FIELD OF THE INVENTION

The present invention relates to a processing apparatus, and in particular to processing apparatus for use to improve preservation of products susceptible to oxidisation. BACKGROUND OF THE INVENTION

In our busy society processed food and food prepared for convenient eating is in demand. Time is short and so foods prepared ready for consumption or use are popular in supermarkets or eateries. Prepared foods may include a pre-cut salad for a quick lunch, or prepared fruits and vegetables for ready use in preparing meals quickly. For many foods, such as avocados, rapid oxidisation on exposure to air degrades the fruit. The fruit turns brown and does not appear attractive to eat and over time the oxidisation also degrades the taste and hence the value of the product. Green tea is prized for its fresh taste and nutritional benefits which may be easily lost if allowed to oxidise before preparation. It is therefore beneficial to process with minimised oxidation. While it is easy to keep manufactured foods preserved, it is less easy to preserve natural foods. Consumers are also less ready to accept use of preservative additives added to the food which hence will be consumed. Consumers, and food retailers therefore demand preservative free products, however, a prolonged shelf life and life in the fridge at home is also highly desirable. Some methods have been tried to treat fruit such as cut avocado to inhibit polyphenol oxidase and slow down the browning of oxidation. For example, heat treating or adding oxygen scavengers to the packaged product. These methods do improve the situation when compared to the cut fruit in the air but do not significantly reduce the oxidation. All known methods start trying to stop the oxidation after the cutting of the avocado, when the exposure to oxygen of the cut surface has already occurred. Oxidation occurs very rapidly at this early stage and so the early oxidation before treatment by known methods causes slight browning of the fruit at the time and leads to further oxidation over time. None, of the aforementioned known methods of treating fruit to try to slow oxidation commence the processing to avoid the oxidation before processing starts, and none completely prevent the polyphenol oxidation. The inventor has, through careful research and development, invented a new processing method that significantly improves the prevention of degradation of foods through oxidation, for example. The invention enables a cut avocado to be prepared and packaged using the new method, and to remain fresh and looking fresh 12 days after cutting, a most significant improvement over the known means of trying to prevent oxidation. The invention is clearly applicable for a great many fruits, vegetables and other food stuffs, including green tea, and enables the shelf life of the cut and processed product to be dramatically improved. It is foreshadowed that once known about the invention will be found useful in numerous other manufacturing processes or other applications. In the industry an improved method of preservation of these oxidation susceptible products has long been desired, without the need to resort to the use of chemical additives or treatments that the consumers may reject due to preconceptions of health implications. The inventor has developed a unique apparatus and method to address these long existing problems, which may be applicable for many products and industries.

The following describes a non-limiting example of the invention being used with reference to processing avocado. Avocado is a useful example as a valuable fruit which oxidises rapidly, degrading the product in terms of appearance and flavour within a very short time frame. Once browned avocado appears unattractive and will not be able to be sold. Avocado is a food with a high wastage problem due to its rapid degradation but is a highly nutritious and otherwise valuable product to producers and consumers. However, the invention is not intended to be in any way limited to use for avocado processing, other than as defined in any claim, but rather may be used with any product susceptible to oxidation. It is envisaged that many food products, for example, may benefit from use of the invention, as well as numerous non-food products.

For clarity, any prior art referred to herein, does not constitute an admission that the prior art forms part of the common general knowledge, in Australia or elsewhere.

It is an object of the present invention to provide a processing apparatus that at least ameliorates one or more of the aforementioned problems of the prior art. It is a further object of the present invention to provide a method of processing that at least ameliorates one or more of the aforementioned problems of the prior art. DISCLOSURE OF THE INVENTION

Accordingly, the present invention provides a processing apparatus for products susceptible to oxidisation, the processing apparatus including: at least one chamber in which processing of the product can occur, the chamber including an entry through which the product can be introduced; and

an oxygen reduction means, for reducing the oxygen levels within the chamber; wherein the oxygen levels in the chamber are kept low through use of the oxygen reduction means so oxygen levels are already low at the point of processing the product.

The processing apparatus may take any suitable form. The processing apparatus may be laboratory scale, larger scale for processing products or may be a manufacturing plant. The processing apparatus may include other processing steps or stages to prepare the product.

The processing may include any suitable preparation of the product for sale. The processing may including cutting or chopping food products for sale as prepared foods. The processing may include actions chosen from the following group: chopping; cooking; coring; cutting; dicing; drying; frying; juicing; peeling; pureeing; or slicing.

