WO2011040820A1

WO2011040820A1 - Lactic acid bacteria suitable for producing partly fermented meat and a process for producing partly fermented meat by establishing conditions suitable for the proliferation of such lactic acid bacteria

Info

Publication number: WO2011040820A1
Application number: PCT/NO2010/000354
Authority: WO
Inventors: Erik Magistad Berge; Anna Ragnhild Berge
Original assignee: Fjell & Fjord Mat As
Priority date: 2009-09-30
Filing date: 2010-09-30
Publication date: 2011-04-07

Abstract

The present invention concerns lactic acid bacteria being suitable for producing raked/fermented or partially fermented meat, wherein said lactic acid bacteria may be probiotic, ferment meat, having a high tolerance for acid conditions and are slime-producing while being able to live/grow at low water activity down to a water activity of 0,6. The lactic acid bacteria may additionally form vitamin B3 (niacin) and optionally the antibiotic nisin. The lactic acid bacteria may be anaerobic, aerobic or facultatively anaerobic. It is also disclosed a process for fermenting sugar-treated meat wherein such microorganisms are brought to proliferation by adding sugar in a layered manner wherein simple sugar species are added before more complicated sugar species.

Description

LACTIC ACID BACTERIA SUITABLE FOR PRODUCING PARTLY FERMENTED MEAT AND A PROCESS FOR PRODUCING PARTLY FERMENTED MEAT BY ESTABLISHING CONDITIONS SUITABLE FOR THE PROLDJERATION OF SUCH LACTIC ACD3 BACTERIA

Ambit of the invention.

The present invention concerns lactic acid bacteria (lactobacilli) being suitable for producing raked/fermented or partially fermented meat, and particularly such lactic acid bacteria belonging to the genus Leuconostoc or Gemella and that possesses the

identifying features that they ferment meat at low temperature (down to 0°C), that they possess a high tolerance for acid conditions (down to pH 1), that they produce slime, and that they optionally may produce vitamin B3 (niacin) and optionally the antibiotic nisin under the proper growth conditions and that they optionally may proliferate/grow at a low water activity (down to 0,6) and that they optionally may be probiotic.

The present invention concerns particularly the use of the lactic acid bacterium

Leuconostoc mesenteroides and/or Gemella morbillorumn possessing the characteristics indicated supra, for producing the raked/fermented meat products by using sugar as an addition to the meat product prior to or during the raking/fermenting process, wherein the raking/fermenting process may proceed under anaerobic conditions or optionally under aerobic conditions by the proliferation and/or addition of sufficient amounts of Leuconostic mesenteroides and/or Gemella morbillorum, and starter cultures of

Leuconostoc mesenteroides and/or Gemella morbillorum suitable for such fermentation of meat. Such lactic acid bacteria are used particularly on meat that has been pre-treated with sugar or together with a combination of salt and sugar for the treatment of meat, both from land-dwelling animals and fish, and that provides a meat product by partial fermentation that possesses the features of a raked/fermented product, wherein the actual treatment of the meat progresses very much faster than conventional fermentation of corresponding meat and wherein the rakmg fermenting process progresses at low temperatures (below 0°C such as in the temperature interval 0-28°C) and optionally under vacuum or under an inert or modified atmosphere. The invention concerns additionally a starter culture of such microorganisms as indicated supra as well as a concentrate of such a starter culture of such microorganisms.

Furthermore, the present invention concerns a process for producing such a raked meat wherein the bacteria mentioned supra are selected by establishing fermentative

conditions being selective for such bacteria. Prior art.

The use of lactic acid bacteria for processing food products is previously known and constitutes a relatively large area within the food industry. There are particularly used lactic acid bacteria for the production of cheeses and whey milk products, and there exists a vast number of special lactic acid bacteria being known for such purposes. The fermenting of meat has also been conducted by the use of lactic acid bacteria

Thus it is known from JP patent 2008-133251, JP patent 2008-178398, JP 3266948 and US patent application 2004/0185164 to use lactic acid bacteria for fermenting fish meat and meat from domestic animals. However, nothing is mentioned here about the addition of sugar species or that the meat being sugar treated prior to the starting of the fermentation.

It is furthermore known from KR patent 20070053858, EP 1415547, WO 02/45518 and WO 2007/086752 to use a starter culture of lactic acid bacteria for fermenting meat at low temperatures.

Basis for the invention.

It is known to pre-treat meat with sugar from US patent 5.607.713. Such a sugar treatment produces an increase of the solids content ratio (the dry matter content) in the meat. Here it is also specified that it is obtained a decrease of the amount of organic acids, while the microbiologic purity simultaneously is maintained in the meat. Such treatment includes that the meat, either in a fresh, pre-treated (e.g. radiated) or stored (frozen/thawed) condition, is contacted with sugar, preferably in the form of a powder, whereby there is produced an exudates (extract). The exudates comprise an aqueous extract from the meat where it has been assimilated heavy metals, toxins, decomposition products, etc. that mainly comprise waste materials. Such waste materials may be produced during the slaughter of animals.

In live or slaughtered animals there progress a number of organic and biochemical reactions producing waste substances such as the creation acids at the onset of rigor mortis, while the quality of the meat dill depend on the condition of the slaughtered animal prior to its butchering (stress, feed, exercise, etc.). Such reactions may produce a bad taste, smell or consistency of the meat. It will also be mentioned that unwanted natural taste substances being present in the meat, e.g. the taste being present in the meat from, animals in heat such as reindeer, sheep, pigs, cattle, etc. or e.g. the smell/taste of bins/barns, that may be removed through the treatment of such meat with sugar.

