Process for making a simulated potato product

Abstract: A simulated potato product in sliced form is obtained by co-extruding a core containing at least about 80% by wt potato mash within a shell of a composition containing at least about 70% potato mash without addition of water.

Description: FIELD OF THE INVENTION This invention relates to food products, in particular those comprising potato. When preparing potato products intended for eating as a separate snack or as a component of another product, eg a ready cooked meal, a considerable degree of handling is necessary in the preparation and cooking of the potato feedstock. BACKGROUND TO THE INVENTION Potatoes are a valuable source of nutrition and the amount of handling necessary to prepare them can make them uneconomic as a food product prepared for large scale production. The present invention provides a process for the preparation of a potato product suitable for such production. The product resembles, ie simulates, slices of a potato vegetable which has been subjected to a cooking stage, eg baking, and then sliced. GENERAL DESCRIPTION OF THE INVENTION According to the present invention there is provided a method of preparing a sliced potato product comprising coextruding a core composition containing at least 80% by weight of potato mash within a shell of a potato composition containing at least 70% by weight of potato mash without addition of water. Preferably the core composition comprises above 90% by weight of potato mash and the shell composition comprises at least 80% by weight of potato mash. The separate compositions may include suitable colouring and/or seasoning materials to make the composite slice more comparable to the natural product. Additionally, the colouring/seasoning can provide a distinct product having a specific flavour. In order to provide the appearance of a peripheral skin the shell will show, in section, about 15% to about 25% preferably to about 22% of the area of the total slice. However this upper limit could be increased to give a more distinctive skin, if a specific product design required it. Potato mash is formed by boiling potatoes and mashing them to form a product which is deformable but retains its shape. The shell, ie skin, being formulated from potato mash, adheres to the core and remains intact during production and packing. Additionally, the extrusion may be performed using shaped sections in the extrusion nozzle which give a section other than that associated with a sliced vegetable. Thus, the outer surface of the nozzle may be given a corrugated effect to provide an outer shell, ie the baked potato skin, of varying thickness. Such variations can imitate those decorations which would be applied by a cook in the preparation of a meal. These variations would be particularly useful if the slice was intended as a snack produce for consumption as a separate foodstuff. The slices will usually be made at an angle of 90° to the axis of extrusion, however other angles may be chosen to provide elongate slices. The separate slices will have a consistency of section derived from the extrusion process. The shell will preferably contain a flour to provide a dough consistency. Usually this flour will be present in the range of about 1% to about 5% by wt. Literature EPA 0402178 (Unilever) describes an extruded vegetable product, especially made from potato, in folded or convoluted form. US 4167588 (Willard) and GB 1 509 722 (Willard) describe the fabrication of a whole baked potato from potato mash and a skin prepared from baked potato pieces. The objective of these Willard disclosures is to simulate a complete baked potato both for appearance and taste. These disclosures teach that the outer "skin" layer of the potato product must have a higher solids content than the core. SPECIFIC DESCRIPTION OF THE INVENTION An example of the process and product of the invention will now be given with reference to the accompanying diagrammatic drawings in which: Figure 1 is an axial section through a co-extrusion device; Figure 2 is an enlarged view in the direction I-I of Fig. 1. The co-extrusion apparatus comprises a barrel 1 having a cylinder 2 positioned co-axially within it to form a peripheral annulus 4. A potato composition is introduced into the annulus through the input port 6 and a mash composition into the central core volume 3 through port 5. The apparatus includes a flow control valve 7 to vary the flow of mash from port 5 into core 3. The paths of the two inputs are shown hatched for clarity. One formulation for the core and the periphery were prepared: Core formulation Ingredient wt% potato mash 92.20 rice flour 3.53 potato granules 3.35 salt 0.78 Celacol* 0.10 ascorbic acid 0.04 Total 100.00 Edge (skin) formulation potato mash 79.144 water none added seasoning 10.01 rusk 2.40 rice flour 3.03 potato granules 2.876 poppy seeds 1.20 salt 0.75 starch 0.3 Celacol 0.166 ascorbic acid 0.034 Total 100.00 These formulations, ie Core + Shell, were co-extruded at a temperature of 10°C in a weight ratio of shell:core in the range from about 15:85 to about 25:75 and preferably to about 22:78 to give an extruded product comprising a central core with a shell. The extrusion apparatus had input port 6 at 45° so the two streams came together separated by only 45°. This port 6 also had a valve to control the flow of outer shell material. Additionally the co-axial barrel 1 and cylinder 2 were constructed to have the sectional profile of the desired product along the whole of their length. When sliced across the extrusion axis at 90° and fried, slices of a potato product resembling baked potato was obtained. The shell could be visually distinguished from the core after subjecting the slices to frying. From Figure 2 it is seen the section of the extrusion nozzle, and thus the slice section, is not circular but approximates the section of a natural vegetable. Other sections, eg square and hexagonal, can be used to provide a novelty product. The product according to the invention thus simulates a slice of a baked potato at least in appearance.

Claims: A method of preparing a sliced potato product comprising coextruding a core composition containing at least 80% by weight of potato mash within a shell of a potato composition containing at least 70% by weight of potato mash without addition of water, the potato mash in each case being obtained by boiling potatoes and mashing them. A method according to claim 1 wherein the core composition comprises above 90% by weight of potato mash. A method according to claim 1 or claim 2 wherein the shell composition comprises at least 80% by weight of potato mash. A method according to any preceding claim wherein the weight ratio of the shell:core is in the range of from 15:85 to 25:75. A method according to any preceding claim wherein the weight ratio of the shell:core is up to 22:78. A method according to any preceding claim wherein the shell contains flour.

Inventors: BAMFORD SARAH JANE, BAMFORD, SARAH JANE
Applicants: UNILEVER NV, UNILEVER PLC, UNILEVER N.V.
Application year: 1993
Main classification: A23L1
IPC codes: A23L1