WO2000028830A1

WO2000028830A1 - Method and system for treatment of food items

Info

Publication number: WO2000028830A1
Application number: PCT/IL1999/000608
Authority: WO
Inventors: Oren Gafri; Yuri Livshiz
Original assignee: Pulsar Welding Ltd.
Priority date: 1998-11-13
Filing date: 1999-11-12
Publication date: 2000-05-25
Also published as: IL131802A; AU1175100A; IL131802A0

Abstract

A method and system for the treatment of food items is provided. In accordance with the invention, an electric current is rapidly discharged through a discharge apparatus, this giving rise to a very strong and abrupt force which bounces onto the food item. By one embodiment, the discharge apparatus involves discharging electric current through a fluid which causes evolution of plasma, vapor or both, which in turn yield a pressure wave which bounces onto the food item. In accordance with another embodiment the apparatus comprises a discharge coil which is associated with a displaceable metal object whereby the discharge causes magnetic repulsion which induces a rapid movement in the displaceable metal object giving rise to a mechanical force which bounces onto the food item.

Description

METHOD AND SYSTEM FOR TREATMENT OF FOOD ITEMS

FIELD OF THE INVENTION

The present invention relates to a method and system for the treatment of food, particularly meat. In particular, the present invention relates to a method for tenderization of meat.

BACKGROUND OF THE INVENTION

For many types of uses, meat has to undergo prior treatment including smoking, salting, flavoring, chemically treating, etc. Fresh meat is usually still and unpalatable and in order to make is more palatable, it very often undergoes a treatment, which may be a chemical treatment or a mechanical treatment intended to make it more tender. One form of treatment involves breaking of the micro texture of the meat by applying an abrupt pressure while the meat is within a liquid medium. In such tenderization techniques the meat is immersed in a container and then a small explosive charge is detonated within the liquid creating a pressure wave which tenderizes the meat.

GENERAL DESCRIPTION OF THE INVENTION

It is an object of the invention to provide a method and system for the treatment of food items in general and meat in particular. It is a particular object of the invention to provide a method and system for tenderization of food item, particularly meat; draining of blood out of meat; acceleration of rate of impregnation of food items with liquids; and disinfecting of food items. In accordance with one aspect, the invention provides a method for treatment of a food item, comprising: rapidly discharging an electric current through a discharge apparatus, whereby a strong and abrupt force is generated bouncing onto said food item. In accordance with one embodiment of the invention, said discharge apparatus is a discharge-in-fluid (DIF) apparatus in which a current is discharged through a fluid causing the formation of plasma, vapor or both, which in turn yields the generation of a pressure wave which bounces onto the food item. This embodiment will be referred to herein as the "DIF embodiment" . In accordance with another embodiment of the invention, the discharge apparatus comprises a discharge coil associated with a displaceable metal object, e,g, a metal piston and as a result of current discharge through the coil, and generates eddy currents in the piston a magnetic force arises which rapidly pushes the piston away from the coil which in turn applies a force onto the food item. The force is applied either directly or the piston pressurizes a fluid in which the food item is embedded creating a pressure wave which then bounces onto the food item immersed within the fluid. This embodiment will be referred to herein as the "displaceable member embodiment" .

The method in accordance with the DIF embodiment comprises: (a) immersing the food product in a liquid;

(b) discharging an electric current within the liquid yielding formation of plasma, vapor or both, thus generating a pressure shock wave within the liquid that bounces onto the food item.

The method in accordance with the displaceable member embodiment comprises:

(a) providing a displaceable metal member associated with a coil such that when an electric current is discharged through the coil, said metal member displaces to generate a mechanical force;

(b) placing the food item such that when said metal member exerts a mechanical force, at least some of said force bounces onto said food item; (c) discharging current through the coil.

