WO2005120239A1

WO2005120239A1 - Fruit treating apparatus and procedures

Info

Publication number: WO2005120239A1
Application number: PCT/NZ2005/000122
Authority: WO
Inventors: Lionel Gordon Evans
Original assignee: Fresh Appeal Limited
Priority date: 2004-06-10
Filing date: 2005-06-09
Publication date: 2005-12-22
Also published as: AU2005251661A1

Abstract

Apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus comprising or including irradiation apparatus to receive produce pieces into an induced and/or forced liquid vortex, there being at least one UV source capable of irradiating such produce pieces whilst in the vortex and/or downstream thereof, and immersion apparatus to receive the UV irradiated produce pieces and to carry the produce pieces down through a bath of a different liquid to that of irradiation apparatus and up to a discharge zone.

Description

FRUIT TREATING APPARATUS AND PROCEDURES

FIELD OF THE INVENTION The present invention relates to a process and apparatus for use in a process for treating fruit.

BACKGROUND ART In PCT/NZ02/00168 (published as WO03/017773 of The Horticulture and Food Research Institute of New Zealand Limited) discloses a process for the treatment of fruit pieces and particularly apple pieces. There is a need for suitable procedures and apparatus to provide for a systems handling of such a process and it is to various aspects of such methodology and such apparatus that the present invention is directed.

