HK1061776A - A method and an apparatus for inhibiting of pathogens when producing sliced food - Google Patents

Description

Method and apparatus for inhibiting pathogens in sliced food products

The present invention relates to a method and apparatus for producing sliced food products (sliced food).

In the last few years there has been an increasing interest in the presence of pathogenic microbial cells in food products. The food industry has applied new methods to avoid food becoming carriers for pathogenic microbial cells. However, a particular problem is that the food is heat-treated for sterilization, then sliced and individually packaged. Pathogens that adhere to the sterilized item cannot be exposed to compete with natural non-pathogenic bacteria. To avoid pathogens, a combination of different approaches is used in the industry to "deplete" pathogens and thus eliminate their possibility of growth. For these methods to work, a high level of hygiene and process control at all stages is necessary.

It is known that certain organisms, either by themselves or by producing substances, can selectively inhibit pathogenic bacteria on the surface of sliced food products. This biopreserving bacterium is therefore part of the company's program to inhibit the growth of pathogenic bacteria on sliced food products. However, there is no application system today that can add such bacteria in sufficient quantities to the slices and spread them over the surface of the slices to avoid growth of pathogenic microbial cells on all surface parts.

The object of the present invention is to provide a method for producing sliced food products, characterized in that an agent inhibiting the development of pathogenic microbial cells is automatically added to the surface of the slices in an amount sufficient to render the product safe for use after storage at freezing temperatures for a considerable period of time.

The present invention is based on the following observations: if the preparation inhibiting pathogens is added to the sliced pieces of food (which are produced during the slicing of the food) during the slicing process, it can be effectively applied to the surface of the sliced pieces.

The method according to the invention is therefore characterized in that: in slicing, a preparation inhibiting pathogens is added to the cut off slice surfaces of the food product, which results in the cut off slice surfaces during slicing.

The present invention takes advantage of the fact that: the cut-off piece surfaces exposed during the slicing process have a well-defined position and can therefore be effectively hit by drops (drops), jets, etc. of the preparation inhibiting pathogens, which are generated by means mounted in front of the cut-off piece surfaces of the food. When a slice is dropped onto a previously cut slice, after the preparation inhibiting pathogens has been applied and the slice has been cut, the surface of the cut slice will contact the back of the previous slice, where part of the preparation will be stored, which is also important for the efficiency of the application.

The pathogen-inhibiting formulation is preferably applied by one or more nozzles directed against the exposed surface of the cut pieces of food. The nozzle can place the formulation on the exposed surface of the cut-out piece, or can apply the formulation to the side of the piece before cutting and partially to the back of the piece after cutting. The preparation will also hit the working knife, which has the advantageous side effect that the preparation can be transferred to the incision by means of the knife. The nozzle is preferably a spray nozzle, for example, which produces droplets of a preparation inhibiting pathogens.

The preparation that inhibits the pathogen may comprise bacteria that are effective against pathogenic microbial cells, such as listeria organisms, by producing bacteriocins, either directly or indirectly.

The preparation for inhibiting pathogens is added in an amount such that the occurrence of microbial cells on the slices is inhibited for at least 4 weeks when the slices are stored at 5-10 ℃ in an inert gas or vacuum package. In this manner, the sliced food product can be safely protected against the occurrence of pathogenic microbial cells throughout the shelf life (shelf life) of the food product.

The pathogen-inhibiting formulation is preferably applied by two nozzles, one of which is placed directly opposite the cut-off slice surface, facing the surface, and the other of which is placed on the side of the cut-off slice surface, facing the food and the side of the cut-off slice surface of the food. This has been shown to produce very effective results for the formulation.

The pathogen-inhibiting agent is preferably added in an amount of less than 0.1ml per square centimeter of cut sheet surface so that no significantly wet sections are produced.

During the slicing process, the slices are stacked or lapped together, whereby the effect of the preparation inhibiting pathogens can be enhanced by the above-mentioned placing of the preparation on the back side of the preceding slice.

The slices may be stacked or lap wrapped to effectively preserve the effects of the treatment for a long period of time.

In a preferred embodiment of the method, the preparation inhibiting pathogens is added to all surfaces of the food before slicing, whereby a very effective protection of the sliced food against pathogenic microbial cell development during storage is achieved.

The method according to the invention may be used in all types of food products that are at risk of contamination with pathogenic microbial cells or other harmful bacteria. Especially food products that may be boiled, heated or otherwise treated.

The amount of the agent that inhibits pathogens is added in an effective amount, and need not be very large. For example: 10 per gram of sample⁴Individual colony forming unit organisms (10)⁴cfu/g) Already, it is able to inhibit listeria organisms. To avoid Listeria, it is preferred to add at least 10 per gram of sample⁴cfu can be effective against listeria organisms.

