EP2019051A1 - New packaging for liquid products - Google Patents

Abstract

The package has a permeable material in a form of film, on an exchange surface of the package, where the material is permeable to liquid water and water vapor. The ratio of the exchange surface to a mass of liquid product is 1.2, where co-efficient of permeability of the material to oxygen and coefficient or permeability of the material to carbon dioxide ranges between specific values. A membrane seal is fixed above the package, where the package is in the form of bag. An independent claim is also included for a method for preserving and using a liquid product containing yeast.

Description

FIELD OF THE INVENTION

The present invention relates to the field of packaging and storage of liquid products for food and more particularly relates to a packaging for packaging liquid products containing yeast.

BACKGROUND

Yeast in aqueous suspension is a product particularly sensitive to its storage conditions, especially its environment (temperature, pH, CO ₂ / O _{2 content} ...), and particularly exposed to contamination. It is thus a particularly difficult product to package which therefore requires hygienic storage conditions to maintain both its microbiological quality, its performance especially in terms of ferment power and its organoleptic qualities.

• une surproduction de CO₂ avec une diminution du pH par production de carbonates
• une augmentation de la consommation des sucres de réserve par diminution de la teneur en tréhalose ce qui entraîne une diminution de sa durée de conservation
• une surproduction d'éthanol.

In addition, the storage of yeast in suspension under inappropriate conditions and a variation in its storage conditions have consequences in terms of its metabolism. Thus, the increase in fermental and / or respiratory metabolism causes:

• overproduction of CO ₂ with a decrease in pH by carbonate production
• an increase in the consumption of reserve sugars by reducing the trehalose content, which leads to a reduction in its shelf life
• an overproduction of ethanol.

This can result in a loss of microbiological quality and performance, including fermentability and degradation of its organoleptic qualities.

Its activity and responsiveness, if they are guarantors of its good performance during use, are a specific disadvantage to the preservation of such a product. For its good conservation, it is then desirable in practice to maintain the yeast in aqueous suspension at a low temperature, of the order of 4 ° C and to provide specific degassing means, in particular for the release of the gases produced by the yeast , in particular CO ₂ . Vents orifices have thus been described as specific means of degassing, in the Applicant's patent EP792930B1 and in patent applications WO04048253A1 and WO0202428A1 . It is also desirable to limit the gas exchange (oxygen of the ambient air) in particular to limit the development of contaminants.

These conservation requirements are thus incompatible with the constraints of the so-called consumer market where the act of purchase by the consumer often leads to a break in the cold chain and where the packaging is frequently handled, shaken and knocked over. And, the presence of a vent necessarily above the liquid level makes including handling by the general public difficult.

This is the reason why such a product is currently marketed only to professionals of the bakery.

The Applicant has already described in one of his previous patent applications WO04048253A1 the fresh yeast in aqueous suspension can be stored in a volume of 1 to 100 liters, which is kept in a refrigerated cabinet at a temperature of -2 to 12 ° C. Although this packaging constitutes an important technological advance, the Applicant has found that this solution is not yet fully satisfactory, particularly in the case of yeasts with particularly active metabolisms and / or storage temperatures above 5 ° C and / or when the packaging is shaken. This often requires in practice the installation of an additional vent. A long shelf life of 6 to 8 weeks is not required for this type of packaging as it is aimed at bakery professionals and the yeast cream is intended to be consumed quickly. This conditioning is not intended for general public use, involving conservation for a relatively long period (typically 8 weeks) and storage conditions often involving a break in the cold chain and frequent shaking of the packaging.

It has been described in the patent application WO0202428A1 a packaging provided with a degassing vent, and whose volume is between 0.1 and 100 liters. The packaging object of this application has the same disadvantages as those of the previous document. Again, such packaging is not an adequate and usable solution to meet the constraints of the consumer market.

Packaging solutions have certainly been described in the literature for the packaging of food products such as fruit, vegetables and cheese, but the preservation of these products does not require conditioning that degasses the CO ₂ and / or limits the supply of oxygen, while isolating a product in liquid form from its environment. The water produced during the On the contrary, the preservation of some of these products is very often an undesired product which it is desired to release outside this type of packaging. Also, these packages are not likely to provide usable technical solutions for the packaging of liquid products containing yeast.

Packaging solutions have also been described in the literature for the packaging of soft drinks, but the preservation of these products requires, in this case, a seal to contain the dissolved gas. Also, such packages are not likely to provide usable technical solutions for packaging liquid products containing yeast.

