WO2006014115A2

WO2006014115A2 - A juice concentration process

Info

Publication number: WO2006014115A2
Application number: PCT/NZ2005/000201
Authority: WO
Inventors: Ronald William Russell; Stuart Selwyn Steel
Original assignee: Rs Industries Nz Ltd
Priority date: 2004-08-05
Filing date: 2005-08-05
Publication date: 2006-02-09
Also published as: NZ533340A; WO2006014115A3

Abstract

The present invention relates to a process for treating a fruit, vegetable or vegetable plant matter juice including the steps of: a) filtering the juice, b) removing water from the filtered juice to concentrate the proteins and other beneficial nutrients in the juice to form a concentrate, wherein steps a) and b) are operated at less than substantially 20°C.

Description

A JUICE CONCENTRATION PROCESS

TECHNICAL FIELD

This invention relates to a juice concentration process. In particular, though not solely, this invention relates to a method of processing fruit, vegetable juices and/or plant matter juices into dried juice concentrate powders.

BACKGROUND ART

The processing of vegetables and/or fruit matter (also referred to as "vegetable" or "vegetative" matter hereinafter) to obtain an initial juice extract is well understood by those skilled in the art of juice making. It is recognised that such "raw" unprocessed (or only partially processed) juices contain usual nutrients for human or animal consumption. For example, some food items, such as kiwifruit, contain high levels of soluble proteins, anti-oxidants, enzymes, vitamins and chlorophylls useful for general health.

Some juice manufacturers also add extra nutrients to the unprocessed or partially processed juices they produce in order to maximise health benefits to end consumers. However, often such additional ingredients are synthetically produced which may not be desirable if the product is to be marketed as being a "natural juice". Therefore, a way in which fruit, vegetative or vegetable matter can be used to produce a natural raw juice which can subsequently be processed in order to retain and/or concentrate any factors associated with nutrition or well being is desirable. In the case of a concentrate it could also be used as a condiment or direct concentrate for consumption. In particular, a powdered concentrated product is desirable, and the present invention attempts to achieve such an outcome. Whilst a number of methods exist in the preparation of juices from a vegetative matter feed to produce a raw juice from vegetable or fruit matter, such as, for example, the simple process flow diagram of Figure 1 which illustrates a generalised carrot juice production facility - and is generally indicative of the present processes employed in juice manufacture. The processes of the type shown in Figure 1 are all relatively crude and are not operated at conditions able to achieve enhanced nutrient recovery for example from the stock feed of carrots. The process and technologies illustrated in Figure 1 also do not anticipate the significant differences and advantages conveyed by the present invention.

A number of juice or puree (high solids content solution) generating processes and/or methods of producing powdered products have been found by the applicants, although none appear to anticipate or even teach the advantages of the present invention.

A significant disadvantage of the existing vegetable or fruit juice concentrating processes lies in the non-optimised conditions of juice treatments which have tended not to explore methods of enhanced juice nutrient recovery, in particular, protein recovery. Each of the patents described below do not provide disclosure of a process for enhanced method of protein and nutrient recovery, especially for the subsequent formation of a dried concentrated juice powder. A number of patents are briefly described below in which their main aspects are illustrated which display their non-relevance to the present invention.

However, a selection of the patents found are discussed herein; for example NZ 0299874 relates to the preparation of a homogenised vegetable or fruit juice which is incubated at between 0⁰C to 70⁰C for 5 minutes to 24 hours before then being pasteurised. NZ 0237469 relates to a process for processing a dry plant green juice powder with an alkaline extract - obtained by burning seaweeds to form an ash at a temperature of between 300° to 1000⁰C and treating the ash with water or an aqueous acid solution such that the dispersion of the food product in water has a pH in the range of 6.2 to 9.5. Also described is a process for forming a product involving the essential steps of squeezing raw edible green plants to form a green juice followed by obtaining the alkaline extract (as previously mentioned) and adding it to the juice before then spray drying or lyophiliziing the green juice.