The known sugar treatment being mentioned supra, will remove all or parts of such waste substances and taste degrading substances in addition to said toxins and heavy metals. Such unwanted substances will be present in the exudate from the meat subsequently to the treatment. This exudate is discarded. Such a sugar treatment that previously is known from US patent 5.607.713, used for saccharose treatment of meat for improving its storing capacity. Further treatment of such saccharose treated meat is, however, not mentioned in US patent 5.607.713 disclosing that sugar treated meat represents a final product that may be stored or consumed, and wherein there may be added salt or spices for enhancing the taste of the meat, and wherein the meat may be stored subsequently to the sugar treatment at e.g. cooling conditions or frozen.

It will also be possible to conduct the sugar treatment disclosed supra on meat that has been frozen.

The advantage of treating the meat with sugar is that it is thereby used a process which I reproducible, and does not decompose the structure of the meat and may

change/improve the organoleptic properties (taste) of the meat since the exudate contains unwanted taste substances in addition to a substantial part of the used sugar. According to the prior art this exudate has, however, been discarded since it may contain unwanted taste substances or other components that are not wanted in the sugar- treated end product. However, this exudate may be suitable as a growth medium for the lactic acid bacteria according to the present invention. The exudate may thus in an alternative embodiment of the present invention function as a growth medium for a starter culture of the relevant lactic acid bacteria or at least as a growth medium for producing such a starter culture.

In the pre-treatment of the meat with the addition of sugar, it is additionally avoided that there is used a starting material where it has been added conservatives since many conservatives either enter into reactions with substances in the meat (proteins, lipids, sugars, etc.) or become introduced into the food chain or both. Reaction products between conservatives and the meat or the conservatives per se, may be difficult to break down in the body and or their excretion from the body may be difficult, something which further represents a health and environmental risk.

In the open sugar treatment of the relevant meat there is formed an exudate which, according to the prior art is discarded, whereby the time period of the sugar treatment of the meat becomes adjusted in relation to the mass/size of the meat. The open treatment of the meat with a sugar or sugar composition is conducted by placing the meat on a surface such as a grid or a screen, and wherein the top of the meat is covered q.s.

{quantum satis) with the relevant sugar (however in such a way that the sugar does not fall off the meat in significant amounts). The sugar will then (depending on the thickness of the piece of meat, the quality of the meat, the type of meat, etc, easily being determined by the person skilled in the art) be dissolved in the meat juices and slowly penetrate the piece of meat and carry along the harmful and unwanted components mentioned supra.

As a guideline it is indicated that the meat is to be treated openly in a time interval of 1- 7 hours per cm thickness of the relevant piece of meat, more preferred 2-5 hours per cm thickness of the piece of meat, most preferred 3-4 hours per cm thickness of the piece of meat. These intervals are, however, provided as a guideline because, as mentioned supra, other factors than the thickness of the piece of meat determine the time of the sugar treatment. Generally, it my however be mentioned that the open sugar treatment is terminated when a sugar-containing exudate no longer appears from the piece of meat, and this may be observed directly or be determined empirically from the relevant type/quality/thickness of the piece of meat.

For obtaining an optimal sugar treatment it is preferred that there first is added the sugar compound in a powder form and subsequently to such sugar types have been assimilated into the meat it will be added more complicated compositions such as a sugar granulate. Such an addition may be performed either intermittently by adding the different sugar forms in succession, or the sugar addition may be performed in layers so that the sugar is added all at once, the powdery sugar being located at the bottom and the more complicated ones in succession upwards. The sugar layers in such a layered additive will normally be equally thick. Alternatively there may be added unequal amounts of sugar in the different layers, meaning that the bottom layer of sugar in powder form is somewhat thinner than the layers above because the sugar in the open sugar composition will be distributed as a cone, and if the amount of sugar in each layer were to be equal, the topmost layers will have to be thicker than the ones below. The thickness of the layers or the amount of sugar will depend on how many layers and how many different types of sugars that are used. When it is referred to "more complex" types of sugar supra, this also refers to the physical presentation of the sugar (powder, particles, granulate, etc.) and not necessarily to the chemical assembly of the sugar molecules. Thus there may be used one sugar type throughout the entire treatment (glucose, fructose or saccharose), but where the physical appearance of the sugar particles are different from layer to layer as explained supra, or there may be used different types of sugar in the separate layers, but with the more coarse particles upmost in the sugar additive.

The above disclosed distribution of sugar refers normally to the open sugar treatment and not to the closed sugar treatment (see infra).

In addition to the unwanted/harmful substances being leached from the meat through the sugar treatment, it also seems that other components become removed together with the sugary exudate. E.g. it seems that degrading enzymes such as proteases ad lipases may be leached and removed with the exudate.

The above disclosed process represents an open process, i.e. a process wherein the exudate from the sugar treatment may be removed freely.

For creating a raked/fermented product there may be started from such an openly sugar treated meat product as disclosed supra, or there may be used a fresh meat material as a starting point, and such fresh meat may be placed in a closed container such as vacuum bags or other gas-impenetrable bags or other type of gas-impenetrable container of plastic, metal or similar together with sugar, salt and optionally taste enhancers such as spices, for subsequently to rake such refrigerated and vacuumed meat for a suitable period of time to obtain an end product. Such a fermentation proceeds by using lactic acid bacteria that exist naturally in the meat, and this type of rake process is disclosed in European patent application 07709204.7.

