CS258486B2 - Method of raw pastries' artificial drying - Google Patents

Abstract

Process for the artificial drying of uncooked dough, in which the temperature of the dryer in the first phase after the commencement of drying is kept above 100 DEG C and, at the same time, the humidity of the dryer is regulated in such a manner that its lower value is at most 5%, but preferably from 2 to 4%, lower than the current relative equilibrium humidity of the drying uncooked dough, and then in a further, second phase, the temperature and the humidity of the air in the dryer are reduced together in such a manner that the lower value of the relative humidity becomes at most 8%, preferably from 4 to 8%, lower than the current relative equilibrium humidity of the drying uncooked dough.

Description

The invention relates to a method for artificially drying raw dough products.

As is known, the production of dried dough products (macaroni, spaghetti, spiral noodles, barley egg flour) can basically be divided into two main phases. These are the production of dough of the appropriate shape and then the drying process.

The basic raw material for dough production is flour for the industrial production of pasta, which in many respects differs from flour used in bakery or confectionery. Only glassy wheat is suitable for the industrial production of pasta, which makes it possible to produce a uniform, coarse-grained semolina or bran-free flour and to obtain on a large scale a rigid, flexible gluten of good quality. For this purpose, grit (triticum durum) ground from glassy wheat is best. Glassy wheat gluten is particularly stiff and elastic. In the case of known technologies, the quantity and quality of gluten is of decisive importance for the quality and first of all for the cooking and mechanical properties of the dried pasta.

The gluten content of other ground wheat products is generally lower and also the quality is unfavorable for pasta production.

The grain structure of vitreous wheat allows the production of grit having a grain size of 250 to 400 µm, which is favorable for use in pasta production. no other type of wheat (triticum aestivum) has all the qualitative properties described above. .

This implies that the quality of pasta from wheat flour of the species triticum aestivum does not reach the quality of hard grist pasta; the mechanical properties and cooking properties of the resulting products are equally disadvantageous.

The yield of glassy wheat is considerably lower than that of triticum aestivum; furthermore, areas with a Mediterranean climate are primarily suitable for the production of vitreous wheat. For this reason, the price of hard grinders is significantly higher than that of wheat of the species triticum aestivum. ,

The main stages in the production of dried pasta are as follows:

preparation of raw materials, mixing (pasta production) thickening shaping drying

As is known for the purpose of drying pasta products, it is to provide the product with such properties that it resists mechanical action during further processing and does not serve as a breeding ground for the multiplication of microorganisms. Drying pasta is a job that needs to be done with great care and expertise, with leadership decisively affecting product quality. According to the general consciousness, drying pasta is a very simple task, which is not true. In particular, the drying of the fibrous goods constitutes a special, demanding task, first and foremost with regard to the precise adjustment of the temperature and relative moisture content during the entire drying process.

The initial, i.e., the simplest, method of drying pasta is to dry in the natural environment or in the open air. This is mainly used in Mediterranean areas where the most common airflow is from sea to land, so that drying is carried out in air with a reasonably high relative moisture content. Due to the high moisture content, drying takes a long time. During drying, the product, when water evaporates from its surface layer, is transferred to a room with a temperature of 12-15 ° C generally to the cellar.

It is left there for 8 to 10 hours. It is then brought back to the open air, followed by surface drying. This work is carried out as long as the moisture content of the product is not about 12 to 13% by weight, this process usually takes several days. In the design of artificial drying devices, it has been primarily sought to reduce the drying time while maintaining product quality. Therefore, it was considered important to reduce moisture slowly and carefully in drying technologies. Therefore, the drying time for fiber products was 48 to 72 hours, and for small products 24 to 36 hours. The maximum drying temperature was 30-32 ° C, then 40 ° C. The relative moisture content was maintained at between 65 and 75% by weight.

These drying machines for these technologies were not produced until the late 1950s. Thereafter, the lines for the complete production of pasta began to be used, which are fully mechanized continuous lines and provided with measuring and control devices. In the drying apparatus, a so-called pre-drying method is carried out, in which the pasta introduced into the drying apparatus is heated gradually from an initial temperature of 28 to 30 ° C to a temperature of 48 to 50 ° C. The moisture content in the air is 80 to 85% by weight, the passage time of the pasta is 50 to 70 minutes. The moisture content of the pasta introduced into the pre-drying device is 30 to 32%, the moisture content of the pasta coming from the pre-drying device is about 22 to 23% by weight. The next phase is heating to balance relatively large moisture and strain gradients in the pasta. The temperature in this phase is 60 to 65 ° C, the relative moisture content is 90 to 95% by weight. The passage time - i.e. the heating up to 60 minutes.

