FR2640472A1 - Method for manufacturing instant agglomerated cereals in order to form a creamy consumable product - Google Patents

Abstract

The present invention relates to novel methods for producing pre-cooked instant agglomerated cereals which are capable of dissolving readily in a liquid in order to give cereals with a creamy consistency, and it relates to the products prepared using these methods. The initial dry cereal mixture is moistened and cooked in an extruder which extrudes the cereal mixture in expanded form. The cereal mixture is then ground in a grinder with a screen having openings of at least approximately 2.4 mm diameter, and then agglomerated products are formed by measuring the ground cereal mixture into an agglomeration apparatus. The granules are then dried to a moisture content of approximately 4 to 7% and, at this point, they are ready to be packaged or to be combined with a desired liquid. The methods of the present invention offer the additional advantage of it being possible to mix heat-sensitive ingredients into the product after extrusion of the mixture and before it is measured into the agglomeration apparatus.

Description

Process for making instant agglomerated cereals to form a creamy consumable product
The present invention relates to methods for making pre-cooked instant cereal products, and more particularly to methods of extruding, reducing in size and agglomerating a dry cereal mixture to prepare instant cereals capable of being rapidly dispersed in liquids to form a creamy consumable product.

Methods have already been described for preparing cereal products, in which dry cereal ingredients are wetted and heated using extruders and drum drying techniques, and are then dried before being packaged as described in the patent
US No. 4,044,159. Other processes have been described for producing grain-like products which can be readily dispersed in liquids (see, for example, Patents
US Nos. 3,615,674 and 4,016,337).

However, none of these methods indicates the method of the present invention which produces an instant pre-cooked cereal product having a consistency and taste of high quality, which can be easily dissolved in liquids without forming lumps in less than 60 seconds, and more typically in less than 30 seconds. The new methods of this invention also have advantages, since they use the efficient heat transfer method of an extrusion process and make it possible to add heat-sensitive ingredients to cereals during manufacture.

The resulting new products can provide high quality cereals with a creamy consistency after mixing with a liquid, such as milk or water, which are particularly suitable for feeding young children. In addition, the products can dissolve quickly and instantly in liquids, which allows a quick and easy preparation of a creamy product appetizing for consumption.

The present invention relates to new methods for producing instant pre-cooked agglomerated cereals which can be easily dissolved in a liquid to obtain a creamy consistency. The starting dry cereal mixture is moistened and cooked in an extruder, which extrudes the cereal mixture in expanded form. The cereal mixture is then ground in a mill equipped with a sieve having openings of about 2.4 mm in diameter, or less. Granules are formed by dosing the mixture
cereal ground in an agglomeration apparatus. The granules are then dried to a moisture content of about 4 to 7%, and at this point they are ready to be packaged or to be combined with a desired liquid. Preferably, the cereal mixture is extruded from the extruder with a moisture content of about 14 to 16% and at a temperature of about 104 to 1270 C. It is further preferred that the cereal mixture is extruded from the extruder under shape of a sausage and it is cut with a flake blade of about 12.7 to 19 mm in diameter which, after drying, have a density of about 21 g / 100 ml of the product. Typically, the extruder has a die opening of about 3.2 to 6.4 mm in diameter. In the agglomeration stage, it is preferred that the moisture content of the extruded product is adjusted to about 14%. Another advantage of the processes of the present invention is that heat-sensitive ingredients can be mixed into the product after extrusion of the cereal mixture and before it is dosed in the agglomerator.

Although the methods of the present invention are particularly suitable for producing cereals for young children, they can be used to produce any products of the pre-cooked cereal type, which one wishes to be able to
disperse quickly and easily in a liquid Furthermore, thanks to the methods of the present invention, the product can be obtained with good yield, since the intermediate products have a low moisture content, which reduces the drying time required and produces a intermediate product easier to grind. For the purposes of this invention, the term "instant creamy cereals" refers to cereals which can be easily dissolved in a liquid in less than 60 seconds without leaving or forming lumps, and more typically in less than 30 seconds with only stirring minimal.