From said patent it is known that lactic acid bacteria proliferate on the meat that has been treated with sugar. Such lactic acid bacteria may also reduce the breakdown of the meat by lowering the pH of the meat by providing an environment that is unfavorable for growth of other (harmful and degrading) bacteria and fungus, while providing special (favorable) taste qualities to the meat, etc. According to the prior art it is also well known that for producing a salt- and sugar- treated meat product it is also possible alternatively to place a salt/sugar composition with the correct amount of salt (not q.s.) in a vacuum plastic bag or other type of gas- impenetrable and sealed container and place the bag/container under a soft vacuum (see supra). Evidently, if a non-treated piece of meat is placed in a sealed container (e.g. a vacuum bag of plastic) together with the correct amount of salt and sugar, an exudate will not be removed from the meat. Such a process is, however, advantageous since it is possible to add the exact amount of sugar that is to be fermented by the lactic acid bacteria, and an exact amount of salt may also be added since the system is a closed one. However, as mentioned earlier both the salt and the sugar penetrate the meat during the treatment, solving the problem with the somewhat dryer character of the meat subsequent to the open sugar treatment.

On account of the growth of lactic acid bacteria inside the vacuum bag the sugar is in this embodiment consumed and leaves the salt for enhancing the taste of the meat. The starting material for such a treatment may either be fresh meat or meat that has been pre-treated with sugar as disclosed earlier. The salt also becomes evenly distributed throughout the meat during the vacuum treatment period even if the salt/sugar composition is placed at a location inside the vacuum bag before vacuuming and refrigerating the bag.

A salt concentration that is elevated in the meat that is treated may, however, work as an inhibitor on the growth of lactic acid bacteria, and such an inhibition may be avoided by ensuring that the lactic acid bacteria of the type according to the present invention is present in the meat material. This may be ensured by e.g. adding a starter culture of the relevant lactic acid bacteria to the meat, either to the fresh meat in a closed process or to the sugar pre-treated meat in an open process.

Performing the above disclosed rake/fermenting process with naturally occurring lactic acid bacteria as according to the prior art, represents an uncertainty concerning control of the raking process and the state/quality of the end product since non-optimal lactic acid bacteria may proliferate and make the end product of a poorer quality. Thus there exists a need for guiding and controlling the raking process from its start to its end for ensuring that a uniform end product is formed in every fermentation. This is also important with respect to food safety, especially for human consumption.

There exist a vast number of lactic acid bacteria that may grow and thrive on different growth substrates. Thus lactic acid bacteria being suitable for fermenting milk and diary products (e.g. sour milk, whey or yoghurt) may be less suitable for fermenting meat. Likewise different lactic acid bacteria may. demand different kinds of growth conditions and less favorable lactic acid bacteria may under given conditions compete with and remove those lactic acid bacteria that are wanted for the relevant raking process.

Definitions.

Sugar, in the context of the present invention, is meant to comprise mono-, di or oligo- or polysaccharides, e.g. saccharose, mannose, etc., preferably saccharose or fructose or mixtures thereof, and the sugar may be present in the form of a powder, a granulate or a solution. Sugars with low metabolic reaction rate and consequently a low calory content such as palatinose, may be used. An example of a sugar product without any sweet taste, is trehalose.

In connection with the expression "meat" this will in connection with the present invention be suggested to comprise all forms of meat from land-dwelling animals (bovines, porcines, ovines, etc.) as well as water-living fish. It is preferred that the meat originates from domestic animals, cattle, pigs, game (moose, reindeer, deer, etc), birds (turkey, chicken, quail, grouse, etc.) or fish (herring, salmon, halibut, cod, etc.).

The expression "water activity" being used in the present disclosure, is defined according to the equation infra a_w = p/p₀ wherein p represents the vapor pressure of water above a sample (in connection wit the present invention a sample of a sugar-treated meat material) at a given temperature, p₀ represents the vapor pressure of pure water at the same temperature, and a_w is an expression for the water activity in the relevant sample.

In connection with the expression "simple" and "complex" sugar compounds it is meant a reference to the chemical composition of the sugar compounds. Thus "simple" sugar compounds will refer to monosaccharides, whereas more "complex" sugar species will be disaccharides or polysaccharides. Within disaccharides and polysaccharides the sugar element units in the chemical structure may be equal or different. As an example of a "simple" sugar type it may be mentioned glucose/dextrose, mannose, galactose, fructose, whereas more "complex" sugar types may be represented by sucrose/saccharose, lactose, maltose, while even more "complex" sugar types may be represented by amylose.

It is also possible to perform the fermentation with a more fine-powdery sugar at the start of the fermentation and then increase the size of the sugar grains successively through the fermenting process for in this manner to start the fermentation with a material with a relatively large surface area versus the mass, and complete the fermentation process with large-grained sugar types/sugar granulate.

General disclosure of the invention.

It is explained supra that the relevant meat product is treated under vacuum. The vacuum will favor growth of anaerobic bacteria, among others lactic acid bacteria. Alternatively it may be possible to displace/fill the relevant bag/container where the fermenting is to proceed, with an inert gas (e.g. nitrogen) or other gas or gas

composition such as C0₂ optionally mixed with nitrogen or where the modified atmosphere may comprise smoke, especially smoke from juniper or other resin- containing wood-type or bark for optionally to include this flavor in the meat during the fermentation. This as an alternative method for promoting growth of the relevant anaerobic fermenting lactic acid bacteria according to the present invention. Using an inert atmosphere during the fermentation will not affect the other fermenting parameters such as temperature and duration as mentioned earlier.

