NO136903B - PROCEDURE FOR THE PREPARATION OF A FRUITFUL FOOD. - Google Patents

Description

The invention relates to a method for producing a food product that simulates the texture of fruit, whereby a mixture of fruit mash or puree and an alginate or pectate sol is brought into contact with dissolved calcium ions so that the sol in the surface of the mixture gels and gives a product containing fruit mash or puree distributed between a liquid or plastic core of alginate or pectate sol and a solid exterior of calcium alginate or pectate gel.

Such a method is described in British patent document no. 556 718, but this method has the major disadvantage that the product's resemblance to natural fruit is small. E.g. is the cherry product, despite being cheap, only acceptable as an imitation candied cherry. The problem is that the products develop an even texture during storage. It has now been shown that heating the product within a certain temperature range prevents or reduces gelation of the initially gelling interior. The invention is therefore characterized in that the product is heated, within 1 hour of being brought into contact with the dissolved calcium ions, to a temperature in the range of 70-100°C for at least 2 minutes, to prevent complete gelation of the sol in the interior of the product.

If the product is not heated, the calcium ions that diffuse inwards towards the core from the exterior of the calcium alginate or pectate gel cause gelation of the core and progressive hardening thereof. The dissolved calcium ions with which the sun and the fruit material are brought into contact are preferably provided by a solution of the calcium salt of an edible organic acid, e.g. lactic acid, malic acid, citric acid or fumaric acid. Alternatively, a solution of calcium chloride can be used. The concentration of dissolved calcium salt is usually in the range 0.5-20% by weight.

An edible, organic acid, e.g. citric acid, lactic acid, malic acid or fumaric acid can be included in the calcium salt solution so that the fruit product gets a desired acidity or bitterness. Preferably, the sol mixed with the fruit material is extruded below the surface of the calcium salt solution and the extrudate is cut into portions while suspended in the solution. (A suitable apparatus for extrusion in this way is described in British patent document no. 727 475.) By this method, rounded pieces can be obtained which in shape resemble gooseberries or cherries.

Heating of the product to prevent solid gelation of the core is carried out, in the case of alginates, preferably at a temperature of 85°C or higher. In this method, pasteurization is achieved at the same time.

The heating is preferably carried out after the product

is withdrawn from contact with the dissolved calcium ions. The product is preferably kept in the calcium salt solution for 10-30 minutes, depending on the thickness of the desired skin and then heated within 1 hour, preferably within 30 minutes, after it has been removed from the solution. If the product is to be canned in a syrup or filled in pies in a viscous base mass, it is preferably heated in the syrup or base mass. In this case, the syrup or base material preferably contains a small amount, e.g. up to 0.5%, of a calcium salt such as dicalcium phos-.fat. It has been found that this prevents cracks in the solid exterior of the product, which would otherwise occur in a small proportion of the simulated berries.

The invention is particularly well suited for imitating gooseberries, grapes, cherries and blackcurrants, which have a firm exterior around a relatively fluid core. However, artificial fruits having an appealing texture can also be formed from fruit pulps of apples or pears or apricots, although the texture formed for these will not correspond to the texture of the real fruit.

Fruit mash or puree to be used in the method according to the invention can be obtained by any method which - even if the structure of the fruit as such is destroyed so that juice is released from the fruit structure which it encloses - nevertheless stops short before all the fruit's structural elements are destroyed. The fruit mash or puree contained a proportion of edible, insoluble material which contributes to the edible texture of the simulated fruit produced. The fruit mash or puree suitably constitutes 25% or more, by weight, of the mixture of the fruit material and the sun when whole fruit from which the mash or puree is made is used. A somewhat lower level of fruit materials can be used if it has a high content of insoluble solids, e.g. the pulp that remains after squeezing fruit juice. When the lower levels of fruit materials are used, flavoring and coloring agents are preferably also incorporated in the sun.

The sol used in carrying out the invention is preferably based on sodium alginate. Alginates that have a high content of mannuronic acid residues (mannuronic acid:guluronic acid ratio higher than 1:1 and preferably approx. 1.5 - 3:1) are preferred when a very marked difference between the textures of the core and the outer is desired (as with gooseberries ). In this case, the core can be more fluid than the initial mixture of fruit mash or puree and alginate sol. Alginates which have a high content of guluronic acid residues (mannuronic acid:guluronic acid ratio less than 1:1 and preferably about 0.4 - 0.6:1) are preferred when a core which is plastic but not liquid is desired (as in cherries). In this case, the core can be sufficiently gelled so that the product can be cut up without the core spilling out, even if the core can be squeezed out from the solid. exterior. The proportion of alginate in the product is usually 0.5 - 3% by weight. A pectate can be used instead of an alginate. However, it has been found that the texture of the exterior after heating is not as firm when a pectate is used.

