WO2020043925A1

WO2020043925A1 - Rice flour modified by means of hydrothermal treatment with a microwave, obtainment method and uses of same

Info

Publication number: WO2020043925A1
Application number: PCT/ES2019/070553
Authority: WO
Inventors: Felicidad RONDA BALBÁS; Marina VILLANUEVA BARRERO; Joanna Harasym; José Mª MUÑOZ MUÑOZ; Pedro A. CABALLERO CALVO; Sandra PÉREZ QUIRCE
Original assignee: Universidad De Valladolid
Priority date: 2018-08-29
Filing date: 2019-08-02
Publication date: 2020-03-05
Also published as: ES2745456B2; ES2745456A1

Abstract

The present invention relates to gluten-free flour modified by means of a hydrothermal treatment with a microwave. Also described is a method for obtaining the modified flour and the use of same to produce gluten-free doughs and baked goods, pastries and biscuits for consumption by people suffering from coeliac disease or diseases associated with it. The main steps of the obtainment method are the moistening of the flour to 15-35% w/v water and the treatment of the moist flour with a microwave.

Description

MODIFIED RICE FLOUR THROUGH HYDROTHERMAL TREATMENT

WITH MICROWAVES, METHOD OF OBTAINING AND USES OF THE SAME

FIELD OF THE INVENTION

The present invention is encompassed within the agri-food sector and more specifically within the production of bakery, pastry and biscuit products.

BACKGROUND OF THE INVENTION

The increase in the number of diagnosed celiac patients and other patients with gluten sensitivity, makes gluten-free diets currently of great importance in the food sector. As a consequence, the market for gluten-free products (SG) is growing rapidly. One of the main problems for celiac patients is the limited variety of gluten-free quality foods and the difficulty and cost to achieve them.

Gluten is a set of proteins, contained in cereal flour, such as wheat, barley, rye, oats, or any of its varieties and hybrids, such as spelled, spelled, kamut and triticale). Gluten is the triggering factor for celiac disease and associated disorders.

Gluten is appreciated in the food industry for its unique viscoelastic qualities, which provide elasticity to the flour dough, which, together with fermentation, allows the bread to obtain volume and the elastic and spongy consistency of the breads and baked doughs. During baking, gluten is responsible for the fermentation gases being retained inside the dough, causing it to rise, pushing it up. After cooking, gluten coagulation is responsible for the product not deflating once cooked.

Due to the presence of gluten in cereals, the production of bakery, pastry and biscuit foods for celiac patients or those with gluten sensitivity is very complicated. Despite the efforts made to improve their quality, the SG bread doughs lack cohesion and elasticity, are handled with greater difficulty that wheat masses and also have little gas retention capacity. As a result, the breads have low volume, brittle texture and faster hardening, in addition to presenting a pale, unattractive color, and an unpleasant taste.

The SG diet is often unbalanced and unhealthy, as it is characterized by excessive fat intake and reduced protein intake, complex carbohydrates and dietary fiber.

The use of SG grain flours in baked goods is technologically very complicated due to the absence in these products of a structural protein network, which gluten provides in normal flours. Wheat proteins, when hydrated and subjected to mechanical work during kneading, are responsible for forming a viscoelastic network capable of keeping the rest of the flour constituents together. This network also retains the carbon dioxide that is produced during fermentation, giving the dough a texture and physical characteristics suitable for the manufacture of food such as bread, pastries and cookies.

The absence of this protein network in SG flours has important technological problems: 1. It is responsible for a weak, almost nil, retention in the mass of the gas generated during fermentation. 2. This causes poor dough development during fermentation and baking and leads to bakery products of very low volume and high hardness, which also have accelerated aging. 3. SG formulations require high hydration of the doughs, which leads to mixtures that are more similar to whipped doughs than the usual wheat bread doughs. They have a low consistency and are more sticky and more difficult to handle. 4. Because of this, the appearance and conformation of the SG bread is usually of the type of bread.

