheat species significantly affects the quality of the industrially produced couscous. In particular, the processing of the couscous during industrial production is severely hampered as a result of the lower quality of the raw materials and / or the alternative grain sources: for agglomeration, the couscous is usually steamed in a layer of several centimetres thickness. This layer, also known as 'cake', when formed from low quality durum wheat semolina or from, e.g., bread wheat flour is typically very sticky and therefore difficult to break up in order to obtain the desired smaller agglomerates.

[0009] Another disadvantage is the low water absorption capacity of the industrially produced couscous. The ability of the pre-cooked and dried instant couscous to take up water is however essential for preparing the ready-to-eat dish. The limited water absorption capacity therefore makes it more difficult for the end consumer to further process the industrially prefabricated couscous and leads to a noticeable reduction in the quality of the finished dish.

[0010] There is thus an urgent need for new and improved couscous production methods that can compensate for the above-mentioned shortcomings and quality fluctuations associated with the use of different starting materials to ensure the production of couscous of consistently high quality. This problem is solved by the present invention, especially by the subject matter of the claims.

[0011] In a first aspect, the present invention provides a first method for preparing couscous from ground cereal grain, wherein the first method comprises a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase or any combination thereof. In another aspect, the present invention provides the use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a sulfhydryl oxidase, a tyrosinase, a peroxidase, a phenol oxidase, a protease, an amylase, or any combination thereof for preparing couscous from ground cereal grain.

[0012] Couscous is a traditional North African dish typically made from ground durum wheat. Traditionally, the wheat is ground to semolina before being sprinkled with water and rolled by hand to form small aggregates or granules. To keep these aggregates from sticking to each other, they may be sprinkled with dry flour. The aggregates are then repeatedly sieved, so that granules that are too small fall through the sieve and can be again rolled into pellets. This labour-intensive process continues until all the semolina has been formed into small couscous granules.

[0013] Nowadays, most couscous is produced industrially as a pre-cooked and dried instant product that only needs to swell in hot water before consumption. Although it is labelled as couscous on the packaging, this instant product is not yet actual couscous, but merely couscous semolina, as the term couscous, strictly speaking, only describes the finished dish. However, for the sake of simplicity, the end product obtainable by the method according to the invention is herein referred to as couscous. In other words, the term "couscous" in the context of the invention describes a granular product of cereal flour or semolina which has been mixed with water, agglomerated, steam cooked and dried.

[0014] Accordingly, the first method for preparing couscous of the present invention preferably comprises the following main steps of a) providing ground cereal grain, b) moistening the ground cereal grain with water, c) rolling and, optionally, grinding the moistened ground cereal into agglomerates, d) exposing the agglomerates to water vapour, e) mechanically separating caked or clumped agglomerates, f) drying the agglomerates, and, preferably, g) grinding and / or sieving the dried agglomerates, wherein the at least one enzyme is preferably mixed with the ground cereal grain prior to or during step b).

[0015] A person skilled in the art will however be aware that the preparation of couscous can comprise further method steps in addition to the steps a) - g) described above. For instance, the ground cereal grain provided in step a) may be sieved before the addition of the at least one enzyme in order to obtain semolina or flour of relatively uniform particle size. Alternatively, pre-sieved ground cereal grain with the desired particle size can of course be purchased commercially from third parties. In step b), the ground cereal grain is hydrated to a target moisture content of about 30-40 % (w / w), preferably of about 34 to 36 % (w / w), e.g., 34, 35, or 36 % (w / w), in order to create optimal conditions for the subsequent agglomeration of the ground cereal grain into more coarse couscous granules. Preferably, said water content is not surpassed before steaming or exposure to water vapour.

[0016] In the context of the invention, the terms “agglomerate” or “granule” refer to a more or less solidified accumulation of previously loose semolina or flour which is obtained by mechanically rolling and / or grinding said semolina or flour after it has been moisturized (i.e., wettened) with water, as described herein. Step c) is traditionally done by hand but is automated in the industrial production of couscous where it typically takes place in a suitable drum or tumbler and takes approximately 2-8 minutes. One or more further sieving steps are typically carried out between steps c) and d), because, preferably, the agglomerates produced in step c) should end up having a relatively uniform size of about 1000-2000 pm. Noticeably larger or smaller agglomerates are separated from the remaining granules by these additional sieving steps and are fed back to method step c). Accordingly, the couscous production method is typically characterised by repetitive cycles of rolling and sieving agglomerates of moistened ground cereal grain to ultimately obtain a final product comprising essentially only agglomerates of the desired size (Figure 1). After agglomeration has been completed, the agglomerates are cooked by exposing the agglomerates to water vapor (herein also referred to as steam) for about 5-15 minutes, preferably for about 6-12 minutes (step d). During industrial production, the freshly formed agglomerates are applied to a conveyor belt in a 3-4 cm high layer and cooked in the "steamer". During this step, the agglomerates clump together to form a product known as cake.

[0017] Before the subsequent drying step f), this cake must therefore be mechanically separated or broken up (step e) to enable effective drying. Step e) is particularly problematic if semolina or flour from cereals other than durum wheat are used without addition of enzymes. For example, using Triticum aestivum or Triticum spelta, it is very hard or can even be impossible to break up the cake, at least using state of the art machines and procedures used for production of couscous. Thus, improving processability by addition of enzymes in the method of the invention mainly refers to improving the ability of the cake to be broken up, which is required for effective drying as well as for obtaining a consistent size of the couscous semolina.

[0018] The drying step f) preferably takes place at temperatures of more than 70 °C, more than 75 °C, more than 80 °C, more than 85 °C or more than 90 °C, e.g. 90-100 °C such as 90, 91 , 92, 93, 94, 95, 96, 97, 98, 99 or 100 °C. In some embodiments, the temperature may also be higher than 100 °C, e.g., 101-200 °C, such as 101-120 °C, 120-150 °C or 150-175 °C. The method of the invention preferably further comprises an additional step g) of grinding and sieving the pre-cooked agglomerates in a mill to break up any remaining lumps. The final sieving further allows for sorting of the obtained couscous based on the coarseness of the individual couscous grains. The term “cereal” refers to a grass cultivated for its edible grain, i.e. , the dry fruit (caryopsis) of the cereal plant.

[0019] In principle, the cereal grain from which the couscous is to be prepared can be any type of cereal grain, e.g., it may be wheat, rye, oat, barley, millet, rice or maize. Because couscous is typically prepared from wheat, the cereal grain preferably is wheat. However, couscous or products that resemble couscous can also be obtained from other cereal flours or semolina, in particular barley, millet or rice flour. A couscous-like dish made from maize is better known as polenta.

[0020] If the cereal grain is wheat, it may be any type of wheat, e.g., it may be Triticum aestivum, Triticum durum, Triticum dicoccum, Triticum spelta, Triticum monococcum or a mixture thereof. However, preferably, the wheat used in the method of the invention is Triticum aestivum.

[0021] Triticum aestivum, better known as common wheat or bread wheat, constitutes approximately 90 % of the globally produced wheat. In the context of the invention, it is also referred to as soft wheat (in contrast to durum - hard - wheat). It is a hexapioid wheat species and contains on average about 11 % protein (dry weight) (Zilic et al., 2011. Characterization of proteins from grain of different bread and durum wheat genotypes. Int. J. Mol. Sci. 12(9), 5878-5894). Gluten constitutes about 75-85 % of said total grain proteins and stores carbon, nitrogen and sulphur to support seed germination. Gluten is a protein mixture composed of prolamins and glutelines, which, in the context of wheat, are usually referred to as gliadins and glutenins, respectively. Glutenins form protein aggregates stabilized via intermolecular disulfide bonds that become attached to the monomeric gliadins. Collectively, gluten proteins form a matrix with viscoelastic and adhesive properties (Shewry et al., 2002. The structure and properties of gluten: an elastic protein from wheat grain. Phil. Trans. R. Soc. Lond. 357, 133-142). T. aestivum carries rather soft grains that can be conveniently milled into fine flour. As a result, the gluten networks become exposed and can be easily brought together during the mixing and kneading of dough made of bread wheat, thereby creating new protein-protein interactions within the growing gluten network. Accordingly, doughs prepared from T. aestivum are usually high in strength and elasticity and are therefore preferred for bread making.

[0022] T. aestivum can also be used for products other than bread, e.g., for cakes, cookies, biscuits and crackers. In principle, flour from bread wheat may also serve as raw material for couscous production. However, the high elasticity and stickiness of moistened bread wheat flour tends to negatively affect the production of couscous. Because flour or semolina formed from T. aestivum quickly clumps upon addition of water, it is difficult to form individual coarse-grained agglomerates required for the characteristic consistency of couscous.

[0023] Therefore, the wheat species used for preparing couscous traditionally is Triticum durum, herein also referred to as durum wheat. T. durum is a tetrapioid wheat species, probably derived from the tetra- ploid species Triticum dicoccum, and the second most cultivated species of wheat after T. aestivum. The Latin name Durum translates as hard, as the grains of T. durum are known for being highly resistant to milling. T. durum is therefore mostly processed into more coarse-grained semolina rather than into fine flour. T. durum is described to contain slightly higher levels of gluten compared to T. aestivum (Zilic et al., 2011). However, because the gluten- and starch-rich endosperms are often only partly cracked in Durum semolina, the gluten is less readily available. Doughs made from durum wheat semolina are therefore less elastic and sticky than those made from bread wheat flour. Accordingly, semolina made from T. durum is only rarely used for baking bread and is instead particularly suitable for making pasta and couscous. However, the comparatively high procurement costs of durum wheat force many pasta and couscous manufacturers to use wheat of lower quality, which can have a negative impact on the processability of the milled product.

