AQUEOUS SOLUTION FOR DISINFECTING AN ANIMAL PRODUCT, A METHOD AND A PLANT FOR SUCH DISINFECTION

Abstract: A composition for disinfecting an animal product comprising an electro-chemically activated, anion-containing aqueous solution. A plant for treating an animal product including a water reservoir (12), a salt feed device (16) for creating an aqueous salt solution, an electrolysis device (18) to produce anolyrte and catolyte solutions, an anion mixing tank (28), and a treatment container (30) to apply the solution to an animal product.

Description: AQUEOUS SOLUTION FOR DISINFECTING AN ANIMAL PRODUCT, A METHOD AND A PLANT FOR SUCH DISINFECTION This invention relates to a composition for disinfecting an *mwwn4 product, to a method of disinfecting an animal product, to a treatment plant and to an animal product disinfected with such a composition. ■Background to the Invention: For the purposes of this specification, the term "animal product'' should be construed to include wr-hm its meaning the carcass or a product obtained from the carcass of an animal, including its .skin, coat, hide or feathers and the word "ammaT should be construed to include within its meaning sheep, cattle, goats, pigs, chickens, ostriches, fish .and the like .from which a carcass or a product could be obtained. The .Applicant envisages further that the invention will be applicable particulariy, but not exclusively, to the treatment of animal products in the form of food and food-related products. Such products include fish, .meat and meat-related products such as sausage casings, offal, waste produced in mear-produciπg plants such as fisheries, abattoirs and the hke. It is also envisaged that treatment would result in shelf life extension through decontamination of the various products. Object of the Invention : It is accordingly an object of the invention to provide a novel composition for disinfecting annual products as weil as the related aπήnal products and method. Summary of the .Invention : In accordance with a first aspect of the invention there is provided a method of disinfecting an animal product, the method including the step of exposing the animal product to a composition comprising an elecu-o-chemicaHy activated, anion-containing aaqueous solution. The solution may be an aqueous solunon of a salt The salt may be sodium chloride. In particular, it may be non-iodated sodium chloride or potassium chloride. The method may include doe steps of diluting the anios-contaizuxtg solution to a pre-determined concentration and exposing the animal product to an appropriate quantity of die diluted anion-containmg solution and for a predetermined time period in a treatment facility. If desired, the method may include a preliminary step of washing or rinsing the animal product in a washing vessel prior to treatment in the treajmeat container. Washing or rinsing may be with water obtained from, the said source of w.ater. The method may then include collecting effluent water from the washing vessel, clarifying die effluent water by exposing it to an appropriate quantity of the cation-containing solution, disinfecting the clarified water by treating it with an appropriate quantity of the diluted amoa-cβntaimng solution and re-cuculating the clarified and diasinfected water. The anion-coπtaiπmg solution and the cadoa-coπtai∑ύng solution may be produced by an electro-chemical reactor or so-called electrolysis device. The electro chemical reactor may include a through flow, electro chemical cell having two co-axial cylindrical electrodes with a coaxial diaphragm between them so as to .separate an annular inter electrode space into a catalytic and an analytic chamber. The anion-conbrining solution is referred to hereinafter for brevity as the "anolyte solution" and the cation-containing solution is referred to hereinafter for brevity as the "catholyte solution". During the electrolysis process, various .radical c-ώon and radi.cal .amon species are produced. Generally, a 10% aqueous NaCl solution of water is added to tap water where it is electrolysed in the anion and cation chambers to produce radical cation and radical anion species having extremely high redox potentials of between +500 and +1170 mV and about -980 V .respectively. These species may be labile after about 96 hours with no residues so as to disappear being produced The anolyte solution generally may have a pH of about 2-S and a .redox potential of about +1170 mV. The species present in the anolyte solution may include CIO ; CIO " ; HC1O; Off ; HO,- ; H 2 O 2 ; O 3 ; S-O and These species .have been found to have a synergistto anti-bacterial effect wh Λ is generally stronger than that of chemical b-ictericides and has been found to be particularly effective against viral organisms and spore and cyst forming bacteria. The catholyte solution generally may have a pH of about 12-13. The species present in the catholyte solution may include NaOH; KOH; GA^OH^ ; Mg (OH^ ; HO' ; H 3 O 2 - HO,- ; B J 0 : - ; OH " ; Of . Exposing the animal product or carcass to the anolyte solution may mclude soaking, rinsing or (hoping the animal product in the .anolyte solution., applying the anolyte solution via an atomising or fogging process or freezing the anolyte solution and using the ice produced to pack the animal product. The .soaking, rinsing or dipping process is suitable for products