FR3040588A1 - PROCESS FOR TREATING SEEDS FOR OBTAINING FOOD PRODUCTS - Google Patents

Abstract

This process of industrial seed treatment comprises the following successive stages: - Soaking seeds, - Seed germination, - Seed cooking, - Seed drying, and - Dehulling seeds. Application to the preparation of food products based on cereals and legumes.

Description

The present invention relates to a method of treating seeds for obtaining food products.

The field of the invention is that of the agri-food industry. It is about treating natural products to make food for human consumption. The products concerned here are seeds and more particularly cereals and legumes.

It is recognized that cereals and legumes are an interesting dietary supplement especially for their intake of proteins and certain amino acids that are not synthesized by the human body. Cereals and legumes are complementary in the supply of essential amino acids. Indeed, cereals do not provide lysine or tryptophan while legumes do not provide methionine or cysteine but are rich in lysine. The combination of legumes with cereals is of nutritional interest because, in comparison with the use of cereals alone, it increases the protein content, provides a better balance of essential amino acids, provides more of soluble and insoluble fibers, to provide iron and B vitamins, in particular B 9, and also to reduce the glycemic index (by increasing the amylose / amylopectin ratio).

Legumes also have the advantage of being low in fat and having a low glycemic index. They are therefore of real interest for human nutrition. As such, the National Health Nutrition Program recommends daily consumption of vegetables and legumes.

However, legumes in particular include antinutritional factors that make it difficult for the human body to assimilate the proteins it supplies. Antinutritional factors are substances contained in a food ingredient that decreases its digestibility, leading to digestive discomfort and / or flatulence. These are for example inhibitors of trypsin, tannins, lectins, galactooligosides and phytates. The reduction of these antinutritional factors makes it possible to increase the digestibility of a food.

In addition, legumes in their natural state sometimes have an altered and unpleasant taste.

The object of the present invention is therefore to provide means, in the form of at least one method, making it possible to limit antinutritional factors and thus to increase the digestibility of these cereals and / or legumes. The process will also increase the value of the protein content of the treated seeds. Preferably, the method will also improve the taste of certain legumes. To this end, the present invention provides a method of treating seeds, characterized in that it comprises the following steps: - soaking of the seeds, - seed germination, - baking of seeds, - drying of seeds, and - dehulling of seeds seeds.

It has been found that the succession of these three stages, which each of them taken separately is known and current in itself in the agri-food field, made it possible to very significantly limit the antinutritional factors in the seeds, and more particularly in the legumes which have Naturally, antinutrients are more important than in cereals. It has been observed that this process also makes it possible to increase the value of the protein content of the seeds.

The seeds used are mostly dry, with a moisture content of less than 11%. The soaking step (rehydration of the seeds) prior to the germination stage is advantageously a step of soaking in water in a volume allowing the seeds to be covered, preferably a volume greater than 3 times the volume of the seeds, for example between 3 and 10 times the volume of seeds. Depending on the nature of the seeds, the soaking step lasts for example between 1 and 50 hours and at a temperature between 2 ° C and 10 ° C, preferably at 7 ° C. The seeds are preferably completely immersed during the dipping step in water. The water used for soaking may advantageously be supplemented with a disinfecting product (solution based on chlorine and / or acetic acid) to obtain a debacterized water.

In the process proposed by the present invention, seed germination is carried out for example at a temperature between 10 ° C and 30 ° C in a humid environment with a humidity level greater than 80%. This germination can be done in the absence of light or preferably with a blue light.

Preferably, the ambient air during the germination stage is saturated with water. To maintain and / or guarantee this saturation, it is proposed that the seeds are regularly sprayed, directly or indirectly, with water during the germination stage. In the case of indirect spraying, water is sprayed into the enclosure containing the seeds but the spray is not directed towards the seeds.

To promote homogeneous germination of the seeds, the latter are preferably arranged in a container in a layer whose thickness is between 10 and 50 cm for the germination step.