[0024] Triticum spelta, also referred to as spelt or dinkel wheat, is relict crop, which enjoys growing popular- rity among more health-oriented consumers. Spelt is a hexapioid wheat and is most commonly used for baking breads, rolls and other pastries. It may also be employed in beer brewing or for the distillation of spirits.

[0025] Triticum dicoccum, better known as emmer wheat or hulled wheat, is considered to be one of the oldest domesticated crop species. Emmer is a particular stress-resistant wheat and therefore can grow on comparably poor soils. Similar to T. durum, emmer possesses relatively hard grains. Emmer wheat is most famously employed in the production of a particular type of Italian bread (pane di farro) but may also be used for garnishing soups or for preparing beer.

[0026] Similar to emmer and spelt, Triticum monococcum (einkorn wheat) is an ancient wheat and is characterized by a high protein and fat content. It is commonly consumed in Provence, France, and may be used as an ingredient of bulgur.

[0027] In the present invention, the preferred wheat species used for preparing couscous is Triticum aestivum, because it is by far the most cultivated wheat species in the world and therefore considerably cheaper and far more available than T. durum, T. dicoccum, T. spelta and T. monococcum. Accordingly, using T. aestivum for producing the couscous thus reduces production costs and results in a final product that may be sold at a lower price.

[0028] The couscous has to be prepared from ground cereal grain. In the context of the invention, the term “ground cereal grain” is used as a generic term encompassing flour, semolina or a mixture thereof.

[0029] In the context of the invention, “flour” refers to a fine powder obtainable by grinding or milling raw cereal grains to a particle size of preferably less than 150 pm, e.g. 50-149 pm. Smaller particles may also be contained. Cereal flour may either be whole grain, i.e., it may be prepared from the endosperm, germ and bran together, or it may be a refined flour, i.e., it may be prepared only or partly from the starch-rich endosperm. Semolina refers to the more coarse, purified millings of various cereals including wheat, rice or maize. It is however typically obtained from milling hard wheat species, e.g. T. durum. The average particle size of semolina and flour may vary considerably depending on the employed milling technique and the type of cereal used. However, the particle size of semolina is commonly in the range of more than 250 pm to about 1000 pm, e.g. from about 300 pm to about 750 pm (en.wikipedia.org / wiki / Semolina; Sacchetti et al., 2011. Effect of semolina particle size on the cooking kinetics and quality of spaghetti. Proc. Food Sci. 1 , 1740-1745) and is therefore larger than that of flour. However, ground grain products with particle sizes smaller than 250 pm are often still referred to as semolina. In the context of the invention, the ground cereal grain is therefore considered to be semolina if it has a particle size of more than 150 pm, e.g. of 150-1000 pm. During semolina production from wheat, the bran and germ of the wheat are flaked-off, while the starch-rich endosperm is cracked into coarse fragments. These endosperm pieces form the actual semolina when separated from the bran. The semolina can optionally be further ground into finer particles to produce flour.

[0030] In the context of the invention, the mean particle size is preferably analysed by sieving using, e.g., a test sieve shaker such as a Ro-Tap® (www.haverparticleanalysis.com / en / sieve-analysis / ro-tapr-test- sieve-shaker / ), Vibratory Sieve Shaker AS 200 Control (www.retsch.com / products / sieving / sieve- shakers / as-200-control / function-features / ). An air jet sieve such as the Laboratory Air-jet Lab sieve KLS (gkm-net.de / en / laboratory-air-jet-lab-sieves.html) can also be used. Alternatively, particle size may also be determined by laser diffraction or spectrometry (Hareland, 1994. Evaluation of flour particle size distribution by laser diffraction, sieve analysis and near-infrared reflectance spectroscopy. J. Cereal Sci. 20(2), 183-190).

[0031] In one embodiment, the cereal used for preparing the couscous is milled to flour with an average particle size of less than 150 pm, more preferably less than 125 pm, less than 110 pm or less than 100 pm. The finer the particle size of the ground wheat, the larger the reaction surface for the at least one enzyme added to the ground cereal grain. E.g., at least 50 %, preferably at least 75 %, at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 % or at least 99 % of the cereal is provided as flour e.g., as defined herein. Optionally, 100 % of the cereal used for preparing the couscous is milled to flour. Accordingly, typically, less than 50 %, preferably, less than 25 %, less than 20 %, less than 15 %, less than 10 %, less than 5 %, less than 4 %, less than 3 %, less than 2 % or less than 1 % of the cereal are provided as semolina. Optionally, the ground cereal used for preparing the couscous does not comprise any semolina at all.

[0032] The proportion of semolina may however also be higher, e.g., at least 25 %. It may for instances constitute at least 30 %, at least 35 %, at least 40 %, at least 45 % or at least 50 % of the cereal grain used for preparing the couscous. In preferred embodiments, the majority of the cereal grain used for preparing the couscous may be provided as semolina, e.g. at least 60 %, at least 70 %, at least 80 %, at least 90 %, at least 95 %, at last 95 %, at least 96 %, at least 97 %, at least 98 % or at least 99 %. Most preferably, the entire ground cereal used for preparing couscous is provided as semolina. Preferably, the semolina used for the preparation of couscous has an average particle size larger than 150 pm, preferably larger than 200 pm or larger than 300 pm, more preferably, larger than 400 pm, larger than 450 pm, or larger than 500 pm.

[0033] In some embodiments, it may also be preferable to first form the couscous agglomerates from moistened semolina and then mix them with finer flour.

[0034] The present invention proposes a modification of the conventional production method for couscous in which at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase or any combination thereof is mixed with the ground cereal grain, i.e. the flour or semolina, prior to rolling / agglomerating the moistened ground cereal grain to couscous granules (i.e. prior to or during step b) of the above-described method).

[0035] WO 2007 / 080503 A2 describes the production of an easily digestible couscous with the aid of an additional hydrothermal treatment of the couscous, the digestibility of which can be tested by amylase. An enzymatic treatment during the production of the couscous was however not considered in this document.

[0036] In pasta production, enzymes such as hemicellulases, lipases and oxidases are already successfully used to specifically control and / or manipulate the properties and the processability of the pasta dough and to compensate for quality fluctuations of the used raw materials (US 3520702 A; Qi Si and Drost-Lustenberger, 2002. Enzymes for-bread, pasta and noodle products. In: "Enzymes in Food Technology", Whitehurst, R.J. and Law, B.A. (eds.), p. 19-56; Brijs et al., 2004. Combined effects of endoxylanases and reduced water levels in pasta production. Cereal Chem. 81 (3), 361 - 368; Popper, 2020. Enzymatically stabilised pasta structure and method for preparing the same. EP 3984368 A1 ; Popper et al., 2013. Enzymatic improvement of the quality of pasta and noodles. World Grain 31 (12), 51-55).

[0037] Indeed, the process of producing pasta offers optimal conditions for the use of such enzymes. Pasta is produced by preparing a dough using lukewarm water (30-40 °C) in which the water forms a continuous phase that allows for diffusion processes. The dough is then moulded by rollers or nozzles before being dried with moist, hot air. The cooling limit temperature - i.e. the temperature of the pasta during drying while there is still free water - remains below 50 °C for a sufficiently long time, giving enzymes enough time to influence the final pasta product.

[0038] However, the industrial production process for preparing couscous (Figure 1) differs in many respects from the production process for pasta: in particular, no actual dough is produced in which the water forms a continuous phase that allows for diffusion processes. Thus, the method of the present invention is characterized by the fact that no dough is formed in which the water forms a continuous phase. Instead, only loose agglomerates of the semolina or flour are formed, in which at best very limited diffusion can take place in a thin layer of water on the particle surface. In addition, these agglomerates are exposed to saturated steam typically after the only 2 to a maximum of 8 minutes of the agglomeration process, as a result of which the temperature very quickly rises above the gelatinisation temperature of the starch and the inactivation temperature (for the given holding time) of conventional enzymes. The steaming step typically takes 6-12 minutes. The agglomerated semolina is then dried and, optionally, reduced to the desired target particle size of around 2 mm by crushing and sieving.

[0039] Accordingly, it has been expected that enzymes added to the flour or the semolina during couscous production are unlikely to exert any noticeable effects, as they cannot penetrate to the substrates due to the lack of a continuous water phase (as is the case with pasta doughs after moulding) and because they do not have sufficient time to take effect before the inactivation temperature is reached.

[0040] However, the present inventors for the first time show that the use of the enzymes described herein can indeed have a positive effect on the processing properties of the ground cereal grain during couscous production as well as the quality the end product.

[0041] In a preferred embodiment, the at least one enzyme that is mixed with the ground cereal is a carboxylester hydrolase. Carboxylester hydrolases (also known as carboxylic ester hydrolases) are enzymes that catalyse the hydrolysis of carboxylic esters into alcohols and carboxylic acids. Representatives of this class of enzymes are triacylglycerol lipases (EC 3.1.1.3), which catalyse the hydrolysis of fats (lipids) into their basic components, fatty acids and glycerol.