The products may be any suitable products. The products may be foods. The products may be fruit. The products may be chosen from the group: fruit; grains; milled products; seeds; tea; and vegetables. The product may be tea. The product may be tea chosen from the group: black tea; fresh tea; green tea; oolong tea; purple tea; red tea; white and yellow tea. The product may be green tea. The process may be used to produce a product with a controlled degree of oxidation. Most preferably, the process is used to minimise oxidation of a product susceptible to degradation on exposure to air.

The product may be a fruit chosen from the group: avocado; apple; banana; pear; or quince. The fruit may be avocado. The product may be avocado and use of the processing apparatus substantially prevents discolouration due to oxidisation after processing. Preferably, the shelf life of the processed product is substantially increased by use of the processing apparatus. The product may remain fresh for several days. The product may remain fresh for 7 to 10 days. Where the product is avocado the cut avocado may appear fresh for 10 days or more from the time of processing using the processing apparatus. Preferably, the product remains unaffected by polyphenol oxidation after cutting through use of the processing apparatus. Preferably, the product remains unaffected by polyphenol oxidation after cutting through use of the processing and packaging using the inventive apparatus. Preferably, polyphenol oxidation of the avocado is substantially prevented by use of the processing apparatus until the avocado is again exposed to an oxygen rich environment.

Preferably, the product is a food that it is desirable to prepare and maintain in a fresh state, despite the products susceptibility to oxidisation. The product may be any food susceptible to oxidation. Susceptibility to oxidation may include any form of degradation on exposure to ambient air. Oxidation may be any reaction with oxygen. Preferably, the products susceptibility to oxidation is discolouration due to the reaction with oxygen. The product may degrade in terms of look, taste or texture in response to oxidation. The oxidation may be polyphenol oxidation. The oxidation may be polyphenol oxidation of avocado fruit on exposure to air.

Preferably, more than one chamber is included. Preferably, a main chamber is included. Preferably, the processing of the product occurs within the main chamber. Preferably, an inlet chamber is included. The inlet chamber may take any suitable form. Preferably, the inlet chamber is connected to the main chamber. Preferably, the product is introduced to the processing apparatus through the inlet chamber. Preferably, the entry to the main chamber is via the inlet chamber. From the inlet chamber the product can pass to the main chamber for processing.

Preferably, the entry takes any suitable form. Preferably, the entry is from outside of the processing apparatus to a chamber where processing may occur. The product may be introduced in any suitable manner to the processing apparatus.

In one preferred form of the invention, an inlet chamber is included and the product enters the apparatus through the inlet chamber before entering the main chamber. The entry may be to the main chamber directly. The entry may a chosen from the group: airlock; chute; conduit; conveyor; or door. Preferably, the entry is through a door to the inlet chamber. A transport system may be included. The transport system may be a conveyor or similar to introduce the product. A transport system may be included in one or more of the chambers of the apparatus to move the product from one side to the other. The transport system may take any suitable form. The transport system may be conveyors controllable by the control unit. Preferably, an outlet chamber is included. The outlet chamber may take any suitable form. Preferably, the outlet chamber is included connected to the main chamber. Preferably, the product can be removed from the processing apparatus through the outlet chamber. Preferably, the product is processed in the main chamber before being passed to the outlet chamber. From the outlet chamber the product may be taken for further packaging, storage, transportation or sale. The inlet chamber and the outlet chamber are preferably different chambers. In other forms of the invention the inlet chamber and the outlet chamber may be a single chamber. The inlet and outlet in other forms of the invention may be direct to the main chamber. Preferably, a waste chamber is included. The waste chamber may take any suitable form. Preferably, waste produced by processing the product may be removed from the main chamber by means of the waste chamber. Preferably, waste may be removed from the waste chamber for disposal. The waste may be parts of fruit, for example. The waste may be skin, pips, stones, cores, stalks, ends, leaves, or other parts of a fruit not to be eaten. Preferably, the waste is chosen from the following group: parts of fruit; skin; pips; stones; cores; stalks; ends; leaves; or other parts of a fruit not to be eaten.

