CA1165620A - Fruit preparation - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A process for producing a fruit preparation from a natural fruit juice, the process comprises removing water from the juice by flowing the juice on a heated, recipro-cable, inclinable surface to reduce the water content to 10 to 25% by volume. A crystalline modifying agent is then added to the product. The modifying agent and the product are then blended while heating them. The heating and blending is continued until the water content of the product is in the range of 1 to 15% by volume. An apparatus for producing the preparation is described. The apparatus has a concentrator pivotably mounted at about its center. An end of the vessel can be raised and lowered to reciprocate the vessel about the pivotable mount. The vessel is heated and has a closable outlet at each end. Extractors for vapour produced from the fruit juice heated in the first vessel are provided and blender means to blend the material produced on the concentrator with an added material.

Description

- 1 1 656~) This invention relates to a process and apparatus for producing fruit powder from natural fruit juice, par-ticularly the juice of fruits low in fibre.
Fruit juice is widely available commercially. The natural product is available either in sealed cans or a frozen solid, The most common arrangement is to concentrate the juice to remove about 75% of the moisture and then freeze the concentrated juice in a container~ In order to obtain the drinkable product water is added by the consumer.
These frozen juices must be kept at low tempera-ture at all time to avoid deterioration.
As will be appreciated this type of preparation is quite expensive. The process of concentration is expensive but it is also expensive to maintain the juice concentrate refrigerated during transport to retail outlets, in the retail outlets and in the home.
My U,S. Patent 3,120,439, issued February 4th, 1964, relates to a process for preparing a cof~ee extract.
Liquid coffee ex~ract is subjected to a dehydrating action to reduce its moisture content and trans~orm the liquid concentrate into a pasty substance by advancing the extract by gravity flow along an inclined plane and simultaneously heating the extract to a temperature between about 105 and 250F, The pasty substance is then subjected to a second dehydrating action to reduce its moisture content to between about 1 and 4% by distribu-ting the pasty substance in the form of layers having a thickness about 0.5 millimeters and cooling the layers to about 14F. The product is then ground into pulverulent form.

~ ~ 6~620 My Canadian Patent 886,517 issued November 23rd, 1971 relates to an apparatus and process for drying food in which the temperature o the food is raised to appro~imately 100F and superheated steam is then fed to the product to penetrate the product to affect enlargement of i-ts cellular structure. Hot air is then fed alternately with steam to product. The superheated steam ~s uniformly brought into contact with the product for a period between 10 to 30 seconds to penetrate a first layer of the pieces o~ the food product that are treated. Steam application raises the temperature of the layer to at least 212F. This enlarges the celluar structure of the product in a nonviolent manner and reduces the moisture content. The flow of steam is shut off and the mass is then subjected to a flow of hot air at a temperature between 300 and 350F. The hot air is applied for a time sufficient to remove the moisture from the product that has been treated b~ the steam. That Canadian Patent also describes an apparatus for dehydrating a food pxoduct generally comprising a jacketed container with a conical bottom wall and an open top. A series Oe perforate pipes project upwards in the container and a food product carrying basket is supported on the perforate pipes. Steam and hot air can ~e fed to the perforated pipes and there are valve means for alternately controlling the feed of steam and hot air to the pipes. Condensate can be drained from the bottom of the container and hot air and steam from the food product in the basket can also be removed from the container.

