GB2538706A

GB2538706A - Ultrasound and cryogenic gas to destroy campylobacter and other bacteria on foodstuffs

Info

Publication number: GB2538706A
Application number: GB1508574.9A
Authority: GB
Inventors: Norvill Derrick
Original assignee: Linde GmbH
Current assignee: Linde GmbH
Priority date: 2015-05-19
Filing date: 2015-05-19
Publication date: 2016-11-30
Also published as: GB201508574D0

Abstract

An apparatus 10 comprises a housing 14 having a chamber 18 therein; a conveyor 42 for conveying foodstuff 12 through the chamber; delivery member for a cryogen to the chamber and foodstuff; and an ultrasonic transducer 40 in the chamber to provide ultrasonic energy to the cryogen in the chamber and for contacting the foodstuff in the chamber. Preferably the cryogen comprises nitrogen and the foodstuff is an animal carcass. A method is also provided for substantially reducing bacteria on a foodstuff comprising providing a cryogen and ultrasonic energy to the foodstuff. The cryogen and ultrasound may be provided simultaneously or cyclically. The foodstuff may be exposed to the cryogen and ultrasonic energy for 10 to 30 seconds and may be provided from a distance of 0.15 to 0.61 meters. The ultrasonic energy may be pulsed. The advantage of the invention is to kill bacteria such as Campylobacter on foodstuffs effectively and efficiently without freezing the foodstuff.

Description

SPECIFICATION

ULTRASOUND AND CRYOGENIC

GAS TO DESTROY CAMPYLOBACTER AND

OTHER BACTERIA ON FOODSTUFFS

BACKGROUND

[0001] The present inventive embodiments relate to apparatus and methods to prevent, reduce and eliminate bacteria such as for example campylobacter on foodstuffs.

[0002] The prevention and for most applications the reduction and complete destruction of bacteria on food products, such as for example all kinds of consumable foods, are necessary in order for the food products to be usable and also to comply with at the very least federal regulations and laws. Meat products for human consumption, such as for example, beef, poultry, fish, etc., are especially susceptible to bacteria and other organic contaminants during and after processing of the carcass and of course during storage for same prior to consumption. In such instances, types of decontamination are known to substantially reduce, if not completely eliminate, contaminants and bacteria on the food products prior to same being further processed and/or consumed.

[0003] It is known to use cryogenic nitrogen spray to destroy bacteria, such as campylobacter, on food products. Reference to cryogenic nitrogen is to those gases which originate as such or are the result of evaporation of liquid nitrogen applied to the food product and/or carcasses. Such liquid nitrogen processes are at a temperature range of -320 F to -250' F (-196' C to -15T C).

[0004] Unfortunately, the sole use of cryogenics, such as a cryogenic gas or liquid, to destroy bacteria is relatively expensive and increases the risk of freezing the surface, or an underlying portion of the meat product below the surface, to a temperature where the product can no longer be marketed or sold as fresh; which could make the product undesirable and possibly inedible for human consumption. In addition, the use of cryogenics to destroy the bacteria necessitates large, expensive tunnel freezers to apply, maintain and circulate the cryogenic gas used on the food products.

[0005] Ultrasound has also been used to try to substantially reduce if not eliminate bacteria on food products. However, ultrasound alone does not kill the bacteria, such as campylobacter, and is therefore ineffective for destroying same.

[0006] There have also been attempts to combine ultrasound with steam to destroy bacteria on foodstuffs. However, in order for the steam to be effective, it must be used for an unusually long period of time on the food product which results in the carcass being cooked, a change in carcass meat color and texture, and denaturing the carcass, i.e. removing the fat from the skin of the carcass. All of this results in an ineffective, undesirable and expensive decontamination process which compromises the quality of the meat subjected to the ultrasound and steam. This also means that the amount of time necessary to expose the food product to the ultrasonics and steam would have to be severely limited in order to avoid a product which is unappealing to consumers and therefore, the reduction of time corresponds to a reduction in the efficacy of this type of sterilization process.

[0007] What is therefore needed is an apparatus and method which is relatively inexpensive, and does not require a great amount of time in order to effectively and efficiently destroy bacteria on foodstuffs, such as for example poultry carcasses.

SUMMARY OF THIS INVENTION

[0008] As used herein the words "food product" and "foodstuff", whether singular or plural, pertain to a substance with food value and more particularly the raw material of food before or after processing, whether or not ready to be consumed. An animal carcass can therefore be a food product or a foodstuff.