So that gluten intolerant people have the possibility of taking quality bakery products, without risk of having an adverse immune reaction, gluten-free formulations have been developed that maintain the characteristic viscoelastic properties of wheat. This allows the manufacture of technologically viable fermented bread products (they can be used in typical bakery equipment such as kneaders, grinders and furnaces of the bakery industry), sensory acceptable (in relation to the sensory impressions that occur during the intake of bakery products: slice / crumb hardness, rubberiness, chewiness and stickiness, external and internal appearance of the product, honeycomb quality, hole distribution, uniformity of the size, smell and taste of the product and the aftertaste or taste that appears in the mouth after eating the product) and of a structure similar to that of gluten products.

These formulations include the use of additives, such as hydrocolloids or gums, which maintain the structure and properties of the dough, but, although they favor its handling, retain moisture and improve its appearance, significantly increase the product and, very often, generate honeycomb problems (large irregularity of distribution and size of the crumb alveoli and the presence of defects in the crumb, as it is called the existence of "holes" or large alveoli).

There is therefore a need for SG flours that have adequate physical characteristics to produce easily manipulated bread doughs for the preparation of gluten-free foods such as bread, pastries and biscuits, inexpensive and that do not have alveolate problems.

An economical and clean alternative to food additives are hydrothermal treatments. These procedures are based on the application of heat to previously moistened raw materials (15-30% humidity). Heat transfer in hydrothermal treatments can be done by three mechanisms: radiation, conduction and convection. Radiation consists of heat transfer by electromagnetic waves. Conduction is a type of heat transport that takes place in solids and is produced by direct transmission of molecular energy. Convection consists of heat transfer by groups of molecules that move by density difference or by agitation. The most common mechanisms in feeding are conduction and convection.

One type of hydrothermal radiation treatment is microwaves, a non-ionizing electromagnetic radiation with wavelengths ranging between one meter and one millimeter and frequencies between 300 MHz and 30 GHz. Microwave radiation releases energy that is absorbed or reflected as a function of the dielectric properties of the irradiated material. Most microwave applications are related to the heating caused by this radiation when it interacts with polar molecules or ions charged with a material. Polar molecules, primarily those of water, absorb microwave energy and are oriented with respect to the electric field. The rapid change in its orientation generates heat by molecular friction (Sumnu, 2001).

The use of microwaves is interesting because it has the character of selective heating. Unlike the other systems, its heating depends on the irradiated material, it is that is, the heating depends on the dielectric constant and the frequency of relaxation of the material used.

Microwaves have been used in the food industry with great efficiency in baking, cooking, defrosting, heating, drying, pasteurization, sterilization and enzymatic inactivation operations. However, there is little information on the applications of microwaves in relation to the treatment of flours. Nor are there works in the state of the art that describe the use of flours treated by microwave radiation in baking or information on the functional and nutritional changes that this treatment reports to the final products.

Perez-Quirce et al., 2016 and Pérez-Quirce et al., 2017 describe rice flour treated with microwaves, to decrease the endogenous beta-glucanase activity of the flour. This enzymatic activity, present in native rice flour, causes the hydrolysis of beta-glucans, beneficial for health because it is a soluble fiber.

Villanueva et al., 2018, considered the closest state of the art, describes that intense, prolonged and applied microwave treatments on flour of a humidity of 30% can lead to significant changes in the flour on a microscopic and molecular scale.

However, no state-of-the-art document describes gluten-free flours for the manufacture of gluten-free bakery and bakery products and pastries, with a low cost, with adequate physical characteristics (consistency, texture, easy industrial processing, maintenance of freshness and organoleptic characteristics), avoiding the use of structuring agents such as hydrocolloids and gums.

DESCRIPTION OF THE INVENTION

The present invention relates to modified flour for the preparation of gluten-free bakery, pastry and biscuit dough and foods that comprise it.