The aforementioned difficulties therefore constitute a brake on the use of yeast in suspension. And, at present, only yeasts in solid form, said pressed or dry for which these issues arise in a different way are offered to the consumer of the consumer market. However, when stored under favorable conditions, yeast suspension has undeniable advantages, including its simplified implementation, its predosage, as well as its good performance which makes it also a product highly appreciated by professionals from the bakery. Similarly, no liquid leavened product possibly containing suspended yeast is currently marketed on the general public market, for the same reasons. Now, again, a liquid product containing yeast type liquid leaven however allows a facilitated implementation and obtaining the characteristics of leavened bread, that is to say the organoleptic intake much sought after by the consumer ( flavor characterized by a sour or acetic scent of the crumb), a bread-specific texture and an extended shelf life. While the market for breadmakers for the general public is changing rapidly, the need for products of this type adapted to consumer requirements is also more pressing.

There is therefore a need for a packaging, especially of reduced volume, suitable for the preservation and maintenance of the qualities of liquid products containing yeast. This packaging is particularly necessary for the preservation of liquid products containing yeast in the context of the so-called consumer market where the act of purchasing the product by the consumer frequently results in a break in the cold chain, or even a true thermal shock.

SUMMARY OF THE INVENTION

The present invention relates to a liquid product packaging containing yeast comprising at least one permeable material whose exchange surface S is such that the S / M ratio is at least 1.2 with S expressed in cm ² and M the mass of the liquid product expressed in g and whose coefficient of permeability CP at O ₂ is between 200 and 9000 cm ³ / m ² .24 hrbar, and / or the coefficient of permeability CP at CO ₂ is between 800 to 45000 cm ³ / m ² .24h.bar.

The invention also relates to the use of such a packaging for containing a liquid product containing yeast.

• conditionnement du produit liquide contenant de la levure dans le conditionnement selon l'invention;
• conservation dudit conditionnement de produit liquide contenant de la levure jusqu'à son utilisation à une température de conservation égale ou inférieure à 15°C, préférentiellement égale ou inférieure à 10°C, puis
• optionnellement exposition à une variation de température pouvant aller jusqu'à 35°C pendant une durée pouvant aller jusqu'à 4h, puis
• utilisation du produit liquide contenant de la levure.

The present invention further relates to a method of preserving and using yeast-containing liquid product comprising the steps of:

• conditioning the liquid product containing yeast in the packaging according to the invention;
• maintaining said yeast-containing liquid product package until it is used at a storage temperature of 15 ° C or less, preferably 10 ° C or less, and then
• optionally exposure to a temperature variation of up to 35 ° C for a period of up to 4 hours, then
• use of the liquid product containing yeast.

DETAILED DESCRIPTION OF EMBODIMENTS

Such packaging makes it possible, surprisingly, to maintain liquid products containing yeast with a swelling which is very acceptable commercially because it is not perceptible, ie the increase in volume remains less than or equal to 50% of the volume. initial in the case of a flexible packaging, or without any deformation of the packaging perceptible and at a storage temperature of up to 15 ° C. The variation of pressure inside the packaging can go up to an increase for example 50 mbar or even up to 100 mbar, likewise, in the case of a rigid packaging (of the type tray with lid for milk or cream of milk for coffee).

• le maintien de la qualité microbiologique, avec une perte de biomasse inférieure à 20% de perte en matières sèches levures, préférentiellement inférieure ou égale à 17%, encore préférentiellement inférieure à 5% en particulier pour le levain liquide; et/ou
• la perte de masse totale inférieure à 20%, préférentiellement inférieure à 10% et encore préférentiellement inférieure ou égale à 5% en poids en particulier pour la crème de levure; et/ou
• de limiter dans la crème de levure le développement des contaminants à un seuil acceptable commercialement, en particulier le développement des bactéries lactiques, des coliformes et/ou des levures non boulangères en particulier pour la crème de levure de boulangerie ; et/ou.
• le maintien des performances, notamment en terme de pouvoir ferment avec une perte de pouvoir ferment inférieure à 50%, de préférence inférieure à 30%, et encore préférentiellement inférieure à 20% par rapport à la valeur initiale sur pâte normale.