Similarly, NZ 0243417 relates to obtaining a juice or powder extract from grass leaves, but includes essentially steps such as using a solvent (such as alcohol or acetone) to precipitate materials which can be responsible for cloudy appearances in some beverages made from reconstituted (that is, re-hydrated) powdered juice concentrates.

NZ 0131275 describes a method of spray drying food stuffs at temperatures between 5°C and 35°C, but is silent as to the technical features of processing the juice to form a concentrate.

NZ 0122621 relates to the production of dry powders and concentrates from solutions, such as fruit and vegetable juices by operating a drying stage at very low temperatures only.

Lastly, NZ 0145604 relates to an apparatus only, for forming dried agglomerates from liquid dispersions; but gives no indication of any method by which a liquid dispersion may be obtained.

It is therefore at least an object of the present invention to go some way towards providing a method of juice concentration to address the foregoing problems or to at least to provide the industry with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinence of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

It is acknowledged that the term 'comprise' may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term 'comprise' shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term 'comprised' or 'comprising' is used in relation to one or more steps in a method or process.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

In a first aspect of the present invention, there is provided a method of treating a juice including the steps of:

a. filtering the juice,

b. removing water from the filtered juice to concentrate the proteins and other beneficial nutrients in the juice to form a protein concentrate,

wherein steps a) and b) are operated at less than substantially 20⁰C to achieve enhanced levels of soluble proteins and nutrients in a juice protein concentrate. Throughout this specification the term "juice" may be taken to define a liquid or solution obtained as an extract from plant or fruit matter. For example, carrot juice from pulped carrots, kiwifruit juice from pulped and crushed kiwifruit, apple juice from pulped and crushed apples and so forth. The applicant acknowledges that those skilled in the art of juice manufacture will understand and appreciate that a number of alternative methods for obtaining a juice may be employed to obtain a juice which can then be further processed according to the present invention.

Preferably, steps a) and b) are operated at less than substantially 10⁰C.

Preferably, the juice may be chilled to less than substantially 10⁰C prior to filtration.

Preferably concentration may be carried out by spinning disk thin film evaporator or by membrane filtration. However this should not be seen as limiting as other concentration and filtration methods may be used with the present invention.

Desirable "food items" may contain proteins and/or enzymes, anti-oxidants, and/or chlorophylls. Desirably, the substantially semi-continuous low temperature process as described minimises the likelihood of any protein enzyme, antioxidant or chlorophyll denaturation.

In some embodiments, a non-oxidative atmosphere may be provided for any of steps a), b) and/or c). It is envisaged that gases such as nitrogen, carbon dioxide and/or other inert gases may be suitable for effecting this purpose. A non- oxidative atmosphere may be provided for the entire process.

A non-oxidative atmosphere helps to preserve the quality of the juice (whether in a raw unprocessed, partially processed or fully processed end product) protection from oxidising agents.

In some embodiments, the non-oxidative atmosphere may be provided by non- oxidative gases being fed to the juice at a ratio of greater than about 7.5I inert gas: 10001 resultant raw juice, the resultant raw juice being that formed by the fruit being pressed.

In some embodiments, the non-oxidative atmosphere may be provided by non- oxidative gases being fed to the juice- concentrate at a ratio of greater than about 51 inert gas: 10OOI juice.

These volumes are important to maintain "clarity" of the juice. If the juice is not crystal clear it indicates it has started to oxidise - referred to as "browning" in the industry.

The non-oxidative environment "blankets" or shields the juice (raw, partially processed or protein concentrate), preferably thereby substantially minimising any oxidative effects from juice contact with air. Juices which are less sensitive to oxidation may not require such inert blanketing, or may require less inert volume to provide same.

In some embodiments a decanting process may be used to help remove macroscopic particles.

In some embodiments the decanting process may occur before filtration of the juice in step a)

Preferably, particles more than about 500 micrometers may be removed by filtering from the vegetable, fruit or leaf juice before or during step a).