SUMMARY OF THE INVENTION Accordingly in a first aspect the present invention consists in an apparatus in or for a process of enhancing longevity of mechanically modified produce ("produce"), said apparatus comprising or including UV irradiation apparatus to receive the produce and to irradiate the produce whilst in a first liquid carrier not substantially opaque to the UV radiation, first immersion apparatus to receive the UV irradiated produce and force immersion of the producing whilst being conveyed through, a second liquid, and second immersion apparatus to receive the produce that has been through the second liquid of the first immersion apparatus and to force immersion of the producing whilst being conveyed through, a third liquid, the second immersion apparatus conveying the produce to a discharge zone. Preferably a vibratory screen, vibratory conveyor and/or air knife is provided at at least one transfer, i.e. from UV irradiation apparatus to first immersion apparatus and/or from first immersion apparatus to second immersion apparatus, to reduce carriage of liquid of one system into a following liquid system. Preferably the UV irradiation apparatus is adapted to receive the produce into an induced and/or forced vortex of the first liquid and the UV irradiation apparatus has a UV source capable of irradiating such produce whilst in the vortex. Preferably one of, or each of, the first immersion apparatus has an endless flighted conveyor travelling a locus that is capable of pooling the liquid on or about the conveyor over part of its locus. Preferably the discharge zone from the or each conveyor is above the level of any pooled liquid. Preferably the first liquid is or includes water. Preferably the first liquid has had a CaCl₂ added thereto. Preferably the second liquid is at a temperature above ambient. Preferably the third liquid is chilled. Preferably the third liquid is that of an aqueous preservative system (e.g. a source of calcium and ascorbate ions). In another aspect the present invention consists in an apparatus in or for a process of enhancing longevity of mechanically modified produce ("produce"), said apparatus comprising or including UV irradiation apparatus to receive the produce and to irradiate the produce whilst in a first liquid carrier not substantially opaque to the UV radiation, first immersion apparatus to receive the UV irradiated produce and force immersion of the producing whilst being conveyed through, the first immersion apparatus conveying the produce to a discharge zone. Preferably a vibratory screen, vibratory conveyor and/or air knife is provided at the transfer, from UV irradiation apparatus to first immersion apparatus to reduce carriage of liquid of one system into the following liquid system. Preferably the UV irradiation apparatus is adapted to receive the produce into an induced and/or forced vortex of the first liquid and the UV irradiation apparatus has a UV source capable of irradiating such produce whilst in the vortex. Preferably the first immersion apparatus has an endless flighted conveyor travelling a locus that is capable of pooling the liquid on or about the conveyor over part of its locus. Preferably the discharge zone from or each conveyor is above the level of any pooled liquid. Preferably the first liquid is or includes water. Preferably the first liquid has had a CaCl₂ added thereto. Preferably the second liquid is chilled aqueous preservative system (e.g. a source of calcium and ascorbate ions).. In another aspect the present invention consists in an apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having a first immersion apparatus to receive and to discharge produce pieces, a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces, and at least one of a vibratory conveyor and/or an air knife between the immersion apparatus, said conveyor and/or air knife to have the effect of shedding excess liquid on the produce pieces prior to the second immersion apparatus receiving the discharge from the first immersion apparatus. In another aspect the present invention consists in an apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus comprising or including irradiation apparatus to receive produce pieces into an induced and/or forced liquid vortex, there being at least one UV source capable of irradiating such produce pieces whilst in the vortex and/or downstream thereof, and immersion apparatus to receive the UV irradiated produce pieces and to carry the produce pieces down through a bath of a different liquid to that of irradiation apparatus and up to a discharge zone. Preferably there is at least one of a vibratory conveyor and/or air knife between the irradiation apparatus and the immersion apparatus to have the effect of shedding excess liquid from the produce prior to passage into the immersion apparatus. The same apparatus can apparatus of several aspects of the present invention. The use of apparatus of any aspect of the invention is also an aspect of the invention. In another aspect the present invention consists in a method of enhancing food safety and longevity (collectively hereafter "preserving") of fresh fruit and/or fresh vegetables (hereafter the "produce") that has been subject to a mechanical reduction (i.e. peeling and/or size reduction by cutting [hereafter "pieces"]) thereby to provide a still at least in part substantially "fresh" produce product, which method comprises or includes the steps of subjecting the produce pieces to UV irradiation whilst liquid borne by a liquid not substantially opaque to the UV radiation, taking the UV irradiated produce pieces from that liquid and/or another liquid to an immersion apparatus of a kind adapted to force the produce pieces below a treating liquid bath and then to uplift the pieces above the bath and drop the pieces into a harvesting system. Preferably the harvesting system is a vibratory screen or other such liquid shedding conveyor or an air knife. Preferably liquid is recovered using a vibratory screen or like conveyor prior to the immersion apparatus and preferably fed back as liquid for the UV irradiation. Preferably a bath in which the pieces float is used after UV irradiation and prior to said immersion apparatus. Preferably a bath feeds liquid into the UV irradiation apparatus. Preferably the UV irradiation apparatus irradiates the pieces whilst in and/or immediately after a forced or induced vortex. The UV irradiation apparatus comprises or includes establishing a vortex turbulated flow of water or other liquid system containing the produce pieces through a vertically oriented ultra-violet light transparent tube which is open at both ends, generating a flow of ultra-violet radiation into said tube and through said vortex flow, whereby said microorganisms of or from the produce pieces are exposed to said