The oxygen reduction means may take any suitable form. The levels of other gases may be varied to achieve the same effect, low oxidisation of the product during processing. The oxygen reduction means may be a number of different means of reducing the oxygen levels in the chamber. The oxygen reduction means may include a flame, used to burn oxygen in the surrounding air. The flame may be used for the initial oxygen reduction. The flame may be used to reduce the ambient oxygen levels to a low rate. The flame may be used to reduce the oxygen to around 15%. The flame may be used to reduce the oxygen levels to between substantially 8% and 15%. The means to introduce the flame may be a flame control unit. The flame control unit may cause a naked flame to be lit. Preferably, the flame control unit is a natural gas low temperature burner. Any suitable burner may be used. The flame control unit may be a STICKTITE (Trade Mark) product. A flame control unit may be included in any one or more chamber. Preferably, a flame control unit is included in the inlet chamber. Preferably, a flame control unit is included in the main chamber. A flame control unit may be included in the outlet chamber. There may be a plurality of flame control units. There may be a plurality of flame control units in the main chamber. Preferably, the flame control units are controlled by the control unit for the apparatus. The flame and or flame control unit may also indicate oxygen levels by burning out or failing to burn when oxygen levels are low in the chamber. The oxygen reduction means may include introduction of one or more gas. The gas may include carbon dioxide. The gas may include nitrogen. The gas may be carbon dioxide. The gas may be nitrogen. Preferably, carbon dioxide and nitrogen gas levels are increased to prevent the increase of oxygen levels within the chamber. Preferably, multiple forms of adjustment may be made to reduce and maintain low oxygen levels in the chamber.

The oxygen levels of the chamber are preferably, adjusted to be very low. Preferably, the oxygen level is less than 8%. Most preferably, the oxygen level is close to nil. Preferably, the oxygen level is a very low oxygen level. The low oxygen environment may be no oxygen environment. Preferably, the product is not introduced until the oxygen level falls to 5% or below. Most preferably, as product is introduced the oxygen reduction means is used to reduce the oxygen levels of the introduced air. Preferably, the oxygen levels are brought to substantially nil. Preferably, an inlet chamber is used associated with the main chamber and the oxygen reduction means are used to reduce the oxygen levels in the inlet chamber before the product is introduced into the main chamber. Preferably, the oxygen reduction means is also used to keep the levels of oxygen low in the outlet chamber to substantially prevent the exposure to oxygen of the cut product. Preferably, a flame is used to burn the initial oxygen and carbon dioxide gas allowed into the chamber to assist to prevent further ingress of oxygen from outside. Several stages of oxygen reduction may be used. Further stages of maintenance of low levels of oxygen may be used. The oxygen reduction means may be used to change the oxygen levels in any part of the apparatus. The oxygen reduction means may be used to lower the oxygen levels in any of the main chamber, inlet chamber or outlet chamber. Any part of the apparatus may act as substantially as an airlock to reduce the ingress of ambient air into the chamber. Where multiple chambers are included the inlet chamber and outlet chamber may act as airlocks to the main chamber.

Preferably, a control unit is included. The control unit may take any suitable form. The control unit may be a computerised control unit. Preferably, the processing apparatus can be controlled through use of the control unit to enable entry of a product for processing and after processing enabling the product to be removed. The computerised control unit may control the flame control units. Power may be provided to other parts of the apparatus via the computerised control unit.

Preferably, one or more sensors or monitors are included to monitor the oxygen levels. The sensor or monitor may be associated with the product itself. Preferably, sensors are included in each chamber to monitor the oxygen levels in the chamber. Preferably, the oxygen levels in one or more chamber can be seen by the operator. The oxygen levels may be recorded on a display. A display may be associated with the control unit. The control unit may be controlled through use of the display such as a touch screen in some forms of the invention. In other forms of the invention buttons or switches may be used instead.

The sensors may be carbon dioxide sensors that detect and report the levels of carbon dioxide in the surrounding atmosphere. The sensors may be oxygen sensors that detect and report levels of oxygen in the surrounding atmosphere. The sensors may be chosen from the group: Vernier (Trade Mark) carbon dioxide gas sensors; Vernier (Trade Mark) oxygen gas sensors. Any suitable oxygen sensors may be used.

Preferably, feedback is used so that the oxygen levels are automatically maintained at a suitable low level within the chamber. The monitors and control unit may keep the oxygen at a suitable low level in the chamber during operation. In this way once the operator switches on the control unit the oxygen levels are monitored and oxygen reduction means operated to lower the oxygen levels and then maintain the oxygen levels at the low rate during operation. Preferably, the initial oxygen reduction is through means of a flame to burn the oxygen in the air until spent. A vacuum pump may be used to remove exhausted air. Preferably, carbon dioxide and or nitrogen are then introduced to assist to prevent reentry of oxygenated air. The burning of the flame may be caused to occur again when the monitors of the oxygen levels read that oxygen has increased to a particular point. Introduction of carbon dioxide and nitrogen may be then caused to occur on control from the control unit where the oxygen rises from the nil or very low levels.