For creating an environment favoring proliferation of the relevant lactic acid bacteria (especially Leuconostoc mesenteroides) there is first added simple sugar types to the meat to start the fermentation under the relevant fermenting conditions as mentioned supra, and when this sugar compounds has been "consumed", there is successively added more complex sugar species for promoting conditions during the fermentation favoring the special lactic acid bacteria that are suitable for the creation of the raked meat according to the invention. Alternatively and preferably there may be added such sugar species in a layered structure and simultaneously onto the meat so that the simple sugar species lies closest to the meat surface at the start of the fermentation process, and where the more complex sugar species are added on top of the simple sugar species. The ratio between the simple versus the more complex sugar species lies within the interval 10:90 to 90:10, e.g. 20:80 to 80:20, or 30:70 to 70:30 or 40:60 to 60:40 such as 50:50 where there is equally much of the simple as the complex sugar types. For producing an alternative ground/minced and additionally fermented product, it may also be possible to treat the relevant meat with sugar initially as explained supra, for obtaining a sugar-treated meat product intermediate, and then grind/mince this intermediate meat product (optionally together with a salt addition and or an addition of spices/taste enhancer additive as explained supra within this area as explained supra) to create a ground product. Such a ground product may be placed directly under vacuum or in a modified/inert atmosphere at the above indicated conditions for fermentation in the relevant time interval. It may also be possible to ass a starter culture of Leuconostoc and/or Gemella bacteria, preferably Leuconoztoc mesenteroides with the particular features indicated in the introduction, for ensuring an optimal fermentation of the ground meat.

Alternatively it may also be possible to grind fresh meat to a ground product and then place this ground meat inside a vacuum container together with sugar, salt and optionally taste enhancers/spice and place this under vacuum or under a modified atmosphere and store this at a low temperature as explained supra for fermentation under closed conditions. Also in this closed fermenting process it may be relevant to add a starter culture of the lactic acid bacteria according to the present invention.

The amount of added starter culture, optionally in the form of a starter culture concentrate being suitable for the proliferation of the lactic acid bacteria according to the present invention, is not critical since the other conditions for growth of such lactic acid bacteria initially is optimized for such growth, i.e. by performing the fermentation at a soft vacuum or in an inert/adjusted oxygen-deprived or oxygen-lacking atmosphere, at low temperature, optionally at adjusted pH (see infra), at low salt concentration as explained supra. The amount of starter culture will normally lie within the interval lxl 0³ to l lO⁹ bacteria per kg meat, more preferred lxlO⁴ to lxlO⁸ per kg meat, e.g. lxlO⁵ to lxlO⁶ bacteria per kg meat, even if more or less bacteria of the bacterial strain(s) according to the invention may be used if it is selected to add a starter culture of bacteria at all.

Concerning fermentation of sugar-treated meat with lactic acid bacteria according to the invention both under open and closed conditions, it may also be possible to lower the pH of the meat down to pH 1 , where the preferred pH lies within the interval pH 7-2, more preferred 6-2, particularly 2, 3, 4 or 5. pH at the fermentation with a bacterial culture according to the invention may in an alternative embodiment lie at pKa for lactic acid. Generally speaking such an alternative acidification of the meat or mince may be performed by adding a physiologic or organoleptic acceptable acid such as acetic acid or lactic acid, preferable lactic acid. The lactic acid fermentation with the lactic acid bacteria according to the invention will proceed at low temperature (0-15^°C, more preferred 0-10°C). The optimal fermentation time will depend on the type of meat that is treated. The fermentation temperature will lie within the temperature interval 0-10°C, more preferred 0-6°C, most preferred up to 4°C for water-dwelling animals (salt and fresh water fish), and will lie within the temperature interval 0-15°C, more preferred 0-10^°C, most preferred below 8°C for meat from land-dwelling animals (pig, cow, bull, poultry, etc.).

If a closed sugar or salt/sugar treatment with fresh meat is performed, the amount of salt should not exceed 10% (w/w) based on the weight of the piece of meat which is to be treated. The amount of salt will under such closed-system conditions normally lie within the interval 2-5% (w/w) even if other amounts also may be possible such as 1%, 3%, 7%, 10% (w/w) etc. The preferred salt concentration will not exceed 3,5%.

A salt concentration within the intervals mentioned supra may also be used in the open treatment of the meat. A preferred salt concentration will preferably be up to 3,5%.

In an open salt/sugar treatment system it is also preferred that the salt content of the end product does not exceed 10% (even if this is harder to control than in the closed system environment (see supra).

The open treatment of meat with a salt/sugar composition thus has several advantages both through the simultaneous addition of salt during the sugar treatment, and also as an enhancer for providing suitable growth conditions for subsequent growth of the lactic acid bacteria according to the invention in the meat.

By adding the salt/sugar composition to the meat it will also be possible to add other spices and taste enhancers to the meat after the salt/sugar treatment has ended in the open system treatment mode or simultaneously with the salt/sugar composition in the closed system mode. Examples of such spices/taste enhancers are pepper, nutmeg, ginger or mixtures of spices, fruit

(fresh/dried) e.g. apple, pear, pineapple, papaya, dates, figs, etc., vegetables such as carrot, horseradish, turnip, radishes, etc. and also herbs. Other taste additives may also be introduced in the form of essences (whiskey-essence, rum-essence, etc.).

The condition of the end product treated with lactic acid bacteria according to the present invention (taste, smell, texture, color, etc.) depends on the selection of the above mentioned factors such as the added amount of salt and/or spices and/or taste enhancers (or other components such as colorants), the treatment temperature, the treatment period, etc. However, since the condition of the end product also depends on the taste of the consumer, the determination of the strength and duration of the treatment or post-treatment process will be individual, but the determination of the quality of the end product may easily be found via routine tests and the knowledge of the person skilled din the art. By operating within the above mentioned parameters the person skilled in the art will easily be able to make a product with the wanted taste, smell and texture.