ultra-violet radiation while passing down said tube, and recovering the liquid carrier directly or indirectly after it has exited said tube. Preferably said vortex is augmented by projecting a jet of liquid substantially tangentially into said tube at or adjacent the top thereof. Preferably the rate of flow of said jet is controlled so as to control the dwell time of said produce pieces in said tube. In one alternative the strength of said ultra-violet radiation is varied while said microorganisms are exposed in said tube. Preferably said produce pieces have been permeated with a preserving agent (e.g. calcium chloride solution) before being placed in said vortex flow. Preferably said produce pieces are dried after exiting said tube. Preferably said ultraviolet radiation has a wavelength of 200 to 280 nanometres. Most preferably said ultraviolet radiation has a wavelength of about 253.7 nanometres. Preferably the ultraviolet radiating means to generate the UV flow is a low pressure mercury vapour quartz tube (preferably cooled (e.g. by air) to about 42°C). Preferably said tube is constructed of a fluoropolymer. In one alternative the means for supplying liquid into said tube comprises a funnel having a spiral flow path therethrough. In another alternative there is provided a tangential liquid jet to impart a controllable vortex within said tube in combination with said funnel. In a still further embodiment there is provided a tangential liquid jet as the sole means for supplying said liquid. Preferably said low pressure mercury vapour quartz tube radiates ultraviolet radiation at a wavelength of 253.7 nanometres. Preferably there is a casing surrounding said ultraviolet radiating means, the inner face of said casing having reflecting means for reflecting ultraviolet radiation. Preferably there is a temperature control system associated with said tube and said ultraviolet radiating means for controlling the intensity at which said ultraviolet radiation is radiated. Preferably there is a temperature control means for controlling the temperature of said liquid flowing through said tube. Preferably there is a means for continuously feeding said produce pieces into said infeed tank. Preferably there is a holding tank downstream of said draining means into which, said draining means may discharge water and produce pieces that have passed through said tube. Preferably there are means to convey produce pieces out of said holding tank. Preferably there are means for recycling liquid from said holding tank to said infeed tank. Preferably said means to recycle said liquid comprises or includes a main tank, a pipe discharging water from said holding tank to said main tank, conduit means from said main tank to said infeed tank, a pump and a filtering system in said conduit means, the distal end of said conduit means returning liquid into said infeed tank. In another aspect the present invention consists in apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having, a first immersion apparatus to receive and to discharge produce pieces, (optionally) a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces, and at least one vibratory conveyor to or from a or the immersion apparatus, said conveyor to have the effect also of shedding excess liquid on the produce pieces. In another aspect the present invention consists in apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having, in series, a first immersion apparatus to receive and to discharge produce pieces, and a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces, and (optionally) at least one vibratory conveyor to or from a or each immersion apparatus. In another aspect the present invention consists in apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having, in series, UV irradiation apparatus to irradiate the produce pieces whilst in a first liquid system as carrier, a liquid recovery and/or recycle system that involves a vibratory conveyor adapted to shed excess liquid from the produce pieces, and an or a first immersion apparatus to receive and produce pieces directly or indirectly from the vibratory conveyor, to immerse them in a different liquid system, and to discharge produce pieces, and (optionally) a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces. Preferably each liquid system is aqueous based. Preferably the UV irradiation apparatus is of a vortex type as herein described. Preferably the immersion apparatus is as herein described. In another aspect the present invention consists in apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having, in series, a first immersion apparatus to receive and to discharge (preferably UV irradiated) produce pieces, and a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces, wherein prior to one immersion apparatus a vibratory screen or equivalent vibrator sheds excess liquid of an earlier liquid system of the overall system. In another aspect the invention is apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus comprising or including irradiation apparatus to receive produce pieces into an induced and/or forced liquid vortex, there being at least one UV source capable of irradiating such produce pieces whilst in the vortex and/or downstream thereof, and immersion apparatus to receive the UV irradiated produce pieces and to carry the produce pieces down through a bath of a different liquid to that of irradiation apparatus and up to a discharge zone. Preferably the apparatus to receive the UV irradiated produce pieces includes a reservoir containing or to contain a liquid as a bath, a flighted endless conveyor that serially presents flights to a loading zone at which the immersion apparatus receives the UV irradiated produce pieces and wherein each flight serially flight receives thereon produce pieces to be immersed in the liquid of the bath and later presents the pieces initially received on the preceding flight to said discharge zone from whence the pieces leave the flight, and wherein the loading zone to discharge zone involves an initial flight supported lowering of the pieces and thereafter a following flight uplifting of the pieces and/or liquid in the bath until such time as the pieces are supported by said following flight out of the liquid of the bath and carried at least in part thereby to the discharge zone. Preferably the discharge zone of the immersion apparatus involves a gravity supported cascading of the materials from said following flight or in any event involves a cascade. Preferably said immersion apparatus is followed directly or indirectly by a vibratory conveyor through which or down which liquid in excess of requirements can move whilst the pieces are advanced (preferably upwardly). Preferably said apparatus is of a kind as defined in our New Zealand Patent Application No. 481550. Preferably the UV