Preferably, carbon dioxide and nitrogen gas tanks are associated with the processing apparatus. Preferably, pipes with valves controlled by the control unit enable or prevent carbon dioxide or nitrogen entering the chamber. Other forms of control or suppression of oxygen may be used instead. These may be automatically controlled or manually controlled on the operator becoming aware of the increase in oxygen levels through monitors.

The control unit may be centrally controlled by a computer system. The control unit may be fully manually controlled. Most preferably, the control unit maintains low oxygen in the chamber during the entire period of operation.

Preferably, the product is packaged in a low oxygen environment. Preferably, the product is packaged during processing. Preferably, the product remains in a low oxygen environment from the first cut into the product, until the product is packaged, sealed away from the air to enable removal from the processing apparatus. The product is therefore not exposed to the air during processing to maintain freshness. Preferably, the product is introduced to a low oxygen environment before processing, is processed and packaged within the low oxygen environment. Preferably, the packaged product is kept in a low oxygen sealed packaging. Preferably, the product is sealed in a container which prevents ambient air from entering. Preferably, the product is packaged in a sealed carbon dioxide and nitrogen rich gas environment to substantially prevent oxidation while packaged. Preferably, the packaging significantly prolongs the shelf life of the processed product. Preferably, the packaging during the processing substantially prevents oxidation of the product until the package in opened. In this way oxidation is substantially prevented from the start of preparation, during preparation and during packaging and sealing in a low oxygen container. For the entire process the product is prevented from exposure to air. During the entire process the product is substantially isolated from oxygen.

Preferably, the control unit controls doors of the inlet chamber, main chamber and outlet chamber to enable the product to be introduced, processed in the main chamber, packaged and removed through the outlet chamber. Preferably, doors are included on the chambers. Preferably, the doors are controlled doors. Preferably, the controlled doors are controlled by a control unit, to enable the operator to open and close the doors. Preferably, the doors are moveable between a closed and open state. Preferably, the doors seal in the closed state. Preferably, the doors enable the product to move in or out of the chamber in the open state. Preferably, in the closed state the door is sealed. Preferably, the doors are sealed against ingress of air. Preferably, the operator can press a button or similar to cause a control door to open or close. Preferably, the operator will open a control door to the inlet chamber and the product placed inside. The control door to the inlet chamber is preferably, quickly closed to seal the product inside the inlet chamber. Preferably, a control door between the inlet chamber and the main chamber may be used and the operator move the product from the inlet chamber to the outlet chamber. The main chamber may include sealed access for the operator to work within the main chamber. The sealed access may be through one or more access ports. Preferably, a plurality of access ports are included. Preferably, each access port is associated with a sealed glove into which an operator can put their hand so as to work within the main chamber in a sealed fashion to prepare the product. Other forms or access may be used instead.

Preferably, an operator can move the product from the inlet chamber to the main chamber through a control door by hand through the sealed access points. Preferably, in the main chamber the product can be processed. Where the product is fruit the fruit may be cut and prepared ready to eat. The fruit may be avocado and the fruit cut in half to remove the stone and sliced suitable for packaging and sale.

Preferably, packaging materials are also put in the inlet chamber. Preferably, packaging materials are also put in a low oxygen environment with the product for processing. The product may be prepared and put in a container in the low oxygen environment. The product may be presented in the container ready for sale. Preferably, the packaging occurs in a low oxygen environment and therefore the sealed container maintains a low oxygen environment for the prepared product. Preferably, the product is packaged during the processing and maintained in a low oxygen state throughout.

Preferably, the operator uses sealed gloves through the access ports to process the product. Once processed the operator may use the controlled door to move the product from the main chamber to the outlet port. Preferably, the control door is quickly closed between the main chamber and the outlet port. When the outlet port is opened therefore, air may be substantially prevented from entering the main chamber.