[0009] There is therefore provided apparatus and method embodiments wherein a combination of ultrasound and cryogenic gas and/or cryogenic liquid is used on a food product to substantially reduce if not eliminate bacteria on the food product such as for example poultry.

[0010] In particular, an apparatus is provided for substantially reducing if not eliminating bacteria on a foodstuff, the apparatus including a housing having a chamber therein, and an inlet and an outlet in fluid communication with the chamber; a conveyor for conveying the foodstuff through the chamber; a cryogen delivery member having an outlet for providing a cryogen to the chamber and the foodstuff; and an ultrasonic transducer disposed in the chamber for providing ultrasonic energy to the cryogen in the chamber and for contacting the foodstuff in the chamber.

[0011] There is also provided a method for substantially reducing if not eliminating bacteria on a foodstuff, which includes providing cryogen and ultrasonic energy to said foodstuff for a select amount of time for destroying the bacteria.

[0012] Another embodiment also provides the cryogen and ultrasonic energy in combination with each other.

BRIEF DESCRIPTION OF THE DRAWING

[0013] For a more complete understanding of the present embodiments, reference may be had to the following description taken in conjunction with the drawing Figure, of which the Figure shows an apparatus and method for the destruction of bacteria on foodstuffs.

DETAILED DESCRIPTION OF THE INVENTION

[0014] Before explaining the inventive embodiments in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

[0015] Referring to the Figure, an apparatus is shown generally at 10 for destroying bacteria, such as for example campylobacter bacteria, on foodstuffs. The apparatus and method of the present embodiments call for the use of ultrasonics and cryogenic gas and/or cryogenic liquid to substantially reduce if not eliminate the bacteria on for example a poultry carcass. The ultrasonics and cryogenic gas and/or cryogenic liquid can be provided together as a combination. It is understood that reference to a food product or a foodstuff herein is with respect to any product that can be ingested by humans or other animals, for purposes of the description and by way of example only, and reference shall be to poultry or poultry products by way of example, and not by way of limitation.

[0016] The apparatus 10 of the Figure is shown for use with an animal carcass 12, such as that of poultry for example. The apparatus 10 can be a freezer tunnel and includes a housing 14 having a sidewall 16 defining a chamber 18 within the housing. The sidewall 16 has formed therein an inlet 20 and an outlet 22 each of which is in communication with the chamber 18 such that the carcass 12 can pass from the inlet 20 through the chamber 18 and be expelled from the outlet 22 for use or subsequent processing. The carcass 12 is provided to the inlet 20 in a direction of conveyance indicated by the arrow 24.

[0017] The carcass 12 has most likely been de-feathered or de-furred, and eviscerated, leaving only the carcass with skin thereon. This is the foodstuff that will usually be treated by the apparatus and method embodiments herein.

[0018] A pipe 26 or conduit has a first end connected to a source (not shown) of a cryogenic gas and/or cryogenic liquid, and a second end 28 terminating in the chamber 18. The pipe end 28 branches or is split into a "T" section, with each branch 30, 32 provided with holes 34 or orifices from which a cryogen spray 36 is provided to the chamber 18. The pipe 26 can deliver a liquid cryogen, such as for example a liquid nitrogen (N2 or LIN), which is conveyed under either the effect of gravity or induced pressure, through the holes 34 to provide the spray 36 into the chamber 18. Alternatively, one or more of the holes 34 may be provided with spray nozzles 38 to better atomize the liquid cryogen for introduction into the chamber 38 to provide a more effective heat transfer at the carcass 12. A zone or region shown generally at 39 within the chamber 18 indicates where a majority of the atomized liquid cryogen is now present for contacting the carcasses 12 as same are conveyed through the chamber 18.

[0019] An ultrasonic transducer 40 is positioned in the chamber 18 in relative close proximity to the carcasses 12 being conveyed through the chamber. The transducer 40 is positioned such that it will transmit ultrasonic waves or energy to each of the carcasses 12 passing thereby, but at a distance sufficient to provide the sonic waves to each of the carcasses on an individual basis. In effect, each carcass 12 is blanketed or covered with the atomized nitrogen spray and the ultrasonic transducer provides sonic waves to the carcass to break through a laminar layer of air close to and on the surface of the carcass being treated. The ultrasonic waves excite the molecules of the air, thereby facilitating the use of the cryogenic gas to contact the surface, the cryogenic gas being at an extremely low temperature to rapidly destroy bacteria, such as campylobacter, at the surface of the carcass 12. The use of the ultrasonic waves emitted from the transducer 40 onto the carcass in combination with the cryogenic spray reduces the amount of time necessary that the carcass has to be exposed to the spray and therefore, greatly reduces the amount of cryogen which must be employed by the apparatus 10 to effectively destroy the bacteria. This combination of the cryogenic spray and ultrasonic energy provides for a more cost effective use of the cryogen. Each of the carcasses 12 is exposed to the ultrasonic waves for a period of time of from ten (10) seconds to thirty (30) seconds.