In such conditions of conservation, it allows, in addition, after 8 weeks:

• the maintenance of the microbiological quality, with a biomass loss of less than 20% yeast dry matter loss, preferably less than or equal to 17%, more preferably less than 5%, in particular for liquid leaven; and or
• the total weight loss less than 20%, preferably less than 10% and even more preferably less than or equal to 5% by weight, in particular for the yeast cream; and or
• limiting in the yeast cream the development of contaminants at a commercially acceptable level, in particular the development of lactic acid bacteria, coliforms and / or non-baker's yeasts, in particular for baker's yeast cream; and or.
• the maintenance of performance, particularly in terms of power ferment with a loss of power ferment less than 50%, preferably less than 30%, and still preferably less than 20% relative to the initial value on normal paste.

In a particularly interesting way, these advantages are not altered when the packaging is subjected to a break in the cold chain. A deliberately excessive thermal shock simulated at 35 ° C for 4 hours does not cause significant deterioration of the product in terms of microbiological qualities or in terms of performance.

Such packaging finally makes it possible to offer the consumer of the consumer a product with advantageous properties with a deadline of consumption adapted to a distribution chain that can be long as is the case of large and medium surfaces. On average, the packaging according to the invention makes it possible to offer conditions for the preservation of liquid products containing yeast up to 6 weeks, or even 8 weeks, and this, advantageously especially in the case of product storage conditions. general public with possibly breaking the cold chain.

According to the present invention, the term liquid product containing yeast, a liquid suspension, typically an aqueous suspension, comprising yeast. This is usually fresh yeast or dry yeast resuspended. According to a preferred embodiment of the present invention, the yeast is a fresh yeast. Advantageously, said yeast during its packaging comprises at least 10 ⁵ units forming colonies (CFU) of yeast per gram, preferably at least 10 ⁸ units forming colonies (CFU) of yeast per gram, and advantageously at least 10 ⁹ units forming colonies (CFU) of yeast per gram.

The yeast-containing liquid product has a preferential content of at least 0.03% by weight of yeast living cell solids, preferably at least 0.1%, and still more preferably at least 5% by weight. dry matter of yeast.

The packages according to the invention are particularly suitable for the preservation of the yeasts used for their fermentative activity. These include yeasts belonging to the family Saccharomycetaceae (classification of The Yeasts, a taxonomic study, Kurtzman CP and Fell CW, 4th Edition, Elsevier, 1998 ). The invention thus relates mainly to baker's yeasts, but may also relate to oenological, distillery and / or brewery yeasts for which storage problems in liquid form arise.

Oenological, distillery and / or brewery yeasts are preferentially chosen from the genus Saccharomyces , in particular S. bayanus, and S. cerevisiae in particular the varieties uvarum, calbergensis, and cerevisiae , the genus Kluyveromyces especially K. thermotolerans , the genus Brettanomyces especially B. bruxellensis, the genus Torulaspora especially T. delbrueckii , alone or in a mixture.

The baker's yeast is preferably a yeast selected from Saccharomyces cerevisiae , Saccharomyces chevalierii and Saccharomyces boulardii .

The product containing yeast is liquid, that is to say it has a viscosity of less than 20,000centipoise, preferably less than or equal to 1000centipoise, measured at a temperature of about 10 ° C. using a standard viscometer, for example a JP Selecta ST2001 viscometer (L1 = needle, speed = 10 rpm up to a viscosity of 600 centipoise, speed = 1.5 rpm above 600 centipoise) on a 500 ml sample. Baking pastes are typically not liquid products.

The liquid product containing yeast has a density of preferably between 1.01 and 1.25 and preferably between 1.05 and 1.15.

By liquid yeast product, is meant in particular according to the present invention, yeast cream, preferably bakery and liquid leaven.

By yeast cream, preferably bakery, it comprises a liquid suspension, typically an aqueous suspension, living yeast cells preferentially bakery, said suspension having a preferred dry matter content of at least 12% by weight and generally between 12 and 50% by weight (extended definition of yeast cream). Preferably, the liquid yeast cream meets the definition of yeast cream in the strict sense, that is to say that it has a solids content between 12 and 25% by weight, and more preferably between 15 and 25% by weight. and 22% by mass. However, the present invention is also useful for creams of yeast preferably bakery with higher solids content, that is to say at least 25% by weight, such as in particular the creams of yeast bakery said to high density containing one or more osmotic agents, such as for example polyhydroxy food compounds and food salts. Such creams of high density bakery yeast, which can 25 to 48% by weight, or 25 to 46% by weight, are known and are, for example, described in US Pat. WO91 / 12315 and WO03 / 048342 .

