FIELD OF THE INVENTION

The present invention relates to gluten-free pasta, to a method for the manufacture of gluten-free pasta from faba beans and to the use of ground and air classified faba bean fraction in the manufacture of gluten -free pasta . BACKGROUND OF THE INVENTION

Pastas are typically made from wheat which is not very nutritious and typically comprises mainly simple carbohydrates, very little vitamins and minerals. Wheat and also other cereals comprise gluten, which is a protein formed of gliadin and glutenin . The western diet is commonly based on wheat and other gluten containing cereals. The consumption of gluten may cause adverse effects in part of human population. Celiac disease is an autoimmune intolerance to gluten, resulting in the degradation of the intestinal villi and decrease in macro- and micro-nutrient absorption. A variety of symptoms, such as diarrhea, bloating, weight loss, skin rashes, spontaneous abortions etc. may occur as a result of gluten consumption. There is also a clea r link between celiac disease and diabetes I and II.

The only treatment for celiac disease is life-long gluten-free diet. The amount of gluten- free products on the market increases constantly. Typically gluten-free pastas are made of a single ingredient, such as rice or maize. These starch based pastas have much higher GI than wheat pastas. There are also other commercially available gluten-free pastas based on soy and peas, having lower GI than wheat and different organoleptic and rheological properties.

The speed at which carbohydrates are absorbed is expressed by the glycemic index (GI) : the higher the index is, the faster the carbohydrate absorption results and consequently insulin absorption. In the long run, this affects the insulin production process and leads to diabetes onset. Glucose has GI of 100.

EP 1749450 describes gluten-free pasta comprising 50-90 wt% of a naturally gluten- free raw source of starch (maize or potato), 2-60 wt% of gluten -free flour (derived from bean, pea, lentil etc.), 0.5-30 wt% of gluten -free protein source (lupin flour), 0.1- 5 wt% of gluten-free emulsifier (lecithin etc.) and water. Generally, there is a growing need to decrease the consumption of animal based proteins and to increase the availability of plant based proteins. Legumes, such as beans provide cheap and nutritious foods as they comprise high amounts of proteins. Particularly faba beans may contain typically about 35-38 wt% of proteins, but they contain no gluten. On the other hand faba beans also contain antinutritional factors (ANFs), which may have negative effect on the health of the individual consuming faba beans. Examples of said ANFs are tannins, lectins, trypsin inhitors, phytic acid and toxic vicine and convicine, which may cause a disease called favism, a severe hemolytic anemia. These ANFs limit the use of faba beans in foods and animal feeds. Various methods have been suggested for the removal of ANFs, such as germination, extrusion cooking, autoclaving and toasting. Further, McKay A M, ] Appl. Bact. 1992, 72, 475-478, describes partial reduction of vicine and convicine in faba beans by growth of Lactobacillus plantarum on faba bean suspensions. Despite the ongoing research and development there is a need for a gluten-free pasta with improved nutritional properties, low GI and acceptable organoleptic and rheological properties, comparable with those of traditional pastas.

SUMMARY OF THE INVENTION

An object of the invention is to provide new gluten-free pasta based on faba beans.

Another object of the invention is to provide a method for the manufacture of gluten- free pasta from faba beans. The present invention relates to new gluten-free pasta based on faba beans.

The present invention also relates to a method for the manufacture of gluten-free pasta from faba beans, where the method comprises the steps of grinding faba beans, subjecting the ground faba beans to fractionation by air classification, separating a fraction having average particle size of about D50 = 20 - 100 μιη and D90 = 40 - 200 μιη, and blending gluten-free flour comprising the separated fraction with water to obtain pasta dough.

The present invention also relates to the use of a faba bean fraction having average particle size of about D50 = 20 - 100 μιη and D90 = 40 - 150 μιη in the manufacture of gluten-free pasta. The present invention also relates to new nutritionally valuable gluten-free pasta based on faba beans, having decreased ANF content, high protein content and low GI.

Characteristic features of the invention are presented in the appended claims. DEFINITIONS

The term "ANF" refers here to anti-nutritional factors present in unprocessed faba beans, including tannins, lectins, trypsin inhitors, phytic acid, vicine, and convicine.

The term "gluten-free" means here that a product contains not more than 20 ppm of gluten.

DETAILED DESCRIPTION OF THE INVENTION

It was surprisingly found that the amount of ANFs of faba beans can be decreased to low levels, with a method which comprises the steps of grinding faba beans, subjecting the ground faba beans to fractionation by air classification, whereby typically at least a coarse fraction and a fine fraction are obtained. The ANFs are predominantly concentrated in the fine fraction and thus the coarse fraction is particularly suitable ingredient for the manufacture of gluten-free pasta. Faba beans are naturally gluten- free.