In accordance with another aspect of the invention, there is provided an apparatus for treatment of a food item, comprising:

(i) a current discharge device for rapidly discharging an intense current therethrough, the discharge generating a mechanical force;

(ii) an enclosure for holding the food item such that a mechanical force generated within said device at least partially bounces onto said food item;

(iii) one or more electric discharge circuitries for discharging an intense and rapid current through said device. In accordance with the DIF embodiment, the apparatus comprises:

(i) a container holding a liquid for receiving the food item;

(ii) one or more electric discharge circuitries comprising each one or more discharge electrodes within said container and a current generator for discharging an intense and rapid current between said at least one electrode and another at least one electrode or a component of the container to yield formation of plasma, vapor or both within the liquid, thus giving rise to a pressure shock wave that bounces onto the food item.

The apparatus in accordance with the displaceable member embodiment comprises: (i) a displaceable member associated with a coil such that upon rapid current discharge through the coil, said member is displaced whereupon it generates a mechanical force;

(ii) an enclosure for holding said food item and being associated with said displaceable member such that upon its displacement a mechanical force is applied onto the food item contained within said enclosure;

(iii) an electric discharge circuitry for discharging an intense and rapid current through said coil. Carrying out the invention by the DDJ embodiment

The food item is immersed in the treatment fluid and then an electric current is discharged through the discharge circuitry generating a spark within the fluid which causes the formation of plasma, vapor or both. The rapid formation of plasma and/or vapor causes a shock wave which travels within the fluid and eventually bounces onto the food item which is immersed therein. This bouncing pressure wave may have one of several effects on the food item. For one, the travelling pressure wave which penetrates the food item, causes there microscopic morphological changes which soften or tenderize it. Tenderization is required, for example in the case of fresh meat, raw vegetables intended for rapid cooking, and others. In addition, the treatment of the invention may also be used to disinfect a food item: the shock wave, which raptures cell membranes or cell walls, kills most microorganisms (e.g. bacteria, fungus, protozoa) as well as various higher order organisms (e.g. nematodes or other worms) which may be present in the food item. In the specific case of meat, the shock wave may assist in chaining blood out of the meat product. Additionally, the microscopic morphological changes caused by the shock wave may facilitate the impregnation of food items with various ingredients including, for example, flavorants, salt solution, enzymes for subsequent food treatment, and others. For the latter purpose, the food item will typically be treated, by the method of the invention, while immersed in a fluid, which is to be impregnated into the food product. Furthermore, the subjecting of the food to a shock wave treatment in accordance with the invention may also serve to reduce subsequent cooking time of the food item. The fluid is typically a liquid, preferably an aqueous liquid (water or an aqueous solution). For the purpose of treatment in accordance with this embodiment of invention, the food item may immersed directly into the fluid within the container, or at times may be immersed in a fluid while it is enclosed within a flexible, shock wave transmissive bag or sheath, e.g. a flexible plastic film sheath typically fitted tightly onto the food item. The food item may also be contained within a secondary container having at least one shock wave-transmissive wall permitting the shock wave to travel into the secondary container.

The term "electrode" used herein refers to a device forming part of the discharge circuitry and designated specifically as such, namely to have this specific 5 function. A specific example of an electrode is a device with a defined discharge tip. Typically, the electrode is an elongated member electrically insulated but for its discharge tip. In accordance with embodiment of the invention, the electric discharge circuitry comprises two or more electrodes, and the current discharge is between such electrodes. The apparatus may comprise one or more pairs of such l o electrodes for discharge of electric current between the electrodes of each pair.

In accordance with another embodiment, the electric discharge is between an electrode and another component of the container. Such a component may, for example, be a metal wall section of the container, a panel within the container, e.g. a panel serving as shock wave reflector. As may be appreciated, from an electrical 15 point of view, such a component is an electrode, although not designated specifically as an electrode and not shaped as such.

