MXPA01002583A - Solution useful for bacterial decontamination of foodstuffs and method for using same - Google Patents

Abstract

The invention concerns a method for treating foods characterised in that it comprises a step which consists in contacting said food with a solution having an OH-concentration ranging between 0.02 and 0.2 and in that said solution further comprises a tribasic salt of orthophosphoric acid such that the ratio of the initial OH-ion concentration, expressed in equivalent per litre, to the orthophosphate concentration is not less than 1/4, advantageously 1/3. The invention is useful for bacterial decontamination of foodstuffs.

Description

USEFUL SOLUTION FOR BACTERIAL DECONTAMINATION OF FOODSTUFFS AND METHOD OF USING THE SAME DESCRIPTION OF THE INVENTION The present invention relates to aqueous solutions useful for bacterial contamination of food products. It is more particularly related to low-concentrated solutions containing both a basic compound and a tribasic phosphate. Bacterial contamination of food products is a problem that increasingly concerns the authorities and the distribution societies of food products. Indeed, bacterial contamination causes an alteration of the food and can cause serious poisoning in the final consumer; whether this intoxication is a direct intoxication when the food is consumed raw without destruction of the microbial flora, whether this food is contaminated by the toxins released by the bacteria, in the course of its life or because of its death. The problem is particularly acute in the case of animal products.

Numerous procedures for decontaminating food products have already been proposed. However, only some of them present a balance between their cost and the efficiency that allows their use on an industrial scale. In fact, the problem is complex because it is convenient, on the one hand, to decontaminate the surface of the product and, on the other hand, to avoid a subsequent recontamination, either in the course of the treatment, or in the course of a subsequent or preceding rinsing. On the other hand, the effectiveness of decontamination must be extremely fast; The fault of which the treatments can not be carried out on an industrial scale would imply considerable treatment volumes. Furthermore, when the treatment is directed to terrestrial animal carcasses and an aqueous phase is applied, a prolonged contact has the risk of being harmful and may lead to the taking of weight by incorporation of water in the food products treated by the procedure, taking weight that is regulated in many countries. The problem of contamination is particularly acute in food or food products that have not undergone any preparation, and / or that have not been cooked. Vegetable products can be cited directly after harvesting and animal products immediately after fishing or killing. Thus, as products that can be treated, the carcasses of dead animals are found shortly after the slaughter of the animals for their consumption. Without this being limiting, we can mention the quadruped carcasses, particularly bovidae such as bovines (for example buffalo, uros, bison), antelopes, sheep, goats (including game animals such as deer). , chamois, chamois, elk, moose of Canada, chamois, roe deer), suidae (for example pigs, boars, peccaries), logomorphs (such as rabbits, hares, agoutis), as well as poultry carcasses, among which they can cite the totality of wild and / or breeding poultry from the smallest ones (for example couroucous, skylarks) to runner birds (for example ostriches), particularly birds (for example thrushes), gallinaceous lasa (for example chickens, quail, redfish, partridges, turkeys, grouse) and ducks (eg canaries, geese, teals). The treatment can also be applied to reptiles and fish. The carcasses can be treated before, but advantageously after the skinning. In the case of volatiles, it is desirable that it be done after plucking. One of the most troublesome problems in the treatment of animal carcasses lies in the fact that these carcasses must often be washed with high amounts of water, and that this water is often the vector of a transfer of a contamination from a particular carcass to the set of the carcasses. One of the solutions recommended to date is the use of Javel water in concentrations of the order of several hundred ppm, generally around 600 to 800 ppm. However, some scientists consider that the use of Javel water for the treatment of the carcasses could imply a risk of cancer, when the water concentrations of Javel are high, and particularly when they are higher than 500 ppm of chlorine.

This is the reason why one of the objects of the present invention is to provide a technique that is capable of preventing washing and rinsing waters of animal carcasses without this implying the use of a concentration higher than 500 ppm of chlorine content, preferably 200 ppm, and more preferably, 100 ppm. Another object of the present invention is to provide a method for obtaining a decontamination of the washing and rinsing waters using waters that have few mineral materials, preferably at most 2% by mass. These objects and others that will appear below are achieved by means of a food treatment process comprising a step of contacting the food with a solution having an OH concentration "comprised between 0.02 and 0.2 N (equivalents per liter) and by the fact that a tribasic salt of orthophosphoric acid is added thereto so that the ratio between the initial concentration of OH- ions and the concentration of orthophosphates expressed in equivalents is at least equal to 1/4, advantageously 1/3 , preferably to 1/2, more preferably to 1.

