WO2018169386A1

WO2018169386A1 - Anti-bacterial liquid food cleansing solution

Info

Publication number: WO2018169386A1
Application number: PCT/NL2017/050160
Authority: WO
Inventors: Brian Patrick LUINING; Gerardus Jan VISSER; Justïenne Marie Louise WENDT-DE LANGE
Original assignee: Wafa Industries B.V.
Priority date: 2017-03-14
Filing date: 2017-03-14
Publication date: 2018-09-20

Abstract

De invention relates to a method for preparing a meal, comprising subjecting raw meat to an antimicrobial treatment by contacting the surface of the meat with an acidic antimicrobial aqueous liquid comprising citric acid, acetic acid, a salt (such as Na Cl or KCl), which liquid is essentially free of surfactants and which liquid is essentially free of alcohol, and then further processing the meat to obtain the meal. The invention further relates to an acidic antimicrobial aqueous liquid suitable for use in a method according to the invention, and to a concentrate from which said liquid can be prepared.

Description

ANTI-BACTERIAL LIQUID FOOD CLEANSING SOLUTION

The present invention relates to a method for preparing a meal, comprising meat. The invention further relates to an antimicrobial edible acidic aqueous liquid and to uses thereof. The invention further relates to a concentrate suitable for preparing the antimicrobial edible acidic aqueous liquid.

Meals comprising meat form an important part of nutrition. They can be prepared in an industrial, artisanal environment, in households, but also outdoors.

Cleaning solutions for foodstuffs, e.g .to remove soil or pathogenic bacteria are known. Some comprise alcohol, which is disadvantageous because it is a flammable product and alcohol is not by all consumers considered an acceptable component to treat food products. Hypochlorite and the like have also been employed. US 2003/0099745 relates to a food washing composition that does not require alcohol and that does not alter texture and taste of the food, as may be the case for hypochlorite. The food washing composition comprises an organic acid, an inorganic acid and a surfactant, is essentially free of alcohol and has a pH below the pKa of the organic acid. There is an Example which claims to achieve a three fold reduction of microorganisms (species non-specified) on lettuce leaves compared to tap water. The need for a surfactant, which is generally a synthetic compound and generally not appreciated to be part of the food to be consumed, is a serious drawback of this composition.

Moreover, for meat-containing food products extra care has to be taken, that their microbiological quality is satisfactory. Meat based products are notorious causes of infection by pathogenic microorganisms such as pathogenic bacteria, e.g. salmonella and pathogenic fungi via the food are major causes of discomfort, serious illness or even death.

It is an object of the present invention to provide a method for preparing a meal, comprising an antimicrobial treatment of a raw meat, that does not require the use of surfactants, hypochlorite or the like, by which treatment the microbiological quality of the meat is improved. It is further an object to provide a product suitable for use in the antimicrobial treatment of raw meat.

It has now been found that this is achievable by using an aqueous solution of two specific organic acids and a salt.

Accordingly, the invention relates to a method for preparing a meal, comprising subjecting raw meat to an antimicrobial treatment by contacting the surface of the meat with an acidic antimicrobial aqueous liquid comprising citric acid, acetic acid, a salt (such as NaCl or KCl), and then further processing the meat to obtain the meal. The liquid is essentially free of surfactants and generally essentially free of organic solvents, in particular of alcohol. The further

processingcan be done in a usual manner e.g. cooking (which term is used for any heating step wherein the structure of the product is altered, such as boiling, grilling, baking, roasting etc.) grinding, seasoning, blending with other food ingredients.

The invention further relates to an antimicrobial edible acidic aqueous liquid, comprising citric acid, acetic acid and a salt, which liquid is essentially free of surfactants. Further, said liquid is generally essentially free of organic solvents, in particular of alcohol. This antimicrobial edible acidic aqueous liquid is typically for use in a method according to the invention.

The invention further relates to an aqueous liquid concentrate the concentrate having a an acetic acid content of 2- 10 wt.%, a citric acid content of 2-10 wt.%, a salt content of 5-25 wt. % and a water content of 55-91 wt. %, based on total weight of the composition. The concentrate is essentially free of (added) surfactants. The concentrate is essentially free of alcohol and generally essentially free of other (added) organic solvents. Prior to use in accordance with the invention such concentrate typically is diluted with water (e.g. tap water) to provide an antimicrobial edible acidic aqueous liquid according to the invention.