In accordance with the method and apparatus in accordance with the present invention, the distance D (m) between the food item and the zone through which the electrical current is discharged, is determined by the following 20 equation (1):

D = k x W/P (1)

Wherein W is the discharge energy (kJ)

P is the total weight of the food item (Newton) k is a dimensionless coefficient having a value between about 20-50. 25 In accordance with one embodiment of the invention, step (b) of the method includes a single electric discharge. In accordance with another embodiment, said step (b) includes a number of discharges one after the other which in combination give rise to a treatment result of the food item.

By one specific embodiment, the electric current is discharged 30 simultaneously or consecutively from several electrodes. In accordance with one embodiment of the invention, the apparatus comprises a discharge zone and a treatment zone separated from one another by a pressure wave transmissible partition or diaphragm, which may be made of a flexible material, e.g. rubber or another be made of a pliable material such as a polymeric film. In such an apparatus, the one or more electrodes are included within the discharge chamber, and the food item to be treated is placed in the treatment chamber. The pressure wave generated in the discharge chamber in consequence of the electrical discharge, travels through the partition into the treatment chamber where it bounces onto and penetrates into the food item. By another embodiment, the treatment zone is separated from the discharge zone by a partition made from a rigid material formed with an aperture, the aperture's diameter less than 10 times, preferably less than 100 times the cross-sectional area of the discharge zone.

In accordance with an embodiment of the present invention, the treatment is a continuous process in which the food items are made to continuously travel, e.g. by a conveyor belt, one after the other, into and through the container or a treatment zone thereof, into a The time interval T (sec) between consecutive discharges is typically in accordance with the following equation (2):

T = d/v (2) Wherein N is the food item moving speeds (m/sec), and d is the distance between consecutive food items (m). The treated food product, is typically meat. In the following, the invention will be specifically described with reference to meat tenderization in accordance with the invention, as being understood that the invention is not limited thereto. The meat, typically fresh meat, is usually placed in the container wrapped or enveloped in a pliable or flexible envelope or packet. The envelope may be made by a variety of suitable materials, typically thermoplastic material such as polyethylene or propylene.

The container may be made of metal, concrete, ceramic, and in general of any suitable material that can withstand a pressure shock within the container. Carrying out the invention by the piston embodiment

The apparatus in accordance with the piston embodiment comprises an enclosure for holding the food item and being in association with a displaceable metal member which is in turn associated with a discharge coil. The association is such that upon rapid discharge of an intense current. through the coil, the eddy current generated within the metal displaceable member and a magnetic force is generated causing it to displace and this in turn generates a mechanical force which impacts onto the food item. Typically, the enclosure holding the food item is a receptacle made of a rigid non- electrically conducting material having an open end snugly receiving the displaceable member. The food item which is placed within the receptacle is then either directly pressed by the displaceable member upon its displacement or, alternatively, the food item is immersed within a fluid, typically a liquid and the displacement of the metal member pressurizes the fluid causing a pressure wave which bounces onto the food item. The invention achieves a long felt want as it provides a cheap, fast and repeatable means for food tenderization.

For better understanding, and by way of example only without it being considered limiting, the invention will now be further illustrated in the following detailed description of some specific embodiments, with reference to the annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic cross-sectional view through an apparatus in accordance with one DIF embodiment of the invention in which the electric current discharge occurs between two electrodes.

Fig. 2 is an enlarged cross-sectional view of an electrode that may be used in the apparatus of Fig. 1.

Fig. 3 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of the invention, for simultaneous treatment of a plurality of food items employing a plurality of parallel discharge arrangements.

Fig. 4 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of the invention comprising a discharge chamber and a treatment chamber separated by a flexible membrane.

Fig. 5 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of the invention comprising a discharge chamber and a treatment chamber, separated by wall with an opening.

Fig. 6 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of ^"the invention comprising a pressure wave reflector associated with the electrode.

Fig. 7 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of the invention comprising pressure wave reflecting plates. Fig. 8 is a schematic cross-sectional view through an apparatus in accordance with another DIF embodiment of the invention for treatment of food items in a continuous process.