The baking of the seeds is preferably carried out in water at a temperature of between 80 ° C and 100 ° C. Thus, the baking of the seeds is preferably in boiling water. The duration of the baking of the seeds can be between 20 and 30 minutes.

After dehulling, the seeds may be crushed. We then obtain semolina. It is also possible to pass the seeds obtained, once dried and dehulled, in a grinding wheel for the production of flour.

The semolina obtained by grinding can be used for making foods similar to pasta. The seeds used to make these pasta type foods, for example are formed by a mixture containing between 40 and 50% legumes, for example 45%, and cereals (100% complement). These legumes will preferably be selected from chickpeas, beans, yellow peas, horse beans, lupins and lentils.

Details and advantages of the present invention will become more apparent from the following description, which gives a preferred embodiment of the present invention.

The method which will be described below is intended to improve the digestibility of seeds such as cereals and legumes. Another goal is to increase the protein value of these seeds. Another goal is to improve the taste of certain legumes and / or cereals.

Cereals means seeds from grasses and certain plants of other families (wheat, rye, oats, barley, rice, maize, millet, sorghum, etc.) used for human food and domestic animals, especially when they are reduced to flour.

Legumes are dicotyledonous plants whose fruit is a pod used as a vegetable (peas, chickpeas, beans, ...), forage (clover, alfalfa, ...) or for wood (rosewood).

Most often, these seeds are dry (with a moisture content of less than 11%). When provided, they are not entirely pure. Conventionally for the food industry, the seeds should be riddled with light debris and small stones that may be present. It is known to carry out by ventilation the removal of light debris and by stone removal the removal of pebbles contained in the mixture.

Then, the seeds being dry, it is first provided a soaking operation to allow their subsequent germination. The dipping operation is preferably carried out in water which may optionally be added with a disinfectant (chlorine solution and / or acetic acid for example) to remove bacteria and / or other additive. The seeds are then preferably fully immersed to ensure that each of them soaks well. The temperature of the soaking bath will be relatively low, of the order of a few degrees. It is preferably less than 10 ° C, for example between 2 ° C and 7 ° C.

The seeds should be allowed to soak for a long time so that they are well moistened with water. The soaking time will depend on the type of cereals and the type of legumes. Soaking times for cereals will be of the order of a few tens of hours, for example between 1 and 50 hours, most often in the range of 18 to 36 hours, while for legumes, a soaking of a few hours, for example from 1 to 20 hours, most often from 4 to 18 hours, will be sufficient.

Once the seeds are well soaked and impregnated with water, they are removed out of the water, usually out of a so-called soaking tank, then washed. The washing may be carried out for example with running water, optionally with an additive.

To achieve seed germination, they are preferably arranged in a relatively thin layer (preferably less than 50 cm thick) in a chamber protected from sunlight. To promote germination, the seeds can be illuminated by a blue light. The temperature of the chamber will be maintained between 10 ° C and 30 ° C, preferably around 20 ° C (between 15 and 25 ° C). As well as the temperature and the lighting, the hygrometry will also preferably be controlled in the germination chamber. A humid atmosphere will be maintained in the enclosure. The hygrometry will preferably be greater than 90% and, preferably, the air in the germination chamber will be saturated with water. To maintain and guarantee this saturation in water, it can be expected to regularly spray water in the enclosure, directly on the seeds or indirectly. The germination stage is carried out until the appearance of seeds visible to the naked eye on the seeds. It usually lasts between 36 and 48 hours but can last up to 72 hours. The next step in seed preparation is a cooking step. The seeds are then brought to a temperature of between 80 ° C. and 100 ° C. for a few tens of minutes.

The sprouts are preferably immersed in boiling water (which is therefore around 100 ° C) for a duration of a few tens of minutes, for example between 20 and 30 minutes. However, for some cereals a shorter cooking time may be sufficient and in contrast, some legumes may require a longer cooking time (up to 2 hours).