The invention further relates to the use of the edible acidic aqueous liquid according the invention to improve the microbiological quality of a meat product. Preferably, the edible acidic aqueous liquid according the invention is used to reduce the meat product's count of one or more pathogenic bacteria selected from the group of Salmonella, Escherichia (such as E. coli), Coliform, Staphylococcus (such as S. aureus), Aeromonas, Shigella, Campylobacter and cyanobacteria. In a further embodiment, the count of one or more pathogenic fungi is reduced.

A method according to the invention has been found effective to significantly reduce total microbial cell count. A five-fold reduction or more has been found feasible. In particular, good results have been achieved with reducing the count of Salmonella, wherein the total number of colony forming salmonella cells on the raw meat is reduced by the antimicrobial treatment by a factor 4 or more, in particular by a factor 10 or more, more in particular by a factor 25 or more.

The use of the acidic antimicrobial aqueous liquid has been found to be effective in reducing the count of pathogenic microorganisms, whilst no undesirable changes in texture or taste occur. To the contrary, in a treatment according to the invention it is possible to improve the tenderness of the meat. Further, meat treated in accordance with the invention does not suffer from and unacceptable loss of succulence. Also, an undesirable sour taste of the meal can be avoided. It is considered that in this respect the replacement of acetic acid by another acid is undesired.

Further, it was found that contact with the skin of a person handling the antimicrobial aqueous liquid during a method of the invention is not disadvantageous. The scent of acetic acid on the skin of a person that had been in contact with the liquid or the scent of acetic acid on the treated raw meat was found to be faint at most. Without being bound by theory it is considered that the presence of the salt contributes to this, possibly because it contributes to a accelerated evaporation of the acetic acid.

Further, the concentrate has a satisfactory shelf-life. It can be stored for e.g. 3 months or more, in particular 6 months or more, 1-2 years, without unacceptable precipitation of ingredients, despite the relatively high content of citric acid.

It is in particular an advantage of the invention that it allows the improvement of microbiological quality without needing any substances that are not commonly used as food ingredient. It is possible to make use of a solely components that occur in nature, namely acetic acid, citric acid, NaCl/KCl and water. Good results have been achieved with an embodiment wherein the antimicrobial edible acidic aqueous liquid respectively concentrate essentially consists of acetic acid ( vinegar), citric acid and one or more salts selected from the group of NaCl and KC1. In a further advantageous embodiment, the antimicrobial edible acidic aqueous liquid respectively concentrate essentially consists of vinegar, citric acid , one or more salts selected from the group of NaCl and KC1 and one or more natural food ingredients in particular one or more natural flavouring ingredients, e.g. one or more herbs or spices.

A method, antimicrobial liquid or concentrate according to the invention in particular useful for the treatment of a lean raw meat, with a relatively low blood content. In a preferred embodiment the raw meat is poultry. In particular good results have been achieved with chicken meat. In a further preferred embodiments, the meat product comprises meat from an aquatic animal, such as a fish, a crustacean or a mollusk. In such meat, the count of cyanobacteria is preferably reduced. In a further advantageous product the raw meat is an edible insect or is based on edible insects.

The antimicrobial treatment in method or use according to the invention is carried out be contacting the raw meat with the acidic antimicrobial aqueous liquid. This can in principle be done by any means, e.g. sprinkling or dipping. Preferably, the meat is submerged in the acidic aqueous liquid.

The contacting is usually carried out for a duration of at least 10 min., although an antimicrobial effect may be observed within less than 10 min.

Preferably the contacting is carried out for 15-60 min. in particular 15-35 min, more in particular for about 20 to about 30 min.

The contacting usually takes place at a temperature in the range of 2- 40 °C, in particular at a temperature in the range of 18-35 °C, more in particular at ambient temperature..

After contacting with the acidic antimicrobial aqueous liquid, the meat can be processed further, e.g. cooked or used for the preparation of a raw meat dis and directly consumed or it can be stored (typically chilled) before or after further processing. It is not necessary to remove, e.g. wash off, any residual acidic antimicrobial aqueous liquid. In general it is preferred not to remove any residual antimicrobial aqueous liquid from the surface of the treated meat, because such removal, e.g. washing with domestic water, can contaminate the surface with fresh microorganisms.