It is advantageous that the concentration of orthophosphate species is at least equal to 0.01 M and at most equal to 0.1 M. The initial concentration of OH- ions is advantageously at least equal to 0.05 M. By initial concentration of OH- ions is meant the concentration of OH- ions of the solution without tribasic salt of orthophosphoric acid. In other words, this is the concentration of OH- ions that is obtained in the absence of the tribasic salt of phosphoric acid, more generally in the absence of any phosphate. This value of the OH ions can easily be measured by techniques well known to those skilled in the art by means of a pH meter with electrodes adapted to the type of medium and to the pH domain considered, that is to say the domain comprised between about 12 and around 13. The values are given for a temperature of 25 ° C and under atmospheric pressure, taking into account the inherent risk of using a very basic solution to denature the food, it is preferable to use solutions that present an initial concentration of ions OH- at the most equal to 0.1 N (which corresponds to 25 ° C at a pH of 13.) It is also preferable that the concentration of phosphate ions in the solution is at most equal to 0.1 N and this to prevent the solution It is highly loaded with initial elements.To obtain a significant effect of synergy between OH ions "and phosphate species, it is preferable that the latter be present in a concentration at least equal to 0.02 M. OH ions are advantageously in the form of alkali hydroxides, ammonium hydroxides, or quaternary phosphonium, or in the form of cation hydroxide (s) masked by complex ation (essentially neutral complexing agents complexing or sequestering as for example the crown ethers). However, taking into account the enormous amounts to be treated and the price of the latter compounds, it is preferable that the cations associated with both the hydroxide ion and the P043 ~ ion be alkaline or mixtures of various alkalines. Lithium is not preferred, by far, for this application, the most effective are potassium, rubidium and cesium, a good compromise lies in the use of sodium ion or potassium ion and their mixtures. Rubidium and cesium, although they give excellent results, are very expensive for this type of application. The OH ions can be introduced in any manner known to the person skilled in the art, either in the form of very weak salts of acids, or by reaction of precipitable compounds (for example a successive mixture of trisodium phosphate associated with a hydroxide of calcium, thus precipitating the phosphate and leading to the formation of soda in situ.) You can also use products of the type oxilita (Na202) that can give rise to soda and hydrogen peroxide, which will reinforce the action of the anti-pollution system, and this in basic conditions that give oxygenated water an extremely short life span. It is also possible to consider introducing the OH ions "in the form of alcoholates, which will give a hydroxide and an alcohol, which can be evaporated in the course of the treatment, to the water." The alcohol does not modify, up to a concentration of about 5%. %, the properties of the solution.

However, it is simpler to introduce the hydroxide ions in the form of alkali hydroxide (s) but also alkaline ferrous, or a mixture of alkaline phosphates. The solution focused by the present invention is particularly well suited for rinsing, and may for example be used before or after another decontamination treatment of the products themselves. It can be used more specifically to avoid contamination after a contamination stage, for example in the system designated by the Anglo-Saxon term "tank cooler" ie in a cooling system in a high performance water container. The solution according to the present invention is equally usable for decontamination, it is sufficient to adapt the contact time. However, when the concentration of mineral ions is low, an extension of the contact time has the risk of being harmful, and can lead to weight gain by incorporating water into the food products treated by the procedure, taking weight that It is regulated in many countries.

The decontaminating system has the advantage of being compatible with many other decontaminating systems, which are organic or mineral. The effect of the solutions according to the invention can be reinforced by oxidants; among these, permanganates and bichromats can certainly be cited, but the latter are colored, and can under certain conditions lead to precipitates, which can cause discomfort to the procedure. Also oxidants containing ozone and / or hydrogen peroxide, even hypochlorites are preferred. From the point of view of the effectiveness of the treatment, it is desirable that the oxidizing power of the solution be at least equal to 0.001 N, sold at 0.002 N, preferably at 0.005 N (equivalent of electron per liter). However, it is advisable to limit as much as possible the concentration of these agents, which do not always have a good reputation. Also one of the best agents would be ozone, if it were not for its cost. If not, in case of potentiation of the solutions according to the invention by the oxidants, it is advisable to limit the oxidizing power to 0.05 N, advantageously to 0.02 N, preferably to 0.01 N.