irradiation apparatus involves a UV source positioned axially within and/or about the axis of the vortex. Preferably the irradiation apparatus has the effect of receiving the pieces and providing some semblance of singulation or separation thereof as they flow to a discharge. Preferably the irradiation apparatus discharges pieces into a bath. Preferably that bath includes the same liquid as provides the vortex but not necessarily so. Where the liquids are different preferably an uplifting device e.g. a vibratory screen or other conveyor can be provided. Preferably a vibratory conveyor preferably to substantially free the pieces of excess liquid or any other conveyor can be utilised to move pieces from the irradiation apparatus to said immersion apparatus. Optionally said immersion apparatus is followed by a second immersion apparatus which receives either a cascade of the discharge from the first immersion apparatus or vibratory conveyor or other conveyor handled pieces therefrom. Optionally one or more of the liquid systems used in the irradiation apparatus or the immersion apparatus or the serial immersion apparatus can be at an elevated temperature. Preferably however at least some, if not most, and if not all of such liquids are at ambient or a near ambient temperature or one that might be considered as a cold process. In still a further aspect the present invention consists in, in a process for enhancing longevity of produce, the use of UV irradiation apparatus to irradiate the produce having at least some modified surfaces (e.g. by cutting, peeling or the like) whilst in a first liquid carrier system, apparatus to at least in part convey the irradiated produce from the irradiation apparatus while shedding at least some of the liquid of the first liquid system, and apparatus to force immersion of the produce shed of at least some of the liquid of the first liquid system and to force the produce through the liquid of a second liquid system. Preferably the UV irradiation apparatus irradiates the produce when in a vortex flow. Preferably a vibratory screen or other endless conveyor is utilised. If desired a vibratory screen up which the produce self advances can be utilised. Preferably the forced immersion apparatus is apparatus substantially as herein described. Preferably the use is in respect of the treatment of mechanically reduced fresh vegetable and/or fruit material. In a further aspect the present invention consists in produce pieces treated by an apparatus of any aspect of the present invention and/or by apparatus of any aspect of the present invention. In still a further aspect the present invention consists in apparatus for performing a process substantially as herein described with reference to any one or more of the accompanying drawings. In yet a further aspect the present invention consists in plant or apparatus for performing a process substantially as hereinafter described with reference to the accompanying drawings. The present invention is directed to the treatment of produce vis fresh fruit and/or fresh vegetables and in particular peeled, cut, sliced and/or like fruit and/or vegetables. We see apparatus and procedures in accordance with the present invention being applicable in respect of procedures as in the aforementioned WO03/017773 or derivatives or variations thereof or therefrom. That specification determined a procedure that was applicable to fruit such as apples but was equally applicable to other fruits (such as pears and persimmons) and which is applicable to vegetables (such as, for example, squash, pumpkin, carrot and radish) thereby to improve shelf life of, for example, sliced or any other mechanically modified pieces for a period of, say, 21 days at low temperature but without a requirement for constant refrigeration below 4°C. The treatment regime materials utilised in procedures of the present invention however are not critical and all variations are envisaged. The present invention relates to the apparatus and methodology arising from the use of such apparatus which has application in such a procedure but not necessarily so. As used herein the term "and/or" means "and" or "or" and in some circumstances can mean both. As used herein the term "s" following a noun means the singular and plural forms of that noun. As used herein the term "vortex" includes any circulatory, spiral or other such flow whether symmetric, asymmetric or otherwise. As used herein "UV" refers to light at or near UV wavelengths suitable for the purpose as disclosed in, for example, the aforementioned WO03/017773. As use herein "produce" includes fresh and/or live fruit and/or vegetable (e.g. apples, pears, squash, pumpkin, carrot, radish, persimmons, broccoli, cauliflower, kumara, onions, beans, etc). As used herein "chilled" is preferably below 10°C e.g. preferably from O°C to about 8°C. To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred forms of the present invention will now be described with the accompanying drawings in which Figure 1A is a side elevation view of the preferred arrangement for the UV apparatus where it feeds via a bath to a vibrating screen or like conveyor so as to shed excess liquid from the produce pieces for recovery and if desired some measure of recycle, the apparatus showing a tangential inflow as well as an axial inflow from a first bath, Figure IB is a view A- A of the apparatus of Figure 1A, Figure 1C is a plan view of the apparatus of Figures 1A and IB, Figure ID is a view B-B of the arrangement of Figure 1 A, Figure 2A shows immersion apparatus in accordance with the present invention in side elevation with respect to its service tank, Figure 2B is a plan view of the arrangement of Figure 2 A, the cloud like form in each of Figures 2A and 2B, Figure 3 shows how the apparatus of Figure 2A if desired can piggy back in part upon a similar immersion apparatus, a service tank provision not being shown for. the ease of explanation, Figure 4 A shows the apparatus of Figures 1A and 2 A combined as they would be in use showing how the vibratory roller can arrange for movement of produce pieces from the UV irradiation apparatus to the immersion apparatus, Figure 5 is Figure 4 showing how if desired there can be the piggy backing of the immersion apparatus, Figure 6 shows a floor layout suitable for an arrangement as shown in Figure 4B, Figure 7 shows a side elevation sectional view of one embodiment of a UV irradiation apparatus, Figure 8 is a top plan view of a funnel for supplying liquid from the infeed tank into the top end of the treatment tube of the apparatus shown in Figure 7, Figure 9 is a side elevation sectional view of an alternative embodiment of a portion of UV irradiation apparatus as shown in Figure 7, Figure 10 is an isometric view, partly exploded, of the embodiment shown in Figure