The antimicrobial edible acidic aqueous liquid usually has a pH of about 3.0 or less. The pH is usually more than 1.0, in particular 2.0 to 3.0, preferably 2.5-3.0.

The antimicrobial edible acidic aqueous liquid usually comprises 0.5-5 wt. %, preferably 1.0-2.5 wt.%, more preferably 1.5-2.5 wt. % acetic acid.

The antimicrobial edible acidic aqueous liquid usually comprises 1.0-5 wt. %, preferably 1.5-5 wt. %, more preferably 2.5-5 wt. % citric acid.

The antimicrobial edible acidic aqueous liquid usually comprises 2.5-

12.5 wt. %, preferably 5- 10 wt.% chloride salt. The chloride salt is usally NaCl, KCl or a combination thereof.

The water content usually at least 70 wt. %, preferably 75-95 wt.%, in particular 82.5-91 wt.% water. Water usually at least substantially forms the balance of the liquid, in addition to the citric acid, chloride salt and the acetic acid. Minor components that may be present in particular are those that are present in small amounts in the ingredients to formulate the aqueous liquid, e.g. from tap water and/or vinegar.

The antimicrobial edible acidic aqueous liquid usually is essentially free of salts other than chloride salts. A minor amount of other salts may be present, e.g. because they form part of ingredients, such as (tap) water or vinegar, used to prepare the liquid. If present, the total content of salts other than chloride salts is generally less than the content of chloride salt, and preferably less than 1 wt. %, more preferably less than 0.5 wt.%.

The antimicrobial edible acidic aqueous liquid usually is essentially free of organic acids other than acetic acid and citric acid. A minor amount of other organic acids may be present, e.g. because they form part of the ingredients, e.g. vinegar, used to prepare the liquid. If present, the total content of organic acids other than acetic acid and citric acid is generally less than the content of acetic acid, and preferably less than 0.5 wt. %, more preferably less than 0.2 wt. %.

In an advantageous embodiment, the antimicrobial edible acidic aqueous liquid according to the invention has a total organic acid content in the range of 3.0- 15 wt. %, preferably of 3.5- 12 wt. %, in particular 4.0-7.5 wt.%, based on total weight of the composition.

Usually, the antimicrobial edible acidic aqueous liquid essentially consists of food-grade ingredients.

The antimicrobial edible acidic aqueous liquid may be a packaged product. In an advantageous embodiment, it is made (directly before use) by mixing an aqueous liquid concentrate according to the invention and water, which may be domestic water, in particular tap water.

The aqueous liquid concentrate according to the invention preferably has an acetic acid content of 3-5 wt.%.

The aqueous liquid concentrate according to the invention preferably has a citric acid content of 5- 10 wt.%.

The aqueous liquid concentrate according to the invention preferably has a salt content of 10-20 wt. %.

The aqueous liquid concentrate according to the invention preferably has a water content of 65-82 wt. %, based on total weight of the composition.

The aqueous liquid concentrate according to the invention usually has a total organic acid content of at least 7 wt. %. The total organic acid content usually is less than 20 wt. %. Said concentrate preferably has total organic acid content in the range of 8-15 wt. %, more preferably of 8- 10 wt. %, based on total weight of the composition.

Usually, the concentrate according to the invention essentially consists of food-grade ingredients.

The aqueous liquid concentrate according to the invention usually is essentially free of salts other than chloride salts. A minor amount of other salts may be present, e.g. because they form part of ingredients, such as (tap) water or vinegar, used to prepare the liquid. If present, the total content of salts other than chloride salts is generally less than the content of chloride salt, and preferably less than 2 wt. %, more preferably less than 0.5 wt.%.

The aqueous liquid concentrate according to the invention usually is essentially free of organic acids other than acetic acid and citric acid. A minor amount of other organic acids may be present, e.g. because they form part of the ingredients, e.g. vinegar, used to prepare the liquid. If present, the total content of organic acids other than acetic acid and citric acid is generally less than the content of acetic acid, and preferably less than 1.0 wt. %, more preferably less than 0.4 wt. %.