As a guideline for the duration of the treatment of the meat with a salt/sugar mixture in a closed system (vacuum container) to give a fermented and salt-containing end product where it has been used a salt/sugar mixture with salt within the interval specified supra (up to 10% (w/w), preferably within the interval 2-5% (w/w), e.g. 2-3% (w/w) relative to the weight of the meat), this will normally lie within the interval 1,5 - 2 days per kg meat.

If there is used a mixture of salt and sugar instead of a pure sugar treatment as explained supra, the amount of sugar that is to be added to the salt/sugar mixture, relates to the salt/sugar ratios specified in the disclosure supra. This will proved a suitable environment for the lactic acid bacteria according to the invention to grow in.

The duration of the salt/sugar and lactic acid bacteria treatment in a closed system under vacuum or with a modified inert atmosphere with lactic acid bacteria according to the present invention may, however, be longer or shorter than what has been indicated supra depending on the wanted condition of the end product, the temperature whereby the treatment is conducted, the type of meat that is treated (normally the fermentation of fish has a shorter duration than the fermentation of meat from land-dwelling animals, and there may even exist variations within e.g. the type of animal meat that is treated) etc. The exact duration of the salt/sugar fermentation may be determined by a person skilled in the art through observation and by consulting the above given disclosure since the addition of the salt/sugar mixture in a known amount as optionally a starter culture of the lactic acid bacteria according to the invention in a closed system, will provide a stable and predictable environment for the fermentation to proceed in. However, no extraordinary actions need to be taken for establishing the wanted duration of the treatment in view of the above given disclosure and guidelines and also based on the examples given infra.

When treating the meat with a salt/sugar mixture and subsequently via the growth of lactic acid bacteria according to the invention for further treatment of the salt/sugar-treated meat, there will be produced meat products with an unknown quality up to the present, i.e. with a

simultaneously included saltish or other spiced or smoked flavor, wherein the properties of the previously sugar-treated meat is suitable for further treatment steps, e.g. as specified supra, and different meat products with special taste qualities on account of the effect of the lactic acid bacteria.

Concerning the growth of lactic acid bacteria according to the present invention, such bacteria may under their own conditions (see supra) optionally proliferate spontaneously during the sugar or salt/sugar treatment and give the advantageous effects being specified supra. However, it may, as mentioned supra, also be advantageous to add a starter culture of lactic acid bacteria to the meat for ensuring that the growth of other bacteria becomes suppressed through selection and competition with the lactic acid bacteria. Such a starter culture may be added to the meat before or after the removal of the exudate in the open treatment mode or simultaneously with the addition of the sugar or salt/sugar mixture in the closed system mode. A starter culture of lactic acid bacteria according to the present invention may optionally originate from earlier fermentations, e.g. through the addition of fluid from the closed system - ferrmentation bags/containers. The exudate from the open sugar treatment process may also be suitable as a medium for growth of a starter culture of lactic acid bacteria according to the present invention. Alternatively there may be made separate bacterial cultures from a suitable growth medium containing nutrients and optional growth factors for the selected lactic acid bacteria. Also growth conditions such as pH and temperature is adjusted for a suitable growth of the lactic acid bacteria according to the invention. The volume of starter culture that is to be added will normally lie in the interval 1-10 ml and is not critical since the growth of lactic acid bacteria only needs an initial push for survival in for inhibiting the growth of other bacteria in the system.

For obtaining a better control with a raking process using an openly sugar-treated meat or sugar- treated meat in a closed process (see supra), there is a need for optimizing the conditions for growth of the relevant lactic acid bacteria with the particular features , and optionally in addition add a starter culture of such bacteria for ensuring that the relevant lactic acid bacteria out- compete the other unwanted bacteria during fermentation.

Particularly such bacteria, that my be used for fermentation under a soft vacuum or in a modified atmosphere, at low temperatures (0-28°C, preferably 0-10°C) and at a salt concentration, belong to the family Leuconostoc or Gemella, especially Leuconostoc, and more particularly the most useful lactic acid bacterium Leuconostoc mesenteroides. Bacteria of the family Gemella are normally Gemella morbillorum. The relevant bacteria may also ferment meat at a relatively low water activity (down to 0,6).

When adding sugar a possible way to do this is by using several different sugar types on top of each other. In an open sugar treatment the raw material (meat) is e.g. placed on a suitable surface/screen and there is sprinkled on a mixture of 4 sugar species in the form of first saccharose (sprinkle sugar, coarse type), then saccharose (powdered sugar, fine type), then powder of fructose (fruit sugar) and maltose (malt sugar). In an open treatment of the meat this mixture is placed with a free drain in the above indicated number of days in a refrigerating room at the above given temperature. Grain number on the surface of lactic acid bacteria of the type according to the present invention is in the interval 100 million to 1 billion per gram meat product.

After the sugar treatment there may, in this particular embodiment, be added salt (suitable type, not lake salt (nitrite) without anything being done to the raw material, and this laid to diffusion/airing has been obtained. The salt content may in such a product e.g. be about 2 %.

For obtaining a sugar-treated mea product as specified supra, where the meat subsequently to the sugar treatment is subjected to a further processing/treatment (see supra), it will be necessary to add salt as a taste enhancer or as a spice per se (since parts of the taste substances in the meat have been removed through the open sugar treatment).