such as offal which can be handled with relative ease, either manually or nwclatanically. The redo potential of the anolyte solution can be monitored during the process so that the disinfecting process can bemonitored and controlled cm a continuous basis. The ato i.fing or fogging process is suitable for products such as carcasses when suspended in a chiller. The atomising or fogging process may include die step of .atomising the anolyte solution into the atmosphere in an enclosure to be treated, forming droplets of between 5 and 100 micremettes. The atnmi-H-ng nr fogging -process is preferably repeated atpre-determme mtervals so as to maintain a suitable level of anolyte solution concentration in the atmosphere, thus using the optimum microcidal and other properties of the anolyte solution in accordance with the .required administration rate. The anolyte solution also may be applied by an atomising process in air ducting systems to destroy air-borne micro-organisms. The use of frozen anolyte solution has been found to extend the usable life of animal products packed in the frozen anolyte solution, eg. fish; In accordance with a second aspect of the invention, there is provided a treatment plant for treating an animal product in accordance with the method of the invention. The treatment plant may include supply means for supplying water, feed means for feeding a suitable salt into the water to produce an aqueous salt solution; an el.2ctrolysis device for electrolysing the aqueous solution to produce a> anolyte and a catholyte solution; a mixing and dilution tank for mixing and diluting the anolyte solution; an<"> means for applying the anolyte solution to a product. The treatment plant may include recycling means for recycling anolyte .and catholyte sohitioπ into spent process water to disinfect the spe-tt τoc-ss water. In .accordance with a thiid aspect of the invention thee is provided a composition for disinfecting an animal product comprising an electro chemically activated an containing aqueous solution, the solution being substantially as herein defined. In accordance with a fourth aspect of the invention there is provided an animal product characterized in having been disinfected with a composition and/or in a plant or a process as herein defined. Detefled Description of the Invention : Preferred embodiments of the invention wul now be described by way of an example, with reference to the accompanying schematic drawing illustrating a treatment plant in accordance with the invention, and by way of tests with reference to die tables. With reference to die drawing, drinking quality water is provided as shown at 11 in a water reservoir 12. If the process and the plant is to be operated with water inferior to drinking quality water, a pre-treatmeπt step may be executed in the water reservoir 12, or in a container upstream of the water reserv ir. 12 to raise the quality of the water to that of drinking quality water. A mother line 14 conducts water from the water .reservoir 12 to wherever drinking qaahtv water is required in the process as will become apparent hereinafter. Reference numeral 18 indicates an electro-chemical reactor or so-called electrolysis device. Water from the mσtherϋne 14 is exposed to sodium chloride as indicated at 16 to produce a sodium chloride solution. The sodium chloride solution is fed into the electrolysis device 18, as well as water from die water reservoir as indicated by reference numeral 20. .By electrolysis, an anion-contarπing solution or anolyte solution is produced as indicated by reference numeral 22. Also a c-uion-ccΩ-aining solution or catholyte solution is produced as indicated by reference numeral 24. The anolyte solution at 22 is admixed with water from the motiwrime in a manifold valve 26 to produce an anolyte solution of predetermined strength which can selectively be directed into an anion mixing tank 28. Animal product to be treated in accordance with the invention, for example an offal in an abattoir, is introduced into a washing container 36 as indicated by reference numeral 44. In tie washing container 36, water is drawn from d e motherline 14 as indicated at 38 to wash the animal product. .After washing, the animal product is transported as indicated by reference numeral 40 into a treatment container 30. Effluent water is collected from the washing container 36 as indicated -by reference numeral 42. The pre-washed animal product is exposed in the treatment container 30 to an appropriate quantity of the anolyte solution from the mrxfng tank 28 to disinfect the animal product. The disinfected animal product is transported to a product processing and packaging station 32 where is further processed Used solution after disinfection is collected from the treatment container 30 as indicated by refere-αce numeral 34. The effluent water at 42 and the used solution at 34 .are added and are conducted as indicated by reference numeral 46 to a clarification container 48 where it is exposed to an appropriate quantity of the catholyte solution 24 to clarify it by means of floccularion, clarification or the like. The clarified water is conducted as indicated by reference ntmreral 50 to a disinfecting container 52 where an appropriate quantity of the anolyte solution of predetermmed strength is obtained via the mamfold valve 26 to produce disinfected water which is