For the purposes of the present invention, the term "modified flour" is defined as the fine powder obtained from the ground, humidified and microwave treated cereal. The term "dough" refers to the mixture of flour with water and yeast. A "gluten-free dough" is the mixture of flour with water and yeast in which the flour lacks gluten (gluten-free cereal flour). The doughs used in the invention comprise rice flour as gluten-free cereal. In a preferred embodiment, the gluten-free dough or dough is used in the manufacture of bakery, biscuit and pastry products.

The term "bakery products" refers to any food consisting of a dough comprising flour, yeast and water, cooked in an oven.

The term "bakery products" or "bun" refers to any food, normally sweet that, in addition to comprising flour, yeast and water, includes other ingredients that make the food spongy, such as milk, butter or eggs. The buns can be of different types depending on the dough used (puff pastry, sponge cake dough, brioche dough, choux dough dough, scone dough, or donut dough, for example).

The term "biscuit products" or cookies, refers to any sweet or savory pasta made with a dough of flour, eggs, sugar, oils or butter and other ingredients, which is baked in the oven until it is crispy. The cookie dough may or may not have yeast.

In a preferred embodiment, the modified flour is obtained from flour selected from the group comprising rice, buckwheat or buckwheat, teff, amaranth, quinoa, corn, sorghum or millet. In an even more preferred embodiment, the modified flour is obtained from rice flour.

Rice flour is the result of grinding the healthy and clean cereal grain. Flour results in a change in the physical properties of rice grain, but maintains the same nutritional characteristics. Celiac or gluten-sensitive people find a food alternative in rice flour, since it does not produce the adverse effects caused by flours obtained from other cereals, such as wheat.

For the purposes of the present invention, "additive" or "food additive" is defined as any substance that, without itself having nutritional value, is intentionally added to food or beverages during its manufacturing or preparation process to change, intensify or maintain its color, texture, flavor, shelf life or any other property. The invention relates to a method of obtaining modified flour for the preparation of gluten-free doughs that comprises applying a hydrothermal treatment to the flour. For the purposes of the present invention, hydrothermal treatment is defined as a treatment comprising the steps of:

a) flour humidification; Y

b) heat treatment with microwave energy.

The method of obtaining the modified flour for the preparation of gluten-free dough includes:

a) obtaining gluten-free cereal flour;

b) humidifying the flour from step a); Y

c) treatment of the moistened flour from step b) with microwave.

Obtaining gluten-free cereal flour in step a) comes after grinding the healthy and clean grain of a gluten-free cereal. Gluten-free flour is obtained from gluten-free raw materials naturally, such as rice, buckwheat or buckwheat, teff, amaranth, quinoa, corn, sorghum or millet.

The humidification of the flour in step b) comprises, firstly, measuring the native humidity of the flour to be treated and then adding water to obtain a final moisture of the product between 15 and 35% by weight by volume (p / v). In a preferred embodiment the humidity is between 20 and 30% w / v. The moistened flour is packaged in an airtight container and allowed to stand so that moisture is balanced throughout the product.

The microwave heat treatment in step c) is performed by applying microwaves to the humidified flour obtained in step b) in a microwave chamber. Microwaves are electromagnetic waves; generally between 300 MHz and 30 GHz, with an oscillation period of 3 ns (3 ^c 10 ⁹ s) at 33 ps (33 ^c 10 ¹² s) and a wavelength in the range of 1 m to 10 mm. The frequency of the waves in the treatment of the invention is 0.50 to 30 GHz. In a more preferred embodiment, the frequency of the waves is 0.913 to 3 GHz. In an even more preferred embodiment, the frequency of the waves is 2.45 GHz. Microwave treatment, at any of the above frequencies, takes place over a period between 10 seconds and 60 minutes. In a more preferred embodiment, the treatment takes place over a period between 2 and 16 min.

