NO762936L - - Google Patents

Description

The present invention relates to food products of that kind

which are popularly called "snacks" and more specifically such products which have been produced by extrusion.

Food products sold under the name snacks are many and of a varied nature. Such products include goods such as potato slices and "corn flakes" puffed cereal products and biscuit products (e.g. flavored biscuits) and the like. Usually such snack items are eaten outside the usual meals, but sometimes it can also form part of such a meal. Many different snack products are often served at the same time.

People usually have very different tastes when it comes to snacks.

A person can e.g. at ease try snack products of different kinds and on this basis choose a type that particularly suits the person in question. Extensive attempts have been made to refine snack products. Great efforts have also been directed at finding new such products that are distinctive

somehow.

The present invention relates to a method for the production of new puffed snack products. In the past, such snack products of the puffed type have usually been produced by processing flour-like material in a screw extruder under elevated pressure and temperature. Thus, when the treated material leaves the extrusion apparatus, a considerable expansion will take place.

According to the present invention, flour-like material is mixed with water and possibly other materials to form a hydrated material in particle form. This hydrated particulate material is then supplied to a suitable extrusion apparatus, such as e.g. one Collet extruder, and is extruded in this apparatus under considerable temperature and pressure. The temperature and pressure must be sufficient for the material to boil and be in such a state that sufficient expansion takes place after the extrusion process.

The expanded extrudate can then be fed between a pair of pressure surfaces, such as consists of a pair of rollers, so that the expanded material is compressed. The thus compressed extrudate can then be cut into pieces of the desired size. These pieces can be toasted and inserted with an oil and/or seasoned. Alternatively, the pieces can be deep-fried in fat. The compressed extrudate can also be processed in other ways. The surface can e.g. colored to resemble fat and lean sections of bacon slices.

The present invention can be carried out by using different types of grain or other starchy material. Typical materials that can be used are rice > wheat, oats, maize, barley and potatoes. If desired, a combination of the aforementioned materials can be used.

The aforementioned flour-like material can be present in finely ground form

flour or, if desired, the particle size of the material can be somewhat larger, e.g. in the form of grits.

The flour-like material can be mixed with water to increase the material's moisture content, preferably to a range of around 13 - 25% and preferably 16 - 22%. The terms "percent", "~andélér£" and the like apply in this presentation to parts by weight unless otherwise stated.

A suitable mixing apparatus can be used, and the method of the invention

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has e.g. successfully carried out in a Hobart-type apparatus

It has been found advantageous to allow the mixed flour-like material to be kneaded for a period of time, e.g. 2 hours or more,

so that an even distribution of moisture is ensured throughout the entire mass of material.

A Collet extruder is suitable for use as an extrusion apparatus in carrying out the present invention. A typical apparatus of this kind is shown and described in US-PS 3,358,582. Suitable temperatures for the extrudate at the outlet from the nozzle are in the range 115 - 175°C, and suitable pressures are in the range 35 - 105 kg/cm . The collet extruder can be used either

with or without a cooling jacket and can have a ratio between screw length

and diameter in the range'1:1 to 3:1.

The flour-like material will typically expand three to seven times after extrusion, at which point it will contain many small voids or bubbles. A considerable proportion of the moisture will evaporate during the expansion or puffing. The material's moisture content can e.g. be about 13 to 25% immediately before the extrusion and about 5 to 12% immediately after the extrusion process is completed.

The compression is carried out while the extruded material is in a malleable state and before cooling to solid form. The extrudate,

will be soft and malleable for a short time after extrusion, usually for 2 to 15 seconds. The compression can be carried out using a pair of stainless steel rollers. Alternatively, the compression can be carried out between a pair of reciprocating plates or between a pair of endless belts. If desired, the surface of one or both rolls, surfaces or belts may be patterned which will be pressed into the surface of the extrudate during compression. The thickness after compression can e.g. be between 50 and 5% of the original thickness, and will typically lie between 0.4 and 6.5 mm. The extrudate can be cut before or after compression.

Although various modifications can take place without exceeding the scope of the invention, the following examples will illustrate the method of the invention.

Example I

A snack product with potatoes as raw material was produced according to the present invention by mixing 75 parts

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potato granules and 25 parts corn grits in a fcypen Hobart mixer Sufficient water was added during mixing to create

a total moisture content of around 18%. The mixer was then kept running for 2 hours to ensure even distribution of the moisture. The thus prepared hydrated mixture was then fed to a Collet extruder which worked at a rotation rate of 400 revolutions per minute.

minute. This extrusion apparatus was equipped with a nozzle with five openings, each consisting of a slot of 25 x 0.4 mm. The temperature of the extruded material on the exit side of the nozzle was around 140°C. The extruded strip had a thickness of about 6.5 mm. Immediately after extrusion and while the puffed extrudate was still soft and malleable, the extrudate was compressed between a set of rollers with a waffle pattern on the surface. The waffle squares had a side length of around 6.5 mm.