re-circulated to the water reservoir 12 as imfir.a*riri by reference numeral 54. Tests An electro chemical reactor, including a through flow electro chemical ceil having coaxial cylindrical electrodes with a coaxial diaphragm between mem so as to separate .an aaαalar inter electrode space into a catalytic and an analytic chamber, was used to produce anolyte and catholyte for the tests. Tests to I - 9 In a series of 9 tests, the bactericidal and shelf-life prolonging effect of the anolyte solution was tested on animal products such as offal, meat, fish, hides, etc.. The experimental protocol and the subsequent results axe summarised in Table 1 below in wh h the experiments are numbered from I to 9. In test 4, 3 bovine livers were .submerged consecutively for 2 mmutes. Redox depletion was measured after each submersion as well as microbiological counts. Test 10 A further test was conducted to determine the microbiological quality of beef carcasses after having been fogged with anolyte. Treatment During die test 24 beef carcasses were used, 12 for a control group and 12 for a test group. The 12 carcasses from the control group and the 12 carcasses from the test group were all microbiologically sampled directly after slaughter. After the carcasses had been placed in the respective chillers, the 12 beef carcasses from the test group were fogged with .Anolyte. All the .beef carcasses (treated and controls) were microbiologically monitored after the fogging process was completed. Mjcrobjo-togical SasmpKag All the carcasses were microbiologically monitored using rodac plates. Samples were taken at 4 positions on both the left .and right sides of each carcass i.e. the Lateral .surface at the 7th and 8th vertebrae; Medial side of die hind limb; - Carcass surface at the breast area of the 7dι and 8th rib; Proximal part of the neck area; and Carcass surface in the perineal region. After sampling, the rodac plates were incubated at 25°C for 3 days. A total count per 24cm 2 was then determined. Statistical ' alys's .An ANONA procedure was used to determine differences statistically between treatments. A statistical analysis of the total count of the 12 control and 12 test carcasses is shown in T-able 2. A total count of die beef carcasses of both the control and die test group is shown in Table 3. Microbiological evaluation According to the .statistical analysis the microbial contamination of the 12 Anolyte treated carcasses was significantly lower after .fogging than the contammarioπ level of the control carcasses (Table 2:P= ,0001). Table 3 clearly indicates that the total count of the control group of carcasses vs the test group of carcasses were at a similar levels just after slaughter (log 1,6724 cm. 2 ). However, the total count of die test group was signiδcantiy reduced after fogging from log 1,6/24 cm 2 to log Q,54/24cπr. The test group beef carcasses therefore had si.gnificantly lower total counts than dw control group beef carcasses. Test 11 - 16 A further series of tests were conducted with Anolyte aimed at preventing die oxidation of meat During the trials die following meat carts were used : beef loin steaks, beef topside mince and chicken drumsticks. Treatment The treatment groups woe as follows : 1. Control 2. .Anolyte 4. Catolyte. All the rump and loin .steaks, as well as the chicken drumsticks were submerged into the respective treatment liquids for a period of 3 minutes. The topside mince was treated wrth a hand held sprayer. Shelf life s udy .After each treatment, all the cuts were singly placed on polystyrene trays and ovei wrapped withPVC. All the cuts were then placed in retail display cabinets and displayed for a period of 24, 48, 72 and 96 hours at 4*C. .After each subsequent display period, cuts from each treatment were analysed for colour. Colour SceptrophOatometric τcύcctsncc analyses were used by taking readings from the overwrapped steaks to calculate the percentage of metmyoglobin (MMb), following the procedures of ICrywicld (1979). Statistical .Aiudvsis ANONA procedures were used to determine between treatments over time. A statistical analysis of the metmyoglobin accumulation of loin steaks, topside mince and rump steaks, stored at 4°C for 96 hours, is .shown in Table 4. Metmyogiøbm accumulation (brown discoloration) for main effects is shown in Table 5. Mctmyoglobm accumulation of loin stakra during a shelf life study of #-96h at 4°C is shown in Table 6. Me myeglob accumulation of topside mince during a shelf life, study of 0 - 96 h at 4°C is shown in Table 7. Metmyogfobin accunailation of rump steaks during a shelf life study of 0 - 96 h at 4°C is shown in Table 8. According to statistical analysis, all d e main effects {treatment, meat cut, shelf life period) were significantly influenced (P valves <0.05) by die accumulation of metmyoglobin (Mmb) (Table 4). Metmyoglobin gives an indication of the brown discoloration, which has taken places on each meat cut As shown in Table 5, die samples receiving the -Anolyte treatment discoloured significant (P=0,0147) less during die shelf Kfe study than the control samples, die samples receiving die Catolyte or combined Anolyte-Catolyte treatment Furthsxmore, the loin cuts discoloured less during d e shelf life period than die other two cuts included in die study. Accordmg to a study done by Hood, 1980, a discoloration level of 20% indicates a