Cooking in an oven, in hot air saturated with water, can also be considered. Such cooking is preferably carried out at a pressure close to atmospheric pressure.

After the cooking operation, a dehulling operation is carried out consisting in removing the outer film from the seeds. This operation could be done earlier but it is easier to do after cooking the seeds. The removal of these films is done mechanically.

Removing the outer film of the seeds, which does not contain any protein, makes it possible to increase the ratio of the mass of the proteins to the total mass of the seeds. In some cases, dehulling also reduces the amount of antinutritional factors in the seeds.

When cooking was done with boiling water, or in an oven, the seeds after cooking are not dry. They can then be used for the preparation of salads or to be pureed. It can also be planned to dry them to improve their conservation.

The drying can be carried out for example in two operations, a first pre-drying operation and a second drying step itself.

During the pre-drying, the cooked seeds and optionally dehulled are arranged for example in a concentration ball. Such a device is known in the food industry and serves for example for the production of confectionery. This device makes it possible to evaporate part of the water contained in the seeds. These are placed in a closed chamber which is then heated after possibly being partially evacuated to promote the evaporation of the water contained in the seeds by limiting the heat input.

Depending on the heat input during pre-drying, the seeds may be sufficiently dry to be stored and / or for any use as an ingredient in a subsequent implementation.

The pre-drying can also be completed by the second drying operation, for example by propelling dry and hot air under the seeds. The temperature of the hot air will preferably be limited (less than, for example, 80 ° C.) to limit the Maillard reactions. After this drying operation, the hygrometry rate in the seeds thus treated is preferably less than 10%.

Tests to quantify the contributions of the process according to the invention with respect to seeds used without treatment have been carried out. These tests included three anti-nutritional factors: anti-tryptic factors, galactooligosides and phytates.

For anti-tryptic factors, a measurement of trypsin activity is carried out by assay using a synthetic substrate such as BAEE (Benzoyl-L-Arginyl-Ethyl Ester). The dosage slope is then measured and the result is expressed in BAEE units per milligram (or UBAEE / mg). The ideal here is to have a zero slope. Using only untreated chickpea, the measurements made give on average -1070 UBAEE / mg. For durum wheat semolina, this slope is -16 UBAEE / mg, which means that semolina durum is very digestible compared to chickpea. After treatment of chickpeas, it is possible with the process according to the invention to obtain a zero slope when whole chickpeas are soaked, sprouted and cooked for 20 or 30 minutes.

For galactooligosides, a concentration of this antinutritional factor is measured (in g / kg or in mg / g). It was noted that for this antinutritional factor, soaking (and subsequent germination) made it possible to limit the concentration of galactooligosides and that the cooking had little influence on the levels of this antinutritional factor. It is possible here to go from a concentration of 21 g / kg of galactooligosides in raw chickpeas to about 11 g / kg in treated chickpeas.

The seeds thus obtained, after germination and cooking, and preferably after also dehulling and / or drying, can be used directly for the preparation of culinary specialties: salads, accompaniment of a dish (as is done with rice, wheat , bulgur, ...).

The seeds obtained can also be ground to obtain a semolina or ground to obtain a flour. This semolina and flour can be used to make culinary preparations. Semolina can also be used in salads (for example of the tabouleh type). It is also possible, by remixing semolina to water, prepare pasta type foods. These may for example be made with a proportion of legumes of between 40 and 50%, for example 45%, the complement to 100% being made with cereals. Thus the protein intake of such pasta type foods is higher than pasta made solely from durum wheat semolina. The protein value of pasta-type foods (with 45% legumes) is increased by at least 50% compared to conventional pasta without degradation of digestibility.

By making pasta-type foods (ie using the pasta recipe but using 45% chickpeas and 55% durum instead of 100% durum wheat) , trypsin activity in pasta-type foods is reduced by more than 87% compared to activity in raw chickpea. Cooking these foods does not affect trypsin activity.