The starting dry cereal mixture for the production of instant cereals, as detailed in the methods of the present invention, may contain grains or cereal mixtures, which are capable of expanding in an extruder, such as rice, wheat , oats, corn, barley, etc., as well as mixtures of these cereals and special composites as obtained by formulas with high protein content. Additional ingredients can be calcium phosphates, various proteins, various conventional minerals, vitamins, oils and seasonings.

The ingredients of the dry cereal mixture are first moistened and cooked in an extruder, in which water is added with any other suitable wetting agent to constantly adjust the moisture content of the dry cereal mixture to around 14 to 22%. , and preferably approximately 16 to 20%, and in particular approximately 18 to 20%. If desired, the cereal mixture can be moistened to the moisture contents described above before entering the extruder, but it is preferred to adjust the moisture content using the extruder. It has been found that it is particularly advantageous to use a type of twin screw extruder, having a multiplicity of areas surrounded by a jacket, which can be either heated or individually cooled.

The extruder also advantageously comprises a cutting device, a pressure gauge and a thermocouple.

The pressure gauge and thermocouple are placed immediately before the die, so as to easily control the pressure and the processing temperature. The jacketed heating zones supply heat to the product by conduction and the product also receives the heat given off by the friction developed by the rotating screw. The heat passes from the surfaces of the extruder to the product and achieves the desired cooking.

Advantageously, the extruder is equipped with a cutting blade mounted along the outer surface of the extruder head and periodically rotating in a controlled manner, so as to cut the extruded material into short segments when it leaves the extruder, so that the segments can easily be dried and introduced into a grinder for grinding purposes.

The extruder die may include openings of any desired shape, these openings having a diameter of between approximately 1.6 and 19 mm, the desired dimension being a function of the composition of the dry cereal mixture used, because the expansion of the different grains vary during their extrusion. For a mixture which mainly contains rice flour, for example, an opening having a diameter of about 3.2 to 6.4 mm is preferred, and preferably a diameter of 4 mm. The cereal mixture thus preferably leaves the extruder in the form of a rod of approximately 12.7 to 19 mm in diameter and swollen grains (flakes) having these diameters are cut out therefrom.

The cereal product must be processed in the extruder so that the moisture content of the extruded product is between approximately 12 and 20%, preferably between 14 and 16% and in particular approximately 15%. The temperature of the product during extrusion must be between 71 and 1710C, preferably between 93 and 1710C, and in particular between 104 and 1270C.

The extruded cereal product is then allowed to dry to a total moisture content of between about 7 and 10%, and preferably close to 7%, by any of the conventional methods well known in the art.

The dried product is then ground to give a particle size analogous to a fine powder. Typically, it is ground in a mill equipped with a sieve having openings of about 2.4 mm in diameter, or even less, preferably between 2.4 and 0.8 mm in diameter, and in particular of 1 , 3 mm in diameter.

Once the extruded cereal product is ground to this particle size, it can be mixed with other ingredients if desired, especially with heat-sensitive ingredients whose taste, color, nutritional value, etc. been degraded by the hot work of the extruder. Examples of products that can be added are dairy and other sources of protein, condiments, minerals, fruits, sugars, vitamins, etc.

The dried extruded product (comprising any additional ingredients mixed, if desired) is then fed to an agglomerator (apparatus well known in the art), which uniformly wets the dried product to bring the moisture content of the product up to around 14% while creating small granules of the product. This agglomeration process must allow a certain bond of the particles with each other to create granules which, once dried, mix more easily with a liquid. This can advantageously be obtained by using an agglomerator of the disc pelletizer type (Teledyne Readco,
York, PA; Sprout-Bauer, Muncie, PA). The bowl on which the extruded product falls is tilted, for example, at an angle of 500.The bowl is rotated at a certain speed to allow the dried particles to pass through a spray of water spray and, while the particles bond together due to the addition of water, they fall out of the bowl in the form of small agglomerates or wet granules. The size of the granules can be adjusted by controlling the speed of the disc, the angle of inclination of the disc, the total feed rate, the position of the water and dry cereals relative to the face of the disc. It is also possible to use other agglomeration devices, such as a fluidized bed agglomerator (Glatt, RFA) or a high-speed mixing agglomerator (Bepex's Tripleflex Vertical Agglomerator, Bepex,
Minneapolis, MN).