Figs. 9 and 10 are schematic illustrations of two alternative electric circuitries for discharging the rapid intense electric current pulsed through the PDF electrodes.

Fig. 11 is a schematic cross-sectional view through an apparatus in accordance with one displaceable member embodiment of the invention.

Fig. 12 shows a cross-sectional view through an apparatus in accordance with another displaceable member embodiment of the invention for treatment of food items in a continuous process.

Figs. 13A-13B show the treatment device of the apparatus of Fig. 12 in three operational steps. DETAD ED DESCRIPTION OF SPECIFIC EMBODIMENTS

In the bellow described embodiments reference is made in particular to treatment of meat. However as will be appreciated, the invention is not limited thereto and applies to treatment of food items by the application of a brief and intense pressure, with all the benefits and potential results, as mentioned above. It will be appreciated that the exact treatment conditions including, without limitation, the magnitude of the discharged current, the number of discharges in a given treatment cycle, the dimensions of the treatment chamber and the distance between the zone of current discharge and the treated food item, design of the treatment container, e.g. whether it has one combined treatment and discharge chamber or separated discharge and treatment chambers, etc.

Reference is first being made to Fig. 1 showing an apparatus generally designated 100 comprising a container 102 having a lid 104 hinged to the container at 106 and fixable, in a pressure tight manner, by means of locking mechanism 108. Container 102 is filled with a liquid 110, typically filled to its top, and is provided with an arrangement, such as a horizontal bar 112 for hanging an ankle 114 supporting a meat mass 116. The meat mass is typically encased within a flexible envelope 118, e.g. made of polyethylene.

Fitted within the walls of container 102 are two electrodes 120 and 122 connected to a discharged circuitry 124. Upon discharging of the electric current through circuitry 124, an electric spark 126 is generated within the liquid, causing formation of plasma, vapor or both and thereby creating a pressure wave represented by curved lines 128, which permeates the meat mass. This pressure wave causes breaking of the meat's microstructure to cause it to tenderize. A schematic representation of the structure of the electrodes 120 and 122, by one embodiment thereof, can be seen in Fig. 2. The electrode is formed from a metal tube 140 having a lumen 142 and having a tapered discharge end 144. The electrode is ensheathed by an electrically insulating layer 146. Lumen 142 is connected to a gas source, e.g. air, which is supplied by a compressor or a compressed gas balloon (not shown). Such gas flown, usually at minute quantities, into the liquid within container 102 facilitates the discharge of electric current and formation of plasma within the liquid which creates the aforementioned pressure wave.

Fig. 3 shows an apparatus 200 in accordance with another embodiment of the invention. In Fig. 3, like elements to those of Fig. 1 were given like reference numeral shifted by 100, (e.g. element 206 is equivalent to element 106 in Fig. 1). The reader is referred to the description of Fig. 1 for an explanation of the function of these elements. Apparatus 200 has three discharge circuitries, each with a different electrode 221. Each electrode 221 is incorporated into lid 204 and surrounded by an isolation member 223. ^"In this embodiment a portion of walls 202, which in this case is lid 204, is connected, through lead 231 to discharge unit 224 and thus forms part of the electric discharge circuitry. Thus, upon electric discharge, a spark 225 is generated from each of the electrodes 221 and adjacent portions of the container's walls, creating a pressure wave 229, bouncing onto the food items 216, with the flexible envelope 218 that is held on a support 251. The apparatus in accordance with this embodiment is adapted for simultaneous pressure treatment, in accordance with the invention, of a plurality of food items, three in this specific case (it is clear, however, that the apparatus may be designed for any desired member of food items to be treated simultaneously). An apparatus 300 in accordance with another embodiment can be seen in