Microwave treatment is faster than conventional heating with other hydrothermal treatments known in the sector, such as treatments for convection or conduction Microwave energy absorption takes place at the molecular level, which allows a rapid increase in the temperature of the entire sample volume in a homogeneous manner. In addition, microwave heating uses the dielectric properties of water contained in the moistened flour, and generates heat directly and quickly throughout the volume of the sample. The difference in heating time between microwave treatment and conventional treatment is very important, since it also saves time in the transfer of heat to the material.

The hydrothermal treatment of the flour by microwave changes the physicochemical properties of the starch present in the cereal, without destroying its granular structure. The degree of modification depends on the composition of the starch itself, its origin and the amylose / amylopectin ratio, as well as the arrangement of the starch chains within the amorphous and crystalline regions of the native granules. Unlike the modified flours obtained with the method of the invention, the modified flours obtained by other hydrothermal processes (with excess water), such as pregelatinized flours, have destroyed the granular structure of the starch which gives them greater solubility, greater Enzymatic hydrolysis rate and superior digestibility. You cannot obtain bakery products from these pregelatinized flours, since they do not maintain the typical textural properties of bread. The conservation of the granular structure of the flour starch is observed in the values of the filling curve obtained when analyzed.

The modified flour of the invention has changes in the thickening, emulsifying and stabilizing capacity in the dough that comprises it, with respect to the same unmodified flour. This has been proven by measuring their filling characteristics such as peak viscosity values, viscosity drop and final viscosity, as well as the shape of the filling curves. It has been proven that the doughs that comprise the modified flour and the products prepared from said dough, improve the appearance, consistency, texture and behavior to the changes of temperature with respect to the products and doughs that comprise the same unmodified flour.

The induced changes in the modified flour alter the properties of the gels, which causes rheological and textural changes in the doughs and milkshakes obtained from them. As a consequence, these alterations improve the baking process. In the technical field of the invention, flour and water mixtures are known as gels. The modified flour gives rise to bakery, pastry and biscuit doughs with a consistency greater than doughs with unmodified rice flour. The modified flour also allows a good development of the dough in fermentative processes, giving rise to fermented products with good external appearance, volume and better texture values (hardness, elasticity, cohesivity, rubberiness and hardness after 7 days) than the elaborated product from untreated flour.

The modified flour also facilitates the processing of the dough in the automated processes of the industry for the production of bakery, pastry and biscuit products.

Modified flour has greater water absorption than unmodified flour, which results in final products that maintain their freshness and organoleptic characteristics for a longer time than products that comprise unmodified flour. In a preferred embodiment, the final products maintain their freshness and organoleptic characteristics for at least 7 days.

The modified flour also increases the consistency of the dough and reinforces its structure, decreasing and even avoiding the use of structuring agents such as hydrocolloids and gums.

In addition, the modified flour has no alveolate problems and gives rise to more consistent doughs.

Another embodiment of the invention relates to a dough comprising the modified flour obtained by the method described above.

The dough comprising the modified flour is characterized by having a peak viscosity between 0.5 and 2.5 Pascals (Pa). The concept of "peak viscosity" in a freeze-dried flour or dough is defined in the international standards of the American Association of Cereal Chemists (AACC) Method 76-21.01.

This mass is also characterized by having a filling temperature between 60 ° C and 95 ° C. The concept of "filling temperature" in a freeze-dried flour or dough is defined in the international standards of the American Association of Cereal Chemists (AACC) Method 76-21.01.

The mass is also characterized by having an elastic modulus (G ') between 1400 and 8000 Pa. The concept "elastic modulus (G')" in a mass refers to the quotient between the oscillatory shear stress applied to the mass in a geometry typical of a rheometer and the angular deformation caused therein, multiplied by the cosine of the offset angle between the oscillatory stress applied and the angular oscillatory deformation caused (Steffe, JF, 1992).

The gluten-free dough is also characterized by having a viscous modulus (G ”) between 850 and 5000 Pa. The concept“ viscous modulus (G ”)” in a mass refers to the ratio between the oscillatory shear stress applied to the dough in a geometry of a rheometer and the angular deformation caused therein, multiplied by the sine of the offset angle between the oscillatory stress applied and the angular oscillatory deformation caused (Steffe, JF, 1992).