reduction of 50% in die amount of .sates. If a .cut off point of ca. 20 - 25% m-etmyoglobin is taken as the end of retail acceptability, the topside mince treated with .Anolyte in tiiis ttial achieved a 48 hour shelf life. In contract, all the other mince samples treated (control, Catoiyte, Anolyte- Catolyte combination) only achieved a 24.hour retail shelf Kfe accc-rdmg to this criteria. If this cut off point of ca 20 - 25% metmyoglobin is again applied to die rump steaks assessed during this trial, the rump steaks treated with .Anolyte and Catolyte in tins trial achieved a 48 hour shelf life, while the rump steaks treated with the Anolyte-Catolyte combinations achieved a 24 hour retail .shelf life. In contrast, the control samples were only acceptable cm time 0 of study, e. a 0 hour retail shelf Hfe, according to this criterion. Test 17 A final test was conducted with Anoiyte aimed at deteπnining-the reduction in weight loss in pig carcasses during chilling. The carcasses were stored at about -3°C in a cold room. .An Anolyte atmosphere was produced by means of fogging. The Anolyte, generated at a total flowrate of .about 75βιm/min, had the following characteristics : IDS : 6,04 g/1 pH : 6 - 8 ORP : +762mV Application: 150 ml/m 3 The reduction in weight loss during chilling due to .Anolyte fogging is shown Table 9. A reduction of 132% in weight loss was measured and calαilated The treatment of an animal product as described above has been found to extend the shelf life and quality of the product as a result of the anti-mierobial action of the anolyte solution. Treatment of sausage casings for example resulted in a substantial bacterial count reduction. The Applicant believes that the oxidising free radicals present in die anolyte solution act synergistically at a bacterial cellular level. It has been found that the effectiveness of the anolyte solution depends upon die flow rate through the reactor which determines d e concentration of the anolyte, as measured by the oxidation-reduction potential (O. P), or redox potential of die anolyte solutions, the flow rate tiirough the reactor the exposure time, i.e. the contact time between the contaminated product surface and die anolyte solution and the temperature during application. A flow rate of 750ml/mιn through a pair of electro chemical cells have been found to be most effective. By measunng the redox potential of the anolyte solution during the treatment, for example, of an animal product, the available fr . ee radical concentration can be determined and monitored. Anolyte has been found to be more effective at lower than at higher temperatures and at neutral pH ranges. It will be appreciated that many variations in detail are possible without departing from the scope and/or spiπt of the invention as claimed in the claims hereinafter.

Claims: CLAIMS : 1. A method of disinfecting an animal product, die method including the step of exposing the animal product to a composition comprising ap clectro-chemically activated, anion-containmg aqueous solution. 2. The metiiod as claimed m claim 1, including die steps of diluting ie anion-containing solunon to a pre-determtned concentration arid exposing the animal product to an appropriate quannty of the diluted anion-containmg solunon and for a predetermin-sd tune penod in| a treatment facility. 3. The method as claimed in claim 1 including die step of producmg d e aqueous solunon with an electro-chemical reactor, the reactor including a through flow, electro chemical cell having two coaxial cylindrical electrodes wid a co-axial diaphragm between them so as to separate tan annular inter electrode space into a catalyttc and an analytic chambfcr. 4. The method as claimed m claim 1 wherein the aqueous solution ha a redox potennal of between ---500 and +1170 mV and a pH of about 2J-8. 9/20129 19 5. The method as claimed m claim 1 including at least one of the steps (of soaking, rinsing or dipping the animal product in the solution, applying the solution via an atomising or fogging process and freezing tjic solution and using die ice produced to pack the animal product. 6. The method as claimed m claim 5 wherein the atomising or foggitig process includes the steps of atomising the solution into the aϋnosphe^e in an enclosure to be treated, forming droplets of between 5 .and l θ micrometres. 7. A treatment plant for treanng an ani.mal product in accordance with dip method of the invention, die treatment plant including supply means for supplying water; feed means for feeding a suitable salt into the water to produce an aqueous salt solution; an electrolysis device for electrolysing the aqueous solution to produce an anolyte and a cadiolyte solution; a mixing and dilunon tank for mixing and diluting die anolyte solution. * ] and means for applying the anolyte solution to a product. 8. A composition for disinfecting an annual product comprising an electro chemically activated anion containing aqueous solution. 9. An animal product characterized in having been disinfected with a| composition and/or in a plant and/or a process as claimed in claims 1,| 8 or 9.

Inventors: HINZE GILBERT THEO, HINZE, GILBERT, THEO
Applicants: DAVIS JOANNE T, HINZE GILBERT THEO, MOISEL EKKEHARD WALTER, DAVIS, JOANNE, T., HINZE, GILBERT, THEO, MOISEL, EKKEHARD, WALTER
Application year: 1998
Main classification: A23L3
IPC codes: A23B4, A23L3