Also for a post-treatment of such a sugar-treated meat for producing fermented meat wit lactic acid bacteria according to the present invention, it will be necessary to add salt, optionally in addition to other spices/taste additives/taste enhancers. As an example there will be mentioned that a fermented fish product may contain from 0,5 to 10 %(v/v) salt, and a dried product may contain from 0,5 to 10% (v/v) salt. Additionally, on account of the somewhat weak taste of the sugar-treated meat originating from the circumstance that some of the taste substances have been removed via the sugar exudates, it is preferred to add salt to the meat.

Salt may be added already at the initial sugar treatment step of the meat. By adding salt in the initial sugar material/mixture, the salt will penetrate into the meat together with the sugar to a much larger extent than if they had been after the sugar treatment. The meat obtains a salty flavor after the initial sugar treatment step if a salt/sugar mixture is added at the initial treatment step.

Particularly such a sugar/salt mixture may be present in the form of sugar species or mixtures thereof as indicated previously, and the salt may be present in the form of sodium chloride, but also in the form of sea salt or a salt combination or a salt mixture such as a mixture of sodium chloride/potassium chloride/magnesium chloride for reducing the amount of sodium in the salt, may have a ratio between sugar/salt of 20/80 (w/w), more preferred 50/50 (w/w), even more preferred 80/20 (w/w), e.g. 60/40 (w/w) or any ratio between these values. These ratios relate to an open treatment of the meat wherein much the salt as well as the sugar becoming removed via the exudate, and they also relate to a closed treatment with a salt/sugar composition wherein a much smaller amount of salt is used since the-exudate in a closed treatment is not removed before the container (sealed plastic bag) is opened, and consequently wherein particularly the salt component adds a salty taste to the meat. A salt component of at the most 3,5% (w/w calculated from the weight of the meat) is recommended.

The removal of parts of the water from the meat through the sugar treatment (the removal of the exudate) will leave the meat in a condition of low water activity, something which generally also promotes very poorly the growth of bacteria. From this aspect an appearance of the indicated lactic acid bacteria according to the invention is very favorable since they surprisingly grow under such low water activities and low temperatures. Water activities down to 0,6, but also in the interval 0,6-0,9, more preferred 0,6-0,8, such s at a water activity down to 0,7 may promote growth of the lactic acid bacteria according to the invention.

Said fermentation is conducted under a soft vacuum (e.g. 100-500 mm Hg) or in a

modified/inert atmosphere, and the growth of the relevant lactic acid bacteria according to the invention is also surprising under these conditions. Thus it is possible to place sugar-treated pieces of meat that have been subjected to an open sugar or sugar/salt treatment, in plastic bags for further fermentation under a soft vacuum and at refrigerating temperatures. When such an open pre-treated sugar- or sugar/salt-containing meat is fermented, it is, however, not always possible to know the exact amount of sugar or salt that remains in the material before the fermentation.

When adding a bacterial culture of bacteria according to the present invention it will be ensured that despite an uncertain amount of sugar or sugar/salt that remains after such a treatment, the relevant lactic acid bacteria will ensure that the sugar remaining is consumed through the fermentation of the meat. This also represents one of the advantages of the present invention since the relevant lactic acid bacteria will bring possible uncertainties in connection with the fermentation back into controlled conditions for ensuring the quality of the end product (the fermented meat product).

Example 1 (open conditions).

Fresh halves of salmon with an individual weight of 1-4 kg produced according to common practice within the meat industry (cut, de-boned, filleted, etc.) were placed on a screen of polyamide, and their upper surfaces were covered homogenously with a composition of 80 parts by weight of saccharose powder and 20 parts by weight of sodium chloride in an amount so that the composition does not fall off. The saccharose is dissolved together with the salt in the meat juices, and an exudate is formed. This exudate is removed via drainage. After this treatment the meat has a salty taste and is suitable for further treatment for the production of a fermented fish meat product or ground fish meat/surimi that also may be further treated, e.g. dried. This starting material had a water activity of 0,7.

For a further production of fermented, raked fish-tasting end product it was added a starter culture of Leuconostoc mesenteroides with a bacterial count of lxlO⁷ in a volume of 4 ml growth medium comprising an aqueous medium comprising sugar to the sugar-treated meat. The meat and starter culture was placed in a vacuum bag of polyethylene that was placed under a vacuum of 300 mm Hg and was stored at a temperature of 6°C for 20 days. After t he fermentation the bag was opened to find that the meat had become fermented to an edible and good product.

100-500 mm Hg

The treated meat had a distinct, but not overwhelming salty taste. Example 2 (open conditions).

Fresh pieces of thigh from sheep with an individual weight of 5-10 kg prepared according to common practice within the meat industry were placed on a screen of polyamide, and their upper surfaces were covered with a composition of saccharose powder (50% w/w) and sea salt 50% (w/w) so that it does not fall off. The mixture is dissolved in the meat juices, and is drained off as an exudate. After 20 hours with is treatment the salt/sugar-treated meat is ground to a dough with the addition of a spice mixture in an amount of 20 grams. The ground meat is added simultaneously an amount of 20 liters of water to form a smooth material, and this material was added a starter culture of Leuconostoc mesenteroides with a bacterial count of lxlO⁷ in a volume of 4 ml growth medium in an aqueous medium. This material was placed in a vacuum chamber thaw a vacuumed to a pressure of 300 mm Hg and where the temperature was lowered to 4°C. The ground meat was fermented to a raked product during 3 weeks. After this period the bag was opened and the quality of the fermented meat was tested.

Such a fermented ground material may be injected into sausage skins made of intestines with a diameter of 3cm. The sausage skins are knotted into conventional lengths for the creation of sausages of a regular size. These sausages represent a final consumable product.

The sausages have a distinct, but not overwhelming salty taste together with a taste of the spices composition. Furthermore, the sausages have no taste of sugar on account of the increased number of lactic acid bacteria being present in the sausages and that convert the sugar to lactic acid and lactic acid products.