Accordingly, the present invention provides a processing apparatus for products susceptible to oxidisation, the processing apparatus including: an inlet chamber for introduction of the product; a main chamber in which processing of the product can occur, the main chamber being in communication with the inlet chamber;

an outlet chamber for removal of the processed product, the outlet chamber in communication with the main chamber;

an oxygen reduction means, for reducing the oxygen levels within the chamber; and

a control unit for controlling the oxygen reduction means to for the low oxygen environment,

wherein, the oxygen levels in the chamber are kept low through use of the oxygen reduction means so oxygen levels are already low at the point of processing the product, during processing and packaging before removal of the product from the outlet chamber.

Accordingly, the present invention provides a processing apparatus for preparing avocado with minimal oxidisation, the processing apparatus including: an inlet chamber for introduction of the avocado;

a main chamber in which cutting of the avocado can occur, the main chamber being in communication with the inlet chamber;

an outlet chamber for removal of the cut avocado, the outlet chamber in communication with the main chamber;

an oxygen reduction means, for reducing the oxygen levels within the chamber; and

a control unit for controlling the oxygen reduction means to for the low oxygen environment,

wherein, the oxygen levels in the chamber are kept low through use of the oxygen reduction means so oxygen levels are already low at the point of cutting the avocado, during processing and packaging of the avocado in a low oxygen sealed container, before removal from the outlet chamber.

The invention also relates to a method of use of a processing apparatus, the processing apparatus including a chamber for preparing the product and an oxygen reducing means, the method including the following steps: a) Introducing the product into the processing apparatus;

b) Reducing the oxygen in the processing apparatus by use of the oxygen reducing means; c) Processing the product; and

d) Removing the product

The invention also relates to a method of use of a processing apparatus, the processing apparatus including an inlet chamber, main chamber, and outlet chamber, for preparing the product and an oxygen reducing means, the method including the following steps: a) Introducing the product into the inlet chamber of the processing apparatus; b) Moving the product from the inlet chamber to the main chamber through a controlled door;

c) Reducing the oxygen levels, in the processing apparatus by use of the oxygen reducing means;

d) Processing the product in the main chamber; and

e) Removing the packaged product from the outlet chamber,

wherein the oxidation of the product is minimised throughout due to the low oxygen environment used. The invention also relates to a method of use of a processing apparatus for avocado, the processing apparatus including an inlet chamber, main chamber, and outlet chamber, for preparing the avocado and an oxygen reducing means, the method including the following steps:

a) Introducing the avocado into the inlet chamber of the processing apparatus; b) Moving the avocado from the inlet chamber to the main chamber through a controlled door;

c) Reducing the oxygen levels, in the main chamber of the processing apparatus by use of the oxygen reducing means;

d) Cutting into the avocado only when the surrounding environment is a low oxygen environment;

e) Processing the avocado in the low oxygen environment in the main chamber; f) Packaging the avocado in a low oxygen sealed packaging; and

g) Removing the packaged avocado from the outlet chamber,

wherein the oxidation of the product is minimised throughout due to the low oxygen environment used.

The product may be packaged in the low oxygen environment before removal. The steps may be performed in any suitable order. The levels of oxygen may be reduced before or after the product is introduced to the apparatus. However, the product is not processed until the surrounding environment is a suitable low oxygen environment.

The invention also relates to a product prepared and packaged using the methods. The methods may use the processing apparatus of invention in any of its forms or variants.

INDUSTRIAL APPLICABILITY

The apparatus and method may be used in commercial production of food stuffs. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in connection with a non-limiting preferred embodiment with reference to the accompanying drawings, in which:

Figure 1 is a front view of a schematic of the processing apparatus according to a preferred embodiment of the invention;

Figure 2 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 3" to indicate three days have elapsed since the processing of the samples;

Figure 3 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 5" to indicate five days have elapsed since the processing of the samples;

Figure 4 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 7" to indicate seven days have elapsed since the processing of the samples;

Figure 5 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 8" to indicate eight days have elapsed since the processing of the samples; Figure 6 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 9" to indicate nine days have elapsed since the processing of the samples; and Figure 7 is a view from above of experimental results of an unprocessed and processed sample of avocado labelled "Day 12" to indicate ten days have elapsed since the processing of the samples.

DETAILED DESCRIPTION OF THE INVENTION INCLUDING A BEST MODE With reference to Schedule 3 (9) of Patent Regulations 1991 , we note that labels "DAY 3", for example, are included below the drawings to particularly facilitate understanding of the invention, by indicating the day since processing of the avocado samples.