Preferably, particles more than about 150 micrometers may be removed by filtering from the vegetable, fruit or leaf juice before or during step a).

Preferably, particles more than about 50 micrometers may be removed from the juice before or during step a). Preferably a decanting step may be undertaken prior to membrane filtration in order to remove fibrous particles thereby assisting concentration.

"Macroscopic particles" may be generally defined as any particle of greater than substantially 50 micrometers.

Preferably, the clarification process may be used for juices which have a high sugar content, such as fruit juice, and therefore may be susceptible to fermentation.

Preferably, the juice from step a) may be filtered using a membrane filtration process to obtain a juice protein concentrate.

Preferably, the membrane filtration process may be either a nano-filtration or a reverse-osmosis filtration; each operated at less than about 20⁰C and able to operate at up to about 40 Brix.

If the Brix value is too high for that specific type of juice it will clog the membrane used for filtration. Variation between juices can vary by up to 20 Brix.

Preferably, following the membrane filtration step the pH may be altered using a pH adjusting agent to be between substantially pH 7.0 and about pH 7.4. This pH is required to give the product a pH suitable for human physiology. Such a pH adjusting agent may be any suitable food grade agent, for example potassium hydroxide (KOH) or sodium citrate.

Optionally, additional ingredients may be added to the concentrate membrane filtration product. Additional ingredients may include, for example, maltodextrin.

Preferably, the ingredients are added into the concentrate in a BRST (batch reactor stirred tank).

Preferably, a non-oxidative atmosphere may be provided in the BRST. Preferably, the protein concentrate and additional ingredients are milled in a high shear type colloid mill. Desirably, the resultant product may be milled to ensure it has a smooth, soft paste-like texture.

Preferably, the protein concentrate, with or without additional ingredients, may be stored at less than substantially 2O⁰C, in an agitated system. Preferably, the storage may be for less than substantially 1 hour in-order to minimise ageing, gelling or oxidation.

In a second aspect, the present invention there is provided a process for treating a juice including the steps of:

a. filtering a juice,

b. concentrating the proteins from the juice to form a protein concentrate by substantially removing water in a filtration stage, and then

c. spray drying the protein concentrate from step b),

wherein steps a) and b) are operated at less than substantially 20⁰C, and step c) is operated to achieve a pre-determined particle size.

Preferably, the spray drying at step c) may be operated at less than about 165°C at the dryer juice concentrate inlet and less than substantially 105°C at the dryer powder outlet.

In a tall form drier with concentrate atomisation designed to give large thin walled droplets the drying only takes seconds at a low temperature such as 165⁰C, this time is quick enough that it does not denature proteins present in the concentrate.

Preferably, the spray dryer stage of step c) includes one or more spray nozzles to generate droplets from the protein concentrate of a pre-determined droplet size. Advantageously, the droplet sizes may be determined based on factors such as the actual product, its concentration and viscosity of the pre-heated product and result in a dried particle of predetermined particle size distribution.

Preferably, the protein concentrate may be pre-heated to not more than substantially 65°C prior to introduction to said spray drier.

65⁰C is not pasteurization which is >72°C for 15 seconds. A temperature of 65⁰C is thermalisation, and therefore does kill some types of bacteria. Preheating the concentrate improves the efficiency of spray drying and reduces viscosity.

Preheating to only 45-55⁰C is not preferred because thermophilic bacteria can multiply in this range.

Preferably, pre-heating takes place in an indirect tubular heat exchanger prior to being pumped at high pressure to step c). For example, the protein concentrate may be pumped at the range of 170 to 270 bar.

Agglomeration techniques may include spraying fines from cyclones into the concentrate at the inlet nozzles or partially dried powder into the outlet of the drier prior to the fluidised bed. Desired particles sizes may be those such as illustrated in Figure 5.

Preferably, a cyclone or set of cyclones separate dried protein concentrate particles entrained in the air discharge from the spray drier.

Preferably, dried protein particle fines are recycled from the cyclone(s) for re- agglomeration with protein concentrate being introduced to the spray drier.