A Supplementary Disclosure ~o my above Canadian 1 ~ ~562~

patent describes a process in which the original dehydra-tion process is not carried to completion but is stopped when the moisture content is between 10 to 50~. Additional crystalline ingredients are then added in an amount of about 25% to 50% of the fruit after cleaning but before steaming. A thorough mixing o~ the two components is then carried out.
Both the above patents produce excellent products but involve relatively complicated apparatus. In par-ticular the apparatus described in the United States isboth fairly complicated and demanding of space. The pro-cess and apparatus of the Canadian Patent has the disadvan-tage that they require superheated steam, which can be a difficult material to use and contain. The process of the above Supplementary Disclosure acts, like the process of the Principal Disclosure, on frui-t pieces so the product tends to be high in fibre and thus cloudy even after dilution.
The present invention seeks to produce a simple, ~uick process for producing a product, that, in tests, carried out was rated better than a number of well known products presently commercially available. The invention provides a method for producing fruit powders containing only dehydrated ruit juice in combination with certain crystalline substances, for example sugars or pectin. ~t is particularly important that the product according to the present invention can be packaged and s-tored without refri-geration either in paper oE plastic pouches.
Thus, in a first aspect, the present invention is a process for producing a Eruit preparation from a natural `I ~ 65~20 fruit juice, the process comprising the steps: removing water from the juice by flowing the juice as a -thin film on a heated, reciprocable, inclinable surface to reduce the water content to 10 to 25% by volume; adding a crystalline modifying agent selected from a sugar or pectin to the pro-duct and blending said modifying agent and said product while heating them; and continuing said heating and blending until the water content of said product is in the range of 1 to 15% by volume.
In a particularly desirable aspect the present invention provides a continuous process and the blending is carried out on a heated conveyor belt adapted to feed the modifying agent and product over an inclined surface extending upwardly from the belt. Walls converge inwardly at -the upwardly inclined portion of the inclined surface to force the mixture inwardly to assist blending. IE
necessary the mixture can also be kneaded by passing it between co-operating rol.lers positioned on each side of the belt. Kneading then takes place as the m.ixture pas.ses het-ween the rollers.
The invention also provides a fruit preparationprepared by evaporation of a natural fruit juice as a thin film and having a moisture content in the range 1 to 15 and a content of a crystalline material sufficient to enable solidification of -the preparation.
The invention is illustrated, by way of example, in the accompanying drawings in wh.ich:
Figure 1 is a flow diagram illustrating a process according to the present invention;
Figure 2 illustrates a part of an apparatus for i 1 6~620 carrying out the present inventiont Figure 3 is a plan view of part of the apparatus of Figure 2;
Figure 4 is a section along the line 4-4 in Figure 2;
Figure 5 is a section through another part o the apparatus of Figure 2; and Figure 6 is a plan view of the apparatus of Figure 5.
Referring to the drawings Figure 1 illustrates the carrying out of the process of the present invention with certain additional steps whereby the fruit can be taken from the natural fruit stage right through to the packaged, commercial form. In the process natural fruit juice of fruits low in fibers, for example oranges, gra-pefru.its, lemons, limes, apples, grapes and pin~apples, is squeezed to produce the natural fruit juice. Typically, the molsture content of that juice is in the rarlge 90 to 95%. The natural fruit juice is dehydrated, using appara-tus described ln more detail below, to a molsture contentof between 10 and 25%. This concentrated frult juice may then be treated in the - i~ 1 65~20 apparatus illustrated in Figures 5 to ~ depending on the required product. Various crystalline substances are added to it. Air is blown while a hlending operation is carried out to produce a coarse fruit powder. Kneading may be carried out. Generally speaking the temperature of the product is kept in the range 60F to 170F by heating the vessel in which it is blended, for e~ample to a temperature of 100F to 200F.
f The product from the blending operating may be stored in a carton or plastic container. It has a moisture content typically in the range of 4 to 15% and is a semi-solid material. It can be described as a superconcentrate and can be reconstituted to produce a juice distinguishable from the original juice by adding to it about 4 times its own volume of water.
Alternatively, the superconcentrate can be passed to a kneading where air is blown in to it as it is kneaded.
This produces a drier material having a moisture content in the range 1 to 4%. The blending, kneading and air hlow can all be simultaneously performed :in the vessel o~ Figures 5 and 6.
This product can be crushed while subjected to an air blow. The product is a fruit preparation having a moisture content in the range of 1 to 4% and with a fine crystalline form. This product may also be packaged for use by the consumer. Again it does not require refrigeration.
Like the superconcentrate it can be reconstituted to produce a juice indistinguishable in clarity from the original fruit juice by adding a minimum of 4 times its own volume of water. In this regard it should be pointed out that ex-~ 3 6t~3~