Fig. 4. Like elements to those of Fig. 3 were given the same reference numeral, shifted by 100. The apparatus of this embodiment comprises two chambers, a discharge chamber 333 and a treatment chamber 335 separated by a flexible membrane 337. An electric spark 325 is generated in a similar manner as that explained in Fig. 3 and the generated pressure wave travels through pressure wave transmissive membrane 337 which may, for example, be made of rubber, and eventually hits food item 316 contained in the treatment chamber. The discharge chamber has a general trapezoid-like cross-sectional shape and thus a pressure wave which bounces against one of the slanted walls 339 is reflected towards membrane 337, thus leading to a higher yield of energy bouncing on and penetrating into food item 316.

In Fig. 5 an apparatus 400 in accordance with another embodiment. Here again, like reference numeral to Fig.4 shifted by a further 100 are used to designate the same elements. In this embodiment the discharge chamber 433 and the treatment chamber 435 are separated by a rigid partition 441 with frusto-conical aperture 443. A pressure wave generated in the discharge chamber 433 bounces onto partition wall 441 and consequently a high pressure stream, represented by arrow 443, exits through aperture 453 into treatment chamber 435 yielding a pressure wave that bounces onto the food items. The aperture has typically a diameter at its narrow point of about 3-10 mm. Typically the ratio of the diameter of the partition wall (D) to that of the aperture at its narrowest point (d) is D/d ≡ 100 to 200.

In Fig. 6 an apparatus 500 is seen where electrode 521 is surrounded by a reflector structure 545 which may consist of a single frusto-conical plate, or may consist of several plates which together make up this structure. The pressure wave generated as a result of electric discharge between electrode 521 and structure 545 will create a focused pressure wave directed towards food item 516.

Another embodiment of an apparatus 600 can be seen in Fig. 7. Functionally, this apparatus is similar to apparatus 500 shown in Fig. 6 and like elements were given like reference numerals shifted by 100. In this apparatus is also a reflector structure 647, which in this case depends however from side walls 649. However, from a functional point of view reflector structure 647 is similar to structure 545 in Fig. 6 in that it focuses the pressure wave onto food item 16.

Reference is now being made to Fig. 8 showing an apparatus 700 in accordance with an embodiment of the DIF embodiment of the invention. The apparatus 700 is adapted for continuous food treatment. In this figure, functionally equivalent components to those in the apparatus of Fig. 3 were given reference numerals with a "7" prefix and with the same suffix of the reference numeral of the corresponding component in Fig. 3 (namely shifted by 500) . Apparatus 700 has an elongated chamber 702 with two openings 755 and 766 and accommodating a portion of the conveyor belt 757 supported by pulleys 758A - D. Appended from belt 757 are a plurality of carrying members 759, each carrying a food item 716. The food items are continuously fed into chamber 702 through one of the openings and then continuously pass through the liquid 760 where they are subjected to abrupt pressure waves 729 generated by the electric discharge of electrode 721. Optionally, openings 755 and 756 may be temporarily closed to allow more pressure build up within chamber 702 facilitating at times a more effective treatment of the food item.

It should be noted that the electrodes used in the embodiments of each of Figs. 3-8 may be the same or different than the electrode illustrated in Fig.2.

Two embodiments out of many possibilities of electric discharge circuitries are presented in Figs. 9 and 10. Discharge circuitry 170 in Fig. 9 has an electric power source 172, which may be a capacitor or bank of capacitors, a high current rapid discharge switch 174, e.g. a controlled vacuum discharger (which may be in such devices known per se, e.g. such that disclosed in PCT Application No. PCT/IL97/00383) and a triggering unit 176, which actuates the discharge switch 174. The electric discharge circuitry is typically grounded at 178. Upon triggering of a discharge by a trigger unit 176, switch 174 closes, thus giving rise to a current discharge between the electrodes 180 and 182 within container 184.

Electric discharge circuitry 190 shown in Fig. 10 has similar components to that shown in Fig. 9 and like components have been designated like reference numeral with a prime indication. The difference is in that it comprises a transformer 192 for amplifying the voltage of the discharged current.

