BE1022587B1 - METHOD FOR INCREASING THE LIFETIME OF FOODSTUFFS WITH AN ANTIMICROBIAL COMPOSITION BASED ON LACTIC ACETIC ACIDS - Google Patents

Abstract

The invention relates to a method for increasing the shelf life of meat or fish food products, while maintaining an acceptable appearance, by treating these products with an antimicrobial composition obtained from a fermentation juice containing lactic acid and traces of acetic acid neutralized with an alkali metal hydroxide and free of all traces of impurities.

Description

A method of increasing the shelf life of food products with an antimicrobial composition based on lactic and acetic acids.

FIELD OF THE INVENTION The invention relates to a method for increasing the shelf life of meat or fish-based food products by adding an antimicrobial composition in the form of salts obtained by fermentation to the matrix. using a non-pathogenic bacterium producing lactic acid and traces of acetic acid. The invention also relates to a method for producing an antimicrobial composition by fermentation.

State of the art At present, many commodities are coming to the end of their shelf-life (DLC) without being consumed, which is why increasing the shelf life of these products is an important issue. .

The main source of degradation of perishable foodstuffs is the growth of microorganisms (bacteria, yeasts, molds). In the case of meat, it is generally accepted that the internal tissues of slaughtered healthy animals do not contain bacteria at the time of slaughter.

On the other hand, fresh meat can be contaminated during cutting, chopping, slicing, external contamination of the digestive system, non-sterile containers or handlers.

It is known to those skilled in the art, as described in EP 482322, EP 1300085 and US 5192565, that organic acids have, for the most part, antibacterial properties, however they can not be used in most of the meat and fish products currently available on the market, because of the final appearance they give to food products.

Indeed, because of the decrease in pH they generate, organic acids significantly reduce the water retention capacity of meat or fish. The food products then obtained do not have a sufficiently presentable appearance and become unacceptable to the consumer. In addition, during the preparation of the cooked products, the loss of water decreases the cooking yield thus inducing at the same time a loss for the food industry at the economic level.

In order to remedy this problem, it has already been proposed to use salts of organic acids having a neutral pH which are preferred for the majority of applications in meat or fish matrices.

Indeed, organic acid salts such as, for example, sodium lactate and potassium lactate (with a neutral pH) are commonly used in various sectors of the food industry and authorized by legislation (eg EU -

Directive 95/2 EC: "quantum satis"), the main outlet being the meat industry. They have a bacteriostatic effect and therefore act as preservatives by inhibiting the growth of microorganisms and more particularly bacteria. However their effectiveness is always limited since the dosage to be implemented is low enough not to change the organoleptic properties (especially the taste) of the product.

Still in the same context, it has already been proposed to use other organic acid salts as cited in US Pat. No. 6,387,427, which describes a method of preserving food products comprising the addition of acetate salts. However, the concentrations used in acetic acid salt that improve conservation have a considerable impact on the taste of the product. Indeed, the dosage used is 0.5% of a product containing 72% of potassium acetate. However, it is known that a dosage greater than 1% of pure potassium acetate generally gives an acetic taste to the product. Potassium acetate is also considered a flavor by the Food and Drug Administration (FDA 172.515 Synthetic flavoring substances and adjuvants).

Brief description of the invention

The products Galaflow SL 60 XT and Galaflow PL 60 XT are respectively the sodium salt and potassium salt of lactic acid and acetic acid of natural origin (resulting from fermentation). Applicant (Galactic) found that the XT version of these salts had a mild taste and had much more effective antimicrobial properties compared to standard sodium / potassium lactate products. A lower dose of 20% can be used without significant impact on parameters such as pH, water activity, color and texture of finished products.

The present invention also relates to a process for producing an antimicrobial composition obtained by fermentation of a carbon substrate using microorganisms, characterized in that: a. The microorganisms of fermentation belong to the genera Lactobacillus, Sporolactobacillus, Brevibacillus, Streptococcus or their mixtures; b. The fermentation is operated under a controlled gas flow; vs. The composition comprises lactic acid and acetic acid neutralized with an alkaline hydroxide

Particular routes of the invention are characterized in that the microorganisms are selected from the species Lactobacillus Casei, Streptococcus Thermophilus,

Sporolactobacillus Inulinus or their mixture.

Description of figures

Figure 1 shows the homo-fermentation pathway leading exclusively to lactic acid.

Figure 2 shows the hetero-fermentative pathway with lactic acid, acetic acid and carbon dioxide.

Figure 3 schematically shows the lactate diffusing into the cell and inhibiting its development.