By liquid leaven, it is understood according to the invention a liquid suspension, typically an aqueous suspension, living yeast cells preferentially bakery, living cells of lactic acid bacteria and flour. Preferably, the liquid leaven has a solids content of between 12 and 20% by weight, and more preferably between 15 and 17% by weight.

Stable liquid leavens ready for use and suitable for being packaged according to the invention are in particular those described in the Applicant's previous patents. EP0953288-B1 and WO2004 / 080187-A1 .

Advantageously, the liquid leaven is obtained by the use of a culture medium comprising at least one non-malted cereal flour and water, an inoculation with at least one preparation of heterofermentary lactic acid bacteria and at least one less a yeast preparation, preferably by the additional use of at least one malted cereal flour providing amylases or any equivalent source of amylases and / or at least one seeding by a lactic acid bacteria preparation homofermentaires. During its packaging, it thus preferably comprises at least 10 ⁶ colony forming units (CFU) of lactic acid bacteria per gram and at least 10 ⁴ colony forming units (CFU) of yeast per gram, and more preferably at least 10 ⁹ colony-forming units (CFU) of lactic acid bacteria per gram, at least 10 ⁶ colony-forming units (CFU) of yeast per gram, has a stable final pH of between 4 and 4.3 and a solids content between 13 and 20% and preferably contains from 15 to 30 g / kg of lactic acid and from 6 to 10 g / kg of acetic acid. Its realization is precisely described in EP0953288 . The Applicant has described in this patent that the liquid leaven must be preferentially kept between 0 and 4 ° C so that its qualities and performance can be maintained for a shelf life of 6 to 8 weeks. The packaging according to the present invention now allows the storage of liquid leaven at a higher temperature and up to 15 ° C, preferably between 5 and 15 ° C with good maintenance of its microbiological, organoleptic and its qualities. performance for a shelf life of 6 to 8 weeks.

Another ready-to-use ready-to-use leavening liquid leaven according to the present invention comprises a flour-based culture medium containing at least one cereal flour and water, said medium being inoculated and fermented by at least bacteria homofermentaires lactic acid biotransformers and being inoculated with at least one yeast preparation preferably bakery. The ready-to-use liquid paraffin also preferentially comprises at least one malted cereal flour providing amylases or any equivalent source of amylases. It thus comprises 10 ⁸ colony-forming units (CFU) of lactic acid bacteria of which 60% are homofermentary lactic acid biotransformers per gram, at least 10 ⁶ colony-forming units (CFU) of yeast per gram, have a stable final pH understood. between 3.8 and 4.5 and a solids content between 27 and 35%, contains at least 7 g of acetic acid, preferably 15 to 30 g / kg of lactic acid and 7 to 10 g / kg of acetic acid. . Its realization is precisely described in WO2004 / 080187-A1 .

Preferably, the yeasts used for the production of starter are Saccharomyces chevalierii yeasts, and the homofermentary bacteria are those of the species Lactobacillus plantarum and / or casei , the heterofermentary strains are those of the species Lactobacillus brevis.

According to a particularly advantageous mode, the preferably fresh liquid yeast product, in particular the cream of liquid yeast and the liquid leaven, is stabilized by addition of one or more food stabilizers. These stabilizers retard or avoid settling of the yeast cells of the suspension. Due to their presence (s) in the suspension, the liquid product of fresh yeast, preferably yeast cream or liquid leaven retains its homogeneity for a longer time when it is stored without agitation. Among the various dietary stabilizers useful for the stabilization of yeast cream, there may be mentioned gums, such as xanthan gum, and thermally and / or chemically modified starches, such as acetylated diamidon adipate as defined by US Pat. modified starch E1422. Such stabilized yeast creams are for example described in EP-A-0 792 930 .