The effect of the hypochlorite is reinforced by the system according to the present invention, which allows to use reduced concentrations, in general concentrations lower than 500 ppm (in mass of chlorine Cl 2 in relation to the mass of the treatment solution), more generally lower than 200 ppm, it is still possible to verify an effect between the two systems at concentrations of chlorine content lower than 100 ppm. Other elements such as carbonates can also be added to the solution, provided that this does not alter the initial basicity. Thus, the main use of this solution is a contact with the food product to be treated, this contact is most often made by soaking, spraying or fogging. It is desirable that the duration of soaking, spraying or nebulization is at least equal to 1/2 hour, advantageously at least equal to 1/5, preferably 1/10. It is at least 1 second, advantageously 10 seconds, preferably 20 seconds. The contact can be continued partially after soaking, spraying or nebulization, if there is no rinsing. This contact can be carried out at a temperature at least equal to 0 ° C, sold at around 10 ° C, preferably at 20 ° C. In the present description, the term "around" is used to highlight the fact that the values that follow correspond to mathematical roundings, and particularly that when the number or figures to the right of a number are zeros, these zeros they are zeroes of position and not significant figures, except of course if it is specified in another way. It is preferable, to avoid altering the food, not exceed the temperatures that modify the structure of the food. As regards carcasses and foodstuffs of animal origin and untreated, this contact can be carried out at a temperature equal to 80 ° C, advantageously at 70 ° C. The pressure has only a very small influence on the process according to the present invention, at atmospheric pressure or at a close pressure, and this any altitude. As this has already been mentioned, the food product to be treated is advantageously an animal product, whether carcasses or carcasses after cutting, but the results can be obtained on other products such as eggs. This decontamination system works equally well for compounds that are intended for freezing. The following non-limiting examples illustrate the invention.

EXAMPLES Measurement of the effect of TSP (0.4%) in the presence of different concentrations of NaOH on Salmonella typhimurium IPL and Escherichia coli NIJH-JC2. B.l Principle B.l.l Cultivation An Erlenmeyer flask (10 ml) of Heart and Brain Infusion (BHI) was seeded with a colony of Salmonella typhimurium.

IPL, or from E. coli NIJH-JC2, and then it was placed at 37 ° C on a stirring rack. After 18 hours, the bacterial numbering was, respectively, ~ 6 x 109 and 7 x 109 colony forming units per milliliter.

(CFU / ml). after dilution to 1/500 in BHI culture medium, the bacterial count was 1 x 10 7 CFU / ml. This diluted culture was then used for the rest of the experience.

B.l.2 Samples The different samples of TSP and NaOH were prepared previously, in such a way that the concentrations obtained in these mixtures were twice the concentrations tested at the end. For example, the TSP had a concentration of 0.8%. At t = 0 minutes, 0.5 ml of bacteria (diluted 1/5) were added to 0.5 ml of different mixtures, and left in contact for 30 seconds. Samples of 100 μl were taken, then serially diluted (ratio 10) in sterile distilled water containing NaCl (9 g / 1). 100 μl of each dilution was placed in Petri dishes (BHI + 1.5% agar-agar). For certain samples, 100 μl were placed directly into the Petri dish without being diluted. The boxes were incubated for 18 hours at 37 ° C.

The colonies present in the boxes were counted, and the number of CFUs (colony-forming unit) was deduced.