The next stage or the final stage of the process is the so-called post-drying. The inlet temperature is about 55 ° C, which slowly decreases from 85 to 90 wt%, up to 72 to 76 wt%. In the case of this continuous-drying dryer, the total drying time - together with the pre-drying - is 25 to 30 hours, depending on the product used. These devices are still used today as large-scale industrial production units.

The purpose of the further development in the production of pasta was to further reduce the passage time (drying time) by increasing the moisture and temperature content. This drying plant has been used since the early 1970s as an industrial plant. A feature of these devices is that they are provided with a pre-drying device and an end drying device. The drying air flow rate in the pre-drying device reaches 8 to 10 m / s. The air heating starts at the entrance of the pasta and gradually increases from 30 ° C to 60 ° C. The relative moisture content in the air in the pre-drying device is 85 to 90% by weight. The passage time is about 50 to 70 minutes; during this time, the moisture content of the pasta is reduced from an initial value of 30% by weight to about 18% by weight.

This is followed by heating, which takes about 20 to 30 minutes, to a temperature of 65 to 70 ° C at a relative moisture content of 95 to 98% by weight. The final stage of this process is drying as well; the air temperature is initially 65 to 70 ° C, then slowly decreases and is about 30 ° C in the last 4 to 5 hours of drying. The relative moisture content is about 85 to 90% by weight at the start of the process, then slowly decreases to 75 to 80% by weight. In this case, the drying time is 18 to 24 hours depending on the product.

The solutions described above allow the production of good quality pasta but have the following drawbacks:

Very high quality granular flour (special flour with a high gluten content) is necessary for pasta production. This is always a great problem, since grinders from modern wheat with high yields are not suitable for this purpose at all. The yield of durum wheat suitable for industrial pasta production is low; its grinding is a special task. It is also necessary to take into account the storage of grist. All this adds to the most important raw material for pasta production - flour;

The drying time of the most modern equipment is still about 20 hours; in view of large capacity production lines, very large drying machines are necessary;

Due to the relatively high but long-used temperature, the number of germs in the product will be reduced considerably in the most modern devices, but even in this case, infection can occur during drying, especially at low temperature devices.

The most important object of the present invention is to provide a process for drying dough which can also be carried out industrially and allows to reduce the quality requirements of the basic raw material, i.e. by using this method it is also possible to use grinders of present wheat types with high harvest yields.

A further object of the invention is to reduce the drying time and thus to reduce the size of the drying apparatus considerably, thereby reducing production costs.

A further object of the invention is to reduce the number of germs during drying, i.e. to prevent the infection of the pasta with certainty.

The invention is based on the discovery that the above-described objectives can be perfectly accomplished when the temperature, in contrast to the temperatures used in the prior art drying processes, is increased to more than 100 ° C in the first stage of drying time and maintains a small amount by a maximum of 5% by weight, less than the actual relative equilibrium water content of the pasta to be dried. .

This finding is therefore surprising since, to date, according to the past experience of the pasta industry, it has not been possible to dry at temperatures above 100 ° C without causing significant damage to the product, i.e. without cracking and disintegration, because of very high humidity gradients due to high temperatures, excessively high mechanical stresses occur in drying or dry pasta. In the drying process, therefore, it was not only possible to use temperatures in excess of 100 ° C, but also temperatures in excess of 70 ° C.

In contrast, it has been found that the use of temperatures in excess of 100 ° C is not harmful if the moisture content is set as described above, but rather is suitable for solving the task. This will be explained further.

The present invention relates to a process for drying raw pasta in a drying apparatus, and is characterized in that, in a first stage after the start of drying, lasting one third of the total drying time, the drying temperature is maintained at at least 100 ° C, regulates to a value which is not more than 2 to 5% by weight less than the current relative equilibrium water content of the drying dough, whereupon the temperature and the moisture content are simultaneously reduced in the second drying phase, reducing the temperature to 45 to 75 ° C and the lower value of the relative moisture content is reduced to a value which is 4 to 8% by weight lower than the actual relative equilibrium water content of the drying raw dough.

The moisture content of the dough is measured continuously during drying and the moisture content is automatically controlled based on the measurement results.