The method for the manufacture of gluten-free pasta from faba beans comprises the steps of grinding faba beans, subjecting the ground faba beans to fractionation by air classification, separating a fraction having average particle size of about D50 = 20 - 100 μιη and D90 = 40 - 150 μιη, and blending gluten-free flour comprising the separated fraction with water. The separated fraction is the "coarse fraction" obtained in the air classification.

According to one preferable embodiment 80-70 wt% of gluten-free flour comprising the fraction is blended with 20-30 wt% of water to obtain pasta dough. The gluten-free flour comprises at least 50 wt%, preferably 60-100 wt% of the separated fraction. According to one preferable embodiment the gluten-free flour comprises 100 wt% of the separated faba bean fraction.

In the method for the manufacture of pasta, a mixture is formed of gluten-free flour comprising faba bean fraction having average particle size of about D50 = 20 - 100 μιη and D90 = 40 - 150 μιη, water and optionally additives, followed by blending the mixture to obtain pasta dough. Said pasta dough may be formed it to pasta, which may be used as such as fresh pasta, or optionally be dried at the temperature of 40-80°C, preferably 40-60°C, for 5-15 hours, preferably 8-12 hours.

In a preferable embodiment the separated fraction has the average particle size D50 = 20 - 80 μιη and D90 = 70 - 150 μιη, more preferably the average particle size D50 = 20 - 30 μιη and D90 = 45 - 85 μιη more preferably the average particle size D50 = 25 - 30 μιη and D90 = 70 - 80 μιη.

Faba beans, also known as broad beans and horse beans, are understood to mean here beans belonging to the species Vicia faba L. Several sub-species have been developed, typically adapted to local weather conditions, such as Aurora, Divine, Kontu, Jogeva, Maya, Ukko etc. Faba bean is an important protein source particularly in human food in developing countries and as animal feed for pigs, horses, poultry and pigeons in industrialized countries. The protein content in faba beans may vary between 20 and 41 wt%, depending on both genetic and environmental factors. Faba beans contain no gluten, which makes them suitable for population suffering from celiac disease or other forms of gluten intolerance.

In the method of the invention suitably dehulled faba beans are used as starting material. The dehulling may be carried out using any suitable dehulling method known in the field.

Grinding of faba beans

The faba beans (dehulled faba beans) are subjected to grinding to obtain ground faba beans. The grinding may be carried out by using any suitable grinding, milling, or pulverizing equipment, preferably using impact milling. Suitable milling devices are for example pin disc mills and the like. The grinding may be carried out for at least one pass, suitably from 1 to 3 passes. The grinding temperature can be between 0-80°C, through put 5-300 kg/h (depending on the machine) at atmospheric pressure.

In the examples of the present application the grinding of faba beans was carried out by a 100UPZ pin disc mill (Hosokawa Alpine AG, Germany), with two grinding steps with the maximal speed 17800 rpm. However, similar result can be obtained with other types of mills, for example with pin disc mills equipped with two different motors, whereby one grinding step would give similar particle size distribution. The average particle size of the ground faba bean material after the milling is suitably D50 = 20-100 urn and D90 =50-150 urn.

The grinding parameters are adjusted to provide ground material having the desired average particle size or close to it.

Fractionation by air classification

The ground faba bean material is subjected to fractionation by air classification in an air classifier or air separator where the material stream is injected into a chamber which contains a column of rising air. Inside the separation chamber, air drag on the objects supplies an upward force which counteracts the force of gravity and lifts the material to be sorted up. The materials are separated by a combination of size, shape and density.

The air classification of the ground faba bean material is carried out to provide at least a coarse fraction and a fine fraction.

The coarse fraction has average particle size of about D50 =20-100 μιη and D90 =40- 150 μιη, preferably D50 = 20 - 80 μιη and D90 = 70 - 150 μιη, more preferably D50 = 20 - 30 μιη and D90 = 45 - 85 μιη, still more preferably D50 = 25 - 30 μιη and D90 = 70 - 80 μιη. The protein content in the coarse fraction is suitably 10-35 wt%, preferably 20-25 wt%. The yield of the coarse fraction is typically 56-68 wt%. The coarse fraction is starch rich, typically it comprises from to 35-50 wt%, preferably 40- 45 wt% of starch, all calculated from dry matter. The fine fraction has typically average particle size of about D50 = 12-50 μιη and D90 = 30-85 μιη. The protein content is typically 59-73 wt%, and the starch content is typically less than 35 wt%, all calculated from dry matter. The ANFs, particularly tannins, lectins, trypsin inhitors, phytic acid, vicine, and convicine are predominantly located in the fine fraction.

