WO2014082884A1

WO2014082884A1 - A method of manufacturing of dry potato products

Info

Publication number: WO2014082884A1
Application number: PCT/EP2013/074041
Authority: WO
Inventors: Winfried AHLGRIMM; Michael BOEKER; Christian KASDORF; Edeltraut SIEGMUND
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2012-11-27
Filing date: 2013-11-18
Publication date: 2014-06-05
Also published as: AR093607A1

Abstract

Dry potato products are known in the art. This dried potato products are then in the granular form and can be packaged in quantities assembled in bags. These bags (like tea bags) are then heated in water, so that the dry potato products swell and produce a ready to use product. It is an object to reduce the energy consumption and/or simplify of the process for producing potato flakes. We have found that crushing the potatoes prior to extruding them, provides a better quality dried potato proiduct after drying than the conventional process.

Description

A METHOD OF MANUFACTURING OF DRY POTATO PRODUCTS

Field of the invention

Dry potato products are known in the art. This dried potato products are then in the granular form and can be packaged in quantities assembled in bags. These bags (like tea bags) are then heated in water, so that the dry potato products swell and produce a ready to use product.

Background of the invention

Dried potato products are known in the art and are the basis for many food products. They are often used by consumers, but they are also used as an industrial raw material for pre-processed potato products such as potato dumplings, gnocchi, potato based pasta, instant mash. Especially for the preparation of dumplings and instant mash the way of processing the potato material has a clearly recognisable effect on the taste.

In commonly known processes, the dried potato products are obtained by a complex production process. The conventional process comprises the steps of:

pre-washing the potatoes, sorting out foreign bodies and peeling potatoes and washing the potatoes,

2 cut the potatoes into small pieces,

3 blanching,

4 cooling of the pieces,

5 making mashed potatoes from these pieces

6 Then the mash is mixed with other ingredients, such as spices, cooked

component, vegetables shares or similar.

7 The resulting mass is then formed into so-called flakes. These flakes are

typically floured with starch.

8 Then they are dried

9 And finally after that the dried flakes are ground, so that a dry potato product in granular form is obtained.

Starch flouring gives a less authentic flavour to the potato flakes, and is preferably avoided. Furthermore the conventional process requires a lot of the intermediate products to be reprocessed and added back into the process. DE3340354C1 discloses dry potato granules that are swellable in hot water for the preparation of dumplings by introducing water-permeable bags or the like filled with the granules and, possibly, other dry products into hot or boiling water. A dough mixture is prepared from raw or half-cooked and/or cooked potatoes, potato starch, water and conventional ingredients, granules are formed therefrom and dried, the dough mixture being compressed by an extruder at a pressure of 30 to 120 bar, the temperature of the dough mixture in the extruder not exceeding 100 degrees C, the extrudate formed being cut to form granules and the granules being dried to a residual moisture content of about 10 percent. After swelling, the granule particles do not transform into a homogeneous dumpling dough, but are recognisable as individual particles in the dumpling, such as is the case in home-made dumplings having corresponding raw fractions. A potato dumpling made from these granules thus corresponds in character to a dumpling produced from raw potatoes.

However the cooking is a high energy consuming process,

DE1281825B discloses a method for preparing a dry product of starch containing vegetables such as potatoes.

It is therefore an object of the present invention to provide a process for preparing potato flakes that avoid the requirement of flour dusting.

It is a further object to reduce the energy consumption and/or simplify of the process for producing potato flakes.

It is a yet another object to reduce reprocessing in the process.

It is still another object to provide flakes with improved quality.

It is yet a further object to provide an improved potato dumpling. Surprisingly it has been found that crushing the potatoes prior to extruding them, provides a better quality dried potato proiduct after drying than the conventional process.

Summary of the invention

Accordingly, in a first aspect the invention provides a process for preparing a dried potato product comprising the steps of: crushing peeled un-cooked potatoes, decanting the potato pulp; and extruding the potato pulp.

In another aspect the invention provides a dried potato product obtainable by the process according to anyone of claims 1 to 7.

In a third aspect the invention provides the use of the dried potato product in for preparing a readymade dumpling.

These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about".

Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. Brief description of the Figure

Figure 1 shows a schematic diagram of the conventional process according to the invention, compared to the process according to the invention. Detailed description of the invention

The invention now has the purpose to provide a novel process for the production of potato products.

The process of the invention is different in that the steps 2-7 of the conventional process are replaced by the process according to the invention, comprising the steps of, crushing peeled un-cooked potatoes, decanting the potato pulp, the potato pulp is extruded.

Pre-processing

The potatoes are typically pre-washed and foreign material and bad potatoes are generally separated from the rest of the potatoes.

The potatoes are typically peeled. On industrial scale this is generally done in a steam peeler or corundum peeler, but other peeling devices are also contemplated in the scope of the present invention.

Crushing

In the process of the invention the pre-washed peeled potatoes are crushed without a need for prior cooking, blanching or other means of full or partial cooking of the potatoes. The crushing can be done by means of any physical crusher, preferably by a hammer mill, grater mill or slicing machine and the like.

After crushing the moisture content is typically between 70% to 90%, more preferably between 75% and 85%, ideally about 80%.

Decanting The excess water is then decanted from the crushed potatoes. This may be done by regular decanting processes, but may also include mechanical dewatering means, such as a baler, belt press or horizontal and/or vertical centrifuge. In a decanting process, an inertial force impacts on the solid. This does not coincide with the direction of movement of the liquid. The decanter typically consists of a rotating drum which consists of a cylinder and a cone section. In the drum a screw conveyor rotates. The potato pulp is typically continuously fed via the inlet pipe in the decanter. Due to the centrifugal force, the solid is deposited on the drum wall and the solid material is transported out of the system by the screw conveyor. The solid is transported with the screw to the cone part of the drum. The liquid flows to the end of the cylindrical section.

After decanting the moisture content of the pulp is typically between 30% to 60%, more preferably between 40% and 55%, ideally about 50%.

Extrusion

The thus obtained potato pulp is fed to an extruder and extruded. At this stage further taste enhancing ingredients, such as herbs, spices, cooked ingredients, vegetable puree flakes, and mixtures thereof, may be added. When taste enhancing ingredients are added, the pulp is typically weighed before mixing with the taste enhancing ingredients.

Without wishing to be bound by a theory, it is thought that through the extruder the mass is mixed, and mechanically and thermally treated. This is thought to result into a change in the physical and chemical properties of the potato.

The preferred extruder is a single or twin-screw extruder. In case of a twin-screw extruder, a co-rotating twin-screw extruder is the most preferred.

By extrusion is meant a thermo-mechanical process for shaping of a dough by forcing it through a die or restriction. Extruders are generally classified as high-temperature short - time (HTST) reactors that can transform a variety of raw materials into modified intermediate and finished products. For the invention a so called co-rotating twin-screw extruder is used. A twin - screw extruder consists of two screws, placed in an 8-shaped barrel. Co - rotating twin - screw extruders are the most common in the food and snack industry; this comprises two screws rotating in the same direction (hence called co - rotating). Without wishing to be bound by a theory, it is thought that based on screw configuration the raw potato dough is processed into a a precooked product by the extrusion process. The screw elements is thought to provide a pressure boosting followed by a temperature rise, resulting in starch geiatinization and degradation of the starch of the potato dough.

Drying and further processing

The material outflow from the extruder is then dried and preferably a residual moisture content of between 1 % and 20%, more preferably between 2% and 15%, more preferably between 3 and 10%, ideally a moisture content of about 6% is achieved.

Drying may be done by means of any type of dried, preferably a belt dryer or fluid bed dryer.

The dried, optionally portioned products, may be ground to obtain a granule. The grinding may preferably be done in a hammer mill or roller mill.

The granule may be packaged as an instant mash, or processed to a potato dry product such as potato dumplings, gnocchi and/or potato based pasta and potato snacks.

This is then made-up and used for the corresponding final product application. Dumplings

The dried potato product produced according to the invention is suitable for example for use in potato dumplings, mashed potatoes or instant products, like potato snacks.

Dumplings are prepared after grinding and sieving the dry product. This product is typically transported a hopper (or even a silo) above a filling machine. The outlet of the hopped is preferably equipped with a volumetric dosing system. Boiling bags (also known as boil-in-bag bags) are filled with a preset amount of the potato product, preferably at least 10 g, more preferably at least 50 g, or even at least 80 g, but generally less than 500 g, typically not more than 200g. After filling the bags are closed, e.g. by sealing. Consumers just need to cook the readymade dumpling.