Referring to Figures 1 to 7, a preferred embodiment of the invention will be described, where processing apparatus 1 includes main chamber 12, on supports 14 and 16. Supports 14 and 16 are metal legs to elevate chamber 12 to a height suitable for the person processing. Chamber 12 has a metal floor, walls and roof (none of which are labelled) in the usual fashion to provide a sealed unit, not open to the external air. Chamber 12 provides a sealed area to work with a closable access so that the oxygen levels in the internal environment may be monitored and adjusted. Openings to chamber 12 of course may be included, provided on closure a good seal is again achieved. Other forms of chamber 12, different to the metal walled chamber could be used instead.

It is envisaged that chamber 12 may form part of a factory production line for small or larger scale processing of product. The product may be continuously introduced, processed using the inventive method, and exit through the outlet after processing ready for transportation and sale. The other parts of the factory or processing such as conveyors could be used with the invention. Where conveyors are used these may be linked to an automated processing of opening and closing or a person may take the product from a moving conveyor and then introduce it to the static apparatus 1 , for processing.

Inlet chamber 18 is connected to main chamber 12, for introduction of products for processing, to the chamber before any damage or cutting to the product has occurred. Similarly, outlet chamber 20 enables products to exit ready to be packaged or transported for sale. Main chamber 12 inlet chamber 18 and outlet chamber 20 are formed of a sealed metal floor and walls to maintain integrity. Each of inlet 18 and outlet 20 are in communication with main chamber 12, in a sealed fashion when closed. Inlet 18 and outlet 20 act like an airlock to further maintain integrity within main chamber 12. Waste chamber 22 can be seen below main chamber 12, for disposal of waste product during processing. Where the product is avocado the waste may be the skin and stone which are removed during the processing. Waste chamber 22 can be readily emptied periodically to prevent overfilling, through an outer door. In other forms of the invention the waste chamber 22 may be a waste chute or outlet to a centralised waste depository. Waste chamber 22 is also sealed so that the environment of main chamber 12 where processing occurs may be fully controlled.

The particular form, shape and arrangement of chamber 12, supports 14 and 16, inlet chamber 18, outlet chamber 20 and waste chamber 22 can be varied somewhat. For example the position of the inlet, outlet and wastes may be changed to suit the particular arrangement where the processing is to occur.

Visible at the front of main chamber 12 are access ports 26a, 26b, 26c, 26d, 26e and 26f. Each of these access ports enables access to main chamber 12. Each has sealed gloves (not shown) of a known form, attached of a kind that a person slips there hand into uses as if they were wearing protective gloves inside chamber 12. The three pairs of access ports 26a and 26b. 26c and 26d and 26e and 26f enable work at each of the three positions along main chamber 12. The three positions enable a person to access the inside of chamber 12 at a range of positions or for three workers to be processing products simultaneously. In other forms of the invention the gloves form of these may be varied, and changed to suit the nature of the preparation to be made of the product. Control of the apparatus is through computerised control unit 36. Computerised control unit 36 can be controlled through use of buttons on the outside to operate and once operational will reduce and maintain the oxygen in chamber 12 at low levels throughout the entire processing. More than one means of changing the oxygen levels is used in response to the controls as is explained further below. Control doors 28, 29, 30, 31 , 32 and 33 are the controlled, electromagnetic doors, sealed doors to enable access to each of the sections of apparatus 1 . Flame control units 34 are included in inlet chamber 18, outlet chamber 22 and two in main chamber 12 on towards the roof. Flame control units 34 as illustrated are STICKTITE (Trade Mark) natural gas low temperature burners. Flame control units 34 can be seen to be included at each stage of processing, to remove the first stage oxygen. Control of flame control units 34 and of control doors 28, 29, 30, 31 , 32 and 33 is by computerised control unit 36. The control may be either manually by pressing a button, or in an automated fashion as part of ongoing processing. Each flame control unit can be operated individually to burn to reduce oxygen in an area. Each door can also be controlled and when closed is sealed shut to prevent additional air or oxygen entering an area than is necessary. Main chamber 12 is protected from direct access to the air as each of the inlet chamber 18, outlet chamber 20 and waste chamber 22 have two doors so as to act as an airlock to prevent direct ingress of air from the outside.