In a preferred embodiment, the dough comprising the modified flour obtained by the method described in the previous embodiments is characterized by having:

a peak viscosity between 0.5 and 2.5 Pa;

a start temperature of filling between 60 ° C and 95 ° C;

an elastic module (G ’) between 1400 Pa and 8000 Pa;

a viscous module (G ”) between 850 Pa and 5000 Pa.

The dough comprising the modified flour can food additives. In a preferred embodiment, the amount of additive is between 0.001 and 2% w / w. In a more preferred embodiment, the dough lacks hydrocolloids.

The invention also relates to a bakery, pastry or biscuit product characterized by having been made from a dough comprising the modified flour as described above. In a preferred embodiment, the bakery product has a hardness between 0.05 and 2.5 Newtons (N), more preferably between 0.2 and 1 N. The concept of "hardness" in bread refers to the resistance it offers a slice of bread to the application of a controlled deformation, according to the American Association of Cereal Chemists (AACC) (2000) Method 74-09.

The bakery product is also characterized by having an elasticity between 0.1 and 1.0 (absolute value), more preferably between 0.5 and 0.9. The concept "elasticity" in bread refers to the ability to recover the initial height of a slice after it has been compressed to deform it to a certain extent and after leaving a specified waiting time for such recovery to take place. In a more preferred embodiment, the bakery product made with the dough comprising the modified flour has a hardness between 0.05 and 2.5 N and an elasticity between 0.1 and 1 (absolute value). Another embodiment refers to the use of modified flour obtained by the method according to any of the above embodiments, in the manufacture of a gluten-free dough. In another embodiment, the modified flour is used as an ingredient in the manufacture of doughs with a weakened internal structure. "Masses with a weakened internal structure" refers to beaten doughs, such as doughs obtained from gluten-free raw materials. These doughs require additives to maintain their structure, such as hydrocolloids, to reinforce the internal structure of the dough and that it can be worked to give rise to attractive-looking products suitable for consumption.

The modified flour can be used as an ingredient in the manufacture of bakery, pastry and biscuit products. The use of the modified flour of the invention does not require the modification of the process scheme, machinery or sequence of steps involved in the manufacture of said products.

The modified flour can be added directly during the preparation of the dough of bakery, pastry or biscuit products, or it can be added to marketable preparations for manufacturing such products.

Another embodiment of the invention relates to the use of the modified flour obtained by the method according to any of the above embodiments, as an ingredient in the production of products for the consumption of people sensitive to gluten. In a more preferred embodiment, gluten-sensitive people are people who have been diagnosed with celiac disease or any of its associated diseases, such as sensitivity / intolerance to non-celiac gluten (SGNC), wheat allergy, irritable bowel syndrome or functional dyspepsia among others.

The modified flour, obtained from the method of the present invention, successfully overcomes the problems detected in the state of the art, since it allows the manufacture of dough and bakery products, of gluten-free pastries and biscuits with a low cost, with adequate physical characteristics (consistency, texture, easy industrial processing, maintenance of freshness and organoleptic characteristics for at least 7 days), decreasing and even avoiding the use of structuring agents such as hydrocolloids and gums. DESCRIPTION OF THE FIGURES

Figure 1. Volume of gluten-free breads made with modified and unmodified rice flour (control) at different concentrations and initial humidity conditions. A. Bread size. B. Slice size. C: control (unmodified flour); 1: 30% w / w rice flour treated with 20% initial moisture; 2: 30% w / w rice flour treated with 30% initial moisture; 3: 50% w / w rice flour treated with 20% initial moisture; 4: 50% w / w rice flour treated with 30% initial moisture.

Figure 2. Rheological characteristics of doughs made with modified rice flour. Viscosity profile of the treated doughs with 20% humidity (A) and 30% humidity (B). The solid lines (-) correspond to the untreated native flour (control). The dashed lines (···) correspond to masses with 30% modified rice flour (p / p), the dashed lines (- -) correspond to 50% modified rice flour (p / p) . The gray continuous line (- -) corresponds to the temperature profile.