The aqueous liquid concentrate respectively antimicrobial aqueous liquid according to the invention does not require the presence of inorganic acids. Said concentrate respectively antimicrobial aqueous liquid are usually essentially free of sulphuric acid, phosphoric acid, nitric acid, and preferably essentially free of all inorganic acids. If, present the total content of inorganic acids generally is less than 5 wt. %. Thus, the total content of inorganic acids in the concentrate respectively antimicrobial aqueous liquid generally is 0-4 wt.%, in particular 0-1 wt.%.

The concentrate can be packaged in any container suitable for acidic food-grade aqueous fluids. In a specific embodiment, the invention relates to a tube, spray can or squeeze bottle containing a concentrate according to the invention. The volume of a container containing the concentrate is usually in the range of 50-10000 ml, in particular, 100-2500 ml, more in particular 200- 1000 ml.

The concentrate may be prepared by mixing vinegar, preferably natural vinegar, the citric acid, the salt, optionally other ingredients and optionally additional water. In an embodiment, a solution of the citric acid is mixed with the vinegar. Salt can be added to the citric acid solution, to the vinegar or as a separate aqueous solution. Advantageously, the concentrate is prepared by adding the other ingredients to the water.

The term "a" or "an" as used herein means "at least one" unless specified otherwise.

The term "about" in relation to a value generally includes a range around that value as will be understood by the skilled person. In particular, the range is from at least 15 % below to at least 15 % above the value, more in particular from 10 % below to 10 % above the value, more specifically from 5 % below to 5 % above the value.

The term "substantial(ly)" or "essential(ly)" is generally used herein to indicate that it has the general character or function of that which is specified. When referring to a quantifiable feature, these terms are in particular used to indicate that it is for at least 75 %, more in particular at least 90 %, even more in particular at least 95 % of the maximum that feature.

The term 'essentially free' is generally used herein to indicate that a substance is not present (below the detection limit achievable with analytical technology as available on the effective filing date) or present in such a low amount that it does not significantly affect the property of the product that is essentially free of said substance. In practice, in quantitative terms, unless specified otherwise, a product is usually considered essentially free of a substance, if the content of the substance is 0- 0.5 wt.%, in particular 0 - 0.2 wt.%, more in particular 0 - 0.1 wt.%, based on total weight of the product in which it is present. As will be understood by the skilled person, for certain substances, such as certain surfactants, the presence may be well below 0.5 wt. %, 0.2 wt.% or 0.1 wt. % and still have a significant effect on a property of the product. Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their tails) and hydrophilic groups (their heads). Therefore, a surfactant contains both a water-insoluble (or oil-soluble) component and a water-soluble component. In this respect it should be noted that the hydrophobic group of surfactants is larger than the hydrocarbon group in acetic acid, which - unlike the hydrophobic part of surfactants - does not form micelles. The term surfactant is generally known in the art and typical examples are as described in US

2003/0099745. With the term 'essentially free of surfactants' is meant herein in particular that no surfactant is added (as an active ingredient) to the concentrate or antimicrobial aqueous liquid, and in particular not in an effective amount to significantly alter the surface tension in water or to have an effect on the microbiological quality of raw meat treated in accordance with the ivnention. In general, surfactants will be absent (below a detectible amount) in a concentrate or antimicrobial aqueous liquid according to the invention. In practice, a trace thereof may be present, e.g. due to dilution of the concentrate with water containing a trace of surfactant. Such trace will generally be less than 0.1 wt. %, preferably less than 0.01 wt. % , in particular less than 0.001 wt. % of the concentrate or antimicrobial aqueous liquid.

With the term 'essentially free of organic solvents' is meant herein in particular that no organic solvents is added to the concentrate or antimicrobial aqueous liquid, and in particular not in an effective amount to significantly alter the antimicrobial properties of the concentrate or liquid. Non-edible organic solvents - will generally be absent (below a detectible amount) in a concentrate or antimicrobial aqueous liquid according to the invention. In practice, a trace of edible organic solvents can be present in particular due to the optional presence thereof in an ingredient for the concentrate, such as vinegar.

As used herein, percentages are usually weight percentages unless specified otherwise. Percentages are usually based on total weight, unless specified otherwise.

When referring to a "noun" (e.g. a compound, an additive etc.) in singular, the plural is meant to be included, unless specified otherwise.

As used herein, The term "aqueous" is used herein to describe mixtures with water as only or the major liquid. Generally the water content of an aqueous composition at least 90 wt. % based on total weight of the liquids (substances that are in the liquid state of matter at 25 °C), preferably 95- 100 wt. %.

pH is defined as the apparent pH at 25 °C, as measurable by insertion of a standard pH electrode in the medium of which the pH is measured.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

The invention will now be illustrated by the following examples.