[0042] Besides protein and starch, cereals such as wheat comprise a variety of lipids. The majority of lipids in wheat are esters formed by glycerol and fatty acids. These so-called glycerolipids may be triglycerides, diglycerides or monoglycerides, mono- and di-galactosyl-diglycerides, phospholipids such as A / -acyl-phosphatidyl-ethanolamine, phosphatidyl-ethanolamine, phosphatidyl-glycerol, or phosphatidyl-choline. Other lipids that can be found in wheat are free fatty acids as well as sterol- based lipids and glycol-sphingolipids (Morrison, 1994. Wheat lipids: structure and functionality. In: “Wheat”, Bushuk, W., and Rasper, V.F. (eds.) Springer). Without intending to be bound by the theory, lipases, e.g., triacylglycerol lipases may interact with the acylglycerides present in the ground cereal grains and catalyse their hydrolysis into fatty acids as well as partial glycerides, i.e., mono- and diglycerides. These partial glycerides act as emulsifiers, i.e., they possess a polar or hydrophilic part and a non-polar or hydrophobic part. Phospholipases and galactolipases likewise split off fatty acids, which are highly hydrophobic, from the corresponding polar lipids, hence increasing the polarity of the remaining phospholipid or galactolipid. The resulting lyso-lipids (partial glycerides may subsequently interact with the starch. Furthermore, fatty acids also tend to react with the hydrophobic regions of helical starch molecules, altering their pasting properties (Kibar et al., 2014. Effects of fatty acid addition on the physicochemical properties of corn starch. Int. J. Food Prop. 17(1), 204-218). In addition, partial glycerides may also interact with gluten to promote aggregation and crosslinking of the protein matrix, which further prevents the release of starch when the ground grains are brought in contact with water.

[0043] As a result, the use of a carboxylester hydrolase during couscous production results in the agglomerates produced from the moistened ground cereal grain being less sticky and therefore less prone to clumping together. In the production of couscous, this makes it much easier to break up and loosen the so-called cake, which forms due to the cooked semolina agglomerates sticking together during steaming with water vapour (step d) as described above). In other words, the use of carboxylester hydrolases has surprisingly been found to positively influence the production of couscous by facilitating the formation of couscous agglomerates from moistened ground cereal grains.

[0044] This effect is particularly noticeable when T. aestivum flour or semolina is used to make couscous, which, as described above, in doughs, normally tends to form highly elastic and sticky doughs after the addition of water. However, the above-described effects of carboxylester hydrolases are also observable when flours and semolina from other types of wheat are used, in particular durum wheat and spelt. The use of carboxylester hydrolases can therefore also compensate for fluctuations in the quality of the starting material used for preparing couscous.

[0045] The carboxylester hydrolase of the present invention preferably is a lipase, e.g., a triacylglycerol lipase (EC 3.1.1.1 or EC 3.1 .1 .3) capable of hydrolyzing lipids into fatty acids and mono- or diglycerides, or a phospholipase (EC 3.1 .1 .4, EC 3.1 .1 .32) capable of hydrolyzing diacyl-phospholipids into fatty acids and monoacyl-phospholipids, or a a glycolipase such as galactolipase (EC 3.1.1.26) capable of hydrolyzing diacyl monogalactosides or diacyl digalactosides into the corresponding monoacyl galactosides. In some embodiments, the carboxylester hydrolase may, e.g., be triacylglycerol lipase, EC 3.1.1.3 from Thermomyces lanuginosus (formerly Humicola lanuginose) or a carboxyl ester hydrolase with phospholipase A1 (EC 3.1.1.32), galactolipase (EC 3.1.1.26) and triacylglycerol lipase (EC 3.1 .1 .3.) activity from Fusarium oxysporum.

[0046] An exemplary carboxylester hydrolase suitable for use in the method of the invention may, e.g., comprise an amino acid sequence having SEQ ID NO: 1. Such an enzyme is commercially available as “Pastazym Duo Pure” from Muhlenchemie GmbH & Co. KG. The enzyme may also comprise an amino acid sequence having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to SEQ ID NO: 1 , wherein the enzyme is capable of hydrolyzing lipids in aggregates formed by moistened ground cereal grains, e.g., as defined herein. The enzyme may also consist of SEQ ID NO: 1 . Alternatively, the carboxylester hydrolase may also comprise an amino acid sequence having SEQ ID NO: 2. Such an enzyme is commercially available as "Pastazym Superflex" from Muhlenchemie GmbH & Co. KG. The enzyme may also comprise an amino acid sequence having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to SEQ ID NO: 2, wherein the enzyme is also capable of hydrolyzing lipids in aggregates formed by ground cereal grains, e.g., as defined herein. The enzyme may also consist of SEQ ID NO: 2.

[0047] The at least one enzyme may also be another enzyme capable of promoting aggregation and crosslinking of the protein matrix in ground cereal grain.

[0048] In one embodiment, the cross-linking enzyme may be, e.g., a sulfhydryl oxidase which utilizes molecular oxygen as electron acceptor to oxidize free thiol groups in proteins, thereby promoting the formation of disulfide bonds.

[0049] For instance, the enzyme of the invention may be a sulfhydryl oxidase comprising an amino acid sequence having SEQ ID NO: 3. Such an enzyme is commercially available as "Thiolase" from SternEnzym GmbH & Co. KG. The enzyme may also comprise an amino acid sequence having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to SEQ ID NO: 3, wherein the enzyme is also capable of strengthening the protein matrix in aggregates formed by ground cereal grains, in particular via catalyzing the formation of disulphide crosslinks, e.g., as defined herein. The enzyme may also consist of SEQ ID NO: 3.

[0050] The crosslinking enzyme may also be a transglutaminase (EC 2.3.2.13), e.g., a transglutaminase from Streptomyces mobaraensis, that catalyses the acyl-transfer reaction between E-amino groups of peptide-bound lysine residues and the y-carboxyamide group of peptide-bound glutamine residues. In consequence, individual gluten chains may become permanently cross-linked via isopeptide bonds (Meerts et al., 2017, Enhancing the Rheological Performance of Wheat Flour Dough with Glucose Oxidase, Transglutaminase or Supplementary Gluten. Food Bioprocess Technol. 10, 2188-2198).

[0051] Therefore, the enzyme of the invention may also comprise an amino acid sequence having SEQ ID NO: 4. Such an enzyme is commercially available as “Sternzym PT 8001” from SternEnzym GmbH & Co. KG. The enzyme may also comprise an amino acid sequence having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to SEQ ID NO: 4, wherein the enzyme is also capable of strengthening the protein matrix in aggregates formed by ground cereal grains, in particular via catalyzing the formation of isopeptide crosslinks, e.g., as defined herein. The enzyme may also consist of SEQ ID NO: 4. In another embodiment, the cross-linking enzyme may also be a phenol oxidase, in particular a laccase (EC 1.10.3.2). Laccases are capable of oxidizing a large variety of aromatic compounds. The reaction products of laccases often continue to react non-enzymatically; accordingly, laccase favours the generation of polymers and have the potential to crosslink food polymers such as proteins and non-starch polysaccharides, such as ferulic acid-substituted arabinoxylan hemicellulose, which results in arabinoxylan network formation. In addition, laccase may oxidize the tyrosyl residues of gluten proteins or enhance the disulphide bridge formation in gluten polymers via ferulic acid-derived radicals. In consequence, protein aggregation is increased (Selinheimo, 2008. Tyrosinase and laccase as novel crosslinking tools for food biopolymers, PhD Thesis, VTT publications, 693).

[0052] Therefore, the enzyme of the invention may also comprise an amino acid sequence having SEQ ID NO: 5. Such an enzyme is commercially available as “Suberase” from Novozymes A / S. The enzyme may also comprise an amino acid sequencing having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to SEQ ID NO: 5, wherein the enzyme is also capable of strengthening the protein matrix in aggregates formed by ground cereal grains and catalyzing the formation of an arabinoxylan network, e.g., as defined herein. The enzyme may also consist of SEQ ID NO: 5.

[0053] The at least one enzyme may also be a peroxidase (EC 1.1.11 .7). Previous studies have demonstrated that the use of peroxidases can significantly increase the hardness and decrease in adhesiveness of doughs formed from wheat flour (Revanappa et al., 2014, Effect of Peroxidase on Textural Quality of Dough and Arabinoxylan Characteristics Isolated from Whole Wheat Flour Dough. International Journal of Food Properties, 17(10), 2131-2141). Without being bound by theory, it is assumed that peroxidases may catalyse the formation of cross-linking between arabinoxylans as well as protein-arabinoxylan that could be responsible for the alteration of the whole wheat flour dough characteristics.

[0054] Surprisingly, the inventors have also found enzymes that can reduce the stickiness of the agglomerated semolina and flours during couscous production and at the same time increase the water absorption capacity of the final couscous product after drying. The latter is particularly advantageous for the end consumer, as they have to leave the industrially produced couscous to swell in water for some time prior to consumption. Higher water absorption therefore leads to faster preparation and a more appealing consistency of the final dish.

[0055] Therefore, in another embodiment, the at least one enzyme is an oxidoreductase. Oxidoreductases are enzymes that catalyse the transfer of electrons from an electron donor to an electron acceptor while utilizing NADP+ or NAD+ as cofactors. Preferably, the oxidoreductase is a hexose oxidase (EC 1.1.3.5), i.e., an enzyme capable of catalyzing the transformation of mono- and oligosaccharides such as beta-D-glucose, D-galactose, xylose, arabinose, cellobiose, lactose, maltose, maltotriose or maltotetraose to corresponding lactones. Most preferably, the oxidoreductase is a glucose oxidase (EC 1.1.3.4), e.g., from Aspergillus niger. Glucose oxidases catalyse the oxidation of glucose to hydrogen peroxide (H2O2) and D-glucono-5-lactone. To catalyse these reactions, oxidoreductases require O2, which is naturally present in cereal flour and semolina. Similar to enzymes from the carboxyl ester hydrolase family, oxidoreductases, especially hexose oxidases such as glucose oxidase, showed positive effects on the processing properties and quality of the final couscous. The enzymes reduced the stickiness of the agglomerated grits and increased the water binding capacity of the couscous during preparation for consumption.