The areas that were most compressed had a thickness of 0.4 mm, while the rest of the tape had a thickness of 6.5 mm. The compressed strips were then cut into pieces with a length of approx. 30 cm.

These cut pieces were then roasted at a temperature of 175°C

for 3 minutes and then added with oil and salt. The thus pressure-treated snack product had a crisper and harder consistency which was very different from the usual non-pressure-treated potato-based products produced by Collet extrusion.

Example II

A snack product on a cereal basis was prepared and mixed in a

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mixer of the Hobart type of 80 parts maize grits, 20 parts defatted maize kernels and 0.25 parts calcium hydroxide with sufficient added water to set the moisture content to 18%. The thus mixed material was then left for 2 hours for complete moisture penetration. The material was then fed to a Collet extruder with a rotational speed of 300 revolutions per minute. minute. This extruder was equipped with a nozzle with three openings. Each opening had the form of a slit with dimensions 18.5 x 0.4 mm. The temperature of the extrudate at the outlet side of the mouth thickness was 140°C. The extruded soft strips were immediately compressed between two rollers with mutually adapted concave oval recesses in the surface. These rollers thus compressed certain areas of the strips, but left a significant proportion of the strips without compression. After cutting and shaking, the pieces were seasoned with oil and salt. The pieces thus produced had a flavor and texture reminiscent of crispy "corn flakes", but were very different from the usual cereal products produced using a Collet extruder.

Example III

A biscuit-like rice product was produced on the basis of polished rice

by setting the moisture content to around 20%. This hydrated rice material was left for moisture penetration for 3 hours and then extruded through a Collet extruder operating at a rotational rate of 300 revolutions per minute. minute. The extruder was equipped with a nozzle with three openings. Each opening was in the form of a slot with dimensions 35 x 1.55 mm. The temperature of the extrudate on the outlet side of the nozzle was 140°C.

The extruded strips had a thickness of approx. 4.5 mm and was compressed, while still in a soft and malleable state, between two smooth rollers to a thickness of about 3 mm. The rolls thus produced were then cut into pieces and shaken. A glaze was then applied to these pieces. This product had the same crunchy texture as a baked rice cracker.

Example IV

Example I was repeated except that the extruded material strip was compressed to a uniform thickness of about 1.5 mm and then deep-fried at 190°C.

Example V

A snack product was prepared by mixing 28% all whole grain rice, 25% whole wheat, 25% corn kernels, 20% tapioca granules and 2% sugar. , The moisture content was set at 19%. The hydrated mixture was extruded through ether. nozzle at 140°C and then puffed to a thickness of about 4.5 mwi. The extrudate was then passed between two pressure rollers with a waffle pattern or protruding ribs. The product thus produced was toasted and inserted with a glaze flavored with maple syrup.

Claims (11)

1. Process for the production of a food product, characterized by boiling a hydrated flour-like material in a pressure chamber at an elevated temperature, so that a mainly gelatinized dough is formed, extrusion of said flour-like material through a nozzle opening to form an extrudate with the desired cross-section and such that the moisture content of the extrudate is reduced in relation to the moisture content of said hydrated material, compression of at least part of said extrudate between two pressure surfaces while the extrudate is still formable, until the distance between the surfaces is such that the thickness of at least parts of the extrudate is substantially reduced, after which the extrudate is cut into sections of predetermined length. 2. Procedure as stated in claim 1, characterized in that the hydrated flour-like material is produced by the addition and uniform mixing of sufficient water so that the moisture level in the material is increased to between 13.0 and 25%. 3. Procedure as specified in claim 2,/ characterized in that the moisture content of the extrudate during said compression is in the range between 5.0 dg and 12.0%. 4. Procedure as stated in claim 2, characterized in that said elevated temperature is in the range 115 to 175°C, and the pressure is in the range 35 to 105 kg/cm <2> . 5. Procedure as stated in claim 2, characterized by the humidity level being between 16.0 and 22.0%. 6. Procedure as stated in claim 5, characterized in that the moisture content of the extrudate during compression is between 5.0 and 12.0%. 7. Procedure as stated in claim 1, characterized in that the flour-like material is composed of 0 to 100% corn, 0 to 100% rice and 0 to 100% potatoes. 8. Procedure as stated in claim 4, characterized in that at least one flavoring additive is added to the material mixture. 9. Procedure as stated in claim^2, characterized in that the material mixture is kneaded for a sufficient time to provide completely equalized moisture content throughout the material mass before it is introduced into the cooking chamber. 10. Procedure as stated in claim 1, characterized in that at least one of the pressure fists is applied so that at least one of the side surfaces of the extrudate during the compression is applied to an irregular surface and thus the thickness of the compressed extrudate varies. 11. Method as stated in claim 10, characterized in that both pressure surfaces are provided with a surface pattern.