isting commercial frozen juices re~uires 3 times -the vol~ne of water to be added, that is the material produced accor~
ding to the present invention is more economical in use.
A particularly preferred process is a continuous process for production of the superconcentrate. However it can be desirable to use a batch apparatus in about 2 hour cycles. One cycle produces the product with 4 to 15~
moisture, the other cycle produces the product with 1 to 4%
moisture. Obviously, the relative length of each cycle can be varied to reflect production requirements.
Figure 2 illustrates schematically an apparatus whereby the natural fruit juice i5 concentrated by gravity flow. That apparatus is a concentrator generally indicated as 10. The concentrator 10 comprises a first vessel 12 having a pivotal mount 14 at about its center. There are means to raise and lower an end of the vessel to reciprocate the vessel 12 about the pivotal mount 14. In the illus-trated embodiment that means comprises a telescopic cylindex 16 which may be hydraulically or pneumatical]~ controlled.
The vessel 12 is elongate with channels 18 extendin~ from its base 20 to receive the ~ruit juice - see Figure 4.
There are reservoirs 22 formed at each end of the vessel 12 and the juice being concentrated congregates in reservoirs 22 when the end of the vessel at which a particular re-servoir is positioned is lowered. Each reservoir 22 has avalved outlet 23. Immediately upon filling the reservoir 22 the telescopic cylinder 16 is raised and the juice then flows in the direction o~ the okher reservoir 22.
There are means to heat the first vessel which, as shown in Figure 4, may comprise internal channels 24 so that ~ 1 6S~,~0 steam may be blown through channels 24. Alternatively, electrical heating elements may be positioned in -the channels 24. The arrangement is such that the vessel 12 should be heated to a temperature in the range of 150 to 250F in order to maintain the product temperature in -the range of 110F to 170F. Vapour produced in the heating of the fruit juice in the vessel 12 is extracted by the use of a hood 26 having an exhaust pan 28 positioned in it.
The apparatus of ~igures 2 to 4 is an extremely effective evaporator. The fruit juice to be concentrated is placed in the vessel 12 which is heated to the above tem-perature range. The vessel 12 is tipped by use of the telescopic cylinder 16 and the juice runs to the lower end as a relatively thin film so that extremely effective heat transfer is achieved. When all the juice is in the lower reservoir 22 the -telescopic cylinder 16 is again operated to make the juice run down to the other end of the vessel 12, again passing over heated surfaces as it flows in the channels 18~
It is particularly important to note that the water content of the juice is rapidly evaporated ~rom a thin film of juice as the juice flows back and forth in the vessel 12. The juice never boils so that the natural ingredients of the juice are not destroyed by bein~ sub-jected to excessive heat.

In a batch process the product from the apparatus of Figures 2 to 4 is fed to a blending apparatus. That apparatus is illustrated particularly in Figures 5 and 6.

However, the apparatus of Figures 2 to 4 also includes kneading means. The apparatus comprises a second vessel 30 I :~ 6~;2() to receive material from the concentrator 10. There is a shaft 32 substantially coaxial with the vessel 30. ~here are drive means for the shaft 32 ~not shown) in the form of~ for example, an electric motorO When khe apparatus is to be used for kneading, for example in the production of a powder as distinct from the superconcentrate, an arm 34 is rotated by the shaft 32 in a substantially radial plane of the vessel 30. The arm 34 is in two parts each attached to the shaft 32 by a bearing 36. Arm 34 may be removed~ Each part of arm 34 can rotate within the bearing 36. There are a plurality of kneader heads 38 mounted on the arm 34. A
gear wheel 40 is mounted on the shaft 32 and meshes with pinions 42 on each part of arm 34. The arrangement is such that the arm 34 rotates in a substantially radial plane of the vessel 30 and, at the same time, the kneader heads 38 rotate in a direction perpendicular to the plane. Each part of arm 34 may extend upwardly outwardly to avoid hitting the inclined base of the vessel 30.
There is a duct 44 whereby air may be b:Lown into the vessel 30 again when the powder is requixed~ As indi-cated particularly in Figure 6 a fan 46 may be used to blow the air. There are heating elemen-ts 48 positioned in the walls of the vessel 30.
The vessel 30 also has means to blend material in the vessel comprising an arm 50 shaped to conform to the base of the vessel 30 and mounted to rotate with the shaft 32 by a bearing 52.
Figures 7 and 8 illustrate diagrammatically a continuous process according to the present invention. As indicated generally in ~igure 7 material from