[0056] An exemplary glucose oxidase suitable for use in the method of the invention may comprise an amino acid sequence having SEQ ID NO: 6 or SEQ ID NO: 7. An enzyme of SEQ ID NO: 6 is commercially available as “Sternzym Gloxy”, and of SEQ ID NO: 7 as “Sternzym Gloxy TGO”, both from SternEnzym GmbH & Co. KG. The enzyme may also comprise an amino acid sequence having at least 80 %, at least 85 %, at least 90 %, at least 95 %, at least 96 %, at least 97 %, at least 98 %, or at least 99 % sequence identity to either SEQ ID NO: 6 or SEQ ID NO: 7. The enzyme may also consist of SEQ ID NO: 6 or 7.

[0057] In yet another embodiment, the at least one enzyme is a hemicellulase, i.e. , an enzyme capable of breaking down and hydrolysing hemicellulose. Hemicellulose is a polysaccharide molecule found in the cell walls of plants that is often associated with cellulose but has a distinct composition and structure. Hemicellulose can comprise a variety of sugar building blocks, including xylose, arabinose, mannose and galactose. Examples of hemicellulose include xylan, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan.

[0058] Preferably, the hemicellulase is endo-1 ,4-p-xylanase, (EC 3.2.1.8), a hemicellulase that degrades the linear polysaccharide xylan into xylose. The hemicellulase may be e.g., the endo-1 , 4-p-xylanase of Trichoderma reesei (renamed Hypocrea jecorina).

[0059] A person skilled in the art would have had no expectation of success using hydrolytically acting hemicellulases such as endo-1 , 4-p-xylanase during couscous production, as these enzymes, based on theoretical considerations, should weaken rather than strengthen the structure of the dough agglomerates and should therefore have a negative impact on couscous production. Surprisingly, however, it was found that hemicellulases also reduce the stickiness of the agglomerated semolina and increase the water absorption of the couscous during preparation for consumption, which leads to an improved consistency of the prepared couscous and therefore a better mouthfeel for the consumer.

[0060] In a further embodiment, the at least one enzyme may also be another type of hydrolytically active enzyme that can advantageously affect the ability of the final couscous product to absorb water, such as, e.g., a protease, also known as peptidase or proteinase. Proteases are enzymes that catalyse the break-down of proteins into smaller polypeptides or single amino acids, a process known as proteolysis. Proteases may be able to degrade gluten in wheat. Preferably, the protease is derived from a fungus such as Aspergillus oryzae or Aspergillus niger as well as from Bacillus subtilis or Bacillus licheniformis.

[0061] Finally, the at least one hydrolytically active enzyme may also be an amylase. Amylases catalyse the hydrolysis of starch into sugars. Preferably, the amylase is an a-amylase (EC 3.2.1.1). It may, however, also be a [3- or glucoamylase (EC 3.2.1.2 or EC 3.2.1.3, respectively).

[0062] Collectively, the present invention is also directed to the use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a sulfhydryl oxidase, a tyrosinase, a peroxidase, a phenol oxidase, a laccase, a protease, an amylase, or any combination thereof for improving the processability of ground cereal grain during the preparation of couscous and / or for increasing the ability of the finished and dried couscous to absorb water.

[0063] In the context of the invention, the term "processability of ground cereal grain" means the ability of the cake produced by cooking the moisturized and agglomerated ground cereal product in water vapour to be mechanically separated into couscous semolina. The processability of ground cereal grain is considered low if the agglomerates tend to clump and stick together during couscous production, especially when they are cooked in steam, so that further processing, e.g., thorough drying is difficult or impossible.

[0064] Processability is improved if the use of at least one of the enzymes mentioned above results in the cake sticking or clumping together to a lesser extent than if no enzyme was used, i.e., if it can be mechanically separated more easily. An increase in the water absorption capacity of the finished and dried couscous is further observed if the finished couscous produced with the aid of at least one of the enzymes described above can absorb more water than couscous produced without enzymes.

[0065] In the context of the invention, the at least one enzyme that is mixed with the ground cereal grain may also be a combination of at least 2, e.g., at least 3, 4, 5, 6, 7, 8, 9, or at least 10 of the herein disclosed enzymes. For instance, the at least one enzyme may be a combination of different carboxylester hydrolases, e.g. a combination of a tri a cyl glycerol lipase and a phospholipase, a combination of a triacylglycerol lipase and a galactolipase, a combination of a phospholipase and a galactolipase or a combination of triacylglycerol lipase, a phospholipase, and a galactolipase. The at least one enzyme may also be a combination of enzymes of the same type, e.g., a combination of at least two different triacylglycerol lipases that may, optional, be derived from different sources. The at least one enzyme may also be a combination of two or more of the herein disclosed structure-building enzymes such as, e.g., any combination of the herein described carboxylester hydrolases, oxidoreductases, sulfhydryl oxidases, transglutaminases, peroxidases or laccases.

[0066] However, in a preferred embodiment, the at least one enzyme is a combination of an enzyme having primarily a structure-forming / crosslinking functionality with a primarily hydrolytic enzyme described herein. A preferred combination of enzymes that can be used in the method of the invention is, e.g. a combination of a hemicellulase and a) a carboxylester hydrolase, and / or b) an oxidoreductase.

[0067] Without being bound by theory, it is assumed that the simultaneous use of hydrolytic enzymes like hemicellulases, amylases or proteases can further enhance the structure-forming / cross-linking effects of the carboxylester hydrolases and / or oxidoreductase described herein by increasing the availability of water through the release of pentosan or starch gels as well as hydrated proteins.

[0068] Typically, the at least one enzyme is mixed with the ground cereal grain at a concentration of about 1-500 ppm (1-500 mg / kg), preferably of about 10-400 ppm (10-400 mg / kg), or of about 50-300 ppm (50-300 mg / kg). However, the optimal enzyme concentration can vary depending on the enzyme used and / or whether more than one enzyme is to be added. For instance, if the at least one enzyme is a hemicellulase such as, e.g., an endo-1 ,4-p-xylanase, the enzyme is preferably mixed with the ground cereal grain at a concentration of about 50-150 ppm (50-150 mg / kg). If, in another embodiment, the at least one enzyme is a glucose oxidase, the enzyme concentration may be slightly higher, ranging preferably between about 100 and 200 ppm (100-200 mg / kg). A carboxylester hydrolase as described herein may be mixed with the ground cereal grain at a preferred concentration of below 100 ppm (100 mg / kg), e.g., at a concentration of about 30-60 ppm (30-60 mg / kg).

[0069] In some embodiments, the at least one enzyme is provided as a dry powder, such as a lyophilised or spray-dried powder, which is mixed directly with the ground cereal grain before the ground cereal grain is moistened for the formation of the couscous agglomerates (i.e. prior to step b) as described above). This may lead to a particularly homogenous mixing. The enzyme powder preferably has a particle size of 10-1000 pm, preferably of less than 1000 pm, less than 900 pm, less than 800 pm, less than 700 pm, less than 600 pm or less than less than 500 pm. The particle size should therefore preferably be in the range of 10-500 pm, e.g., of 15-300 pm or 20-200 pm. Most preferably, the at least one enzyme is provided as a powder having an average particle size of 25-150 pm. Optionally, the enzyme may also be provided as a liquid preparation, i.e. it can be dissolved in water and optionally stabilised with, e.g., glycerol, sorbitol and / or salts. In addition or alternatively, the at least one enzyme may be dissolved in or added to water prior to being mixed with the ground cereal grain. Preferably, the enzyme is mixed with the water that is used to moisten the ground cereal grain prior to the formation of the couscous agglomerates (i.e., during step b) of the above-described method and prior to step c). The mixing of the at least one enzyme with the ground cereal grain should be sufficiently long and thorough to ensure an even distribution of the enzyme. The skilled person will be able to assess when the ground cereal grain has been sufficiently mixed with the at least one enzyme.

[0070] Semolina or flour made from common bread wheat (Triticum aestivum) is white to beige in colour.

[0071] This means that couscous made from bread wheat lacks the yellow colouring that is characteristic of traditional couscous made from durum wheat semolina. Colouring agents can be used to compensate for this deficiency. In industrial production processes, these colouring agents are typically added via the water used to moisten and agglomerate the wheat flour / semolina. The dispersion of the colouring agent in the agglomeration water is intended to achieve a better distribution of the colourant in the end product.

[0072] Surprisingly, however, it was found in the present invention that the addition of a dry and finely powdered colouring agent, in particular a powder of riboflavin and / or curcumin, directly to the dry ground bread wheat leads to a more homogeneous colour distribution than when these colourants are first dispersed in water before mixing with the flour / semolina.

[0073] In a further aspect, the present invention therefore also provides a second method for preparing couscous from ground cereal grain, wherein the second method comprises a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of 10-1000 pm.

[0074] As in the first method of the invention disclosed herein, also the second method for preparing couscous of the present invention preferably comprises the following main steps of a) providing ground cereal grain, wherein the ground cereal grain can be provided in the form of flour or semolina, as already defined herein, b) moistening the ground cereal grain with water, c) rolling and, optionally, grinding the moist ground cereal grain into agglomerates, d) exposing the agglomerates to water vapour, e) mechanically separating caked or clumped agglomerates, f) drying the agglomerates, and, preferably, g) grinding and / or sieving the dried agglomerates, wherein the colouring agent is added to the ground cereal grain prior to step b). In other words, the dry colouring agent powder is admixed with the dry ground cereal grain prior to the addition of water during couscous production. The colouring agent is therefore not dissolved in water prior to being mixed with the ground cereal grain.