The device for producing a food product in the form of a sheet is of the type comprising a slicer with one or more knives for slicing the food product by repeated cutting of the food product, characterized in that the machine comprises means for applying a preparation inhibiting pathogens to the surface of the cut-off sheet produced when the sample is sliced.

A preparation inhibiting pathogens is understood to be a preparation inhibiting the development of pathogenic microbial cells.

Food products are here understood to be, for example, meat products, such as sausages of different types, smoked sliced meat, boiled or smoked ham, beef, processed pork back or sausages made from rolled meat.

The invention is described in detail below with reference to the accompanying drawings, which show a schematic view of a microtome equipped with a nozzle containing a solution for inhibiting pathogens.

Microtomes (1) were of conventional construction and were manufactured by Dixie Union, Germany as model SL 482. It comprises a duct (2) for a cut sample (3), such as a large red intestine, and a device (4) for continuously guiding the sample to an eccentrically mounted disc blade (5). At the end of the slicer, a conveyor (6) with a conveyor belt (7) is mounted, which can take hold of the piece (8) cut by the knife. The conveyor belt (7) runs during the slicing process, which means that the slices will be placed overlappingly on the conveyor belt. The speed of the conveyor belt may increase rapidly with a short burst of draw so that every 10 or20 slices do not overlap with the preceding slice. In this way, a series of 10 or20 slices appear on the conveyor belt.

Above the conveyor belt (7) and facing the surface (3a) of the cut-off pieces of the sample to be cut, there are nozzles (9) which supply a solution inhibiting pathogens and compressed air from a moisture disinfection unit of Clean Tech a/S Danmark, type Desinfector200 through two tubes (10, 11). In operation, the nozzle produces a cone of moisture (12) from a solution that inhibits pathogens. The droplets of moisture hit the surface of the piece cut off by the food, such as the end face (3a), and adhere to the end face surface and other surface parts, such as the back of the piece and the blade. Droplets of such a size do not substantially spray into the room (as opposed to droplets from the normal spray nozzle of a wet gas disinfection apparatus, which must spray into the room).

Also mounted above the level of the conveyor (7), but laterally to the sample end face (3a), is a further nozzle (13) of the same construction as the first nozzle (9), also supplied with solution and compressed air from the same wet gas sterilizing device via pipes (14, 15). When the nozzle (13) is operated, it generates a pathogen-inhibiting preparation moisture (16) corresponding to the nozzle (9), but the droplets of moisture hit other surface parts, such as the sides of the sample and the cut-off chip surface (3a) and the back of the cut-off chip.

The effect of the addition of the agent inhibiting pathogens during the slicing of the meat product was examined with the apparatus of the following example.

Example 1

This example describes the production and slicing of sausages (saucisson) using the addition of a biological preservative solution, which shows the effect of the added solution on meat slices during long term storage after packaging with inert gas.

Production of crude red sausage

14 kg of coarse red sausage made from the following components

％ kg

Pork shoulder 15% fat 51.937.27

Pork cheek meat, 40% fat meat 18.032.52

Water 21.202.97

Potato flour 3.730.52

Soybean isolate 1.400.19

Caseinate (EM-HV) 1.400.19

Phosphate N15-150.310.04

Vacuum salt 2.000.28

Nitrite 60ppm 0.8g

Aggregate 100.0014.00

Shoulder meat, pork cheek meat and half of the water, nitrite, vacuum salt and phosphate are mixed in a bowl-shaped meat grinder, which runs 10 cycles (rounds) with a cutter at 3000rpm per minute. After the material was chopped, the soy isolate, caseinate, potato flour and the rest of the water were added and the meat grinder was run for 5 cycles first at a knife speed of 2000rpm and then 25 cycles at a speed of 4000 rpm.

The minced meat was filled into sterilized artificial intestines (guts) (50 mm in diameter) under vacuum, and the sausage was prepared. The sausage is heat treated in boiling hood at 80 deg.C for 1 hr, and then sprayed with cold water at 10 deg.C. After the heat treatment, the sausages were removed with an operator with a sterile bag turned out on his hands, placed in a box washed with alcohol and placed in a freezer at 2 ℃ until they were to be cut.