By raw dough product is meant an intermediate product which is generally produced in the preparation of raw materials by mixing, i.e., dough preparation; followed by thickening and shaping. The water content before drying is about 25 to 30% by weight. By drying, the water content of the intermediate is reduced to 12% by weight. In this way, the dried raw dough product is a product sold as dried pasta. ·

The first drying phase in the process according to the invention is understood to mean the insertion of the pasta into the drying chamber. It is not yet advantageous to use a temperature above 100 ° C, but a lower temperature of about 80 ° C is used. According to the invention, the critical first phase lasts 1/3 of the entire drying time, during which the temperature is above 100 ° C and the moisture content is controlled as described above. Reducing this time, for example below 1/4 of the drying time or substantially prolonging it, for example by 50% of the drying time, does not produce the desired result.

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However, the duration of 1/3 must not be viewed strictly, as the duration used depends in practice on the actual water content of the raw dough introduced as well as on the type of dough.

There has been talk of above 100 ° C in the first drying phase, but this has its sensible limits; it is not advisable to raise the temperature in the drying device above 120 to 125 ° C, since this does not bring any advantages, and conversely, there may already be some drawbacks, for example coloring with a slightly yellowish to brown tinge due to the surface formation of dextrin.

In the second stage of the drying process according to the invention, the temperature in the drying device is to be reduced. This temperature reduction should preferably be carried out slowly, the temperature in the drying device should eventually drop to 75 ° C and the moisture content should also be reduced accordingly, so that the relative moisture content in the drying device is always only at most 6% by weight. but preferably 4 to 8% by weight, less than the relative moisture content corresponding to the actual equilibrium water content of the drying pasta. Cooling to 75 ° C is a minimum requirement, it can also be conducted at lower temperatures, in practice, cooling is generally conducted up to temperatures of 45 to 50 ° C, naturally while reducing the relative moisture content. These low temperatures also include - relative to the equilibrium content - as described above, the relative values of the moisture content.

The characteristic values of the relative moisture content of pasta with different contents / water - at average mean temperatures (50 to 80 ° C) - are given in the following table:

Water content in dough% wt.

Relative equilibrium content by weight

1040

11.547

12.553

1356

13.560

14.567

15.571

17.577

18.580 .85

22.590

29.599

Smaller deviations from these values occur at higher or lower temperatures.

According to the table, for example, the actual equilibrium content of the dough is 85% by weight, at a water content of 20% by weight, for a dough with a water content of 10% by weight but 40% by weight.

During the process, an intermittent drying device can be used in which the raw dough is placed and in which the change in temperature and moisture content takes place substantially around the dough. However, it is preferable to use a continuous-running dryer, that is to say such a drying apparatus in which the drying raw dough is in motion and drying of the dough is achieved by passing it through regions of a drying apparatus of different temperature and different moisture content.

In order to reach the temperature, known heating is used and the moisture content of the drying device is controlled by ventilation or by adding steam. With regard to safety, it is advantageous to automate the technology. It is preferable that not only temperature and relative moisture content is measured continuously during this automation and these are controlled, but it is desirable to continuously measure the water content of the dough and use these values during control. This is because the desired technological parameters can be safely set.

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There are a number of known solutions for temperature measurement and control. For example, the moisture content can be measured or controlled by a sensor described in Hungarian patent 179,324, by means of which the water content of the raw dough is measured by a dielectric method and the signals of such a measuring device can be used for control.

As mentioned above, ventilation is also a means of regulation. It is advantageous to limit the air flow in the drying device, for example to use an air flow rate of 2 to 4 m / s and for an adequate moisture content in the air, for example in the absence of an additional heat method. using chemical means). ’

The advantage of the invention is that, in contrast to the prior art methods of drying pasta, it is also possible to produce from the grind of average quality dried pasta of excellent quality by the method according to the invention. This is due to the fact that during the drying process there is a continuous diffusion from the inner layers of the dough towards the surface and consequently the average moisture content of the raw material, which is initially 25 to 30% by weight, is reduced to 12% by weight. As the drying temperature rises to 100 ° C, the diffusion rate of moisture increases considerably - especially with dough with a higher water content. The moisture content of the drying device is maintained at a condition corresponding to a dew point of 98 DEG C. as a result of which no large moisture gradient is formed in the dough and cracks and tendency to occur are avoided.