Example 1

Table 1: Formulation examples of a concentrate according to the invention

Example 2

The test formulation of Example 1 was diluted with an equal amount of Dutch tap water to form the antimicrobial edible acidic aqueous liquid. The antimicrobial effect of the antimicrobial edible acidic aqueous liquid (Tl, T2) was tested by comparison the effect of the antimicrobial edible acidic aqueous liquid on raw chicken strips after 15 or 30 min of submerging in the liquid at room temperature (about 20 °C) compared to a similar treatment with tap water (CI, C2). Total content of viable micro-organism cells was determined. For total viable counts, sample dilutions of the chicken strip samples were plated on

Petrifilm AC plates from 3M, according the Eurofins - KBBL protocol ML/AL/42.. To determine the number of Salmonella, sample dilutions of the chicken strip samples were plated on Xylose Lysine Deoxycholate (XLD) agar and counting the black and pink (specific for Salmonella Senftenberg 775W, which is H2S negative) colonies after 24 hours incubation at 37 °C. Al tests were performed in duplicate. The results are as follows:

Table 2:

The results show that a significant effect is reached after 15 min., with a reduction from 60000 (average) to 29000 (average) for total cell count and a five fold reduction for salmonella, a notorious pathogenic organism.

After 30 min. the reduction in the total cell count was more than five fold, and the reduction in salmonella was more than 35 fold.

Example 3

The test formulation of Example 1, which was a clear, transparent liquid with a slightly pungent (acidic) odour and a pH around 2.0 was used to treat chicken strips that had been contaminated with three Salmonella strains

(ATCC 13076, ATCC 13311, and NCTC 9959) and a Campylobacter strain (C jejuni) each provided by Eurofin, Wijhe, NL.

To prepare contaminated and non-contaminated test units, the contents of four packages, containing 250 gram chicken strips each, were combined and mixed homogeneously by hand in a sterile plastic bag. To prepare contaminated test units 400 grams chicken strips were transferred to a clean sterile plastic bag.

The strips were contaminated with the Salmonella and Campylobacter test strains. The target level of each species was 5-6 log cfu/g. Test units were prepared by transferring portions of 50 grams contaminated chicken strips to sterile 350 ml sample pots. To prepare non-contaminated controls portions of 50 grams non- contaminated chicken strips were transferred to 350 ml sample pots. In total 6 contaminated and 6 non-contaminated test units were prepared to test the effect of the test formulation in triplicate and compare the results against treatment with water.

The effect of the test formulation on the micro-organisms present on the chicken strips was assessed by adding 50 ml of the test formulation diluted with water (1: 1) to three contaminated and three non-contaminated test units and loosen the chicken strips in it using sterile plastic spoons.

Immediately after adding the diluted test formulation, 10 grams of chicken strips were removed from the test units to determine the initial levels of micro-organisms present on the chicken strips. Each sample was mixed 1:9 with Maximum Recovery Diluent to neutralize the diluted test formulation and prepare serial dilutions for plating on selective and non-selective media A second and third sample of 10 grams was taken from each test unit after 15 and 30 minutes contact time respectively, to determine the levels of micro-organisms after treatment with the diluted test formulation. The procedure was repeated with water instead of the diluted test formulation using the remaining contaminated and non- contaminated test units.

To assess the effect of the diluted test formulation on the microorganisms present, the chicken strip samples taken from the test units after 0, 15 and 30 minutes contact time, as well as the contaminated and non-contaminated chicken strips, were examined for Total Viable Count (TVC), number of

Enterobacteriaceae, Number of Salmonella and Campylobacter. For total viable counts, sample dilutions of the chicken strip samples were plated on Petrifilm AC plates from 3M, according the Eurofins - KBBL protocol ML/AL/42. Colonies were counted after 48-62 hours of incubation at 30 °C. To determine the number of Enterobacteriaceae, sample dilutions of the chicken strip samples were plated in (pour-plate method) Violet Red Bile Glucose Agar. Colonies were counted after 24 hours incubation at 37 °C. To determine the number of Salmonella, sample dilutions of the chicken strip samples were plated on Xylose Lysine Deoxycholate (XLD) agar and counting the black and pink (specific for Salmonella Senftenberg 775W, which is H2S negative) colonies after 24 hours incubation at 37 °C. To determine the number of Campylobacter, sample dilutions of the chicken strip samples were plated on Charcoal Cefoperazone Deoxycholate Agar (CCDA) and counting the grey colonies specific for Campylobacter after 44 hours incubation at 42 °C.