As soon as the wet agglomeration process is completed, the wet granules are dried in any of a number of dryers, such as fluidized bed dryers or vibrating hearth ovens, which are typically used in this process. technique in conjunction with agglomeration devices. The wet granules are dried quickly at low temperature, for example at about 800C, until the moisture content is reduced to about 7% of the total weight or until the dried product has a density of about 19 to 24 g per 100 ml of the product, preferably approximately 19 to 21 g per 100 ml of the product, and in particular 21 g per 100 ml of the product. The agglomerates are sieved to remove oversized grains. The undersized grains can be recycled at the agglomeration stage.

The preferred product is one which can pass through a 2.36 mm mesh screen, but which cannot pass through a 0.85 mm mesh screen, although a wider range may also be used. All sieve sizes considered here correspond to the French standard.

To further illustrate the invention, the following example will be given. It is understood that the particular details of this example should not be considered as limitations in the sense that they can be modified, as will be readily understood by those skilled in the art.

EXAMPLE
The following components are mixed to create a mixture
dry cereal
Ingredients Weight (kg)
rice flour 60.3
soybean oil 1.21
vitamins and
minerals 1.23
The cereal mixture is dosed at a uniform rate in an MPF-50 twin screw extruder, manufactured by Baker Perkins (Grand Rapids, MI), which adjusts the moisture content of the cereal mixture with water so that when the mixture enters the extruder cylinder, it has a moisture content of approximately 188. The extruder is equipped with screws having the following profile spacing stop: 6.35 mm
feed screw: 229 mm
six front pallets at 300
feed screw: 76 mm
single pitch feed screw: 51 mm
a pallet
single thread: 152 mm
feed screw: 76 mm
single thread: 76 mm
The die cage was a two-hole 4mm die.

The length of the cylinder had a ratio of 15: 1 (length / diameter of the screw). The feed rate was 90.7 kg / h, the pump setting was 5.9 and the motor drove the auger at a speed of 400 rpm. The load per meter was 70%. Steam was introduced into five heating zones of the extruder so that the temperature of zone 1 was 160C, that of zone 2, 52 "C, and that of zones 3, 4 and 5, 820C. The mixture wet was discharged from the die under a pressure of 10 MPa, at a temperature of 1140C and with a humidity rate of 15%.

It was found that the extruded product was expanded, on average to a diameter of about 12.7 to 19 mm with a moisture content of about 15%. The product was cut into expanded flakes and allowed to cool. The flakes were dried in ambient air to form a crunchy bead. The dried product was then ground in a grinding apparatus
Fitzpatrick model D fitted with a 1.3 mm sieve) (Fitzpatrick
Company, Chicago, Illinois), the device rotating at low speed. The density of the ground cereals was 31 g / 100 ml.

At that time, the humidity of the product was 7%.

The crushed grain was then agglomerated in a Sprout-Bauer 406 mm disc pelletizer. The disc operated with a feed rate of 27.2 kg / h, a disc speed of 3.5 rpm and a bowl angle of 50. Water was sprayed on the disc and on the grain. Small spherical granules formed when the cereals were brought to a moisture level of about 14%.

The wetted agglomerates or granules were dried in a drying oven with hot air rises in trays at 820C for 15 min. The dried product had a density of 21 g / 100 ml. It was passed through a series of sieves to determine its particle size as follows
Mesh dimensions% pellet retention
sieve
1.6 mm 3
1.18 mm 5
0.85 mm 32
0.60 mm 35
on bowl 24
The cereals retained by the 0.85 mm mesh screen and sieves with larger mesh dimensions were collected for use as instant cereals.