The process according to the invention even favorably influences the dough structure, the starch grains in the dough by heat effect and encloses the protein components, which increases the stability of the pasta, improves the cooking properties on a large scale and even reduces the losses in cooking. During the high-temperature drying process, the protein components precipitate, which again contributes to the stability of the pasta and further reduces the 2-losses in cooking. All these changes can be examined in the microscopic examination of pasta. A comparison of the cooking properties of the pasta prepared by the process according to the invention with the pasta according to the known methods is shown in Table 2.

Table 2

Cooking properties of pasta products

Time

Control

Sample boiling swelling% wt.

% swelling

5 120 uncooked, flour strips in the middle 115 not cooked 10 149 the flour strips have not yet disappeared 168 boiled, good substance smooth surface, no flour strips 15 Dec 181 no flour strips, sticky surface, soft, crumbly texture 176 good substance, smooth surface ⁴ 20 May 215 No change 181 good substance, the surface is not slimy 25 221 No change 187 good substance, somewhat slimy surface

continuation of Table 2

Cooking properties of pasta products

Time Control Sample boiling swelling swelling % wt. % wt. ³⁰ 235 very soft, very crumbly structure 191 No change cooking residue * /% / 7.58 4.36

⁺ Boiling time is 12 minutes

A further advantage of the method of drying the raw dough according to the invention is that the drying time is considerably shorter compared to the known drying methods. Indeed, the drying time obtainable by artificial drying methods of 18 to 24 hours can be reduced to about 1/3, i.e. 6 to 8 hours, using the method according to the invention. This is explained by the fact that the diffusion of moisture is accelerated very quickly at the high temperature of use of the raw dough in the state of its highest humidity, but due to a precisely controlled moisture content in the air, no moisture gradient occurs and hence pasta quality is not affected

A further advantage of the process according to the invention is that the risk of increasing the number of microorganisms due to the high number of germs and the temperature used in excess of 100 [deg.] C. is virtually eliminated. This also means that, in contrast to the prior art processes, a germ-free end product can be produced.

An additional advantage of the process according to the invention is that even when the dough is made from flour having high polyphenoloxydase activity, a characteristic brown coloration does not occur in the final product. This is explained by the fact that said enzyme activity virtually ceases with respect to high temperatures.

The accelerated method has the further advantage that the space required for the dryer is considerably less. Thus, even in smaller drying devices, the same amounts of pasta as before can be dried using the prior art methods in about 3 times larger drying devices, or, for example, in continuous operation, the drying devices can operate at significantly greater capacity if adequate temperature and moisture control are maintained.

The process according to the invention can be applied to pasta of all kinds and sizes.

The invention is further explained by means of one exemplary embodiment without being limited thereto.

Example, embodiment

The raw macaroni preparation is introduced into the drying apparatus at the temperature and humidity ratios below. It can be dried according to the method of the invention as follows:

Time (minutes) Dry temperature (° C) Humid Temperature (° C) insertion 80 60 10 100 ALIGN! 85 15 Dec 118 98

Time (minutes) Dry Temperature (° C) Humid temperature (° C) 30 100 ALIGN! 95 60 100 ALIGN! 92 60 92 ⁶⁴ 60 88 80 60 84 76 30 83 75 25 82 72 60 80 70 60 78 68 30 75 64 removal

The total drying time according to the method described above is about 500 minutes. The cooking properties of the produced starting product as compared to the control product according to the prior art are shown in Table 2.

The term dry temperature refers to the actual temperature of the drying device, and the term wet temperature refers to the temperature value in the drying device measured by a wet thermometer. The latter is suitable for controlling the moisture content of a drying device.

Claims (2)

SUBJECT OF THE INVENTION Process for artificially drying raw pasta, characterized in that, in the first stage after the start of drying, lasting one third of the total drying time, the drying temperature is maintained at least 100 ° C, wherein the lower air humidity limit is controlled to a value which is by 2 to 5 W of mass, lower than the current relative equilibrium water content of the drying raw dough, whereupon the temperature and the moisture content are simultaneously reduced in the second drying phase, the temperature being lowered to at least 45 to 75 ° C and the lower relative value The moisture content is reduced to a value that is 4 to 8% by weight lower than the actual relative equilibrium water content of the drying dough. 2. Method according to claim 1, characterized in that the moisture content of the dough is measured continuously during drying and the moisture content is automatically controlled on the basis of the measurement results.