Alternatively, a two stage fluidised bed may be used to separate dried protein concentrate particles entrained in the air discharge from the spray drier. The two stage fluidised bed may have heating capacity at the particle inlet end and a cooling capacity at a agglomerated particle outlet end is used to generate a final protein particulate product. Preferably, the particles may be cooled to less than substantially 35⁰C; though even more preferably the particles may be cooled to less than about 30⁰C.

The finished product (protein concentrate) from the fluidised bed may then be sifted according to size, preferably minimising any clumps or oversize agglomerated particles over 600 micrometers.

Preferably, the finished product may be stored with an inert gas blanket. The storage may be in hoppers or similar storage vessels, or bags.

Preferably, the bags may be multi-walled and/or have a oxidative gas impermeable liner. Alternatively, other storage devices may also include a non-oxygen permeable liner. Advantageously the storage vessels or bags or storage devices may also be purged with an non-oxidative gas prior to filling with powder.

Preferably, the food items may be vegetable, plant and/or fruit powders.

Preferably, the dried powders have a bulk density of about 35 micro-molars per gram of finished product.

Dried powders with a bulk density below 25 micro-molars per gram are very light and bulky.

Preferably, the average residence time of protein concentrate droplet passing through the dryer may be less than substantially 3 seconds.

Preferably, the pre-determined particle size may be determined by measurement in an infralizer such as a Malvern infralizer.

Preferably, positive displacement pumps are utilised to move raw juice and partially concentrated juice through the process in-order to substantially minimise potential contact with air or other oxidising gases. These pumps may operate at pressures of around 25 to 40 bar, without incorporating oxidising gases, such as air.

Preferably, steps a), b) and c) are completed within about 12 hours of initiation. This along with lowered temperatures limit the denaturation of proteins and antioxidants.

In a further aspect of the present invention, there is provided a juice protein concentrate produced by a method substantially as described above.

In an even further aspect of the present invention, the protein concentrate may be re-hydrated with an aqueous solution to substantially form a re-constituted juice concentrate.

In another aspect of the present invention there is provided a process substantially as hereinbefore described wherein the process allows for a juice protein concentrate to be manufactured having increased levels of soluble proteins and/or anti-oxidants compared to an initial plant or fruit matter juice. Such antioxidants may for example be, Lutonarin, Saponarin and/or enzymes such as Actinonin.

BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 illustrates an example of a process flow diagram for an existing carrot juicing plant;

Figure 2 illustrates a process flow diagram of one embodiment according to the present invention;

Figure 3 illustrates a process flow diagram of a further embodiment of the present invention;

Figure 4 illustrates how particle size may be determined using a Malvern system for a leaf juice powder juice embodiment; and

Figure 5 illustrates the particle size distribution for a leaf cut juice protein powder product.

BEST MODES FOR CARRYING OUT THE INVENTION

According to a first aspect of the present invention, and with reference to Figures 2 and 3; in a first embodiment a process for soluble protein recovery and concentration 1 from juices 2 obtained from vegetative matter input 3. In particular, figures 2 and 3 illustrate the embodiment which comprises the steps of:

a. filtering a juice 4,

b. concentrating the proteins from the juice to form a protein concentrate by substantially removing water in a filtration stage 5, and then

c. spray drying the protein concentrate 6 from step b),

wherein steps a) and b) are operated at less than substantially 20⁰C, and step c) operates to achieve a pre-determined particle size. Although, in an alternative embodiment steps a) and b) may be operated at less than substantially 10⁰C in order to further minimise the likelihood of any protein denaturation, and minimise enzymatic activity (helping reduce any enzyme affects on the proteins).

Advantageously also, the juice should be collected and immediately reduced in temperature (to preferably less than about 10⁰C prior to filtration) to help minimise any denaturation or enzymatic activity, for example in a chiller 7. Protein denaturation and reduction in enzyme is greatest in the fresh or raw juice generated from a vegetative feed after leaves or fruit are recently cut or picked, with the longer the time period that goes by and the higher the temperature, the quicker proteins denature and enzymatic activity decreases.