Other ingredients may be included in the product, e.g. freeze/thaw stabilizers, e.g. boiled starches and cellulose ethers, thickeners such as modified starches and edible gums, and sugar. At least part of the sugar is preferably incorporated at the stage where the alginate or pectate sol is made, since it helps the dispersion of the sodium alginate or pectate.

The following examples will illustrate the invention.

EXAMPLE I

This example shows the application of the invention to the production of simulated whole gooseberries. An alginate sol was prepared from the following ingredients:

The sodium alginate and sugar were mixed dry in a powder mixer, and water was added to make an alginate sol in a continuously running turbine mixer.

A prickly pear puree mixture was prepared by mixing the following ingredients:

The alginate sol and the gooseberry puree mixture were mixed in equal parts in a continuous-in-line mixer ("Oakes 4M") with. high cutting force and low residence time. The mixture of sun and fruit puree was then extruded into a trough containing a solution with the following composition:

The extrusion was carried out through nozzles with a diameter of 1.6 cm, located below the surface of the calcium lactate solution. During the extrusion, a skin of calcium alginate gel formed around each extrudate of sun and fruit puree, and when each extrudate reached a length of 1 - 1.5 cm, it was separated at the nozzle. As they fell through the solution, the cut pieces assumed a rounded shape resembling the shape of a gooseberry, and they were deposited on a conveyor belt that transported them along the trough. After 10 minutes, the pieces were removed from the calcium lactate solution, the exterior or gel being thick and strong enough to withstand accumulation in a container. The pieces were immediately placed in an aqueous syrup with the following composition:

After standing for half an hour, the pieces were heated to 90°C (steamer) in the aqueous syrup to prevent the core from becoming a solid gel, and they were canned while still hot. They had a texture very similar to that of canned whole gooseberries.

EXAMPLE II

This example shows the application of the invention to the production of simulated whole cherries.

An alginate sol was prepared by the method described in Example I, from the following ingredients:

A cherry puree mix was prepared by mixing the following ingredients:

The alginate sole and cherry puree mix were mixed in equal parts in an "Oakes 4M" mixer. The mixture of sun and fruit puree was then extruded into a trough containing a solution with the following composition:

Extrusion was carried out through nozzles with a diameter of 1.5 cm located below the surface of the calcium lactate solution. During the extrusion, a skin of calcium alginate gel formed around each extrudate of sun and fruit puree, and as each extrudate reached a length of 1 - 1.5 cm, it was separated at the nozzle. On falling through the solution, the cut pieces assumed a rounded shape, but generally similar to the shape of cherries, and they were deposited on a conveyor belt which transported them along the trough. After 20 minutes, the pieces were removed from the calcium lactate solution and allowed to drain onto a metal cloth conveyor belt. The pieces were immediately placed in an aqueous syrup with the following composition, the ratio between simulated fruit and syrup being 3:2.

The pieces were heated to 85°C in the aqueous syrup and held at this temperature for 3 minutes so that the core was prevented from becoming a solid gel. They were then filled into jars which were sealed while still warm. They had a texture very similar to that of canned, whole cherries. When filling the mixture of simulated cherries and thickened syrup in pies and baking, the simulated cherries retained their texture.

Claims (4)

1. Process for producing a food product that simulates the texture of fruit, whereby a mixture of fruit mash or puree and an alginate or pectate sol is treated with an aqueous solution containing dissolved calcium ions so that the sol in the surface of the mixture is gelled into a product containing fruit puree or puree distributed between a liquid or plastic core of alginate or pectate sol, and a solid exterior of calcium alginate or pectate gel, characterized in that, within 1 hour after the mixture has been brought into contact with the dissolved calcium ions, the treated mixture is heated to a temperature in the range of 70 to 100°C for at least 2 minutes to prevent complete gelation of the sol in the interior of the product . 2. Method as stated in claim 1, characterized in that the mixture is brought into contact with the aqueous solution containing calcium ions, for 10-30 minutes. 3. Method as stated in claims 1 and 2, characterized in that an alginate is used with a ratio between mannuronic acid residues and guluronic acid residues greater than 1:1, and that as fruit puree. or puree gooseberry mash or puree is used so that the fruit product becomes a simulated gooseberry with a liquid core of gooseberry mash or puree in an alginate sol. 4. Method as stated in claims 1 and 2, characterized in that an alginate is used with a ratio between mannuronic acid residues and guluronic acid residues less than 1:1 and that a cherry puree or puree is used as fruit puree so that the fruit product becomes a simulated cherries with a core of cherry mash or puree in a calcium alginate gel that is plastic compared to the solid exterior.