Figure 4 shows that some bacteria, such as Listeria, produce lactate and acetate in the absence of oxygen.

Figure 5 shows a comparison of the productivity (g / l) of lactic acid (LA) and acetic acid (AA) as a function of the fermentation conditions.

Figure 6 represents a comparison of the lifetime by counting the total number of aerobic bacteria (CFU / g - ISO 4833) as a function of time.

Detailed description of the invention

Galactic uses natural raw materials and high quality to produce its lactic acid which is the basic component for the production of these salts. The lactic acid L (+) of the applicant is obtained by fermentation of a sugar without GMO with the help of a natural microorganism (wild type), non-pathogenic, non-genetically modified, and generally recognized as safe (GRAS ).

Fermentation of lactic acid is carried out by lactic acid bacteria (LAB), which uses sugars in two different ways: • The so-called Embden-Meyerhof homo-fermentative route, which converts sugars into lactate (Figure 1). • a hetero-fermentative pathway that via the phosphoketolase pathway (pentose-phosphate pathway) leads to the production of carbon dioxide, lactate and acetate (Figure 2).

Galactic has surprisingly discovered that it is possible to slightly activate the hetero-fermentative pathway of its production microorganism which is strictly homo-fermentative under normal conditions. Indeed, a precise control of the equilibrium of the gases (oxygen / nitrogen / carbon dioxide) and preferably other parameters of the fermentation step, allows the concomitant production of traces of acetate with the massive production of lactate.

According to a preferred embodiment, the fermentation is carried out under a flow of controlled gas whose gas is composed of oxygen and CO2. More preferably, the gas flow is composed of oxygen (15 to 35%) and CO2 (65 to 85%). More preferably the controlled gas flow is between 0.1 and 0.01 vvm (volume of gas per volume of medium per minute).

The Galaflow SL 60 XT and Galaflow PL 60 XT respectively are the sodium salt and potassium salt of lactic acid and acetic acid of natural origin (neutralization of the acid with an alkali metal hydroxide sodium or potassium) and are much more effective 20% less than the standard sodium and potassium lactate solutions obtained from lactic acid by exclusively homo-fermentation. Indeed, thanks to the concomitant presence of lactate and acetate (in the minority), a double retroactive effect is operated.

To grow, food-borne pathogens and other bacterial contaminations must produce energy (in the form of a molecule called adenosine triphosphate: ATP). When sodium (or potassium) lactate is added to the food, it spontaneously enters bacterial cells and inhibits the chain of enzymatic reactions leading to the production of ATP (eg glycolysis). On the other hand, a process called "homeostasis" takes place whereby cells attempt to remove excess lactate by ion pumps located in their membranes. This survival process requires a considerable energy requirement and therefore a large amount of ATP that will no longer be available to support cell growth (Figure 3).

In their process of energy production and therefore survival and development, certain bacteria, such as Listeria, generate, under anaerobic conditions, both lactate and acetate (Figure 4). Therefore, with the same principle as that described above, the concomitant addition of lactate and traces of acetate provides better protection.

The product resulting from the fermentation will then be, as for the generally marketed sodium and potassium lactates, freed from all traces of impurities by multiple purification steps (ion exchange resins, activated carbons, evaporation, distillation, crystallization or any other techniques well known to those skilled in the art).

The food products, meat or fish, are then brought into contact with a quantity of the antimicrobial composition according to the present invention (as for example Galaflow XT) in order to act on the shelf life of these products. Generally, these amounts are between 1% and 5%, by weight of the product to be treated, of a solution containing from 50 to 70% and preferably from 59.5 to 60.5% lactate and from 0.1 to 1%. , 5% and preferably from 0.5 to 1.0% of acetate. However, other levels or concentrations can be used without affecting the efficiency of the process of the invention, Galactic having demonstrated the effectiveness of its Galaflow XT range in several applications such as sausages, mortadella, etc. Other details and particularities of the invention, given hereinafter by way of non-limiting examples, emerge from the description as some possible forms of its implementation.

Example 1

A culture of Lactobacillus casei was cultured in Bbraun Biostat B reactors on a fermentation medium at 52 ° C. and maintained at pH 6.2 with 25% by weight Ca (OH) 2 milk. The fermentation medium is characterized by the following composition: 100 g / l sucrose, 5 g / l Yeast extract, 0.5 g / l K2HPO4, 0.5 g / l KH2PO4, 0.2 g / l MgSO4.7H2O, 0.03 g / l MnCl2. 4H2O, 1 g / l (NH4) Cl, 0.01 g / l FeCl3.6H2O.