Figures 2 and 3 illustrate one example of how a juice may be obtained from a vegetative matter feed 3, which can be fed into a screw press 8 to extract the vegetative matter liquids, or juice 4. The solid vegetative waste matter is conveyed via a conveyor belt, 9 to a pelletizer 10 (pellet generating device for solid wastes), before then being dried in an air dryer 11. The dried pellets may then be stored in a storage vessel, for example a hopper 12 ready for packaging and removal from the juice manufacturing plant.

However, figures 2 and 3 also include a number of the optional additional stages in the process which may be used to fully enhance the recovery of nutrients and proteins from the vegetative matter juice inputs.

The term "juice" has previously been defined, and it is acknowledged that a range of vegetative matter, such as fruit and vegetables may be utilised to form and provide a liquid extract (which preferably contains nutrients such as soluble proteins, anti-oxidants, enzymes, and chlorophylls). It is this juice which is then further processed according to steps a) to c) to desirably form a dried particulate juice concentrate, advantageously high in soluble proteins or other aforementioned nutrients.

The applicant also understands that in order to fully preserve the quality of the juice (whether in a raw unprocessed, partially processed or fully processed end product) protection from oxidising agents is useful. Therefore, ideally a non- oxidative atmosphere is provided for the (chilled) juice and/or the protein concentrate (end product). Gases such as nitrogen, carbon dioxide and/or other inert gases may be suitable for this purpose. The non-oxidative environment "blankets" or shields the juice (raw, partially processed or protein concentrate), for example by the provision of non-oxidative gases being fed to the juice or protein concentrate at rates of greater than about 5 L inert gas: 1000L resultant raw juice; more preferably at addition rates of about 7.5L1000L; and at about 5L inert gas: 1000L protein concentrate.

Advantageously the inert gas "blankets" (or surrounds and protects) the juice and substantially minimises any oxidative effects from juice contact with air. The applicants understand that juices less sensitive to oxidation may not require such inert blanketing, or may require less inert volumes rates of addition. Such protection may also be used to protect protein concentrate powders stored within bags (the bags or storage vessel may be purged with the non-oxidative gas prior to filling).

In order to obtain a quality juice, the raw juice 2 may need to be filtered (or otherwise treated) to remove particulate material. For example, Figures 2 and 3 both illustrate an embodiment where optionally particles of more than about 500 micrometers are removed from the juice during step a), though particles of more than about 150 micrometers or even down to particles of sizing above about 50 micrometers can be removed from the juice during step (a). The removal of such particle size distributions may occur in a single operation, for example in a filter (or set of filters) 4 or can occur in a multi-stage operation such as a decanting and/or clarification step 15 as illustrated in Figure 2. Decanting or clarification processes may be employed in order to remove macroscopic particles, that is, particles of a maximum size of about 500 micrometres. The applicants have also found that preferably a clarification operation is used to remove particles from juices which have a tendency or are susceptible to fermentation. Alfa Laval or Sharpies manufactured juice decanters to clarify the juice may preferably be used, that is high speed horizontal scrolls separate out macroscopic particles of about 500 mircometers in size from the liquid juice.

Following step a), and the optional particle removal stages, the partially processed juice can then be further filtered using a membrane filtration process 16 to substantially remove excess water and thereby maximise the concentration of proteins within the juice to form a juice protein concentrate (that is, preferably the concentration of proteins, enzymes, anti-oxidants and/or chlorophylls are in higher concentration that the raw juice) and may be stored, briefly, in concentrate storage tanks 17. The membrane filtration 16 is referred to as a "cold concentration" stage as either a nano or reverse osmosis membrane filtration process is used to recover as much protein from the juice as possible at low temperatures, that is, at temperatures less than about 2O⁰C. The membranes 16 should be selected on the basis that they are able to operate at up to concentrations of about 40 Brix. For example, in a nanofiltration KOCH-type membranes may be used. Alternatively a vacuum, thin film spinning disk evaporator can be used such as a centritherm.