EXAMPLES

The examples indicated herein are intended to illustrate the invention, without limiting its scope.

Example 1. Preparation of modified rice flour

100 g of rice flour with 30% moisture were placed in a closed container with a perforated plastic sheet. The flour was introduced in a microwave chamber and kept in constant motion during the treatment.

Next, microwave radiation was applied at a frequency of 2.45 MHz and 14.3 W / g of dry flour power for 8 minutes. Once treated flour was removed from the microwave chamber and sieved through a 0.500 mm sieve.

Example 2. Preparation of bread from modified rice flour

Bread was prepared according to the amounts indicated in Table 1, expressed in g / 100 g of solid base flour: Table 1. Dough preparation recipe

Composition g / 100 g

30-100 flour

Sugar 1-10

Salt 1-5

Ce derivative 0.2-5

Vegetable fat 1-10

Yeast s 0, 1-10

Water 70-130

The rice flour of the composition can be standard, unmodified (control) or modified by the treatment of Example 1.

All ingredients were kneaded mechanically in a kneader until a dough with optimum consistency was reached. Then the dough was divided into portions and introduced into molds. It was allowed to ferment for 40 minutes at 28 ° C and then baked at 170 ° C for 20 min.

The characterization of the breads obtained was done by measuring the volume of each bread with a Volscan laser meter. Additionally, it determined:

a) the texture of the crumb, using a TA-XT2 texturometer,

b) the aging of the bread, measuring the firmness of the crumb after 7 days of storage,

c) the color of the loaves, both of the crust and of the crumb.

The results obtained are detailed below. Table 2: Bread volume

The control sample corresponds to bread made with the same recipe as indicated in Table 1, but with untreated flour.

As observed in Table 2, the presence of modified rice flour, in all cases, increases the volume of bread obtained with respect to the control. The highest volume was obtained with the incorporation of 50% w / w modified rice flour with an initial humidity of 20%. Likewise, breads with 30% w / w rice flour with 30% initial moisture also obtained a high increase in volume. The breads obtained are shown in Figure 1.

As can be seen, breads made with the modified flour of the invention give rise to products with better appearance and texture.

Next, the bread quality was measured based on the following parameters: hardness (1), elasticity (2), cohesiveness (3), rubberiness (4) and hardness at 7 days (5). Parameters 1, 4 and 5 are measured in Newtons, while cohesiveness (2) and rubberiness (3) have no units. For this, a TPA (Texture Profile Analysis) type test was performed. The texture profile analysis of the bread was carried out with a TA-XT2 texturometer (Stable Microsystem, UK) with a standard method (AACC International Method 74-09, 2000).

The result of this test is shown in Table 3:

Table 3. Textural characteristics of the breads

Table 3 shows the textural parameters of the breadcrumbs that were obtained with the addition of different doses of rice flour with different initial moisture contents. The study of the rheological behavior of food is important in controlling its quality. In the case of the bakery industry, the measurements of the rheological characteristics of the flour used is of the utmost importance, since they determine the textural characteristics of the final product, which must be suitable for consumption.

To determine if the doughs comprising modified rice flour have suitable rheological characteristics, the peak viscosity (1), the drop viscosity (2), the final viscosity (3), the start-up filling temperature (4) were measured and retrogradation (5) at different moisture concentrations, and compared with the dough prepared with unmodified rice flour (Control). The test was performed with a rheometer (Rheo Pro +, Kinexus, Malvern UK) equipped with an accessory for measuring starch (Starch cell), using standard method 2 (AACC International Method 76-21.01 Standard 2, 2000). The result is shown in Table 4:

Table 4. Mass filling characteristics

The viscosity profiles of the dough prepared with treated flours are shown in Figure 2. The profiles were obtained by mixing 3.5 g of flour (corrected at 14% humidity) and 25 g of water. The dispersed mixture was heated for 1 min at 50 ° C, 7 min 30 seconds from 50 to 95 ° C, maintained at 95 ° C for 5 min and cooled from 95 to 50 ° C in 7 min 30 seconds and maintained at 50 ° C for 2 min.