In the context of this example, two cultures were carried out in parallel starting from the medium described above: • Culture A (control): fermentation operated in strict anaerobic (maintained by a nitrogen sky) • Culture B: operated fermentation with a continuous gas addition (25% O2 - 75% CO2) via a diffuser located under the agitator (Rushton turbine) at a controlled flow rate of 0.01 vvm.

In graph 1, we can clearly observe that unlike culture A (control), culture B carried out with continuous addition of gas makes it possible to generate lactic acid (in lactate form) but also a small amount of acetic acid. (in acetate form).

Example 2

A common formulation of a Frankfurter sausage (fine cooked emulsion) was used to prepare two samples with different compositions and preservative levels (reference: Galaflow SL60 traditional sodium lactate -

Test: Galaflow SL60 X):

The sausage of Frankfurt is prepared according to the following procedure:

In a DADAUX 23L DD cutter, add the VSM, pork shoulder and beef. Cuterrer for 1 minute at speed 1. Add half of the water, the nitrite salt, the phosphates and again cuterrer for 1 minute at speed 1. Add the rest of the water and cuterrer 1 minute at speed 1. At speed 2, add the soy protein as well as the starch and cuterrer for 1 minute. Finally, add the pork fat with the spices, ascorbate and preservative and cuterrer at speed 2 until a melting temperature between 12 and 14 ° C.

Place the melee in a pusher and push in peelable casings. In a cooking oven, smoke the sausages at 42 ° C for 1 hour. Then cook to a core temperature of 76 ° C. Cool the sausages in an ice bath and drain in a cold room between 2 and 4 ° C. After draining, peel the sausages and pack them in a plastic bag and vacuum. Store the packages at 4 ° C.

Once a week for a period of 80 days, pH, water activity (Aw) and total number of aerobic bacteria (CFU / g) were evaluated on the samples.

The shelf life of the product prepared with the traditional sodium lactate - Galaflow SL60 (reference) - was compared with that of the product containing new generation sodium lactate - Galaflow SL60 XT (test). The results are shown in graph 2.

Note that the preparation containing sodium lactate at a content of 2.5% (reference) has a shelf life of 65 days (defined as being the time at which the concentration of aerobic bacteria reaches log 6 cfu / g) while the product containing new generation sodium lactate (test) at a content of only 2% has an extended life of 10 days. The advantage is therefore double.

Claims (13)

A process for producing an antimicrobial composition containing lactic and acetic acid salts comprising: (i) fermenting a carbon substrate with microorganisms, and (ii) neutralizing lactic acid and acetic acid from the fermentation with an alkaline hydroxide; characterized in that: (a) the microorganisms of the fermentation belong to the genera Lactobacillus, Sporolactobacillus, Brevibacillus, Streptococcus or mixtures thereof; and (b) the fermentation is operated under a controlled gas flow. 2. Method according to claim 1, characterized in that it comprises at least one step of purification of lactic acid and acetic acid from the fermentation. 3. Process according to claim 2, characterized in that the purification comprises at least one step selected from ion exchange, activated carbons, evaporation, distillation or crystallization. 4. Method according to any one of claims 1 to 3, characterized in that the microorganisms are selected from the species Lactobacillus Casei, Streptococcus Thermophilus, Sporolactobacillus Inulinus or their mixture. 5. Method according to any one of claims 1 to 4, characterized in that the gas flow is composed of oxygen and CO2. 6. Process according to any one of claims 1 to 5, characterized in that the alkaline hydroxide is chosen from sodium hydroxide or potassium hydroxide. 7. Method according to any one of claims 1 to 6, characterized in that the addition in the matrix of the antimicrobial composition obtained allows the increase in the life of meat or fish food products. 8. Process according to any one of claims 1 to 7, characterized in that the antimicrobial composition comprises from 50 to 70% of lactate and from 0.1 to 1.5% of acetate. 9. An antimicrobial composition comprising the sodium salt and / or potassium salt of lactic acid and acetic acid of natural origin obtained by the process according to any one of claims 1 to 8. The antimicrobial composition of claim 9 comprising 50 to 70% lactate and 0.1 to 1.5% acetate. A method of increasing the shelf life of food products comprising adding an amount of the antimicrobial composition of claim 9 or 10 to the food products. 12. The method of claim 11, characterized in that the antimicrobial composition is added in a proportion of 1 to 5% by weight, based on the weight of the product to be treated. 13. The method of claim 11 or 12, characterized in that the food products are food products based on meat or fish.