Following the membrane filtration step the juice protein concentrate should preferably have a pH in the range of about 7.0 to about pH 7.4. However, if the juice protein concentrate does not fit within this acceptable pH range, it can be altered as necessary, using a pH adjusting agent supplied via a pump and storage tank 18. Such a pH adjusting agent may be any suitable food grade agent, for example potassium hydroxide (KOH) or sodium citrate.

Additional ingredients may also be added to the juice protein concentrate or membrane filtration product to further enhance the nutrients or quality of the concentrate which will eventually become a product for animal (or human) consumption. The ingredients 19 may be added to the juice protein concentrate in a stirred tank system 20 (which may be operated under a substantially non- oxidative environment, for example a nitrogen blanket). Some of the possible additional ingredients may include, for example, maltodextrin partially boiled brown rice flour and kelp powder, although of course a person skilled in the art of nutrition will appreciate that there are a large variety of ingredients or supplements which may be added and combined with the concentrate to enhance an edible product. The protein concentrate (with or without additional ingredients) 21 at this point should be stored in an agitated (or stirred vessel) 17, 22 for no longer than about 1 hour in-order to minimise ageing, gelling or oxidation, and kept to temperatures of less than about 20⁰C.

If there is addition of optional additional ingredients, then the protein concentrate and additional ingredients should be milled in a high shear type colloid mill 23.

Desirably, milling ensures a smooth, soft paste-like texture of consistent viscosity.

A smooth paste-like texture of protein concentrate is required in-order to more easily facilitate pumping by pump 24 of the concentrate to and through the nozzle(s) of a spray drier 6, and to provide a uniform composition in the finished powder.

The spray dryer 6 operating at step c) of the process is operated at less than about 165⁰C at the dryer protein concentrate inlet and less than about 105⁰C at the dryer powder outlet, and may be operated under a vacuum to enhance the drying characteristics of the droplets (particles) formed from the nozzle sprayed under pressure (as well as helping to keep the drying temperatures as low as possible). The spray dryer is designed to operate (including spray nozzle(s)) and form a substantially dried, powdered (particulate) from the wet juice protein concentrate being fed to it, with residence times of droplets (and subsequent dried particles) of about 3 seconds. Although of course, the applicant realises that varying the pressure or temperature conditions within the spray drier will allow the residence time to be altered also. Advantageously the droplets (and substantially dried particles formed), spent a minimum period within the drier exposed to elevated temperatures and the drying medium.

One or more spray nozzles (not shown) generate droplets from the protein concentrate to form pre-determined droplet sizes are necessary in order to allow the droplets to be exposed to the dehumidifying environment of the dryer 6.

Nozzle types used vary from proprietary brands, either single nozzles or clusters of 3, 4, 5 or even up to 6 single specific types with dry fines sprayed into the centre or the outside circumference of the liquid concentrate and even between the concentrate nozzles. The type used may depend on the type of vegetable or fruit juice being dried.

Advantageously, the droplet sizes may be controlled based on a factor of the viscosity of the pre-heated product, nozzle type and feed pump pressure ,then measuring the powder particle size and distribution by a method such as the Malvern system (illustrated in Figure 4) - which relates to leaf juice powders. Particle size distributions are required in order to try and achieve a dried powder product with dissolving capabilities in an aqueous component. It is important that a dried, powdered product be able to be re-constituted in a relatively easy manner by a consumer or user of the product, especially where the powders are mixed into a drink by adding to water or other liquid fruit juices.

The juice protein concentrate may also be pre-heated to not more than about 65⁰C prior to introduction to the spray drier to reduce the viscosity of the concentrate, thereby allowing for reduced pumping pressure requirements and more controlled spray and droplet generation characteristics. For example, an indirect tubular-type heat exchanger 25 may be utilised for this purpose, however of course, there are a number of alternative direct or indirect heating systems which may be used. The juice protein concentrate is pumped at pressures in the range of 170 to 270 bar to the spray nozzles, before being forced out into the dryer.