[0020] Additionally, the ultrasonic energy will also serve to break-up droplets of liquid nitrogen when such droplets make contact with a surface of the carcass, which thereby provides a layer of finely atomized nitrogen droplets contacting the carcass surface. As a diameter of each of the droplets is reduced from exposure to the ultrasonic energy, the evaporate effect or evaporate cooling (phase change) of the liquid nitrogen spray is accelerated, as is the resulting heat transfer coefficient which occurs at the carcass. The ultrasonic energy thereby facilitates the effectiveness of the nitrogen spray being applied to the carcass to destroy bacteria thereon [0021] A conveyor 42 for the carcasses 12 can be of a rail or wire type with shackles 44 extending therefrom to releasably retain a corresponding one of the carcasses 12 for conveyance through the chamber 18 of the apparatus 10. The conveyor 42 may be adjustable with respect to its position transitting the chamber 18, particularly the region 39, to thereby alter the position of the carcasses 12 for selected exposure to the ultrasonic energy and the region 39 in the chamber.

[0022] The carcasses 12 departing the chamber 18 from the outlet 22 have been treated with the combination of ultrasound and cryogenic spray, and are moved in the direction of arrow 46 for use or subsequent processing.

[0023] The provision of the ultrasonic waves from the transducer 40 can also be operated periodically or cyclically, i.e. by pulsing the ultrasonic waves to reduce the electrical/power requirements for the transducer 40 to provide for a more efficient apparatus 10 and method for using same. It is estimated that the transducer 40 should be at a distance from the carcass 12 being treated with sonic waves of not more than 2 feet (0.61 meters) and for many applications the distance is from 0.5 to 2 feet (0.15 meters to 0.61 meters).

[0024] It is also possible in alternate embodiments to have a plurality of the transducers 40 at different positions within the chamber 18 and correspondingly run a plurality of conveyors 42 through the chamber 18 to increase the processing and throughput of a greater number of the carcasses 12.

[0025] The present embodiments provide an increased kill rate of bacteria on foodstuffs, such as animal carcasses, in less time and at a reduced cost. Foodstuffs other than poultry carcasses can be treated with the present apparatus and method embodiments.

[0026] It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described and claimed herein. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result.

Claims

CLAIMSWhat is claimed is: 1. An apparatus for substantially reducing if not eliminating bacteria on a foodstuff, comprising: a housing having a chamber therein, and an inlet and an outlet in fluid communication with the chamber; a conveyor for conveying the foodstuff through the chamber; a cryogen delivery member having an outlet for providing a cryogen to the chamber and the foodstuff; and an ultrasonic transducer disposed in the chamber for providing ultrasonic energy to the cryogen in the chamber and for contacting the foodstuff in the chamber.
2. The apparatus of claim 1, wherein the cryogen comprises nitrogen.
3. The apparatus of claim 1, wherein the foodstuff comprises an animal carcass.
4. The apparatus of claim 1, wherein the conveyor is structurally adapted to be adjustable with respect to delivery of the foodstuff through the chamber.
5. A method for substantially reducing if not eliminating bacteria on a foodstuff, comprising: providing a cryogen and ultrasonic energy to said foodstuff for a select amount of time for destroying the bacteria.
6. The method of claim 5, wherein the cryogen and the ultrasonic energy are provided simultaneously.
7. The method of claim 6, further comprising conveying the foodstuff to an area for providing the cryogen and the ultrasonic energy.
8. The method of claim 5, wherein the cryogen comprises nitrogen.
9. The method of claim 5, wherein the foodstuff comprises an animal carcass.
10. The method of claim 5, further comprising exposing the foodstuff to said cryogen and ultrasonic energy for from 10 to 30 seconds.
11. The method of claim 5, wherein the providing is from a distance of.15 to.61 meters.
12. The method of claim 5, wherein the providing comprises cyclically providing the cryogen and ultrasonic energy to said foodstuff.
13. The method of claim 5, wherein the providing comprises pulsing the ultrasonic energy.
14. The method of claim 5, further comprising conveying the foodstuff to an area for the providing the cryogen and ultrasonic energy.