• Test A1 (levures comprimées fraîches testées en pâte normale):
  • A 20 g de farine incubée à la température choisie pour la mesure, on ajoute un poids de levure comprimée correspondant à 160 mg de matières sèches, cette levure étant délayée dans 15 ml d'eau contenant 27 g de NaCl par litre et 4 g de (NH₄)₂SO₄ par litre ; on malaxe à l'aide d'une spatule pendant 40 secondes, de manière à obtenir une pâte que l'on place au bain-marie réglé à la 30°C; treize minutes après le début du malaxage, le récipient contenant la pâte est fermé hermétiquement ; la quantité totale de gaz produit est mesurée après 60, puis 120 minutes ou plusieurs heures; cette quantité est exprimée en ml à 20°C et sous 760 mm de Hg.
  • Pour toutes les levures susceptibles de donner en 120 minutes un dégagement gazeux égal ou supérieur à 150 ml de CO₂, la quantité de sucres fermentescibles apportée uniquement par la farine est limitante ; en conséquence, le test est modifié de la manière suivante : on ajoute un poids de levure correspondant à 106 mg de matières sèches levure, au lieu de 160 mg, et la lecture de la quantité de gaz produite est par convention multipliée par 1,5.
• Test A₅ (levures comprimées fraîches testées en pâte sucrée).

Preferably, the yeast strains contained in the liquid product have a ferment power on normal paste of between 70 and 190 ml in two hours, preferably between 80 and 160 ml in two hours and still preferably less than or equal to 140 ml in two hours. . The ferment power is measured in accordance with the test described in column 5 of the patent US5741695 performed using a Burrows and Harrison fermentometer in a short baking scheme that can be summarized as follows:

• Test A1 (fresh compressed yeasts tested in normal paste):
  • To 20 g of flour incubated at the temperature chosen for the measurement, a weight of compressed yeast corresponding to 160 mg of dry matter is added, this yeast being dissolved in 15 ml of water containing 27 g of NaCl per liter and 4 g of (NH ₄ ) ₂ SO ₄ per liter; it is kneaded with a spatula for 40 seconds, so as to obtain a paste which is placed in a water bath set at 30 ° C; thirteen minutes after the beginning of the kneading, the container containing the dough is hermetically sealed; the total amount of gas produced is measured after 60, then 120 minutes or several hours; this amount is expressed in ml at 20 ° C and 760 mmHg.
  • For all the yeasts capable of giving, in 120 minutes, a gaseous release equal to or greater than 150 ml of CO ₂ , the quantity of fermentable sugars brought solely by the flour is limiting; accordingly, the test is modified as follows: a yeast weight corresponding to 106 mg yeast dry matter, instead of 160 mg, is added and the quantity of gas produced is conventionally multiplied by 1.5 .
• Test A ₅ (fresh compressed yeasts tested in sweet paste).

Test identical to test A ₁ , but 4 g of sucrose are added to the flour; the total amount of gas produced is measured after 60 minutes and 120 minutes, or several hours.

Preferably, the yeast strains contained in the liquid product do not include the strains with very high ferment capacity on normal paste, that is to say those whose ferment power is greater than 190 ml in 2 hours at 20 ° vs.

Advantageously, the yeast strains used are strains known to be adapted to the presence of weak organic acid, in particular by an adaptation method as described below. The yeast strains have been propagated in the laboratory by conventional methods, with adaptation to the presence of weak organic acid (s), as taught in the patent. US 4,318,991 with addition of 0.1 g to 10 g of short-chain aliphatic carboxylic acids, such as aliphatic carboxylic acids with 2, 3 or 4 carbon atoms, and / or their salts per liter of must.

The yeast strains used may be so-called cold-sensitive strains for producing yeast cream or liquid leaven, as has been described in particular in the patent. EP00878996 .

The yeast or leavening compositions may also contain additives or auxiliaries having a role of bread-making improver and / or a role of maintaining the homogeneity of the suspension. These additives may be oxidizers such as ascorbic acid, reducing agents such as L-cysteine, enzyme preparations having one or more enzymatic activities such as amylase, xylanase, lipase and / or phospholipidase preparations, oxidase such as glucose oxidase. These additives may also be one or more osmotic agents, such as, for example, polyhydroxy dietary compounds and food salts.

The amount of yeast-containing liquid product may vary as long as the characteristics of the package remain respected. According to one embodiment, this is multidose. Preferably, the amount of liquid product containing yeast contained in the packaging corresponds to a product use dose for the production of breadmaking product, that is to say a quantity less than or equal to 100 g and even more preferentially between 20 and 80g. Advantageously, the volume of the product containing yeast is less than 0.1 liter, especially less than or equal to 0.08 liter. Advantageously, the volume of the packaging is less than 0.1 liter.

The invention therefore provides a liquid product package containing yeast, preferably fresh, comprising at least one permeable material whose exchange surface S is such that the S / M ratio is at least 1.2, preferably 1. , 3 with S expressed in cm ² and M the mass of the liquid product expressed in g and whose coefficient of permeability CP at O ₂ is between 200 and 9000 cm ³ / m ² .24 hrbar, and / or the coefficient of permeability CP to CO ₂ is between 800 to 45000 cm ³ / m ² .24h.bar.