[0075] The preparation method may also comprise the further characteristics and steps already described herein, i.e. in particular the one or more sieving steps between steps c) and d).

[0076] As already disclosed herein, the cereal grain used as a starting material can be any one of, e.g., wheat, rye, oat, barley, millet, rice or maize. Because couscous is typically prepared from wheat, the cereal grain preferably is wheat, e.g., it may be Triticum aestivum, Triticum durum, Triticum dicoccum, Triticum spelta, Triticum monococcum or a mixture thereof. However, preferably, the wheat used in the method of the invention is Triticum aestivum (bread wheat).

[0077] The inventors found that the colour homogeneity of the couscous was lowest when comparably coarse colour granules were used for dying the ground cereal grain, independent of whether the colouring agent was added directly as a powder to the dry raw materials before agglomeration or indirectly after dispersion in water.

[0078] Therefore, the colouring agent preferably is a powder with a particle size of less than 1000 pm, less than 900 pm, less than 800 pm, less than 700 pm, less than 600 pm or less than less than 500 pm. Preferably, the particle size of the colouring agent powder should therefore be in the range of 10-500 pm, e.g., of 15-300 pm or 20-200 pm. Most preferably, the colouring agent is a powder having an average particle size of 25-150 pm.

[0079] As the mixture of the colouring agent and the ground cereal grain is moistened with water during the couscous production process, the colouring agent should be water-soluble to ensure that the couscous grains are evenly coloured.

[0080] In a preferred embodiment, the colouring agent is added to the ground cereal grain to obtain a final couscous product that is similar in colour to traditional durum wheat semolina couscous. In such an embodiment, the cereal grain is thus preferably not durum wheat (e.g., it preferably is bread wheat) and the colouring agent is capable of producing a yellow to orange colour.

[0081] For instance, the colouring agent that is to be added to the ground cereal grain may comprise riboflavin. Riboflavin, also known as lactoflavin or vitamin B2, is often used as a colouring agent in the food industry due to its intense orange to yellow colour.

[0082] In another embodiment, the colouring agent comprises curcumin. Curcumin is an intensely orangeyellow, naturally occurring chemical compound from the diarylheptanoid group. Curcumin is the main component of turmeric, which is used together with other spices in curry powder. The colouring agent may also comprise p-carotin. p-carotin is a provitamin A compound characterized by its red-orange colour.

[0083] In some embodiments, the colouring agent may also comprise combinations of riboflavin, curcumin and / or p-carotin.

[0084] For instance, in one embodiment, the colouring agent comprises riboflavin and p-carotin, e.g. in a ratio of 1-10 : 1-10, e.g., of 1 : 1 , 2 : 1 , 3 : 1 , 4 : 1 , 5 : 1 , 6 : 1 , 7 : 1 , 8 : 1 or, preferably, of 9 : 1.

[0085] In another embodiment, the colouring agent comprises riboflavin and curcumin, e.g. in a ratio of 1-10 : 0.1-5, such as 9.5 : 0.5, 9 : 1 , 7 : 3 or 4 : 2.

[0086] In another embodiment, the colouring agent comprises p-carotin and curcumin, e.g. in a ratio of 1-10 : 1-5, such as, e.g., 9 : 3.

[0087] In a preferred embodiment, the colouring agent comprises all three of riboflavin, p-carotin and curcumin, e.g. in a ratio of 1-10 : 1-5 : 0.1-5, such as, preferably, of 8 : 1.5 : 0.5 or 8.5 : 2 : 0.5.

[0088] Of course, the method according to the invention also makes it possible to produce couscous of a different colour by mixing other water-soluble and edible food colourings as a powder with the ground cereal grain. Various commercially available powdered food colourings which are suitable for this purpose and with which, in principle, all conceivable colours can be produced, are known to the skilled person from the prior art.

[0089] The colouring agent is preferably mixed with the ground cereal grain at a concentration of 1-500 mg / kg (1-500 ppm), e.g., of 50-450 mg / kg (50-450 ppm), 100-400 mg / kg (100-400 ppm), 150-350 mg / kg (150-350 ppm) or 200-300 mg / kg (200-300 ppm). In a particularly preferred embodiment, the colouring agent is mixed with the ground cereal grain at a concentration of about 250 mg / kg (250 ppm).

[0090] Traditional couscous made from durum wheat is known for its characteristic durum flavour, which is lacking in couscous made from other types of ground wheat, especially from bread wheat flour or semolina. The present inventors therefore considered that, in industrial processes in which the couscous is produced in a closed process, the use of suitable flavourings could make sense in order to approximate the taste of couscous made from, e.g., bread wheat, which normally has little flavour, to that made of durum wheat semolina. However, due to the volatility of flavourings, it was assumed that any flavouring added before steaming would be lost during the production of couscous as a result of the steam cooking and subsequent drying of the couscous agglomerates.

[0091] Surprisingly, however, it was found that added flavourings survive the production process and can cause a significant change in the flavour of the ready-to-eat couscous. Without being bound by theory, it is thought that the flavouring substances are trapped in the flour particle agglomerates and are therefore less likely to escape.

[0092] In a further aspect, the present invention therefore also provides a third method for preparing couscous from ground cereal grain, wherein the third method comprises a step of mixing a flavour substance with the ground cereal grain.

[0093] The third method according to the present invention also preferably comprises the following main steps of a) providing ground cereal grain, wherein the ground cereal grain can be provided in the form of flour or semolina, as already defined herein, b) moistening the ground cereal grain with water, c) rolling and, optionally, grinding the moist ground cereal grain into agglomerates, d) exposing the agglomerates to water vapour, e) mechanically separating caked or clumped agglomerates, f) drying the agglomerates, and, preferably, g) grinding and / or sieving the dried agglomerates.

[0094] The method may also comprise any of the previously described additional steps or characteristics, including the one or more sieving steps between steps c) and d).

[0095] In some embodiments, the flavour substance is a dry powder having a particle size of 10-1000 pm that is added to the dry ground cereal grain. Similar to the colour agent, the powder of the flavour substance preferably is rather fine, i.e., it preferably has a particle size of less than 1000 pm, less than 900 pm, less than 800 pm, less than 700 pm, less than 600 pm or less than less than 500 pm. It should therefore preferably be in the range of 10-500 pm, e.g., of 15-300 pm or 20-200 pm. Most preferably, the flavour substance is provided as a powder having an average particle size of 25-150 pm.

[0096] The flavour substance can be mixed with the ground cereal grain at a concentration of about 0.01-1 % (w / w), preferably of about 0.05-0.75 (% w / w), more preferably of about 0.1-0.5 % (w / w).

[0097] When the flavour substance is provided as a dry powder as described herein, it is mixed to the ground cereal grain prior to step b). In other words, the flavour substance powder is admixed with the dry ground cereal grain prior to the addition of water during couscous production. In some embodiments, the flavour substance is therefore not dissolved in water prior to being mixed with the ground cereal grain.

[0098] In alternative embodiments, the flavour substance has been dissolved in water prior to being mixed with the ground cereal grain. In such an embodiment, the flavour substance is preferably dissolved in the agglomeration water that is added in the above-described step b) to moisturize the ground cereal grain.

[0099] As already disclosed herein, the cereal grain used as a starting material can be any one of, e.g., wheat, rye, oat, barley, millet, rice or maize. Because couscous is typically prepared from wheat, the cereal grain preferably is wheat, e.g., it may be Triticum aestivum, Triticum durum, Triticum dicoccum, Triticum spelta, Triticum monococcum or a mixture thereof. However, preferably, the wheat used in the method of the invention is Triticum aestivum (bread wheat).

[0100] Possible flavour substances that reproduce or mimic the taste of durum wheat are known from the state of the art. The flavouring agent can be, e.g., SternArom Durum 2432, i.e., a blend of mild roasted components, in particular 2-acetylpyrazine, 2-methoxy-3-methylpyrazine, 2-acetylthiazole, 5- methylfurfural, 3-(methylthio) propionaldehyde and buttery, creamy components, in particular hexanoic acid, butyric acid, propionic acid, diacetyl, dimethylsulfide and 2-heptanone. If these flavour substances are to be used in the method of the invention, the cereal preferably is not durum wheat but any other of the herein described cereals, most preferably Triticum aestivum.

[0101] Even if one of the objectives of the third method according to the invention is the production of couscous from ground bread wheat, which imitates the flavour of couscous produced from durum wheat, it is to be understood that this method is by no means limited to this specific application. Rather, in further embodiments, the third method according to the invention also allows for the preparation of couscous from all kinds of ground cereal grains with various other flavours. The final flavour of the couscous depends on the flavour substance that is mixed with the ground cereal grain as described herein.

[0102] For instance, manzanate mimics the odour of apples. Diacetyl, acetylpropionyl and acetoin produce buttery flavours. Isoamyl acetate can be used to produce banana flavours. Benzaldehyde mimics the flavours of bitter almond and cherry. Cinnamaldehyde produces a cinnamon-like flavour. The skilled person will not have any difficulty in selecting suitable flavouring substances from the large number of compounds known in the prior art.