Example 3 (open conditions).

Fresh pieces of thigh from pig (ham) with an individual weight of 1 -2 kg prepared according to common practice within the meat industry were placed on a screen of stainless steel, and their upper surfaces were covered homogenously with a composition of saccharose powder 70% (w/w) and a mixture of sodium chloride/potassium chloride/magnesium chloride (50/48/2) 30% (w/w) so that it does not fall off. The mixture is dissolved in the meat juices, and the formed exudate that is formed is removed. After 3-6 days the sugar-treated meat, that has a water activity of 0,8, is place in a vacuum bag of polyethylene, and it was added a starter culture of Leuconostoc mesenteroides with a bacterial count of lxl 0⁶ in a volume of 3 ml in an aqueous medium. The remaining sugar in the sugar-treated product is sufficient to start a fermentation. The bag is placed under a vacuum of 400 mm Hg for a period of 30 days. From this fermentation there is formed a completely consumable product with good organoleptic properties and with a distinct salty flavor.

Example 4 (open conditions).

Fresh pieces of thigh from pig (ham) with an individual weight of 1-2 kg prepared according to common practice within the meat industry were placed on a screen of polyamide, and their upper surfaces were covered homogenously with a composition of saccharose powder 70% (w/w) and a mixture of sodium chloride/potassium chloride/magnesium chloride (50/48/2) 30% (w/w) so that it does not fall off. The mixture is dissolved in the meat juices, and the formed exudate is removed. After 3-6 days it is formed a product that is treated for further

fermentation. The sugar-treated meat has a water activity of 0,8, and is placed in a vacuum bag of polyethylene, and it was added a starter culture of Leuconostoc mesenteroides with a bacterial count of lxlO⁶ in a volume of 3 ml in an aqueous medium. The remaining sugar in the sugar-treated product is sufficient to start a fermentation. The bag is placed under an atmosphere of 95% nitrogen and 5% carbon dioxide for a period of 30 days. After this time period the completely matured meat has a distinct, but not unpleasant salty taste. No sweet taste was registered in t matured ham, but three was observed an increase in the number of lactic acid bacteria through a cross-section of the ham.

Example 5 (open conditions). Fresh pieces of thigh from pig (ham) with an individual weight of 1-2 kg prepared according to common practice within the meat industry were placed on a screen of polyamide, and their upper surfaces were covered homogenously with saccharose powder so that it does not fall off. The powder is dissolved in the meat juices, and the formed exudate that is formed is removed. Then a starter culture of 3 ml aqueous medium of Leuconostoc mesenteroides is added to the meat. After 3-6 days there is formed a product that is treated further for maturing. After an initial heating to 10-20°C for 1-2 days, the ham is hung for maturing at 6-10°C. The maturing process continues for 4-12 weeks. After this period of time the completely matured meat has a distinct, but not unpleasant salty taste. No sweet taste was registered in the matured ham, but there was registered an increase in the number of lactic acid bacteria through a cross-section of the ham.

Example 6 (closed condition).

Pieces of trout, each with a weight of 1-2 kg, were placed individually in vacuum bags of plastic. In two thirds of the bags there was added a salt/sugar-mixture consisting of 7 g salt (sodium chloride) and 20 g sugar (saccharose). In the last third there was not done any addition. All the bags were closed and subsequently placed under a vacuum of 550 mmHg and placed in a refrigerator at a temperature of +4°C. This vacuum and temperature was maintained for a period of 14 days for half of the sugar/salt-treated bags and for the non-salt/sugar-treated bags. The rest of the bags were separated into two groups, where each group was held under the existing vacuum for a total period of 1 month, and the other for a total period of two months.

To illustrate and document the effect of the development of lactic acid bacteria the results from these tests are presented in table 1 infra for a better overview.

Example 7 (closed condition).

The same test as described in Example 6, but this time for pieces of ham with an individual weight of 2 kg. The results from this test are presented in table 1, infra.

Table 1

Starting material Pre-treatment Storage time Number of lactic acid bacteria

Trout Untreated 14 days l,9xl0⁴ Trout Sugar treated 14 days 2,3x10"

Trout Sugar treated 1 month 7,9x10⁷

Trout Sugar treated 2 months 2,8x10⁷

Ham (pig) Untreated 14 days l,2xl0⁵

Ham (pig) Sugar treated, 2 months l,3xl0⁸

matured

The lactic acid bacteria found in the treated pieces of meat were Leuconostic mesenteroides and Gemella morbillorum.

For the determination of the number of lactic acid bacteria it was made a preparation on MRS- agar (de Man, Rosa, Sharp) over 3 days, micro aerophilic 30°C. The agar contains all the necessary nutrients for growth of lactic acid bacteria. The detection and determination of amount was conducted with a catalase-test (GBA-Food, Staatliche Akkreditierunsstelle, Hannover, Germany). The number of lactic acid bacteria of the type Leuconostoc

mesenteroides was found to be 6,9xl0⁶ number/g for ham and 3,0xl0⁸ for trout.

The above documented rapid development of lactic acid bacteria under the relevant conditions at low temperature and optionally soft vacuum is very surprising, this despite the fact that growth of bacteria occurs under relatively high salt concentration, low temperatures and vacuum.

When the bags with the sugar-treated and lactic acid fermented meat inside are opened after 1 month and 2 months, it was discovered that all of the sugar had become consumed by the lactic acid bacteria to drive the fermentation. All of the meat tasted good with a characteristic taste of suitably fermented meat and with a suitably salty taste. Even the meat had been treated for 14 days had become fermented to an edible product, but the fermentation could have continued for a longer period.