Reference is now being made to Fig. 11 showing an apparatus 700 in accordance with one piston embodiment of the invention. The apparatus comprises a receptacle 702 made from a rigid, non-electrically conducting material such as epoxy glass. The receptacle has an internal space 704 for receiving a food item to be treated 706, and has an open end receiving a displaceable metal piston 708. Metal piston in turn is an association with a discharge coil device 710 including a flat discharged coil 712. Coil 712 is connected to an electrically discharge apparatus 714 comprising a capacitor or a bank of capacitors 716, a high current rapid discharge switch 718 and an electric potential loading circuitry 720 connected to mains 722.

In use, food item 706 is placed within receptacle space 704 and then piston member 708 is put into place at the opening receptacle 702 and coil device 710 is placed against piston 708. In the embodiment shown, the entire apparatus is placed within two press members 730 and 732. This however is only an example and it is possible also to tightly associate all the apparatus components by other means.

In the shown embodiment, piston member 708 bears directly against food item 706, which food item is typically encased within a flexible container, e.g. within a plastic bag or wrap. In other embodiments, the receptacle may be filled with a liquid, with food item immersed within the liquid, in which case the piston will bear against the liquid' s surface.

Upon current discharge through coil 712, piston member 708 is displaced in the direction of arrow 740 generating force bouncing onto the food item. Where the food item is, for example, meat, this causes it to become tender.

Reference is now being made to Fig. 12 showing an apparatus 800 for continuous treatment of food items in accordance with a displaceable member embodiment. Apparatus 800 comprises a conveyor belt 802, carrying a plurality of metal plates 804, each one of which holds a food item 806. Disposed below the belt is an electric coil 810 connected to a discharge circuitry 812. Treatment device 814 is provided, which is capable of operation with metal plate 804 so that they together define a closed chamber encasing food item 806.

Three consecutive steps of treatment device 814 are shown in Figs. 13A-13C. When the conveyor belt brings one of the food item-carrying plates 804 into position below treatment device 814, device 814 lowers onto the food item (Fig. 13 A) and a closed chamber is thereby temporarily formed around the food item 804. An electric current discharge through coil 810 gives rise to eddy currents in plate 804 and the resulting magnetic repulsion causes an abrupt upward pressure (represented by an upwardly directed arrow 820 in Fig. 13B). Device 814 may then be removed (Fig. 13C) thus freeing the treated food item 806 to travel further on conveyor belt 802. In the above shown embodiment, ^"the food item 806 is treated within a treatment chamber defined by device 814 and plate 804. The movement of plate 804 to apply force onto food item 806 is within a path defined by side walls 815 of device 814. In other cases, the food item 806 may at times be simply sandwiched between a plate such as plate 814 against a counter surface or a block in which case the movement, although not confined by walls, is nevertheless essentially upwards.

By still other embodiments, a metal plate may at times be formed below the belt by pressure which will be applied then on the food item by an upward bias of a belt portion.

Claims

CLAIMS:

1. A method for treatment of a food item, comprising: rapidly discharging an electric current through a discharge apparatus, whereby a strong and abrupt force is generated bouncing onto said food item.

2. A method according to Claim 1, comprising:

(a) immersing the food product in a liquid;

3. A method according to Claim 1, wherein the food item is contained within a container having shock-transmissive wall.

4. A method according to Claim 3, wherein the food item is contained within a flexible bag or sheath.

5. A method according to any one of Claims 1-4, wherein the distance D (m) between the food item and the zone through which the electrical current is discharged, is determined by the following equation (1):

D = k x W/P (1)

Wherein W is the discharge energy (Id)

P is the total weight of the food item (Newton) k is a dimensionless coefficient having a value between about 20-50

6. A method according to any one of Claims 1-5, wherein step (b) comprises a single current discharge.

7.A method according to any one of Claims 1-5, wherein step (b) comprises two or more consecutive current discharges within said container.