The recipe ingredients were kneaded for 12 minutes. The masses were characterized with a rheometer with serrated parallel plates (Rheo Pro +, Kinexus, Malvern UK). The results obtained in the frequency sweep test were adjusted to the power law. The adjustment values are presented in Table 5. Table 5. Rheological characteristics of the masses

The consistency of the masses is evaluated from the high values of the viscoelastic modules G ’and G” established by oscillatory rheological tests. Table 5 shows that the modified flour gives rise to products with better appearance and texture.

The results obtained in table 5, show that the doughs made with rice flour modified with the method of the invention are more consistent than those made with unmodified flour, with both elastic (G ') and viscous (G ”) modules more high and values of tan (d) lower than those obtained in the control mass. From this analysis it is concluded that the doughs prepared with modified flour have better physical characteristics than those prepared with unmodified flour.

BIBLIOGRAPHY

Pérez-Quirce, S et al. (2016). Inactivation of endogenous rice flour b-glucanase by microwave radiation and impact on physico-chemical properties of the treated flour. Food and Bioprocess Technology, 9 (9), 1562-1573.

Pérez-Quirce, S et al. (2017). Effect of microwave radiation pretreatment of rice flour on gluten-free breadmaking and molecular size of b-glucans in the fortified breads. Food and Bioprocess Technology, 10 (8), 1412-1421.

Steffe, JF. (1992). Rheological methods in food process engineering. 2 ^nd Ed. Freeman Press. USES.

Sumnu, G. (2001). A review on microwave baking of foods. International Journal of Food Science & Technology, 36: 117-127. Villanueva, M et al. (2018). Microwave absorption capacity of rice flour. Impact of the radiation on rice flour microstructure, thermal and viscometric properties. Journal of Food Engineering, 224, 156-164.

Claims

1. Method of obtaining modified flour for the preparation of gluten-free dough comprising:

a) obtaining gluten-free cereal flour;

b) humidifying the flour from step a); Y

c) treatment of the moistened flour from step b) with microwave.

2. Method according to claim 1 characterized in that the flour moistened in step b) comprises 15-35% w / v of water.

3. Method according to any of claims 1 or 2, characterized in that step c) takes place at a frequency of between 0.5 and 3 GHz for a period between 10 seconds and 60 minutes.

4. Method according to claim 3, characterized in that step c) takes place at a frequency between 0.913 and 30 GHz for a period between 2 seconds and 16 minutes.

5. Dough comprising the modified flour obtained by the method of any of claims 1 to 4.

6. Mass according to claim 5 characterized by having:

peak viscosity between 0.5 and 2.5 Pa;

start temperature of filling between 60 ° C and 95 ° C;

elastic modulus (G ’) between 1400 Pa and 8000 Pa;

viscous module (G ”) between 850 Pa and 5000 Pa.

7. Dough according to any of claims 5 or 6, characterized in that it additionally comprises at least one additive between 0.001 and 2% w / w.

8. Bakery, pastry or biscuit product characterized in that it has been made with a dough according to any of claims 5 to 7.

9. Bakery product according to claim 8, characterized in that it has a hardness between 0.05 to 2.5 N and an elasticity between 0.1 and 1.

10. Use of the modified flour obtained according to the method of any of claims 1 to 4 as an ingredient in the manufacture of a gluten-free dough.

11. Use of the modified flour obtained according to the method of any of claims 1 to 4, as an ingredient in the manufacture of gluten-free bakery, pastry and biscuit products.

12. Use of the modified flour obtained according to the method of any one of claims 1 to 4, as an ingredient in the production of products for the consumption of people sensitive to gluten.