The results of enumerations of specific groups and species of microorganisms present in the contaminated and non-contaminated chicken strips, before and after treatment with the diluted test formulation, are presented in Tables 3 and 4. After treatment of fresh chicken strips with Meatwash the number of viable micro-organisms and Enterobacteriaceae in naturally contaminated chicken strips, as well as both food pathogens in artificially contaminated chicken strips were significantly lower than in chicken strips treated with tap water. The number of Salmonella and Campylobacter in naturally contaminated chicken strips were below the enumeration limit of 100 cfu/g (2 Log cfu/g). The effect of the diluted test formulation according to the invention on the chicken strips was also visible by eye as the strips turned white upon treatment.

The numbers of target groups was reduced with with 0,5 - 1,5 Log cfu/g; the percentage of the target groups that was killed was between 63 and 97 %.

Table 3. Effect formulation according to the invention on the Total Viable Count (TVC) and number of Enterobacteriaceae (EB) present in naturally contaminated chicken strips, as compared to treatment with tap water.

Test / contact

TVC EB Salmonella Campylobacter time

Log cfu/g Log cfu/g Log cfu/g Log cfu/g

Water / direct

5.9 ± 0.1 4.0 ± 0.1 < 2.0 < 2.0

(t=0)

Water / 15

5.9 ± 0.2 3.9 ± 0.2 < 2.0 < 2.0

minutes

Water / 30

5.7 ± 0.2 3.9 ± 0.1 < 2.0 < 2.0

minutes

Test

Formulation / 5.4 ± 0.2 3.1 ± 0.1 < 2.0 < 2.0

direct (t=0)

^"Test

Formulation / 15 5.2 ± 0.4 2.9 ± 0.2 < 2.0 < 2.0

minutes

Test

Formulation / 30 5.1 ± 0.3 2.3 ± 0.3 < 2.0 < 2.0

minutes The numbers represent results of enumerations in triplicate (3 individual tests) together with the standard deviation. Salmonella and

Campylobacter were below the enumeration limit of 100 cfu/g in all naturally contaminated test units. Table 4. Percentage reduction in viable numbers of Total Viable Count and Enter obacteriace e in naturally contaminated chicken meat and Salmonella and Campylobacter in artificially contaminated chicken meat, after treatment with the diluted test formulation according to the invention as compared to treatment with water.

Parameter 15 minutes treatment 30 minutes treatment

Total Viable Count 77 % 73 %

Enterobacteriaceae 88 % 97 %

Salmonella 63 % 79 %

Campylobacter 76 % 71 %

From the results of the activity tests it is concluded that the antimicrobial edible acidic aqueous liquid according to the invention significantly reduces the total number of micro-organisms present on a meat. The counts of the pathogens Salmonella and Campylobacter were also significantly reduced in numbers as demonstrated by treating artificially contaminated chicken strips with the aqueous liquid according to the invention. The number of Campylobacter cells recovered after 30 minutes incubation was higher than the number of cells recovered after 15 minutes contact time. Both pathogens were reduced 0,5 - 1 Log cfu/g (a reduction of 63 - 79 %), comparable to the reduction observed in the Total Viable Count of naturally contaminated chicken strips (73 - 77 %). The reduction in number of Enterobacteriaceae however, was even more than 1 Log cfu/g (88 - 97%). Remarkably, Total Viable Counts and Enterobacteriaceae were already reduced directly upon contact with the Meatwash, whereas a longer contact period seemed to be required for both food pathogens.

Claims

1. Method for preparing a meal, comprising subjecting raw meat to an antimicrobial treatment by contacting the surface of the meat with an acidic antimicrobial aqueous liquid comprising citric acid, acetic acid, a salt (such as NaCl or KC1), which liquid is essentially free of surfactants and which liquid is essentially free of alcohol, and then further processing the meat to obtain the meal.