9, Figure 11 is a flow diagram showing a cold (Figure 11 A) and hot and cold (Figure 1 IB) process. Figure 12 is a flow diagram depicting a preferred form of the present invention where, for each of the first and second immersion apparatus, an endless flighted conveyor is adapted to drag the produce through a tube configured so as to have a liquid pooling region about part of the locusts thereof.

DETAILED DESCRIPTION The present invention will now be described with reference to the accompanying drawings and processes as disclosed in WO03/017773 or variants thereof. In its simplest form as will be described a radiation apparatus applies UV light to the produce pieces in a first liquid system whereupon there is then forced immersion in a second liquid system after some shedding of excess liquid (preferably with a vibrating screen to avoid the potential contamination an alternative, such as an air knife, may introduce) of the first liquid system from the produce pieces. The forced immersion can be in one or more liquid systems. Temperatures can vary throughout the process as suggested in the aforementioned WO03/017773. A preferred form of apparatus includes a form of UV radiation apparatus exemplified in greater detail hereinafter by reference to Figures 7 through 10 but being shown in a constructional sense with respect to the plant as a whole in Figures 1 A, B and C, 4 A and 4B when in association with a single forced immersion apparatus. In Figure 1 A through D there is shown the UV irradiation apparatus 1 and the outtake vibratory and/or the like screen or the like conveyor 2 which is to take the produce substantially shed of the intake 3 of a forced immersion apparatus 4. Shown perhaps best in Figure 4 A is a first bath 5 supplied by the supply 6 (see Figure