For galactooligosides, pasta-type foods, but with 45% chickpeas and 55% durum wheat, reduce the concentration of galactooligosides by about 2/3 (from 21 g / kg to a value of 5.8%). and 7.1 g / kg depending in particular on the cooking times in the treatment process) compared to chickpeas. On the other hand, once the pasta-type foods are cooked, their concentration of galactooligosides is divided approximately by 2, which makes it possible to obtain concentration levels of the order of 3 g / kg. Thus, despite the presence of chickpeas, a galactooligoside concentration is obtained after cooking which is lower than their concentration in the durum wheat semolina.

For phytates, pasta-type foods with 45% chickpeas and 55% durum wheat have a phytate concentration of between 4.1 and 4.8 g / kg, depending in particular on the cooking times in the process. compared to a concentration of 8.7 g / kg in raw chickpeas. On the other hand, once the pasta-type foods are cooked, their phytate concentration is reduced by about 1/3, which makes it possible to obtain concentration levels of the order of 3 g / kg. Thus, despite the presence of chickpeas, a phytate concentration is obtained after cooking which is lower than their concentration in durum wheat semolina.

It is possible for example with flour obtained from seed treated as described above to make for example pancakes or pancakes (sweet or salty) containing legumes. Such pancakes allow an improved protein intake.

The seeds before drying, as indicated above, can be pureed and used to prepare a hummus. The latter, even prepared only with chickpeas, will be more digestible than a traditional hummus.

The method described above, by virtue of the combination of a germination step and a cooking step, makes it possible to limit the antinutritional factors in the seeds, and in particular the legumes. The latter can then be used in food preparations as is usually done with wheat. The antinutritional factors in the food products then made with a mixture of wheat and legume, for example chickpeas, yellow peas, horse beans, lupins and / or lentils, make it possible to obtain concentrations of order of those for durum wheat, which ensures a good digestibility of these foods.

Of course, the present invention is not limited to the preferred embodiment described above and the variants mentioned but it also relates to all the variants within the scope of those skilled in the art within the scope of the following claims .

Claims (13)

1. Process for the industrial treatment of seeds, characterized in that it comprises the following successive stages: - soaking of the seeds, - germination of the seeds, - baking of the seeds, - drying of the seeds, and - dehulling of the seeds. 2. Method according to claim 1, characterized in that in the soaking step, the seeds are soaked in water debacterized. 3. Method according to one of claims 1 or 2, characterized in that the soaking step lasts between 1 and 50 hours at a temperature between 2 ° C and 10 ° C. 4. Method according to one of claims 1 to 3, characterized in that the seeds are completely immersed during the soaking step in a volume of water corresponding to at least three times the volume of seeds. 5. Method according to one of claims 1 to 4, characterized in that the seed germination is carried out at a temperature between 10 ° C and 30 ° C in a humid environment with a humidity greater than 80%. 6. Method according to claim 5, characterized in that the seeds are regularly sprayed with water during the germination step. 7. Method according to one of claims 1 to 6, characterized in that the seeds are arranged in a container in a layer whose thickness is between 10 and 50 cm for the germination step. 8. Method according to one of claims 1 to 7, characterized in that the baking of the seeds is carried out in water at a temperature between 80 ° C and 100 ° C. 9. Method according to one of claims 1 to 8, characterized in that the baking of the seeds lasts between 20 and 30 minutes. 10. Method according to one of claims 1 to 9, characterized in that after dehulling, the seeds are crushed. 11. Method according to one of claims 1 to 9, characterized in that after dehulling, the seeds are passed through a grinding wheel for producing a flour. 12. Process according to claim 10, characterized in that the semolina obtained by grinding is used for the production of pasta-type foods. 13. The method of claim 12, characterized in that the seeds are formed by a mixture containing between 40 and 50% of legumes selected from all chickpeas, beans, yellow peas, faba beans, lupins and lentils and cereals. (100% complement).