Without wishing to be bound by a theory, it is noted that in the process according to the invention fresh potatoes are directly processed in the extruder and provided with further additives. This combined operation creates an intermediate product, which then can be further processed in a simple way.

The simplified process according to the invention removes or reduces the need for interim flouring with starch. The new dried potato products are characterized by particularly high water absorbency. This allows reducing the use of raw materials compared to material which is made with the standard process. Texture and flavour of the dried products manufactured with the new process are distinguished by their high quality. Detailed description of the figure

Figure 1 shows a schematic diagram of the conventional process according to the invention, compared to the process according to the invention. The part of the conventional process that enclosed by the box is replaced by the process of the invention enclosed by the box the other steps are conventional process steps that may be the same for the conventional process and the process according to the invention.

Examples

The invention will now be illustrated by means of the following non-limiting example.

Examplel : granule preparation of potato products. Fresh potatoes were cleaned by water, and the potatoes were peeled by a steam peeler. The peeled potatoes were crushed by a hammer mill. The resulting size of the potato pieces was between 1 mm and 20 mm. In the next process step the pieces were dewatered to a moisture content of between 30 and 60%. The dewatered potato and other ingredients were mixed in a twin screw extruder. Depending on the specification of the end product following recipe are used:

Recipe 1

80 kg dewatered potato

15 kg potato flakes

1 ,5 kg salt

3,5 kg spice mixture

Recipe 2

70 kg dewatered potato

15 kg potato flakes

2,5 kg salt

10 kg milk components

2,5 kg spice

The extruder was set to the following parameters:

• tempering (temperature end plate: < 1 20 °C)

• extruding (Pressure end plate: 20-50 bar; SME: 5 - 120 Wh/kg)

• cutting (Speed cutting unit: 200-2500 UPM) The flakes were pneumatically transported to a belt dryer. The Moisture content of the end product is between 6-8 %. The last production step is the sieving of the flakes. Therefore a roller mill or a hammer mill is applicable. The grain size for recipe 1 is <4000μηι and for recipe 2 <800μηι.

Process action Parameter

1 ) Provision of potatoes

1 ) Washing 2) Peeling

3) crushing of the potatoes Potato sticks between 1 mm till 20 mm

4) dewatering Dry substance of the potato: 30-60 %

5) extruding a) mixing Recipe 1

80 kg dewatered potato

15 kg potato flakes

1 ,5 kg salt

3,5 kg spice mixture

Recipe 2

70 kg dewatered potato

15 kg potato flakes

2,5 kg salt

10 kg milk components

2,5 kg spice

b) tempering Temperature end plate: < 120 °C c) extruding Pressure end plate: 20-50 bar

SME: 5 - 120 Wh/kg

d) cutting Speed cutting unit: 200-2500 UPM

6) drying Moisture content end product 6-8 %

7) sieving Grain size

Recipe 1 : <4000μηι

Recipe 2: <800μηι

Both recipes resulted in dried potato flakes that were suitable for use for instance as an instant mask or for processing into a dumpling.

Claims

1 A process for preparing a dried potato product comprising the steps of:

a Crushing peeled un-cooked potatoes;

b Decanting the potato pulp; and

c Extruding the he potato pulp.

2 A process according to claim 1 , wherein the potatoes are crushed in a hammer mill.

3 A process according to any one of claims 1 or 2, wherein the potatoes are further mechanically dewatered to a moisture content of less than 60%.

4 A process according to any one of the preceding claims, wherein the potato pulp is mixed with further ingredients selected from spices, herbs, cooked ingredients, and/or vegetable puree flakes prior to extruding.

5 A process according to anyone of the preceding claims, wherein the extruder is a twin-screw extruder.

6 A process according to anyone of the preceding claims, wherein the material outflow from the extruder is dried to a moisture content of 1 -10%.

7 A process according to anyone of the preceding claims, wherein the dried

extrudate is ground to a granule.

8 A dried potato product obtainable by the process according to anyone of claims 1 to 7.

9 Use of the dried potato product in for preparing a readymade dumpling.