The computerised control 36 of the apparatus enables easy operation by a person throughout the whole process, so as to maintain low oxygen levels throughout. Control of the computerised doors between an open and closed stage is useful as their use does not interfere with the other stages of the processing. The sliding doors also act swiftly to minimise the changes to the ambient environment, so in a low oxygen environment only minimal additional air containing oxygen is allowed to enter. Computerised control 36 controls the following:

1. Flame control units 34 burn in the burning state, until the oxygen is depleted, extinguishing the flame.

2. Sensors (Vernier (Trade Mark) carbon dioxide and oxygen sensors are used).

None of the sensors are shown but these are located throughout the chambers to register and report the oxygen and or carbon dioxide levels to the computerised unit 36. The in-house software will be programmed to recognise the levels of oxygen and cause action until the oxygen levels are suitably low for processing.

3. Valves (not shown) operate under control of the computerised control unit 36 to allow carbon dioxide and or nitrogen into a chamber where the oxygen levels are reading at levels where the flame control unit 34 has acted but the oxygen levels still need to be reduced. Carbon dioxide and or nitrogen can be allowed to enter one, some or all of the chambers. In this way the first stage is burning of oxygen by the flame, the exhausted air is then extracted using a vacuum pump and replaced by carbon dioxide and or nitrogen to act against the ingress of further oxygen.

4. Oxygen levels are displayed on a simple display on the computerised control 36 (not shown) linked to the sensor information. The oxygen levels could instead be displayed on each chamber using individual monitors of the sensors, in a known fashion.

5. Once oxygen levels are below 5% in all the chambers controls are released by computerised control unit 36 to enable operation of door 28. The electromagnetic locks (not shown) can then be operated from a closed to an open position, to allow the product to pass into the inlet chamber for processing.

6. Door control is repeated to pass the product from inlet chamber 18, to main chamber 12 through door 29, and again through door 30, to outlet chamber 20. Similar electromagnetic controls enable the product to exit through door 31 when packaged and sealed. Also waste can be put in waste chamber 22 through door

32 on computerised operation and similarly removed through electromagnetically controlled door 33, although only once door 32 is closed again. The "air-lock" style doors can be adapted to only open one at a time to minimise ingress of ambient air and increase in oxygen levels.

7. Alarms are included in computerised control 36 to indicate to the operator if product is within the apparatus and oxygen levels have risen above the desirable level, eg more than 8% oxygen.

In use, a person will take a product to be processed (not shown) but as in the given example an avocado, and introduce uncut into inlet chamber 18 through control door 28. To open control door 28 a button is pressed on the computerised control unit 36, which moves control door 28 from a closed to an open position. As shown control door 28 slides open to one side when released from the lock position by use of the computerised control unit control. Control doors 28, 29, 30, 31 , 32 and 33 are shown as sliding doors, however alternative door arrangements including hinged doors may be used instead.

Once the product is introduced into inlet chamber 18 control door 28 is closed again using a button on computerised control unit 36. Once closed by door 28 inlet chamber 18 is sealed from the outside environment. Controlled door 29 between inlet chamber 18 and main chamber 12 is closed at this point, as is controlled door 30 to the outlet chamber. Use of further controls on computerised control unit 26 causes a flame in an appropriate flame control unit to be initiated. Flames are burned within inlet chamber 18 and main chamber 12 to use the oxygen in the air, once the flame burns out this is a visual indicator that the oxygen in chamber 12 has been used. Removal of oxygen is stage 1 of the chamber 12 preparation process. Stage two is the removal of the oxygen depleted "air" completely from chamber 12 by means of a vacuum pump and pressure sensors of a known form (Honeywell (Trade Mark) RS Stock No. 843-5586). Stage 2 extraction is continued until the oxygen sensors read very low oxygen levels or zero oxygen preferably. After stage 2 introduction of carbon dioxide and or nitrogen assists to maintain the low oxygen environment within chamber 12. Bottles of carbon dioxide and nitrogen (not shown) with outlets controlled by control unit 36 are included to introduce the gases directly into chamber 12. During processing and introduction of the product further use of a flame to burn any introduced oxygen and introduction of carbon dioxide and nitrogen is used to maintain the very low oxygen environment, suitable for processing the product. Close monitoring of the oxygen levels before during and after processing until the product is packaged occurs through use of the system to absolutely minimise the risk of oxidation.

Computerised control unit 34 includes monitors for sensors for oxygen and carbon dioxide levels within main chamber 12. The operator can see the ambient environment conditions through use of these monitors and make adjustments accordingly. When chamber 12 has a suitable low oxygen state of 5% or below control door 29 can be opened and the product moved through use of a conveyor into main chamber 12 and control door 29 closed. A person can use their hands in sealed gloves through the access points 26a, 26b, 26c, 26d, 26e, or 26f, as appropriate. At this point is likely that the oxygen levels will have increased and the flame may again be burned to remove the oxygen. The carbon dioxide and nitrogen levels may also be increased by introduction of more to maintain the low oxygen environment.

