WO2015086809A1

WO2015086809A1 - Method and arrangement for obtaining an extruded/expanded cereal-based sweet biscuit

Info

Publication number: WO2015086809A1
Application number: PCT/EP2014/077540
Authority: WO
Inventors: Luciano LOPEZ JAUREGUI
Original assignee: MOLINOS RIO de la PLATA SA; MOLINOS IP SA
Current assignee: MOLINOS RIO de la PLATA SA; MOLINOS IP SA
Priority date: 2013-12-13
Filing date: 2014-12-12
Publication date: 2015-06-18
Anticipated expiration: 2016-06-13
Also published as: CL2014003389A1; PE20150993A1; BR102014008583A2; UY35840A; AR093967A1

Abstract

A method for obtaining an extruded/expanded cereal-based sweet biscuit with a sugar coating, comprising the steps of: mixing in a mixer the raw materials used for the biscuit with a high proportion of amylaceous products such as rice flour; making the substrate biscuits on which the invention is put into practice, in an extruder using a head with dies forming strips of expanded material. cutting the strips of expanded material with a cutter to the desired length; placing the biscuits, using a vibrating distributor, on a single plane without overlaps, and delivering them onto a conveyor belt, wherein the biscuits are coated with a spray of water or an aqueous solution to improve adherence of granular solids or dry powders such as sugar or a mixture of sugar and dyes; applying granular solids or dry powders; drying the exceeding moisture and caramelizing in an oven; cooling at room temperature, and packaging.

Description

METHOD AND ARRANGEMENT FOR OBTAINING AN EXTRUDED/EXPANDED

CEREAL-BASED SWEET BISCUIT

Field of the Invention

The present invention is directed to a method for applying sugar onto extruded and/or expanded cereal biscuits or a mixture thereof, with a low moisture content, to obtain a sweet flavored biscuit with improved organoleptic acceptability of the product, in terms of flavor, crispiness and appearance.

Background of the invention

Rice is used for manufacturing biscuits, mainly by two methods: puffing and extrusion. In the first method, previously moistened rice grains are placed in a heated matrix. Pressure is applied on said matrix using a heated counterpart for a few seconds. As they rapidly expand, in addition to gellation of starch granules, the water contained therein evaporates, thus causing expansion of the structure to yield a light, edible product, although with a rather unpleasant texture. When using extrusion, low density expanded biscuits are produced from rice flour and ingredients such as salt, sugar, powder milk, etc. The use of other ingredients or higher proportions of the above-mentioned ingredients affects puffing and thereby final texture of the product.

This type of biscuit has a low moisture content and therefore an adhesion agent is required for coating it with granular solids or dry powders. Adherence of ingredients is usually achieved by spraying with any adherent liquid such as oil or a hydrocolloid solution in rotatory drums, and subsequent application of powder ingredients followed by drying, if necessary. In this type of process, the coating affects the entire surface of the product and if oil is employed as an adherent liquid, any excess is perceived by touch by the consumer.

The present invention refers to the application of a sweet coating exclusively on one of the flat faces of the biscuits.

Description of the Drawings

Figure 1 shows the different steps of the process.

Detailed description of the invention

Powder ingredients with a high proportion of amylaceous products such as rice flour are mixed in a horizontal mixer 1 , then the mixture is expanded in a single screw or twin-screw extruder 2 using linear dies, for example, having a thickness of 2 mm and a width of 20 mm, to form fine strips which are cut into the desired length and distributed onto a flat surface. Such formulation is shown in Table I :

TABLE I

The extruder operates at 150 to 400 kg/h and the strips exit the extruder at a linear speed from 10 to 30 m/min, preferably from 15 to 25 m/min, and a reduction of the linear speed is required for the subsequent coating processes and to take more advantage of oven width and obtain longer residence times therein.

The strips are then conveyed to a roller/cutter 3. When cutting the expanded strips, the product has a moisture from 5 % to 15 %, preferably from 8 to 12 % and a temperature from 50 to 95^Q C, preferably from 70 to 85^Q C, which impart flexibility for cutting with scored rollers without generating fine powders.

The resulting biscuits are 2 to 4 cm wide and from 2 to 8 cm long, preferably from 2.5 to 3.5 cm wide and from 2.5 to 3.5 cm long, and are placed on a vibrating distributor 4 consisting of, for example, from 1 to 6 vibrating trays, preferably from 2 to 4 vibrating trays, that allow for placing all the biscuits on a single plane. The biscuits are sent to a conveyor belt operating at a speed from 5 to 20 m/min, preferably from 14 to 18 m/min, which delivers them to a spraying system 5 using water or an aqueous solution. The spray comprising water or an aqueous solution is applied onto the extruded formulation to improve adherence of granulated sugar to the surface, which is applied immediately thereafter.

Spray is generated by forcing water or an aqueous solution through metering nozzles which allow for its pulverization and by regulating air and liquid pressure. Water is sprayed at a rate from 0.005 g/cm² to 0.01 g/cm² to achieve the deposit of granular solids or dry powders from 0.03 to 0.035 g/cm² of biscuit surface, with a homogeneous distribution thereon.

Application of granular solids or dry powders, for example sugar or a mixture of sugar with dyes, flavorings, etc., is carried out in the step of caramelization 6 by means of a curtain generated from a nozzle located 15 - 20 cm away from the conveyor belt and its application rate is regulated through the lower sugar discharge opening by gravity. Another feeding method comprises the use of a slotted surface roller, where the process variable is the speed of said roller.