IB) having an ability to commence the vortex flow down through the apparatus 1 preferably under the influence of any additional liquid input at 7 as described hereinafter in greater detail with respect to Figures 7 to 10. As a consequence of irradiation during transit down the column 8 there is an uptaking of the irradiated apples into a second bath at 9 from whence they pass onto a drainer tray 11 thereafter to be uplifted by the vibratory or the like screen or other drainage assisting conveyor 2 from whence they can be cascaded or otherwise fed down into the forced immersion apparatus via the intake 3. Liquid of the first liquid system is lowered through 13 into a tank that can if desired be return of such liquid to one or other of the baths or for use as the tangential inflow whether after treatment or not. The forced immersion apparatus involves the aforementioned intake 3 and multiple flights on an endless conveyor. These flights moving anti-clockwise with respect to the arrangement in Figure 4 means that within, for example, a stainless steel housing having an outlet 16 flight 17 will move the produce pieces to the left on the carrier belt 19 and will force such pieces in time under the liquid level 20, such liquid pieces being supported prior to that time on the preceding flight 21 on that side of the flight facing that side of the flight 17 which will force the pieces under the liquid up to the level 20 within the forced immersion apparatus. As can be seen means is provided whereby the speed of the conveyor 19 is caused by an appropriate drive at, for example, 22, such that the belt runs taut around a roller 23 and over a supporting drainer surface under the belt 19 between 23 anti-clockwise around almost to the drive 22. As can be seen in turn a flight 17A following a flight 21 A will cause the apple pieces to cascade out of the outlet 16. This cascading out of the apple pieces can be into a below positioned similar or other forced immersion or other immersion apparatus or indeed even a spraying apparatus. As shown however the forced immersion apparatus has almost modified to the form of a kiwi an inverted j or other type configuration such that there can be vertical support down to the liquid and thereafter forcing of the buoyant produce pieces around a submerged locus to be emergent to a position from whence they can cascade out of the apparatus. Figure 6 shows for the arrangement as shown in Figure 4A and 4B how a skid 24 can support the apparatus of Figures 1 A to ID and a skid 25 can support the immersion apparatus. Some overhang at 26 can be provided. Region 49 accommodates piping connections whilst