Contamination with Listeria

To mimic listeria contamination (which occurs in connection with sausage skinning and slicing), sausages were artificially inoculated with a mixture of five listeria strains. The following strains were used:

DMRI 4127-PX: listeria monocytogenes (l.monocytogenes) a, 9(Ti, serotype 4)

DMRI 4128-PX: listeria monocytogenes C, 5(770, serotype 1)

DMRI 4124-PX: listeria monocytogenes A, 2(3894, serotype 1)

DMRI 4125-PX: listeria monocytogenes A, 5(3971, 2, serotype 1)

DMRI 4140-PX: listeria monocytogenes A, 9(Hurdler, H52/KVL412)

These strains were activated separately in BHI broth and purity was controlled on BHI-A. From BHI-A, each culture was grown in BHI-B, and cultured for 13 days at 5 ℃ with the addition of 1.5% sodium chloride (total amount of sodium chloride is 2%). The cultures were mixed in equal amounts and the bacterial load was adjusted to 2X 10 by diluting with physiological NaCl solution²cfu/ml to produce the working solution.

The solution is applied to the whole surface of sausage to make the bacterial count 10cfu/cm²And the sausage was dried in the production shop for 1 hour. Thus, the listeria bacteria have time to adhere to the surface of the meat.

Slicing and biological preservation

The contaminated sausages were cut into 2 mm pieces using the above mentioned apparatus. The slicer had the following settings:

conveyor Belt (Belt) 017

Weight (Weight) 251

Displacement 59

Step (Step) 243

Slices (Slices) 10

Carnosum1043 was diluted in 10 g of lyophilized L.in 1L of physiological NaCl solution to produce a culture solution (bacteria count: 3X 10)⁸cfu/ml) which was added during the slicing process using nozzles 9 and 13. The nozzle was operated at a hydraulic pressure of 1 bar (bar) and a pneumatic pressure of 1 bar, and the seeding level per tablet was about 10⁷cfu/g sample.

Package (I)

The biocorrodized crude sausage pieces were packed in stacks of approximately 100 grams per stack on polystyrene trays. The discs and sheets were packed in oxygen-sealed, double-folded bags (fiiobag) with 20/80 carbon dioxide and nitrogen. Packaging in a shade at 5 deg.C or 10 deg.C for storage.

A package without biological preservative solution was made as a control.

Microbiological assay

After 3 or 4 weeks of storage at 5 ℃ or 10 ℃, the samples were taken out of the tray for microbiological examination. The entire contents of the dish were mixed with physiological NaCl solution and peptone in a ratio of 1: 9 and treated in a bacterial separator (stomacher) for 1 minute.

To determine the bacterial count of Listeria, samples were spread directly onto Oxford agar and incubated at 37 ℃ for 1-2 days. In the case of samples containing a small amount of Listeria, MPN analysis of 3X 3 tubes was performed in Fraser Broth instead. The results of the analysis are shown in the following table. During the slicing process; 10 to⁷carnosum1043 to the level of cfu/g in the rough red intestine, stored at 5 ℃ or 10 ℃, when the incidence of listeria monocytogenes in the rough red intestine (log cfu/g) is present.

Day 21 day 28 at 5 ℃ day 1 day 10 ℃ day 21 day 28

n＝2 n＝6 n＝6 n＝2 n＝6 n＝6

Average 0.51.51.50.83.13.5

Control 1.03.34.60.87.77.4

The table above shows the packaging relative to the control (after 4 weeks the growth of Listeria monocytogenes reached about 10⁵cfu/g level), the growth of listeria monocytogenes in biocorrodified rough red intestine packaging after 3 and 4 weeks of storage at 5 ℃ is very low. The growth inhibitory effects of biopreserving at 10 ℃ were not very different, with an average level of 3.5 for listeria monocytogenes growth after 4 weeks. This level was 4 log units higher than the control.

When slicing with two nozzles 10 is added⁷carnosum's anti-antiseptic (anti-sterile) effect at 5 ℃ or 10 ℃ is considerable at cfu/g level of culture.

Example 2

The purpose of this example was to test whether a biological preservative culture was applied to the surface of the peeled sausage prior to slicing, and also to the slices, to obtain any additional results.

An experiment was performed in the same manner as in example 1, except that l.carnosumi 1043 (10)⁹cfu/ml) solution was added to the entire surface of the raw red intestine, and the solution was manually added using a nozzle having the same configuration as the fixed nozzle.

The microbiological analysis was carried out as in example 1, with the results shown in the following table. Carnosum1043 was added to the surface of the crude red intestine and the crude red intestine was sliced while the same culture was taken at 10⁷The level of cfu/g was added to the slices and then stored at 5 ℃ or 10 ℃ when the incidence of Listeria monocytogenes (log cfu/g) was observed.