8. A method according to any one of Claims 1-5, wherein step (b) comprises two or more simultaneous current discharges.

9. A method according to any one of Claims 1-8, for continuous treatment of a plurality of food items, comprising the following additional steps after step (b): (c) removing said food item from the liquid and immersing another food item in said liquid;

(d) repeating steps (b) and (c) for all food items to be treated.

10. A method according to Claim 1, comprising:

5 (a) providing a displaceable metal member associated with a coil such that when an electric current is discharged through the coil, said metal member displaces to generate a mechanical force;

(b) placing the food item such that when said metal member exerts a mechanical force, at least some of said force bounces onto said food item; 10 (c) discharging current through the coil.

11. A method according to Claim 10, comprising placing the food item with a receptacle having an open end receiving said displaceable member.

12. A method according to Claim 2, for tenderizing or disinfecting the food item.

15 13. An apparatus for treatment of a food item, comprising:

(ii) an enclosure for holding the food item such that a mechanical force generated within said device at least partially bounces onto said food item; 20 (iii) one or more electric discharge circuitries for discharging an intense and rapid current through said device.

14. An apparatus according to Claim 13, comprising:

(i) a container holding a liquid for receiving the food item;

(ii) one or more electric discharge circuitries comprising each one or 25 more discharge electrodes within said container and a current generator for discharging an intense and rapid current between said at least one electrode and another at least one electrode or a component of the container to yield formation of plasma, vapor or both within the liquid, thus giving rise to a pressure shock wave that bounces onto the food item.

15. An Apparatus according to Claim 14, wherein, comprising a member to hod the food item in a fixed position within the container.

16. An apparatus according to Claim 14 or 15, wherein each current discharge circuitry comprises two electrodes and the current is discharged between them.

17. An apparatus according to Claim 14 or 15, wherein each discharge circuitry comprises a single electrode, with the current being discharged between the electrode and a wall or another metal element within the container, electrically connected and forming part of the discharge circuitry.

18. An apparatus according to any one of Claims 14-17, wherein the distance D (m) between the food item and the zone through which the electrical current is discharged, is determined by the following equation (1):

D = k x W/P (1)

Wherein W is the discharge energy (kJ) P is the total weight of the food item (Newton) k is a dimensionless coefficient having a value between about 20-50

19. An apparatus according to any one of Claims 14- 18, comprising a single current discharge circuitry.

20. An apparatus according to any one of Claimsl4-18, comprising a plurality of current discharge circuitries.

21. An apparatus according to any one of Claims 14-20, comprising a single chamber for holding the food item and discharging the current therein.

22. An apparatus according to any one of Claims 14-20, wherein the container comprises a separated current discharge shown and food treatment zone, the two zones being in the pressure wave-transmission connection, whereby a pressure wave generated in the transmission zone is transmitted into or induces a pressure wave in the food treatment zone.

23. An apparatus according to Claim 22, wherein the two zones are separated by a flexible, pressure-wave transmissible partition or diaphragm.

24. An apparatus according to Claim 22, wherein the two zones are separated by a partition made from a rigid material formed with an aperture.

25. An apparatus according to Claim 24, wherein the aperture's area is less than ten times the cross-section area of the discharge zone.

26. An apparatus according to Claim 13, comprising:

(i) a displaceable member associated with a coil such that upon rapid current discharge through the coil, said member is displaced whereupon it generates a mechanical force;

(ii) an enclosure for holding said food item and being associated with said displaceable member such that upon its ^"displacement a mechanical force is applied onto the food item contained within said enclosure;

(iii) an electric discharge circuitry for discharging an intense and rapid current through said coil.

27. An apparatus according to Claim 26, comprising a receptacle made of an electrically non-conducting material having an open end receiving said displaceable member.