In the air classification the content of vicine and convicine in the coarse fraction is reduced by 65 wt%, even 68 wt%. Only one pass in air classification is needed.

The coarse fraction is in the form of powder, such as flour (coarse faba bean fraction). The flour may be used directly for the manufacture of pasta, or it may be packed and/or stored and used later as an ingredient for the manufacture of pasta products.

Blending of pasta dough

In the method 70-80 wt% of gluten-free flour comprising the coarse faba bean fraction is blended with 20-30 wt% of water to obtain pasta dough. The gluten-free flour may comprise at least 50 wt%, preferably 60-100 wt% of the coarse faba bean fraction.

Part of the coarse faba bean fraction may be replaced by gluten-free flour, such as quinoa, buckwheat, rice, maize, potato, tapioca, lentil, amaranth, soy and sorghum flour and mixtures thereof. Also unprocessed fab bean flour may be used.

However, at least 50 wt% of the coarse faba bean fraction is used, calculated from the total (dry) weight of the pasta dough. One or more optional ingredients may be added during blending for varying the properties of the pasta . Examples of optional ingredients are provided below.

Optionally an enzyme may be used as a crosslinking agent for improving the texture of the pasta. Preferably the enzyme is transglutaminase. Suitably it is used in amounts of 10-30 unit/g protein in the pasta dough.

Optionally an emulsifier may be used, suitably in an amount from 0.1- 2 wt%. Suitably the emulsifier is selected from egg, lecithin, esters of mono- and diglycerides of fatty acids, mono- and diglycerides of fatty acids, and mixtures thereof.

Optionally flavoring agents, including salt, spices, herbs, and also coloring agents may be used in the pasta.

As the coarse faba bean fraction has slightly sour taste, salt addition may not be necessary.

Optionally gums, such as guar gum, agar agar, locust bean gum, gum acacia, xanthan gum, gum Arabic, tara gum and the like may be used as structure enhancers. The mixing of the ingredients is carried out at the temperature of 20-27°C, preferably at 22-25°C, suitably followed by a cold-extrusion at the temperature of 30-40°C, preferably at 32-35°C.

The obtained pasta dough may be formed into pasta of desired shape and form, such as spaghetti, lasagna, etc., and it may be drawn through suitable dies, and the pasta may be subjected to drying if desired. The obtained pasta may be dried at the temperature of 40-80°C, preferably 40-60°C for 15-5 hours, preferably 12-8 hours.

The pasta dough may be extruded using equipment well known in the art, suitably using cold extrusion.

The method may be carried out on a small scale or on larger industrial scale.

Gluten-free pasta based on faba beans

The gluten-free pasta based on faba beans according to the invention comprises at least 50 wt%, suitably 50-99.9 wt% of coarse faba bean fraction having average particle size of about D50 = 20 - 100 μιη and D90 = 40 - 150 μιη, and 0.1 - 30 wt% of water. The coarse faba bean fraction refers here particularly to the coarse faba bean fraction separated in air classification. The average particle size is preferably D50 = 20 - 80 μιη and D90 = 70 - 150 μιη, more preferably D50 = 20 - 30 μιη and D90 = 45 - 85 μιη, still more preferably D50 = 25 - 30 μιη and D90 = 70 - 80 μιη.

According to one preferable embodiment the pasta products have high protein content of 20 - 25% (dry product), and they may have improved nutritional properties, such as low GI.

The gluten-free pasta may comprise other gluten-free flour, such as quinoa, buckwheat, rice, maize, potato, tapioca, lentil, amaranth, soy and sorghum flour, or combinations thereof, where part of the coarse faba bean fraction is replaced with said other gluten- free flour or mixtures thereof. Also unprocessed faba bean flour may be used.

The gluten-free pasta may comprise an emulsifier. Suitably the emulsifier is selected from egg, lecithin, esters of mono- and diglycerides of fatty acids, mono- and diglycerides of fatty acids, and mixtures thereof. The gluten-free pasta may comprise flavoring agents, including salt, spices, herbs, and also coloring agents may be used in the pasta.

The gluten-free pasta may comprise an enzyme. Preferably the enzyme is transglutaminase.