50 accommodates pumps/filters heat exchanges etc preferably on a skid. Piping connections can be provided at 51 whilst a chiller plant and control panel can be on the skid 52. An electrical panel can be at 53. Optionally a downstream treatment plant (e.g. a further immersion apparatus) can be accommodated at 55. 56 shows the position whereby a feed conveyor can feed to the arrangement of Figures 1 to ID region 57 shows the prospect of discharge conveyors from the overhang of the immersion apparatus as depicted. The construction of the ultraviolet radiation chamber 10 in one of several embodiments (still others contemplated in Figures 1 to 6) is described with reference to Figure 7. The chamber will be described starting with the central passage and moving radially outward. A tube 34 made from an advanced fluoropolymer ("AFP") which is transparent to ultraviolet radiation (AFP-840TM) defines a passage 36 extending from funnel 14 to outlet pipe 18. The tube 34 is held in position at either end by compression rings 32 and in between by compression bands 35. The rings 32 are preferably stainless steel hose clips. Their purpose is to stop leakage. In the annular chamber 39 surrounding tube 34 there are positioned a series of ultraviolet radiating tubes 30. In the preferred embodiment these tubes are of a low pressure mercury vapour quartz type. The optimum ultraviolet radiation wavelength to achieve maximum germicidal activity is 253.7 nanometres. This is considered to be 100% efficient when the lamps' surface temperature is 42.2°C. The tubes 30 are held at either end in tube holders 29. These are powered by a wiring loom 31. To the outside of the annular chamber 39 surrounding tube 36 is a cylindrical reflector shield 28. Preferably the inner reflective surface 28 is brushed aluminium which is highly reflective to ultraviolet radiation. The ultraviolet radiating chamber construction is completed by a cylindrical outside casing 27 which may be made of stainless steel. At the bottom of the chamber 10 is a base plate 38. From the bottom end of tube 34 there is a funnel-shaped portion 37 which joins the bottom end of passage 36 to the end of outlet pipe 18. In the embodiment illustrated in Figure 7 there is a sleeve fitting 43 over an open end of pipe 18. The funnel 14 leading from the edge of infeed tank 12 into the top of ultraviolet radiation chamber 10 is shown in plan view in Figure 8. An opening through a side of infeed tank 12 through which an aqueous solution containing floating produce pieces passes is provided above a weir 42. From the weir 42 a downward sloping sluiceway 44 leads over a steeply sloping portion 45 down a scrolling portion 46 and into the top of passage 36. A sloping side 48 completes the passageway from the top edge of funnel 14 down to the scrolling portion 46. In the embodiments illustrated in Figures 9 and 10 the passageway 36 is shorter and has a greater diameter than that illustrated in Figure 7. Otherwise the componentry and the construction is substantially the same. In addition, there is provided an auxiliary tangential jet 40 which injects water into funnel-shaped portion 37 as shown by the arrow C in Figure 4. The injection of this jet has an effect on the flow through rate of the vortex formed within passageway 36 as will be explained below. Jet 40 is connected to a source of high pressure water or the like. Three ultraviolet tubes 30 are illustrated. In this embodiment a casing (not shown) surrounds the total irradiation portion of the apparatus, that is both AFP tubes 34, and to the outside of the outer ring of UV tubes 30. A second water jet 40 also directed tangentially into elbow 54 can optionally be provided. It too has a control valve in common with water jet 41. The operation of the UV irradiation apparatus involves produce pieces, for example sliced apples, being caused to travel down the scrolling pathway 46 as its carrier liquid establishes a vortex which then swirls down passageway 36 through the ultraviolet radiation chamber 10. In the embodiment illustrated in Figure 8 the flow rate of the vortex including flow is not able to be varied. In the embodiments shown in Figures 9 and 10 the speed of the vortex is able to be varied by the tangential injection of a jet of water or the like within the main flow i.e. the produce pieces and its liquid carrier. The flow valves of the water jets 40 and 41 are able to control their flow rate. The faster the speed of the resultant vortex the longer is the residence time in the AFP tube or tubes. The effectiveness of ultraviolet treatment depends on the length of exposure to the radiation, the wavelength of the radiation and the intensity of the radiation applied. The advantage of forming a vortex within passageway 36 is that it allows for a controlled dwell time in passage 36 during which it is exposed to the radiation. The pieces of produce (e.g. fruit) within the vortex may remain more or less stationary depending on the speed with which the vortex descends down the passage 36. A vortex, effective in suspending the pieces within the radiation chamber momentarily, can be achieved by the use of an infeed funnel 14 as described with reference to Figure 8. By way of example only a possible process of treating, by way of example, apple slices is as follows. In this respect see Figure 11. In this respect it can be seen that there can be a cold (Figure 11 A) or a hot and cold process arrangement (Figure 11B), the latter using, for example, two immersion apparatus as in Figure 3. A preferred form of the apparatus is that depicted in Figure 12. The solid arrows in Figure 12 show the direction of liquid flows, and in the case of the tubes, also the produce carried thereby. The non-solid arrows depict flows of the produce preferably without any accompanying liquid. In Figure 12, the UV irradiation apparatus is shown with a receiving hopper above the irradiation tube 60 which is to irradiate the produce (e.g. as pieces) as they descend in an induced or forced vortex down to an outlet tube for liquid recovery and then transfer (after shed of excess liquid) into the intake zone of the first immersion apparatus 61. Here the first immersion apparatus is in the form of a tube having a cable or otherwise supported flight system adapted to pass through the tubes to carry down into the liquid pooling region of the locus of the tube, the produce for immersion prior to discharge of the produce at 68 into the second immersion apparatus 62 which is of a like kind but which has its discharge at 69. Preferably each of the two apparatus 61 and 62 is similar in so far as operation is concerned reliant on sprockets each externally of its tube. Each can be independently driven as far as speed and thus produce dwell time is concerned. Such conveyor systems can use seamless stainless steel tubes with a stainless steel cable carrying disc-like flights (e.g. of TEFLON) fixed to a plastics (e.g. TEFLON™) sheeting of the cable. The SS tubes should be bent smoothly (e.g. by the Cojafex Induction Bending process). Shown in the diagram is a heating unit 63 for the liquid of the first immersion apparatus 61 and a chilling unit 5 (e.g. a sludge ice BELUGA™ type chilling unit) for the liquid of the second immersion apparatus 62. A control unit 65 centrally controls the electrical functions. Such control can be of the apparatus 61 and 62 via their respective sprockets (shown as connected to the controller 65) by the broken lines) as well as the heating unit 63, the chilling unit 64 and the circulation system 66 adapted to receiver liquid of the UV apparatus 60 i.e. the first liquid. In the form of the invention as shown therefore, the first liquid is that of the apparatus 60 and recycled by 66, the second liquid is that from apparatus 63 and in apparatus 61, and the third liquid is that chilled by 64 and of apparatus 62. To the extent that there can be any recycling, there is recycling consistent with the needs of a treatment regime of a kind as previously contemplated.