In baking step 7 the exceeding moisture content is dried out and the sugars or mixtures are caramelized to achieve the desired crispiness of the product with values from 2 to 5 % moisture content wet basis. The type of oven to be used in this step is a direct flame oven with air circulation at low speed as this is a light weight product, and the process also includes additional steps involving infrared heat application.

The residence time in the oven is from 2 to 5 minutes, with a conveyor belt speed from 8 to 20 m/min, preferably from 10 to 14 m/min.

The last manufacturing step prior to packaging 9 of the product is cooling 8 wherein the products are conveyed in direct contact with air at room temperature over a residence time of 10 a 20 min to prevent sticking of products to each other and condensation within the airtight containers.

The formulation corresponding to this product is described in detail in the following Table III :

Ingredients %

Extruded biscuit 90 - ■60

Sugar 10 - ^■ 40

TABLE 1

Example 1 :

An extruded biscuit was manufactured using rice flour (92%), powder milk (6%), salt (1 %), and sugar (2 %) under the following process conditions in the extruder:

• Flow rate of dry ingredients: 300 kg/h

• Water added to the extruder: 20 kg/h

• Screw speed: 200 rpm

• Working temperatures: 180; 140; 130; 100; 70; 30 °C

The strips exited the extruder at a speed of 23 m/min, having a width of 32 mm, a thickness of 7 mm, a bulk density of 0.10 g/cm³, and 9 % moisture. Thickness was reduced to 6 mm by means of a roller.

Strips were cut into biscuits that were 3 cm long, 3.3 cm wide and 0.6 cm thick using a roller cutter and they were arranged employing a distributor to prevent overlapping of units. The biscuits were delivered through a conveyor belt at a speed of 12 m/min to a water spraying system. Pump pressure was regulated so as to achieve a dosage of 0.004 g/cm², equivalent to 0.04 g/biscuit, an amount which is sufficient to moisten the surface of the biscuit's upper face.

This was followed by application of sugar onto the moistened face of the biscuit by passage of said biscuits through a curtain of sugar at 12 m/min. The rate thus achieved was of 0.15 g/unit.

Example 2:

An extruded biscuit was manufactured using wheat flour (90 %), powder milk (6 %), wheat bran (2 %), salt (1 %), and sugar (2 %) under the following process conditions in the extruder:

• Flow rate of dry ingredients: 300 kg/h

• Water added to the extruder: 21 kg/h

• Screw speed: 180 rpm

· Working temperatures: 180; 1 60; 1 60; 100; 70; 30 °C

The strips exited the extruder at a speed of 22 m/min, having a width of 32 mm, a thickness of 7 mm, a bulk density of 0.12 g/cm³, and 10 % moisture. Thickness was reduced to 6 mm by means of a roller.

Strips were cut into biscuits that were 3 cm long, 3.3 cm wide and 0.6 cm thick using a roller cutter and they were arranged employing a distributor to prevent overlapping of units.

The biscuits were delivered onto a conveyor belt at a speed of 12 m/min into a water spraying system. Pump pressure was regulated so as to achieve a rate of 0.004 g/cm², equivalent to 0.04 g/biscuit, an amount which is sufficient to moisten the surface of the biscuit's upper face.

This was followed by application of 0.5 % vanilla-flavored sugar onto the moistened face of the biscuit by passage of said biscuits through a curtain of sugar at 12 m/min. The rate thus achieved was of 0.15 g/unit.

Claims

CLAIMS:

1 . A method for obtaining an extruded/expanded cereal-based sweet biscuit with a sugar coating, comprising the steps of:

mixing in a mixer the raw materials used for the biscuit with a high proportion of amylaceous products such as rice flour;

making the substrate biscuits on which the invention is put into practice, in an extruder using a head with dies forming strips of expanded material.

cutting the strips of expanded material with a cutter to the desired length;

placing the biscuits, using a vibrating distributor, on a single plane without overlaps, and delivering them onto a conveyor belt, characterized in that the biscuits are coated with a spray of water or an aqueous solution to improve adherence of granular solids or dry powders such as sugar or a mixture of sugar and dyes; applying granular solids or dry powders; drying the exceeding moisture and caramelizing in an oven; cooling at room temperature, and packaging.

2. The method of claim 1 , characterized in that said spraying is achieved by forcing water or an aqueous solution through metering nozzles which allow for its pulverization and by regulating liquid and air pressure.

3. The method of claim 2, characterized in that said spraying is performed with an amount of water ranging from 0.005 g/cm² to 0.01 g/cm² so as to achieve adherence of granular solids or dry powders from 0.03 to 0.035 g/cm² substrate biscuit, with a homogeneous distribution on the surface of the substrate biscuit.

4. The method of claim 1 , characterized in that drying is performed from 2 to 5 minutes at a conveyor belt speed from 8 and 20 m/ min, preferably from 10 to 14 m/min.

5. The method of claim 1 , characterized in that cooling is by direct contact with air at room temperature over a residence time of 10 to 20 min.

6. An arrangement used with the method of claim 1 , characterized by comprising:

a mixer for mixing the raw materials used for the substrate biscuit;

an extruder ;

a roller/cutter;

a vibrating distributor;

a sprayer; a nozzle for applying granular solids or dry powders an oven ; and

a cooling conveyor.