[0103] It is to be understood that all methods for preparing couscous disclosed herein can be combined. For instance, it is possible to mix the ground cereal grain both with any of the herein disclosed enzymes as well as with a colouring agent and / or a flavouring substance. Preferably, if the cereal is Triticum aestivum, at least one enzyme is used in combination with a suitable colouring agent, optionally, further with a flavouring substance that mimics the taste of durum wheat. In some embodiments of the invention, the at least one enzyme, the colouring agent and / or the flavouring substance can be provided as a premixed powder that can then be added to and mixed with the dry ground cereal grain during couscous production. Of course, the at least one enzyme, the colouring agent and / or the flavouring substance can also be mixed separately with the ground cereal grain, e.g., to adapt the selection or quantity of agents to the needs dependent on the cereal used. It is also possible to, e.g., first mix the dry colouring agent powder with the dry ground cereal grain before adding the at least one enzyme and / or the flavouring substance dissolved in the water used for forming the couscous agglomerates.

[0104] The present invention further relates to couscous that has been prepared from ground cereal grain using a method comprising a) a step of mixing ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase or any combination thereof, b) a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of 10-1000 pm, and / or c) a step of mixing a flavour substance with the ground cereal grain.

[0105] Preferably, the couscous is obtainable by any one of the methods disclosed herein.

[0106] Finally, the present invention relates to a kit comprising: a) at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a sulfhydryl oxidase, a tyrosinase, a peroxidase, a phenol oxidase, a protease, an amylase, or any combination thereof, b) at least one water-soluble colouring agent selected from the group comprising curcumin and riboflavin and, optionally, c) at least one flavour substance.

[0107] The kit can be used for preparing couscous, e.g., in any of the herein disclosed methods.

[0108] The kit according to the invention may comprise or provide further ingredients. It preferably comprises, for example, a manual with instructions on how to use the kit.

[0109] The kit may comprise a single compartment in which the at least one enzyme, the at least one water soluble colouring agent and, optionally, the at least one flavour substance are provided as a premixed powder that can be directly mixed with, e.g., ground cereal grain, when using the kit for couscous production. The particle size of this premixed powder should be in the range of 10-1000 pm, as already described elsewhere herein. Alternatively, the at least one enzyme, the at least one water soluble colouring agent and, optionally, the at least one flavour substance may be present in different compartments of the kit and, optionally, may only be brought into contact with each other before or during use of the kit. If the kit comprises a flavour substance in a compartment that is separate from the rest of the kit components, the flavour substance may be present in the kit either as a powder as disclosed herein or already dissolved in water. Likewise, if the at least one enzyme is provided in a separate compartment of the kit, it may be provided as a powder or as a liquid preparation as defined herein.

[0110] The kit may be stored at a temperature of 2-6 °C for several days to several weeks, e.g. 1 day to 4 weeks, 1 day to 3 weeks, 1 day to 2 weeks or 1 day to 7 days. Preferably, the kit may be stored at 2 - 6 °C for less than 2 weeks. For long-term storage, the kit may be stored at -80 °C for a period of from several weeks to several months prior to use, for example from 4 weeks to 24 months, from 2 months to 20 months, from 4 months to 16 months, from 8 months to 14 months, or for about 12 months. In some embodiments, the kit may be stored at -80 °C for even longer periods before use, e.g. for 3 years, for 4 years, for 5 years, for 6 years, for 7 years, for 8 years, for 9 years or even for up to 10 years.

[0111] Throughout the invention, the term “about” is intended to be understood as ”+ / - 10 %”. If “about” relates to a range, it refers to both lower and upper limit of the range. “A” is intended to mean “one or more”, if not explicitly mentioned otherwise.

[0112] The present invention encompasses, inter alia, the following embodiments:

[0113] 1 . A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof.

[0114] 2. The method of embodiment 1 , wherein the method further comprises the steps of a) providing ground cereal grain, b) moistening the ground cereal grain with water, c) rolling and, optionally, grinding the moisturized ground cereal into agglomerates, d) exposing the agglomerates to water vapour, e) mechanically separating caked or clumped agglomerates, f) drying the agglomerates; and, preferably, g) grinding and / or sieving the dried agglomerates, wherein the at least one enzyme is mixed with the ground cereal grain prior to or during step b).

[0115] 3. Use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof for preparing couscous from ground cereal grain, optionally, wherein the method of embodiment 1 or 2 is used.

[0116] 4. Use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a laccase, a protease, an amylase, or any combination thereof for improving the processability of ground cereal grain during couscous production and / or for increasing the ability of the couscous to absorb water, optionally, wherein the method of embodiment 1 or 2 is used.

[0117] 5. The method of any of embodiments 1 or 2 or the use of any of embodiments 3 or 4, wherein the enzyme is a carboxylester hydrolase selected from the group comprising a triacylglycerol lipase, a phospholipase and a glycolipase.

[0118] 6. The method of embodiment 5 or the use of embodiment 5, wherein the carboxylester hydrolase is triacylglycerol lipase.

[0119] 7. The method of embodiment 5 or the use of embodiment 5, wherein the carboxylester hydrolase is a phospholipase.

[0120] 8. The method of embodiment 5 or the use of embodiment 5, wherein the carboxylester hydrolase is a glycolipase.

[0121] 9. The method of any of embodiments 1 or 2 or 5-8 or the use of any of embodiments 3-8, wherein the at least one enzyme is an oxidoreductase.

[0122] 10. The method of embodiment 9 or the use of embodiment 9, wherein the oxidoreductase is a hexose oxidase.

[0123] 11. The method of embodiment 10 or the use of embodiment 10, wherein the hexose oxidase is a glucose oxidase.

[0124] 12. The method of any of embodiments 1 or 2 or 5-11 or the use of any of embodiments 3-11 , wherein the at least one enzyme is a hemicellulase.

[0125] 13. The method of embodiment 12 or the use of embodiment 12, wherein the hemicellulase is an endo-1 ,4-p-xylanase.

[0126] 14. The method of any of embodiments 1 or 2 or 5-13 or the use of any of embodiments 3-13, wherein the at least one enzyme is a transglutaminase. 15. The method of any of embodiments 1 or 2 or 5-14 or the use of any of embodiments 3-14, wherein the at least one enzyme is a peroxidase.

[0127] 16. The method of any of embodiments 1 or 2 or 5-15 or the use of any of embodiments 3-15, wherein the at least one enzyme is a sulfhydryl oxidase.

[0128] 17. The method of any of embodiments 1 or 2 or 5-16 or the use of any of embodiments 3-16, wherein the at least one enzyme is a tyrosinase.

[0129] 18. The method of any of embodiments 1 or 2 or 5-17 or the use of any of embodiments 3-17, wherein the at least one enzyme is a phenol oxidase.

[0130] 19. The method of embodiment 18 or the use of embodiment 18, wherein the phenol oxidase is a laccase.

[0131] 20. The method of any of embodiments 1 or 2 or 5-19 or the use of any of embodiments 3-19, wherein the at least one enzyme is a protease.

[0132] 21. The method of any of embodiments 1 or 2 or 5-20 or the use of any of embodiments 3-20, wherein the at least one enzyme is an amylase.

[0133] 22. The method of any of embodiments 1 , 2 and 5-21 or the use of any of embodiments 3-21 , wherein a combination of at least two enzymes of any of embodiments 6-21 is used.

[0134] 23. The method of any of embodiments 1 , 2 and 5-21 or the use of any of embodiments 3-21 , wherein a combination of at least three enzymes of any of embodiments 6-21 is used.

[0135] 24. The method of any of embodiments 1 , 2 and 5-21 or the use of any of embodiments 3-21 , wherein a combination of at least four enzymes of any of embodiments 6-21 is used.

[0136] 25. The method of any of embodiments 1 , 2 and 5-21 or the use of any of embodiments 3-21 , wherein a combination of at least five enzymes of any of embodiments 6-21 is used.

[0137] 26. The method of any of embodiments 1 , 2 or 5-13 or the use of any of embodiments 3-13, wherein the at least one enzyme is a combination of a hemicellulase and a) a carboxylester hydrolase, and / or b) an oxidoreductase.

[0138] 27. The method of any of embodiments 1 , 2 and 5-26 or the use of any of embodiments 3-26, wherein the at least one enzyme is mixed with the ground cereal at a concentration of 1-500 mg / kg. The method of any of embodiments 1 , 2 and 5-27 or the use of any of embodiments 3-27, wherein the at least one enzyme is mixed with the ground cereal grain as a powder having an average particle size of 10-1000 pm. The method or use of embodiment 28, wherein the at least one enzyme is mixed with the ground cereal grain as a powder having an average particle size of 25-150 pm. The method of any of embodiments 1 , 2 and 5-27 or use of any of embodiments 3-27, wherein the at least one enzyme is first dissolved in water before being mixed with the ground cereal grain. The method of any of embodiments 1 , 2 and 5-30 or the use of any of embodiments 3-30, wherein the cereal grain is selected from the group comprising wheat, rye, oat, barley, millet, rice and maize. The method of embodiment 31 or the use of embodiment 31 , wherein the cereal grain is wheat selected from the group comprising Triticum aestivum, Triticum durum, Triticum dicoccum, Triticum spelta, Triticum monococcum and a mixture thereof. The method of embodiment 32 or the use of embodiment 32, wherein the wheat is Triticum aestivum. The method of embodiment 32 or the use of embodiment 32, wherein the wheat is Triticum spelta. The method of any of embodiments 1 , 2 and 5-34 or the use of any of embodiments 3-34, wherein the ground cereal grain is semolina, fluor or a mixture thereof. A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of I OWOO pm, preferably of 25-150 pm, wherein, optionally, the method is a method of any of embodiments 1 , 2 or 5-35. A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing a flavour substance with the ground cereal grain, wherein optionally, the method is a method of any of embodiments 1 , 2 or 5-36. Couscous prepared from ground cereal grain using a method comprising a) a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof, b) a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of 10-1000 pm, preferably of 25-150 pm and / or c) a step of mixing a flavour substance with the ground cereal grain, wherein, optionally, the method is a method of any of embodiments 1 , 2 or 5-37.