Once the oxygen levels are reading as nil or negligible then processing may begin. The user will access the product through use of the sealed gloves in access ports 26a, 26b, 26c, 26d, 26e, or 26f. Tools will be available within chamber 12 to cut say, the avocado, in half and take out the flesh, all in a very low oxygen environment. Due to the low oxygen environment oxidation will not occur during the process. Once the fruit is cut as desired, it can be placed in the serving container and sealed, again all within the low oxygen environment. Therefore the environment sealed with the fruit will not cause oxidation, and so the fruit will be maintained in the freshly cut condition, until ready to be consumed or the seal is broken. Once the product is sealed in the container, control door 30 is caused to open through operation of computerised control unit 34, and the container put in outlet chamber 20. The process may be automated through use of conveyors, or as shown will be manually operated. Once control door 30 is opened and the container of sealed product placed inside outlet chamber 20, door 30 is closed again. Operation of controlled door 31 enables the sealed, prepared product to be removed into the air. The sealed contained does not allow air in, instead the avocado is held in the low oxygen environment and remains fresh. The container can now be packed, transported and sold, such as in a supermarket. On closing control door 31 , control door 32 can also be used to get rid of was such as skin or the avocado stone. Waste may be accessed through use of control door 33 at regular intervals to remove the waste as necessary. Closure of all control doors then occurs to reset ready for the next avocado. The flame will be burnt again to remove oxygen that has entered during the removal and clear up process, stage 1 , the oxygen depleted air removed, stage 2 and carbon dioxide and nitrogen introduced to keep the environment low oxygen ready for the next processing.

Referring to Figures 2 to 7, in particular, experimental results are shown over a sequence of days from processing. Boxes 38 and 40 respectively contains avocado samples 42 and 44. Box 38 contains avocado sample 42 which was cut up in air on day 1 and placed in box 38. Box 38 was closed and placed in a refrigerator. Box 40 contains avocado sample 44 which was processed entirely in an oxygen free environment according to the invention from before the cutting took place.

Figure 2 shows after 3 days even in a closed container sample 42 shows browns marks and the signs of the start of deterioration. Often cut avocado starts to brown and oxidise very quickly, before being placed in a container. The container is of course also full of air and oxidation continues to occur to the cut surfaces of the avocado the oxygen in the contain reacts with the surface of the fruit. Sample 44, however, is the sample processed by the inventive method and can be seen to appear fresh, unmarked, no browning or oxidation. Figure 3 shows the respective samples at day 5 since processing. Sample 42 now shows significant browns marks indicating oxidisation. Sample 44 at day 5 still appears fresh, no browning. Figure 4 shows the respective samples at day 7 since processing. Sample 42 continues to increase in the significant browning of oxidisation. Sample 44 still appears unmarked and fresh. Figure 5 shows the respective samples at day 8 and still the browning of sample 42 continues. Sample 44 remains yellow and green, fresh as if just cut. Figure 6 shows the same trend, browning worsening and no change to sample 44. Figure 7 shows sample 42 very blackened at day 10, and it does not look appetising to eat. The lid is now removed from box 40 containing sample 44. Sample 44, processed using the inventive method still appears yellow/green and certainly fresh enough to eat. Deterioration and oxidation is likely to start now air has been introduced and some slight spotting and browning colouration can be seen in the Figures.

The invention is a significant step forward for processing of foods that may oxidise rapidly, to enable these to be prepared for sale at a later date. Importantly the method of processing does not involve use of preservatives and does not alter the nutritional value of the food, it is instead preventing oxygen from acting at all on the product, thereby maintaining the quality of the food.

It will be apparent to a person skilled in the art that changes may be made to the embodiment disclosed herein without departing from the spirit and scope of the invention in its various aspects.

REFERENCE SIGNS LIST:

1 Processing Apparatus 32 Control door waste inlet

12 Main chamber 33 Control door waste outlet

14 First support leg 34 Flame control units

16 Second support leg 36 Computerised control unit

18 Inlet chamber 38 Unprocessed sample box

20 Outlet chamber 40 Processed sample box

22 Waste chamber 42 Unprocessed avocado sample

26a-f Access Ports

28 Control door inlet

29 Control door inlet/main chamber

30 Control door outlet/main chamber

31 Control door outlet