The gluten-free pasta may be fresh pasta, or alternatively dry pasta, which has been subjected to drying for removing of water and thus improving storage stability of the product. Use of coarse faba bean fraction

The coarse faba bean fraction having average particle size of about D50 = 20-100 μιη and D90 = 40-150 μιη, preferably D50 = 20 - 80 μιη and D90 = 70 - 150 μιη, more preferably D50 = 20 - 30 μιη and D90 = 45 - 85 μιη, still more preferably D50 = 25 - 30 μιη and D90 = 70 - 80 μιη may be used in the manufacture of gluten-free pasta. Pasta products having high protein content of 20 - 25% (dry product) may be obtained, having improved nutritional properties.

Unprocessed faba beans contain ANFs that can lower the nutritional value of faba bean products or in some cases have even more severe effects. Air classification reduces the ANFs whereby faba bean flour (coarse faba bean fraction) without adverse effects of faba beans is obtained.

Formation of an elastic food matrix (eg. pasta) from the coarse faba bean fraction may further be improved if desired by the use of texturizing agents such as gums and enzymes in production steps.

Processing of faba beans with the method of the invention results in pastas with improved nutritional profile, textural and sensory properties compared to control gluten-free pastas.

Use of the coarse faba bean fraction obtained by air fractionation results in gluten-free pasta products having equal or better values in most critical textural parameters. For example; instrumental hardness and cohesiveness values of coarse faba bean fraction pasta samples are higher than or similar to the control semolina pasta (after cooking for approx. 8 minutes). On the other hand the parameters such as chewiness, springiness and resilience which are indicators of elastic structure (that is associated with the exceptional elastic gluten structure in regular pasta) and al dente texture are equal or higher than the semolina pasta. Surface adhesiveness value of coarse faba bean fraction pasta samples are almost half of the value of control semolina pasta which shows that starch leaching to outer layer of pasta was controlled better by processing faba beans. However, cooking loss of gluten free pasta samples is twice higher than the control semolina pasta which is an expected outcome in all gluten-free pasta products.

The applicant's own trained sensory panel was used to evaluate the color, elasticity, hardness, chewiness, adhesiveness, sourness and flavor intensity of all pasta samples (unprocessed faba flour (with and without transglutaminase addition), coarse faba bean fraction flour (with and without transglutaminase addition) and control semolina pasta after cooking to optimum cooking time without any salt or sauce addition. Color of processed pasta was found to be different than the other samples. Adhesiveness was not significant. Sourness and intensity of flavor for processed samples were significantly higher than the others. This implies that less salt if any is needed in processed faba bean products.

The invention will now be illustrated with the following examples, where the present invention has been described herein with reference to specific embodiments. It is, however clear to those skilled in the art that the methods and products may be varied within the scope of the claims.

Examples Example 1

Manufacture of gluten-free pasta

Pasta III was manufactured from a coarse faba bean fraction by blending the fraction with 22 wt% of water, forming spaghetti-type pasta and drying the pasta at 55°C for 15 hours. Pasta IV was manufactured in a similar manner, with 20 unit/g with respect to protein, of transglutaminase enzyme (TG). Similar pastas were made of unprocessed faba bean flour (pastas I and II) and semolina flour (pasta V). The pastas were cooked in a conventional manner. Pastas II and IV were manufactured with TG. The particle size distribution of the coarse faba bean fraction was about D50 = 20 - 100 μιη and D90 = 40 - 150 μιη. Cooking loss, water absorption and TPA results for the cooked pastas are given in Table 1 below.

Table 1. Cooking loss, water absorption and TPA results for cooked pasta samples.

Example 2

Determination of antinutritional factors

Antinutritional factors in faba bean flour, in its fractions and in the respective incubated controls and processed samples were determined and they are presented in following Table 2.

Table 2. Anti-nutritional factors in faba bean flour, in its fractions and in the respective incubated controls

Vicine Convicine Trypsin Condensed Phytic acid (mg/g dm (mg/g dm inhibitor tannins (eq (mg/g dm ±SD) (n=3) ±SD) activity (TI cat/lOOg ±SD) (n=2)

(n=3) unit/mg dm dm ±SD)

±SD) (n = 2) ίΠ≡31

Faba bean 11.46±0.22 6.24±0.14 2.09±0.09 17.13± 1.30 22.89±1.30 flour

Fine faba 15.85±0.15 8.54±0.15 4.23±0.69 19.62±0.64 32.49±0.55 bean

fraction

Coarse 5.17±0.07 2.71±0.05 0.47±0.09 13.54±0.34 8.27±0.92 faba bean

fraction