Example 8 (closed system) Pieces of trout, each with a weight of 1-2 kg, were placed individually inside vacuum bags of plastic. The bags were added a salt/sugar mixture consisting of 7 g salt (sodium chloride) and 20 g sugar (saccharose), and a starter culture of lactic acid bacteria of 5 ml was added, where the starter culture consists of an exudates formed in 1 month trout fermentation bags from Example

6. All the bags were closed and subsequently placed under an inert atmosphere of nitrogen (95%) and carbon dioxide (5%) and placed in a refrigerator at a temperature of +4°C. This temperature was maintained for a period of one month. After this treatment period the trout had developed into a well fermented product with good smell and taste properties and that may be consumed directly after opening the vacuum bags.

Example 9 (closed system)

Pieces of ham each with a weight of 1 kg, were placed individually inside vacuum bags of plastic. The bags were added a salt/sugar mixture consisting of 7 g salt (sodium chloride) and 20 g sugar (saccharose), and a starter culture of lactic acid bacteria of 3 ml was added, where the starter culture consists of an exudate formed in 2 months ham fermentation bags from Example

7. All the bags were closed and subsequently placed under a vacuum of 550 mm Hg and placed in a refrigerator at a temperature of +4°C. This vacuum was maintained for a period of 1 month. After this treatment period the ham had developed into a well fermented product with a good smell and taste properties and that could be consumed directly after opening the vacuum bags.

Example 10 (closed system)

Pieces of ham each with a weight of 1 kg, were placed individually inside vacuum bags of plastic. The bags were added a salt/sugar mixture consisting of 7 g salt (sodium chloride) distributed evenly over a layered addition of first 10 g simple sugar species (fructose) at the bottom and 10 g complex sugar species (saccharose) on top, and a starter culture of lactic acid bacteria of 3 ml was added, where the starter culture consists of an exudate formed in 2 months ham fermentation bags from Example 7. All the bags were closed and subsequently placed under a vacuum of 550 mm Hg and placed in a refrigerator at a temperature of +4°C. This vacuum was maintained for a period of 1 month. After this treatment period the ham had developed into a well fermented product with good smell and taste properties and that could be consumed directly after opening the vacuum bags.

Example 11 (closed system) Pieces of ham each with a weight of 1 kg, were placed individually inside vacuum bags of plastic. The bags were added a salt/sugar mixture consisting of 7 g salt (sodium chloride) distributed evenly over a layered addition of first 10 g simple sugar species (fructose and dextrose) at the bottom and 10 g complex sugar species (saccharose in the form of layers of 50/50 sprinkle sugar and sugar granulate, where the sprinkle sugar is placed at the top) on top, and a starter culture of lactic acid bacteria of 3 ml was added, where the starter culture consists of an exudate formed in 2 months ham fermentation bags from Example 7. All the bags were closed and subsequently placed under a vacuum of 550 mm Hg and placed in a refrigerator at a temperature of +4°C. This vacuum was maintained for a period of 1 month. After this treatment period the ham had developed into a well fermented product with good smell and taste properties and that could be consumed directly after opening the vacuum bags.

The developed form of the lactic acid bacterium Leuconostoc mesenteroides that proliferates during the fermentation according to the present invention, can bear more salt than other lactic acid bacteria, simultaneously it can bear more acid, it can bear lower temperatures in the meat and fish during the entire fermentation process, and it can also bear lower water activity in the meat/meat product.

Claims

C l a i m s

1. Lactic acid bacterium being suitable for producing raked/fermented or partially fermented meat, said lactic acid bacterium having the properties of fermenting meat, having a high tolerance for acid conditions (down to pH 1) and being slime-producing while being able to grow at low temperatures (down to 0°C).

2. Lactic acid bacterium according to claim 1, said lactic acid bacterium being able to grow at low water activity down to a water activity of 0,6.

3. Lactic acid bacterium according to claim 1 or 2, said lactic acid bacterium additionally being able to produce vitamin B3 (niacin).

4. Lactic acid bacterium according to claims 1 , 2 or 3, said lactic acid bacterium additionally being able to produce the antibiotic nisin.

5. Lactic acid bacterium according to claims 1 - 4, said lactic acid bacterium being anaerobic, aerobic or facultatively anaerobic.

6. Lactic acid bacterium according to any of the claims 1 - 5, said lactic acid bacterium belonging to the family Leuconostoc or Gemella.

7. Lactic acid bacterium according to claim 6, wherein the lactic acid bacterium is Leuconostoc mesenteroides.

8. Lactic acid bacterium according to claim 6, wherein the lactic acid bactgerium is Gemella morbillorum.

9. The use of a microorganism according to any of the claims 1 - 8 for producing a fermented meat product by treating said meat product with sugar and fermenting at low temperatures and under a soft vacuum or an inert atmosphere.

10. Microorganism starter culture for fermenting a meat product through treating said meat product with sugar and fermenting at low temperatures and under a soft vacuum or an inert atmosphere, wherein said starter vulture comprises lactic acid bacteria according to any of the claims 1 - 8.

1 1. The use of an exudate from meat treated with sugar as a microorganism starter culture according to claim 10.

12. A process for fermenting sugar-treated meat, wherein the meat subsequently to the sugar treatment is placed under anaerobic conditions and at low temperatures, wherein the meat prior to the fermentation is added a sugar composition in the form of successively supplying of simple sugar types at the commencement of the fermentation and subsequently more complex sugar types for creating conditions favoring proliferation of the lactic acid bacteria according to any of the claims 1 - 8.