[0139] 39. A kit comprising a) at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a sulfhydryl oxidase, a tyrosinase, a peroxidase, a phenol oxidase, a protease, an amylase and any combination thereof, b) at least one water-soluble colouring agent selected from the group comprising curcumin, riboflavin and p-carotin and, optionally, c) at least one flavouring substance.

[0140] All literature cited herein is herewith fully incorporated. The present invention is further illustrated, but not limited, by the following example.

[0141] Brief description of the Drawings

[0142] Figure 1 : Simplified diagram of a process for making couscous

[0143] Figure 2: Swelling index of medium-grain couscous (1000-1500 pm) prepared using hemicellulase (HC) or glucose oxidase (GOX)

[0144] Figure 3: Swelling index of fine-grained couscous (500-1000 pm) prepared using hemicellulase

[0145] (HC) or glucose oxidase (GOX)

[0146] Figure 4: (A) Gelatinisation behaviour of couscous prepared with triacylglycerol lipase (TACL)

[0147] (B) Gelatinisation behaviour of couscous with phospholipase A1 (PLA1). Analyses were performed using a Rapid Visco Analyzer.

[0148] Figure 5: Swelling index of fine couscous (99 % of the couscous granules exhibited a particle size of 500-1000 pm) produced in an industrial-scale system from durum wheat semolina (D100) or bread (soft) wheat flour (S100) or a mixture of equal amounts of durum semolina and bread (soft) wheat flour (D50 / S50), compared to couscous prepared from pure bread (soft) wheat flour (S100) mixed with i) a combination of 200 mg / kg transglutaminase and 50 mg / kg glucose oxidase (TG200 / G050), ii) 100 mg / kg glucose oxidase (G0100) or iii) 500 mg / kg transglutaminase (TG500). All trials except for D100 were performed in triplicates.

[0149] Figure 6: Couscous without (A, B) and with 250 ppm colouring (riboflavin and curcumin,

[0150] MCColor B 33122), dosed dry into the flour (C, D) or previously dissolved in the water used for agglomeration (E, F). (A) Couscous, medium grain size, without colouring. (B) Couscous, small grain size, without colouring

[0151] Examples

[0152] Example 1

[0153] In this example, the ability of couscous produced using the method according to the invention to absorb water was tested. For this purpose, the so-called swelling index of the couscous was determined, which describes the swelling capacity of couscous as a quality parameter.

[0154] The swelling index was determined as follows:

[0155] • Weigh 10 g of dry couscous into a 100 mL graduated cylinder.

[0156] • Note the initial volume of the dry couscous (Vo).

[0157] • Weigh 100 mL of water (37 °C) in a separate beaker.

[0158] • Pour the water into the cylinder with the dry couscous. Note the initial volume of the hydrated couscous ( H) immediately after sedimentation.

[0159] • Note the volume of the swollen couscous after 30 minutes (Vs).

[0160] • The swelling index (SX) is the ratio of the volume after swelling to the initial volume (dry or moist).

[0161] Couscous production on a laboratory scale

[0162] The couscous tested was produced as follows:

[0163] 1.1 Medium-grain couscous (1000-1500 m) with hemicellulase oroxidase

[0164] For the production of medium-grain couscous with a target particle size of 1000-1500 pm from bread wheat, between 50 and 150 ppm of a powdered hemicellulase (more precisely: endo-1 ,4-beta- xylanase 2, EC 3.2.1.8, expressed by the gene xyn2) from Trichoderma reesei (renamed Hypocrea jecorina) or 100 to 200 ppm of a glucose oxidase (EC 1 .1 .3.4) from Aspergillus niger (expressed by the gene gox) were used. The enzyme powder and the bread wheat flour were thoroughly mixed in a Hobart mixer for 3 min before making couscous as follows:

[0165] The raw material (flour and, optionally, enzymes) was mixed with water at high speed in a planetary mixer for 8 minutes. The target moisture content of the agglomerates was 35 %. The entire quantity of agglomerates was transferred to an analyser sieve (3.5 mm) and sieved for 0.5 min. The oversized particles [B] on the sieve (> 3.5 mm) were returned to the mixer and the first filtered agglomerates [A] (< 3.5 mm) were sieved for 1.5 min in a 1 mm sieve. The agglomerates on the sieve [D] (1 mm - 3.5 mm) were temporarily stored in a sealable container. The agglomerates that were too fine [C] (< 1 mm) were added to the oversized agglomerates in the mixer and mixed again for 1 min at high speed. The oversized agglomerates [E] were then separated using the 3.5 mm sieve for 0.5 min and discarded. The second filtered agglomerates [F] (< 3.5 mm) were transferred to the 1 mm sieve. The agglomerates [G] (< 1 mm) that were too fine were separated for 1 .5 min and then discarded. The passed third filtered agglomerates [H] were mixed together with the intermediate agglomerates [D], The oversized agglomerates [I] were then separated using a 1.6 mm sieve for 1.5 min and discarded. The quantity of the passed fourth filtered agglomerates [J] (1 mm - 1.6 mm) was recorded for process monitoring. In each case, 150 g of these agglomerates were steamed in 2 pots with test sieve insert (630 pm, 0 20 cm) at full power for 12 min on an induction hob with 3 litres of water. The agglomerates were placed in the centre of the steam sieve with an 18 cm ring, creating a rim. The height of the cake was about 1.5 cm. After steaming, the lumps were broken up for 1 .5 minutes using two forks. The steamed agglomerates were then placed on a drying tray for short pasta from Fava Spa. They were then dried for 30 minutes under maximum ventilation in the Fava laboratory pilot dryer. After drying, the agglomerates were cooled with 18 °C cold air for 2 minutes. The dried couscous from both drying inserts was mixed and ground in a mill at level 24 to break up the lumps. The ground material was sieved in a 1 mm sieve for 1 min. The medium-sized couscous on the sieve [L] (> 1 mm) was then sieved for 1 min in a 1 .6 mm sieve to separate and discard the excessively large particles [M], The strained couscous [N] (1 mm - 1.6 mm) formed the medium-sized couscous. To separate the fine particles [O], the excessively fine couscous [K] was sieved for 0.5 min in a 0.5 mm sieve. The couscous on the sieve [P] (0.5 mm - 1 mm) formed the fine couscous fraction.

[0166] The effects on the swelling index are shown in Figure 2.

[0167] 1 .2 Fine-grained couscous (500-1000 pm) with hemicellulase or oxidase

[0168] For the production of fine couscous of a target particle size 1000-1500 pm from bread wheat, between 50 and 150 ppm of a powdered hemicellulase as above or 100 to 200 ppm of a glucose oxidase as above were added to the wheat flour and all dry ingredients were mixed in the Hobart mixer for 3 min before couscous was produced as described above. The effects on the swelling index are shown in Figure 3.

[0169] Example 2

[0170] Gelatinisation behaviour of couscous

[0171] In the following example, the gelatinisation behaviour of couscous was tested. The gelatinisation behaviour is a quality parameter of couscous indicative of the processability of the wheat agglomerates produced during couscous preparation.

[0172] Couscous produced using carboxylester hydrolases

[0173] In the production of couscous from bread wheat, between 30 and 60 ppm of powdered carboxyl ester hydrolases (triacylglycerol lipase, EC 3.1.1.3 from Thermomyces lanuginosus (formerly Humicola lanuginosa), expressed by the gene LIP, and carboxyl ester hydrolase with phospholipase A1- (EC 3.1.1.32), galactolipase (EC 3.1.1.26) and triacylglycerol lipase (EC 3.1.1.3.) activity from Fusarium oxysporum) were added and all dry ingredients were mixed in the Hobart mixer for 3 min before couscous was prepared according to the method described above. The effects on starch gelatinisation were measured using the Rapid Visco Analyser (RVA) 32.01 and are shown in Figure 4a and Table 1 and Figure 4b and Table 2:

[0174] Table 1 : Gelatinisation behaviour of couscous prepared with triacylglycerol lipase (TACL) from Thermomyces lanuginosus in a Rapid Visco Analyzer (RVA) 31 .01

[0175] Table 2: Gelatinisation behaviour of couscous prepared with phospholipase A1 (PLA1) from Fusarium oxysporum in a Rapid Visco Analyzer (RVA) 31.01

[0176] The results in Tables 1 and 2 show that the gelatinisation temperature of starch is increased by carboxylester hydrolases such as triacylglycerol lipase or phospholipase. This reduces the adhesion of the particles to each other and thus the tendency to clump. The cake formed during steaming can then be loosened more easily and produces smaller lumps that can be more easily broken down to the desired size of the end product.

[0177] Furthermore, the maximum viscosity is also increased. This could explain the improved water absorption of the end product.

[0178] Example 3: Production of couscous from soft wheat in an industrial plant

[0179] In an industrial plant of the manufacturer Fava S.p.A.

[0180] (https: / / www.fava. it / fava_pasta_production_line.asp?line=5&lang=EN), flour from soft wheat was processed into couscous. The process in this plant is carried out in the steps shown in Figure 1 . After agglomeration in the "roller", the agglomerates are applied to a belt in a 3-4 cm high layer and cooked in the "steamer". The agglomerates clump together during steaming. The result is designated cake. Before the subsequent drying step, the cake must be broken up to enable effective drying. By adding enzymes, it was possible to positively influence the behaviour during the breaking up process. The influence of the enzymes is shown in Table 3. Couscous made from durum wheat served as a reference.