Claims

CLAIMS:

1. Apparatus in or for a process of enhancing longevity of mechanically modified produce ("produce"), said apparatus comprising or including UV irradiation apparatus to receive the produce and to irradiate the produce whilst in a first liquid carrier not substantially opaque to the UV radiation, first immersion apparatus to receive the UV irradiated produce and force immersion of the producing whilst being conveyed through, a second liquid, and second immersion apparatus to receive the produce that has been through the second liquid of the first immersion apparatus and to force immersion of the producing whilst being conveyed through, a third liquid, the second immersion apparatus conveying the produce to a discharge zone.

2. A process of claim 1 wherein a vibratory screen, vibratory conveyor and/or air knife is provided at at least one transfer, i.e. from UV irradiation apparatus to first immersion apparatus and/or from first immersion apparatus to second immersion apparatus, to reduce carriage of liquid of one system into a following liquid system.

3. Apparatus of claim 1 or 2 wherein the UV irradiation apparatus is adapted to receive the produce into an induced and/or forced vortex of the first liquid and the UV irradiation apparatus has a UV source capable of irradiating such produce whilst in the vortex.

4. Apparatus of any one of the preceding claims wherein one of, or each of, the first immersion apparatus has an endless flighted conveyor travelling a locus that is capable of pooling the liquid on or about the conveyor over part of its locus.

5. Apparatus of claim 4 wherein the discharge zone from or each conveyor is above the level of any pooled liquid.

6. Apparatus of any one of claims 1 to 5 wherein the first liquid is or includes water.

7. Apparatus of claim 6 wherein the first liquid has had a CaCl₂ added thereto.

8. Apparatus of any one of the preceding claims wherein the second liquid is at a temperature above ambient.

9. Apparatus of any one of the preceding claims wherein the third liquid is chilled.

10. Apparatus as claimed in claim 9 wherein the third liquid is that of an aqueous preservative system.

11. Apparatus in or for a process of enhancing longevity of mechanically modified produce ("produce"), said apparatus comprising or including UV irradiation apparatus to receive the produce and to irradiate the produce whilst in a first liquid carrier not substantially opaque to the UV radiation, first immersion apparatus to receive the UV irradiated produce and force immersion of the producing whilst being conveyed through, the first immersion apparatus conveying the produce to a discharge zone.

12. A process of claim 11 wherein a vibratory screen, vibratory conveyor and/or air knife is provided at the transfer, from UV irradiation apparatus to first immersion apparatus to reduce carriage of liquid of one system into the following liquid system.

13. Apparatus of claim 11 or 12 wherein the UV irradiation apparatus is adapted to receive the produce into an induced and/or forced vortex of the first liquid and the UV irradiation apparatus has a UV source capable of irradiating such produce whilst in the vortex.

14. Apparatus of any one of claims 11 to 13 wherein the first immersion apparatus has an endless flighted conveyor travelling a locus that is capable of pooling the liquid on or about the conveyor over part of its locus.

15. Apparatus of claim 14 wherein the discharge zone from or each conveyor is above the level of any pooled liquid.

16. Apparatus of any one of claims 11 to 15 wherein the first liquid is or includes water.

17. Apparatus of claim 16 wherein the first liquid has had a CaCl₂ added thereto.

18. Apparatus of any one of claims 11 to 17 wherein the second liquid is chilled aqueous preservative system.

19. Apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus having a first immersion apparatus to receive and to discharge produce pieces, a second immersion apparatus to receive the discharge from the first immersion apparatus and to discharge the produce pieces, and at least one of a vibratory conveyor and/or an air knife between the immersion apparatus, said conveyor and/or air knife to have the effect of shedding excess liquid on the produce pieces prior to the second immersion apparatus receiving the discharge from the first immersion apparatus.

20. Apparatus for a method of enhancing food safety and longevity of produce that has been subject to a mechanical reduction, said apparatus comprising or including irradiation apparatus to receive produce pieces into an induced and/or forced liquid vortex, there being at least one UV source capable of irradiating such produce pieces whilst in the vortex and/or downstream thereof, and immersion apparatus to receive the UV irradiated produce pieces and to carry the produce pieces down through a bath of a different liquid to that of irradiation apparatus and up to a discharge zone.

21. Apparatus of claim 20 wherein there is at least one of a vibratory conveyor and/or air knife between the irradiation apparatus and the immersion apparatus to have the effect of shedding excess liquid from the produce prior to passage into the immersion apparatus.

22. Apparatus of claim 19 which is also part of apparatus of claim 20 or 21.

23. The use of apparatus of any one of the preceding claims.