The cereals obtained instantly mixed with water in less than 30 seconds without forming lumps. The water adsorption was 100 ml / 20 g of cereal.

Although the preceding invention has been described by way of illustration and example for ease of understanding, it should be noted that certain changes and modifications may be made thereto while remaining within the scope of the invention, which does not is limited only by the appended claims.

Claims (18)

Claims 1.- Process for producing instant pre-cooked agglomerated cereals, capable of being easily dissolved in a liquid, characterized in that it comprises the following stages a) cooking a wet cereal mixture in an extruder; b) grinding the cereal mixture in a mill equipped with a sieve having openings of about 2.4 mm in diameter or less; c) forming granules by dosing the cereal mixture in an agglomerator; and d) drying the granules to a humidity level of about 4 to 7%. 2.- Method according to claim 1, characterized in that the cereal mixture is extruded from the extruder at a humidity level between about 14 and 16%. 3.- Method according to claim 1, characterized in that the cereal mixture is extruded from the extruder at a temperature between about 104 and 127 C. 4.- Method according to claim 1, characterized in that the cereal mixture is extruded from the extruder in the form of a rod and is cut by a flake blade having about 12.7 to 19 mm in diameter. 5.- Method according to claim 1, characterized in that additional ingredients are mixed in the cereal mixture after extrusion thereof and before it is dosed in the agglomerator. 6.- Method according to claim 1, characterized in that the humidity of the granules is adjusted to about 14% by the agglomerator. 7.- Method according to claim 1, characterized in that, after drying, the granules have a density of about 21 g / 100 ml. 8.- Method according to claim 1, characterized in that the extruder has a die cage opening of about 3.2 to 6.4 mm in diameter. 9. The method of claim 1, wherein the mixture  cereal contains more than 50% rice flour. 10.- Method according to claim 1, wherein the mill is equipped with a sieve having openings of about 1.3 mm in diameter. 11. A composition produced by the method of claim 1, characterized in that it cannot pass through a sieve of 0.85 mm mesh. 12.- Composition produced by the process of claim 2, characterized in that it can easily dissolve in a liquid in less than 30 seconds. 13.- Process for producing instant pre-cooked agglomerated cereals, capable of being easily dissolved in a liquid, characterized in that it comprises the following stages a) heating a dry cereal mixture wet in an extruder; b) grinding the cereal mixture through a sieve having openings of about 2.4 mm in diameter, or less; c) agglomerate the cereal mixture by adding water until its humidity reaches about 14%; and d) drying the cereal mixture so that its density is between approximately 19 and 24 g / 100 ml. 14.- Method according to claim 13, characterized in that the cereal mixture is extruded from the extruder at a temperature between about 104 and 1270C. 15.- Process for producing pre-cooked in-tantanum agglomerated cereals, capable of being easily dissolved in a liquid, characterized in that a mixture is cooked  dry cereal wet at a temperature of about 104 to 1270C in an extruder having a die cage opening of about 3.2 to 6.4 mm in diameter, the cereal mixture is ground, and the cereal mixture is wetted with a agglomerator until the mixture  cereal reaches a humidity level of about 14%, and the mixture is then dried to a humidity level of about 4 to 7%. 16.- Process for producing instant agglomerated cereals, capable of being easily dissolved in a liquid, characterized in that a dry cereal mixture wet in an extruder is cooked at a temperature of approximately 104 to 1270C, the mixture is ground cereal, the cereal mixture is agglomerated with water to form granules and the granules are dried to a moisture level of about 4 to 7%. 17.- Method according to claim 16, characterized in that the cereal mixture is agglomerated with water at a humidity of about 14%. 18.- The method of claim 17, wherein the cereal mixture is extruded from the extruder at a moisture level of about 14 to 16%.