Day 21 day 28 at 5 ℃ day 1 day 10 ℃ day 21 day 28

n＝2 n＝6 n＝6 n＝2 n＝6 n＝6

Average 0.50.1-0.40.5-0.2-0.5

Control 1.03.34.60.87.77.4

It can be seen that no growth of listeria monocytogenes was found in the biocorrodized product after 4 weeks of storage, either at 5 ℃ or 10 ℃. The effect of adding the biological preservative solution to the surface of the peeled sausage before slicing is also significantly improved. The effect is particularly pronounced at 10 ℃, with a 4 log unit improvement being seen over the effect achieved in example 1 after 4 weeks.

When the biological preservative culture is added to the surface of the crude red intestine before slicing and additionally added with two nozzles at the time of subsequent slicing, and stored at 5 ℃ or 10 ℃ for up to 4 weeks, very significant inhibition of growth of listeria monocytogenes can be achieved. In a biocorrodified product, listeria monocytogenes does not grow beyond the allowable levels.

Example 3

The purpose of this example is to check whether lower l.carnosumm 1043 levels of inoculation can be used, as this means that the expenditure for purchasing cultures can be saved appreciably.

The experiment was performed in the same manner as in example 2, with the addition of a biological preservative culture both before and at the time of slicing. The level of culture addition during sectioning was only 10⁴cfu/g sample.

The microbiological analysis was performed as in example 1. The results are shown in the following table. Carnosum1043 was added to the surface of the crude red intestine, and the crude red intestine was sliced while the same culture was performedArticle 10⁴The level of cfu/g was added to the slices and then stored at 5 ℃ or 10 ℃ when the incidence of Listeria monocytogenes (lot cfu/g) was present.

Day 21 day 28 at 5 ℃ day 1 day 10 day 21 day 28 at 1 ℃

n＝2 n＝6 n＝6 n＝2 n＝6 n＝6

Average 0.80.12.11.01.31.4

Control 0.84.25.50.87.67.8

It can be seen that if the inoculation level of L.carnosum1043 is from 10⁷The cfu/g is changed to 10⁴cfu/g, did not achieve the same anti-disinfection effect. After 3 and 4 weeks of storage at 5 and 10c, respectively, a small growth of listeria monocytogenes was observed. The level ratio of Listeria monocytogenes is 10⁷The cfu/g level was two log units higher when added to the solution (example 2). But this still has a significant treatment effect because the biocorrodified product is 4-6 log units lower than the control product. Even at low levels, the added pathogen-inhibiting solution is effective against listeria in sliced products when stored at 5-10 ℃ for 4 weeks.

Claims (12)

1. Method for producing sliced food products, in which a food product (3) is cut into slices (8) by repeated cutting of the food product with a slicer (1), characterized in that a preparation inhibiting pathogens (12, 16) is added to the surface (3a) of the cut-off slices produced during the slicing of the food product.

2. A method according to claim 1, characterized in that the formulation (12, 16) is added by means of one or more nozzles (9, 13).

3. The method according to claim 1, characterized in that the preparation (12, 16) comprises bacteria which are effective against pathogenic microbial cells, either directly or by producing bacteriocins.

4. A method according to claim 1, characterized in that the preparation (12, 16) is added in an amount that inhibits the development of microorganisms on the slices (8) for at least 4 weeks when the slices are stored at 5-10 ℃ in inert gas or vacuum packaging.

5. A method according to claim 1, characterized in that the preparation is added by means of two nozzles (9, 13), one (9) being placed against the surface (3a) of the cut-off piece of food, facing the surface, and the other (13) being placed on the side of the cut-off piece surface (3a), facing the food and the side of the cut-off piece surface of the food.

6. Method according to claim 1, characterized in that said formulation (12, 16) is applied at less than 0.1ml/cm²Is added to the cut-off sheet surface (3 a).

7. A method according to claim 1, characterized in that the sheets (8) are stacked or lapped together during the slicing process.

8. A method according to claim 1, characterized in that the sheets (8) are stacked or overlapped together in inert gas or vacuum packaging.

9. Method according to claim 1, characterized in that the preparation inhibiting pathogens (12, 16) is added to all surfaces of the food product (3) before slicing.

10. A method according to claim 1, characterized in that the food (3) is a boiled, heated or otherwise treated food.

11. The method according to claim 1, characterized in thatIn that at least 10 of⁴cfu/g of a sample of an organism effective against listeria.

12. Apparatus for producing sliced food products, comprising a slicer (1) with one or more knives (5) for cutting a food product (3) into slices (8) by repeated cutting of the food product, characterized in that the slicer (1) comprises means (9, 13) for applying a preparation (12, 16) inhibiting pathogens to the cut off slice surfaces (3a) produced during the slicing of the food product.