After formation of a substantially dried protein concentrate powder, a cyclone or set of cyclones 26 are employed to separate dried protein concentrate particles entrained in the air (drying medium) discharge from the spray drier. The cyclone separates the air used to dry the wet juice protein concentrate from any entrained particle fines not collected from the particle outlet of the spray drier. The dried protein particle fines separated in the cyclone are recycled to be combined with the fresh wet juice protein concentrate being fed to the spray drier nozzles (for re- agglomeration with protein concentrate being introduced to the spray drier).

Once the substantially dried, and agglomerated protein concentrate powder from the spray drier is collected, it is then transported (for example by pneumatic means) to a two stage fluidised bed 27. The fluidised bed 27 has a heating capacity at a particle inlet end and a cooling capacity at a agglomerated particle outlet end is used to generate a final protein particulate product. The particles are cooled to less than about 35°C; though even more preferably the particles are cooled to less than about 3O⁰C prior to final size sorting of the product on a size sifting or sorting bed 28.

The finished product from the fluidised bed 27 is sifted according to size to remove any clumps or oversize agglomerated particles, for example particles over 600 t micrometers are deemed too large and are removed, and may be broken down (or milled) and re-introduced to the system, either to the spray drier 6 or to the particle sifter/sorter 28. The applicant preferably aims to achieve more than about 35 micro-molars of powder per gram of finished product, although of course this is a preferred concentration, differing concentrations (less or more) may be obtained, and may also depend upon the initial feed stock used. The quantities of proteins (and enzymes, anti-oxidants and chlorophylls will vary depending on the fruit, vegetable or other plant matter being processed). The range and particle size distribution of finished dried concentrated protein product varies for the different products, as does the final bulk density of the powder, typically from about 300 to about 750kg. nrf ³.

Given concerns regarding oxidation of the product (or nutrients contained within), the finished product should be stored with an inert gas blanket to minimise such a risk. The storage may be in hoppers or similar storage vessels 29, or bags (not shown).

The types of bags used may be multi-walled and/or have an oxidative gas impermeable liner. Alternatively, other storage devices may also include a non- oxygen permeable liner or they may also be purged with a non-oxidative gas prior to filling with powder.

Preferably, positive displacement pumps 30 are utilised to move feed stock raw juice and partially concentrated juice through the process in-order to substantially minimise potential contact with air or other oxidising gases. These pumps may operate at pressures in the range of 25 to 40 bar, without incorporating oxidising gases, such as air.

Throughout the process, a number of flow balancing tanks may be incorporated, for example tanks 31.

Steps a), b) and c) and/or the additional optional steps described herein should preferably be undertaken and completed within about 12 hours of initiation of a feed stock raw juice to the process.

In a second aspect of the present invention, there is provided the use of a process substantially as described comprising:

a. filtering a juice, b. concentrating the proteins from the juice to form a protein concentrate by substantially removing water in a filtration stage,

where steps a) and b) are operated at less than about 20⁰C to achieve enhanced levels of soluble proteins in a juice protein concentrate.

In a further aspect of the present invention, there is provided a juice protein concentrate produced by a process substantially as described above.

In an even further aspect of the present invention, the protein concentrate may be re-hydrated with an aqueous solution to substantially form a re-constituted juice concentrate. It is a desirable characteristic of the powdered product to be able to be re-constituted with a liquid, such as an aqueous solution which a consumer or user of the product can easily facilitate. For example, the powdered product may be mixed with water to produce a solution of soluble proteins, enzymes, anti¬ oxidants and chlorophylls (and any additional ingredients combined with the protein concentrate prior to the spray drying stage).

In yet another aspect of the present invention, the process substantially as hereinbefore described allows for a juice protein concentrate manufactured having increased levels of soluble proteins and/or anti-oxidants compared to an initial plant or fruit matter juice. Such proteins may for example be, Lutonarin, Saponarin and/or Actinonin.