2 0 a reservoir 22 is fed ouk through ~alve outlet 23. ~l-though not shown in Figure 7 it is desirable that -there be a plurality of concentrators 12 all feeding to one conveyor belt 54. The conveyor belt 54 has drive rollers 56. As particularly shown in Figure 8 there are containiny conveyor belts 58 running alongside the main conveyor belt 54 to ensure that the material remains in position on the main belt 54.
In this embodiment crystalline substance is fed from a hopper 60 onto the belt. There are heating means in the form of pipes 62 positioned beneath the belt 54. Figure 7 shows an embodiment in which there are kneading rollers ~4 positioned in pairs above and below the belt 54. The material is kneaded as it passes between those rollers 64.
Figure 7 also illustrates an air blow system 66 positioned generally above the belt including a Ean 68. However, like the kneading rollers 64 this use of the fan 68 is not essential.
The main components on the conveyor bel-t 54 are inclined surfaces 70 indicated generally at Figure 7 but shown in more detail :in E'i.gure 8. The material is moved along the belt 54 and passes on a surface 70 inclined upwardly. There are side surfaces 72 also inclined upwardly and extending from the main surface 70. There are further upstanding portions 74 at the ends of the inclined surfaces 70 and a downwardly inclined surface 75. The arrangement of this plurality of inclined surfaces 70, 72, 74 and 75 is such that the material passes from the belt 54 onto the main surface 70 where it is blended by the surface 72 tending to turn o~er the material at the side of the surface 70 back ~ 3 ~S~O
in~o the center and by the narrowing a~fec~ of khe upstanding portions 74. The material is forced over the end oE the inclined surface 70 to return -to the belk 54 down inclined surface 75, also assisting in the blending.
There is a doctor knife 76 at the end of the belt 54 so that the material, now well blended, is removed from the belt 54 and fed to a container 78. The upper rollers of the pairs of rollers 64 are also provided with doctor knives 80 to clean the material from the upper rollers.
The device of Figure 7 is useful in producing a powder, that is the material with a lower water content, but without the use of the pairs of rollers 64 and withouk the use oE the air blow system 68, for example, as shown in Figure 8, the system is desirable in producing the super~
concentrate. Production is continuous because oE the use of the conveyor belt.
The embodiment of Figure 7 can use as many pairs of rollers 64 as are Eound to be desirable to produce a product having a water content in the range 1 to 4%.
Generally speaking the apparatus of Figure B does not have a dehydrating effect, principally because of the absence of an air blow. In each case the product is packaged as indi~
cated above and can be transported to the consumer without refrigeration.
Using the process of the present invention a pro-duct may be obtained that, upon dilution with at least 4 times its own volume of water~ may be considered indiskin-guishable from the natural juice in clarity. In consumer tests conducted the product was rated higher than a i J ~ 2 () cross section of widely advertised and widelv sold commer-cial products. It is believed that one reason for this high quality is the concentrakor. The arrangement of the con-centrator is such that the fruit juice is evaporated as a thin film and is never subjected to high temperatures such as would destroy, for example, vitamins in the original product. That is these vitamins and other nutrients come through the process unaltered, which has not been possible in prior art processes.

Claims (15)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for producing a fruit preparation from a natural fruit juice, the process comprising the steps:
removing water from the juice by flowing the juice as a thin film on a heated, reciprocable, inclinable surface to reduce the water content to 10 to 25% by volume;
adding a crystalline modifying agent selected from a sugar or pectin to the product and blending said modifying agent and said product while heating them; and continuing said heating and blending until the water content of said product is in the range of 1 to 15%
by volume.

2. A process as claimed in claim 1 in which the crystalline modifying agent is selected from sucrose, pec-tin, glucose and fructose.

3. A process as claimed in claim 1 including continuing the heating and blending until the moisture con-tent is in the range of 4 to 15%.

4. A process as claimed in claim 1 including kneading the modifying agent and the product simultaneously with the blending, and blowing in air during the kneading and blending to produce a product having a moisture content in the range 1 to 4%.

5. A process as claimed in claim 4 including crushing the product having a moisture content in the range of 1 to 4% and blowing air into the crushing process to produce a powder.

6. A process as claimed in claim 1 in the form of a continuous process, said blending being carried out on a heated conveyor belt adapted to feed said modifying agent and product over an inclined surface extending upwardly from said belt, walls converging inwardly at the upwardly inclined portion of the inclined surface to force the mix-ture inwardly to assist blending.

7. A process as claimed in claim 6 including passing the mixture between co-operating rollers positioned on each side of the belt to knead the mixture as it passes between them.

8. A process as claimed in claim 6 including passing the mixture over a plurality of inclined surfaces, each spaced from the other.

9. A process as claimed in claim 8 including passing the mixture between a plurality of co-operating pairs of rollers, each co-operating pair positioned between two inclined surfaces.

10. A fruit preparation prepared by evaporation of a natural fruit juice as a thin film and having a moisture content in the range 1 to 15% and a content of a crystalline material sufficient to enable solidification of the preparation.

11. A fruit preparation as claimed in claim 10 in which the natural fruit juice is selected from orange, grapefruit, lemon, lime, apple, grape and pineapple.

12. A fruit preparation as claimed in claim 10 in which the moisture content is in the range 1 to 4%.

13. A fruit preparation as claimed in claim 10 in which the moisture content is in the range 4 to 15%.

14. A fruit preparation as claimed in claim 10 in which the crystalline material is selected from sucrose, pectin, glucose and fructose.

15. A fruit preparation as claimed in claim 14 in which the crystalline material is present in an amount in the range 8 to 50% of the preparation.