[0181] Table 3: Effect of the indicated enzymes on lump size after breaking up the semolina cake after steaming

[0182] *Lump size categories: Small: up to 2.5 mm max. diameter; medium: up to 5 mm max. diameter; large: max. diameter larger than 5 mm

[0183] Example 4: Trials on couscous produced in an industrial plant

[0184] In the following example, the swelling capacity of couscous produced in an industrial plant of the machine manufacturer Fava S.p.A. was tested.

[0185] With a capacity of approx. 50 kg per hour, couscous was produced from durum wheat, bread (soft) wheat and a mixture of 50 % durum wheat and 50 % bread wheat and compared with couscous made from 100 % bread wheat with added enzymes. Due to the modern design of the industrial plant with a steam supply from above and below within the steamer, the time to reach the final temperature during the steaming process was particularly short at approx. 2 minutes. Nevertheless, this test confirmed the positive effect of glucose oxidase (EC 1.1.3.4 from Aspergillus niger) in particular on the swelling capacity of the couscous, which led to an increase in the swelling index both at a low dosage (50 mg / kg) and at a higher dosage (100 mg / kg). Transglutaminase (EC 2.3.2.13 from Streptomyces mobaraensis) showed a rather moderate effect even at a high dosage of 500 mg / kg (Figure 5).

[0186] Example 5: Couscous with powdered colourants

[0187] In the production of couscous from bread wheat, 250 ppm (mg / kg) of a powdered mixture of riboflavin and curcumin was added to the wheat flour and all dry ingredients were mixed in a Hobart mixer for 3 min before couscous was produced as previously described. The effects on colouring are shown in Figure 6. The couscous without colourant, with the addition of colourant pre-dissolved in water and with the addition of fine powdered colourant are compared. Note not the dark areas, which are due to a slightly inhomogeneous moisture distribution, but the more intensely yellow- or orangecoloured areas, which indicate an inhomogeneous distribution of the colourant. The analysis showed that, surprisingly, the use of finely powdered dye, which was mixed directly with the dry wheat flour, produced the most uniform colouring.

[0188] Example 6: Couscous with powdered flavourings

[0189] In the production of couscous from bread wheat, between 0.1 and 0.5 % of powdered flavouring preparations (SternArom Cereal 1462, SternArom Durum 2432, SternArom Butter 2630) were added to the wheat flour and all dry ingredients were mixed in a Hobart mixer for 3 min before couscous was produced as previously described.

[0190] The couscous was prepared for consumption by steaming and the ready-to-eat couscous was subjected to a sensory test with sensory-trained participants. The participants had to indicate whether they could detect differences between two compared samples. Couscous made from durum was used as a reference. The result of the sensory test is shown in Table 4.

[0191] Table 4: Result of the sensory analysis of ready-to-eat couscous semolina with added flavour.

[0192] 0 - 3: number of participants that detected a difference

[0193] References: https: / / www.expertmarketresearch.com / reports / couscous-market

[0194] Zilic et al., 2011 . Characterization of proteins from grain of different bread and durum wheat genotypes. Int. J. Mol. Sci. 12(9), 5878-5894.

[0195] Shewry et al., 2002. The structure and properties of gluten: an elastic protein from wheat grain. Phil. Trans. R. Soc. Lond. 357, 133-142. en.wikipedia.org / wiki / Semolina

[0196] Sacchetti et al., 2011 . Effect of semolina particle size on the cooking kinetics and quality of spaghetti. Proc. Food Sci. 1 , 1740-1745. www.haverparticleanalysis.com / en / sieve-analysis / ro-tapr-test-sieve-shaker / gkm-net.de / en / laboratory-air-jet-lab-sieves.html

[0197] Hareland, 1994. Evaluation of flour particle size distribution by laser diffraction, sieve analysis and near-infrared reflectance spectroscopy. J. Cereal Sci. 20(2), 183-190.

[0198] WO 2007 / 080503 A2

[0199] US 3520702 A

[0200] Qi Si and Drost-Lustenberger, 2002. Enzymes for-bread, pasta and noodle products. In: "Enzymes in Food Technology", Whitehurst, R.J. and Law, B.A. (eds.), p. 19-56.

[0201] Brijs et al., 2004. Combined effects of endoxylanases and reduced water levels in pasta production. Cereal Chem. 81 (3), 361-368.

[0202] Popper et al., 2013. Enzymatic improvement of the quality of pasta and noodles. World Grain 31 (12), 51-55.

[0203] Morrison, 1994. Wheat lipids: structure and functionality. In: “Wheat”, Bushuk, W., and Rasper, V.F. (eds.) Springer.

[0204] Kibar et al., 2014. Effects of fatty acid addition on the physicochemical properties of corn starch. Int. J. Food Prop. 17(1), 204-218.

[0205] Meerts et al., 2017, Enhancing the Rheological Performance of Wheat Flour Dough with Glucose Oxidase, Transglutaminase or Supplementary Gluten. Food Bioprocess Technol. 10, 2188-2198. Selinheimo, 2008. Tyrosinase and laccase as novel crosslinking tools for food biopolymers, PhD Thesis, VTT publications, 693.

[0206] Revanappa et al., 2014, Effect of Peroxidase on Textural Quality of Dough and Arabinoxylan Characteristics Isolated from Whole Wheat Flour Dough. International Journal of Food Properties, 17(10), 2131-2141. https: / / www.fava. it / fava_pasta_production_line.asp?line=5&lang=EN

Claims

Claims1. A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transgluta minase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof.

2. The method of claim 1 , wherein the method further comprises the steps of a) providing ground cereal grain, b) moistening the ground cereal grain with water, c) rolling and, optionally, grinding the moisturized ground cereal into agglomerates d) exposing the agglomerates to water vapour, e) mechanically separating caked or clumped agglomerates, f) drying the agglomerates; and, preferably, g) grinding and / or sieving the dried agglomerates, wherein the at least one enzyme is mixed with the ground cereal grain prior to or during step b).

3. Use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof for preparing couscous from ground cereal grain, wherein, optionally, the method of any of claims 1-2 is used.

4. Use of at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a laccase, a protease, an amylase, or any combination thereof for improving the processability of ground cereal grain during couscous production and / or for increasing the ability of the couscous to absorb water, wherein, optionally, the method of any of claims 1-2 is used.

5. The method of any of claims 1 or 2 or the use of any of claims 3 or 4, wherein the at least one enzyme is a) a carboxylester hydrolase, wherein, preferably, the carboxylester hydrolase is selected from the group comprising a triacylglycerol lipase, a phospholipase and a glycolipase, b) an oxidoreductase, wherein, optionally, the oxidoreductase is a hexose oxidase, preferably a glucose oxidase, orc) a hemicellulase.

6. The method of any of claims 1 , 2 or 5 or the use of any of claims 3-5, wherein the at least one enzyme is a combination of a hemicellulase and a) a carboxylester hydrolase, and / or b) an oxidoreductase.

7. The method of any of claims 1 , 2 or 5-6, or the use of any of claims 3-6, wherein the at least one enzyme is mixed with the ground cereal at a concentration of 1-500 mg / kg.

8. The method of any of claims 1 , 2 or 5-7, or the use of any of claims 3-7, wherein the at least one enzyme is mixed with the ground cereal grain as a powder having an average particle size of IOWOO pm, preferably of 25-150 pm, or wherein the at least one enzyme is first dissolved in water before being mixed with the ground cereal grain.

9. The method of any of claims 1 , 2 or 5-8 or the use of any of claims 3-8, wherein the cereal grain is selected from the group comprising wheat, rye, oat, barley, millet, rice and maize.

10. The method of any of claims 1 , 2 or 5-9 or the use of any of claims 3- 9, wherein the cereal grain is wheat selected from the group comprising Triticum aestivum, Triticum durum, Triticum dicoccum, Triticum spelta, Triticum monococcum and a mixture thereof, wherein the wheat preferably is Triticum aestivum.

11. The method of any of claims 1 , 2 or 5-10 or the use of any of claims 3-10, wherein the ground cereal grain is semolina, flour or a mixture thereof.

12. A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of 10-1000 pm, preferably of 25-150 pm, wherein, optionally, the method is a method of any of claims 1 , 2 or 5-11.

13. A method for preparing couscous from ground cereal grain, wherein the method comprises a step of mixing a flavour substance with the ground cereal grain, wherein optionally, the method is a method of any of claims 1 , 2 or 5-12.

14. Couscous prepared from ground cereal grain using a method comprising a) a step of mixing the ground cereal grain with at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a peroxidase, a sulfhydryl oxidase, a tyrosinase, a phenol oxidase, a protease, an amylase and any combination thereof, b) a step of mixing at least one colouring agent with the ground cereal grain, wherein the at least one colouring agent is added to the dry cereal grain as a powder having a particle size of 10-1000 pm, preferably of 25-150 pm and / or c) a step of mixing a flavour substance with the ground cereal grain, wherein, optionally, the method is a method of any of claims 1 , 2 or 5-13.

15. A kit comprising a) at least one enzyme selected from the group comprising a carboxylester hydrolase, an oxidoreductase, a hemicellulase, a transglutaminase, a sulfhydryl oxidase, a tyrosinase, a peroxidase, a phenol oxidase, a protease, an amylase and any combination thereof, b) at least one water-soluble colouring agent selected from the group comprising curcumin, riboflavin and p-carotin and, optionally, c) at least one flavouring substance.

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