Therefore, the process and other aspects as described can be used to facilitate a raw juice from a feed stock of vegetables, fruits and/or plant matter into a dried concentrated protein, enzyme, anti-oxidant and/or chlorophyll powder having reconstitutable characteristics. The applicant has realised that operating a process at reduced temperatures, with substantially optimised operating conditions, filtering a juice, concentrating the components within the juice (preferably removing water), and then drying the juice concentrate into a powdered form is likely to have a significant commercial demand. The dried juice concentrate powder of the present invention may also have enhanced soluble protein characteristics and nutrients compared to existing juice concentration process products. For example, see the results of the table illustrated in Figure 5 are for a leaf cut juice protein powder product.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.

Claims

WHAT I/WE CLAIM IS:

1. A process for treating a, fruit, vegetable or vegetable plant matter juice including the steps of:

a) filtering the juice,

b) removing water from the filtered juice to concentrate the proteins and other beneficial nutrients in the juice to form a concentrate,

wherein steps a) and b) are operated at less than substantially 2O⁰C.

2. A process for treating a juice as claimed in claim 1 , characterized by the additional step of:

c) spray drying the concentrate from step b),

wherein step c) is operated to achieve a predetermined agglomerated particle size.

3. A process for concentrating a juice as claimed in either claims 1 or 2 wherein any of the steps a), b) or c) or a combination thereof are operated under a non-oxidative atmosphere.

4. A process as claimed in claim 3 wherein the non-oxidative atmosphere is introduced into the process at a rate greater than substantially 5 litres inert gas to 1000 litres resultant raw juice.

5. A process as claimed in claim 3 where the non-oxidated atmosphere is introduced into the process at a rate of about 7.5 litres inert gas to 1000 litres resultant raw juice.

6. A process as claimed in any of claims 3 to 5 wherein a non-oxidative atmosphere is introduced into the process at a rate of 5 litres inert gas to 1000 litres protein concentrate.

7. A process as claimed in any of claims 1 to 6 wherein the filtering step a) removes particles greater than 50 micro metres in size.

8. A process as claimed in any one of claims 1 to 7 characterized by the additional step of using a clarifying process and/or decanting process to remove macroscopic particles.

9. A process as claimed in any one of claims 1 to 8 wherein the filtration step a) consists of a membrane filtration able to operate at up to substantially 40 Brix.

10. A process as claimed in any one of claims 1 to 9 wherein after the filtration step a) the pH is adjusted to between substantially pH 7.0 and pH 7.4.

11. A process as claimed in any one of claims 1 to 10 wherein additional ingredients are added to the concentrated protein product of step b).

12. A process as claimed in any one of claims 1 to 11 characterized by the additional step of the protein concentrate and any additional ingredients being milled in a high shear type colloid mill.

13. A process as claimed in any one of claims 1 to 12 wherein the spray drying at step c) is operated at less than substantially 165⁰C at the dryer protein concentrate inert and less than substantially 105⁰C at the dryer juice outlet.

14. A process as claimed in any one of claims 1 to 13 wherein a cyclone or set of cyclones separate dried protein concentrate particles.

15. A process as claimed in any one of claims 1 to 13 wherein a two staged fluidized bed having heating capacity at a particle inlet end and a cooling capacity at a agglomerated particle outlet end is used to generate a final protein particulate product.

16. A product of the process as claimed in any one of claims 1 to 15.

17. A product of any of the steps a), b) and c) produced by the process as claimed in any one of claims 1 to 16 wherein the product is maintained in an inert gas blanket.

18. A liquid product formed from a protein concentrate produced by the process as claimed in any one of claims 1 to 17 wherein the concentrate has been rehydrated with an aqueous solution to substantially form a reconstituted juice concentrate.

19. A process for treating a juice substantially as herein described with reference to the accompanying examples and drawings.

20. A concentrated protein product substantially as herein described with reference to the accompanying examples.

21. A liquid product substantially as herein described with reference to the accompanying examples.