B.2 Results CFU / ml Samples S. typhimurium E. coli Control 7.00 X 106 2.01 x 106 Control (1) 1.20 X 106 2.08 x 106 TSP (0.4%) 4.86 X 106 4.06 x 106 (0.4%) + NaOH (3.1) 1 x 106 2 x 105 0.4%) + NaOH (3.1) 5.02 X 104 2.25 x 104 0.4%) + NaOH (3.1) 5.02 X 104 5.54 x 104 0.4%) + NaOH (3.1) 5.00 X 104 4.32 x 103 0.4%) + NaOH (3.1) 5.02 X 104 1.52 x 104 0.4%) + NaOH (3.1) 5.00 X 104 5.19 x 103 0.4%) + NaOH (3.1) 5.00 X 104 3.75 x 104 0.4%) + NaOH (3.1) 1.37 X 104 3.35 x 102 0.4%) + NaOH (3.1) 2.08 X 104 2.50 x 10 ° NaOH (3.1) 3.88 X 106 2.57 x 106 NaOH (3.3) 3.38 X 106 2.84 x 106 NaOH (3.5) 9.50 X 105 1.80 x 106 NaOH (3.7) 1.78 X 106 4.11 x 105 B.3 Conclusion Used only in 0.4%, the anhydrous TSP does not induce any bactericidal activity during the time of the experiment (30 seconds), either on a culture of S. typhimurium IPL or E. coli NIHJ-JC2. The exposure of these cultures to NaOH, alone, (3.1 to 3.5 g / 1) does not induce bactericidal activity. But used in 3.7 g / 1, soda induces a decrease in CFU / ml of a factor of 4 to 5 over S. typhimurium and E. coli, respectively. Used in association, TSP (0.4%) and soda (3.2 g / 1) induce a 2 log decrease in the number of CFU / ml on the two cultures. An increase in the concentration of soda (3.7 g / 1) increases the bactericidal activity (-4 log) on the culture of E. coli. The simultaneous addition of TSP (0.4%) and NaOH (4 g / 1) induces a reduction in the number of CFU / ml of 3 log for S. typhimurium and of 6 log (limit of the experiment) for E. coli. It seems that a strong synergy is induced between the TSP (0.4%) and soda, when it is added in a concentration higher than 0.4 g / 1 and especially higher than 3.2 g / 1.

Claims (19)

1. CLAIMS 1. Process for the treatment of foods, characterized in that it comprises a stage of contact of the food with a solution having an OH concentration "comprised between 0.02 and 0.2 and by the fact that the solution also comprises a tribasic salt of orthophosphoric acid so that the ratio between the initial concentration of OH ions ", expressed in equivalents, and the concentration in orthophosphates, is at least equal to 1/4, advantageously to 1/3, preferably to 1.
2. 2. Method according to claim 1, characterized in that the concentration in species of orthophosphate is at least equal to 0.01 M and at most equal to 0.1 M.
3. 3. Method according to any of claims 1 and 2, characterized in that the initial concentration in OH ions "is at least equal to 0.05 N.
4. 4. Method according to any of claims 1 to 3, characterized in that the initial concentration in OH ions "is at most equal to 0.1 N.
5. 5. Method according to any of claims 1 to 4, characterized in that the concentration in phosphate ions is at most equal to 0.1 N.
6. 6. Method according to any of claims 1 to 5, characterized in that the concentration of the phosphate species is at least equal to 0.02 M.
7. 7. Process according to any of claims 1 to 6, characterized in that the OH ions "are in the form of alkali hydroxides, ammonium or phosphonium hydroxides, or cations masked by complexation.
8. 8. Process according to any of claims 1 to 7, characterized in that the OH ions "are in the form of sodium or potassium hydroxide.
9. 9. Method according to any of claims 1 to 8, characterized in that the phosphate is an alkaline phosphate or a mixture thereof.
10. 10. Method according to any of claims 1 to 9, characterized in that the step is a step of rinsing.
11. 11. Process according to any of claims 1 to 10, characterized in that the contact is made by soaking, spraying, or nebulization.
12. 12. Method according to any of claims 1 to 11, characterized in that the contact is carried out at a temperature at least equal to 0 ° C, advantageously at 10 ° C.
13. 13. Method according to any of claims 1 to 12, characterized in that the contact is carried out at a temperature at most equal to 80 ° C, advantageously at 70 ° C.
14. 14. Method according to any of claims 1 to 13, characterized in that the contact is carried out at atmospheric pressure.
15. 15. Method according to any of claims 1 to 14, characterized in that the food is an animal feed.
16. 16. Use for animal decontamination of a solution having an OH concentration of between 0.02 and 0.2 and by the fact that a tribasic orthophosphoric acid salt is added thereto so that the concentration in orthophosphate species is at least equal at 0.01 M and at most equal to 0.1 M.
17. 17. Use according to claim 16, characterized in that the ratio between the initial concentration of OH ions "to the concentration in orthophosphates expressed in equivalents is at least equal to 1/4, advantageously to 1/3, preferably to 1.
18. 18. Use according to claims 16 and 17, characterized in that the solution also comprises a bactericide or a bacteriostatic.
19. 19. Use according to claims 16 to 18, characterized in that the solution also comprises at most 200 ppm of Javel water (expressed as chlorine mass Cl 2).