2. Method according to claim 1, wherein the meat is submerged in the acidic aqueous liquid for a duration of at least 15 min., preferably 15-60 min. in particular 20-35 min.

3. Method according to any of the preceding claims, wherein the acidic antimicrobial aqueous liquid is a mixture comprising natural vinegar (providing the acetic acid), the citric acid and the salt.

4. Method according to any of the preceding claims, wherein the meat is selected from the group of mammalian meats, poultry, aquatic animal meats and insects.

5. Method according to any of the preceding claims, wherein the contacting takes place at a temperature in the range of

2-40 °C, in particular at a temperature in the range of 18-35 °C, more in particular at ambient temperature.

6. Method according to any of the preceding claims, wherein the total number of colony forming salmonella cells on the raw meat is reduced by the antimicrobial treatment by a factor 4 or more, in particular by a factor 10 or more, more in particular by a factor 25 or more.

7. Antimicrobial edible acidic aqueous liquid, suitable for use in a method according to the invention, comprising citric acid, acetic acid and a salt, which liquid is essentially free of surfactants and which liquid is essentially free of alcohol.

8. Antimicrobial edible acidic aqueous liquid according to claim 7, having a pH of 3.0 or less, in particular of 2.5-3.0.

Antimicrobial edible acidic aqueous liquid according to claim 7 or 8, comprising

0.5-5 wt. %, preferably 1.0-2.5 wt.% acetic acid;

1.0-5 wt. %, preferably 1.5-5 wt. % citric acid;

2.5-12.5 wt. %, preferably 5-10 wt.% chloride salt;

at least 70 wt. %, preferably 75-95 wt. % water,

wherein all percentages are based on the total weight of the composition.

Antimicrobial edible acidic aqueous liquid according to claim 8,

comprising

1.5-2.5 wt. % acetic acid;

2.5-5 wt. % citric acid;

5.0-10 wt. % chloride salt; and

- 82.5-91 wt.% water,

wherein all percentages are based on the total weight of the composition.

Antimicrobial edible acidic aqueous liquid according to any of the claims 7-10 having a total organic acid content in the range of 3.0-15 wt. %, preferably of 3.5-12 wt. %, in particular 4.0-7.5 wt.%, based on total weight of the composition.

Aqueous liquid concentrate (suitable for preparing an antimicrobial edible acidic aqueous liquid according to any of the claims 7-10 upon dilution of the concentrate with water, e.g. tap water)

the concentrate having a an acetic acid content of 2-10 wt.%, a citric acid content of 2- 10 wt.%, a salt content of 5-25 wt. % a water content of 55-91 wt. % based on total weight of the composition, which concentrate is essentially free of surfactants and which concentrate is essentially free of alcohol.

Aqueous liquid concentrate according to claim 12,

the concentrate having a an acetic acid content of 3-5 wt.%, a citric acid content of 5-10 wt.%, a salt content of 10-20 wt. % and a water content of 65-82 wt. %,

based on total weight of the composition.

14. Aqueous liquid concentrate according to claim 12 or 13, wherein the total organic acid content is in the range of 8-15 wt. %, preferably 8-

10 wt. %, based on total weight of the composition.

15. Aqueous liquid concentrate according to claim 12, 13 or 14, wherein the concentrate is essentially free of sulphuric acid, phosphoric acid, nitric acid, preferably free of inorganic acids.

16. Method for preparing an aqueous liquid concentrate according to claim

12, 13, 14, or 15, comprising mixing vinegar, preferably natural vinegar and an aqueous solution comprising the citric acid.

17. Use of an edible acidic aqueous liquid according to any of the claims 7-

11 to improve the microbiological quality of a meat product.

18. Use according to claim 17, to reduce the meat product's count of one or more pathogenic bacteria selected from the group of Salmonella, Escherichia (such as E. coli), Coliform, Staphylococcus (such as S. aureus), Aeromonas, Shigella, Campylobacter and cyanobacteria..

19. Use according to claim 17 or 18, wherein the meat product comprises meat from an aquatic animal, such as a fish, a crustacean or a mollusk and wherein the count of cyanobacteria is reduced.

20. Use according to claim 17 or 18, wherein the meat product comprises poultry, in particular chicken.

21. Use according to claim 17 or 18, wherein the meat product is an edible insect.

22. Use according to any of the claims 17-21, to reduce the meat product's count of one or more pathogenic fungi.