Advantageously, the coefficient of permeability to O ₂ is between 800 and 2000 cm ³ / m ² .24 hrbar.

Advantageously, the coefficient of permeability to CO ₂ is between 2400 and 8000 cm ³ / m ² .24 h.bar.

The coefficient of permeability is also referred to as the transmission coefficient of a gas. It is measured in accordance with ISO 14105-2: 2003.

The permeable material is generally impermeable to liquid water and preferably to water vapor. It is also possible to combine materials that provide one with O ₂ / CO ₂ permeability properties and the other with water and / or vapor impermeability properties.

According to the invention, the ratio S / M designates the ratio of the exchange surface S of the material expressed in cm ² relative to the mass M of the liquid product containing yeast expressed in grams. Thus, the surface measurement is made out of the packaging welds. The term "exchange surface" refers to this surface facing the liquid product, directly or indirectly through one or more other layers of higher permeability. The exchange surface may be in contact (direct or indirect) with the liquid product but not necessarily. In particular there may be a "sky" or head space in the packaging, whether flexible or rigid. In a knowledge made of permeable material, the exchange surface is formed by the entire internal surface of the know, excluding welds, the filling factor is maximum or not.

The material having the coefficient of permeability may be internally, in the sandwich, or externally.

Advantageously, the S / M ratio is a value even higher than the coefficient of permeability O ₂ and / or CO ₂ is low. Thus, advantageously, the S / M ratio is at least 1.3, preferably 1.4, advantageously at least 3, preferably between 4 and 12, more preferably between 4.5 and 10.

This makes it possible to obtain a flow of gas adapted to the amount of liquid product and the available surface.

A high permeability coefficient makes it possible to have a low available surface area, and therefore a low S / M ratio. This will apply preferably to solid packs of the tray type with cap, wherein the seal will include the permeable film.

On the other hand, if the coefficient of permeability is rather low, the exchange surface will be larger and the S / M ratio will be higher. This will apply preferably to pouch-type flexible packages in which substantially all of the packaging film will comprise the permeable film.

According to one embodiment, the product (S / M) xCP with O ₂ is between 4000 and 20000, preferably between 5000 and 10000. According to another embodiment, the product (S / M) xCP with CO ₂ is between 15000 and 80000, preferably between 20000 and 40000.

Moreover, depending on the type of conditioned yeast strain, or the composition of the liquid leaven and their respective activities, as well as the storage temperature, the permeability and / or the S / M ratio will be varied.

According to the invention, the coefficients of permeability CP at O ₂ and CO ₂ are defined as the transmission coefficients respectively of oxygen and of carbon dioxide expressed in cm ³ per m ² per 24h per bar (cm ³ / m ² .24h.bar) and measured in accordance with ISO 15105-2: 2003 Annex B by a gas chromatograph katharometric detection method with an injection valve and sampling loop. Prior to the measurement, the material is conditioned for 48 hours at 23 ° C. and at a gas moisture content of 0% RH. The permeability coefficient is measured at a temperature of 23 ° C. with a gas humidity of 0% RH. The outer face of the material is subjected to the test gases and the measurements made on 3 test pieces of 50 cm ² . The test gas consists of a mixture of 50% oxygen and 50% carbon dioxide. The chromatographic detection is carried out using a Porapak® Q detector with a detector temperature of 140 ° C, a filament current of 200mA after calibration of the chromatograph with standard gases with a known concentration of oxygen and carbon dioxide.

For further details in CP low O ₂ coefficient of concentration measurements (ie less than 5000 cm ³ / m ² .24 hrbar), the measurement is performed according to ISO 15105 standards. -2: 2003 Annex A and ASTM D 3985-05 using a Systech 8000 instrument. Prior to measurement, the material is conditioned for 48 hours at 23 ° C and a gas moisture content of 0% RH. The permeability coefficient is measured at a temperature of 23 ° C. with a gas humidity of 0% RH. The outer face of the material is subjected to the test gases and the measurements made with 21% oxygen on 3 test pieces of 0.5dm ² . The stabilization time is 24 hours.

If the detection threshold of the device is reached, it is possible to reduce the O ₂ content of the test gases and / or the measured surface to thus be placed again under detection conditions. It is then sufficient to weight the result obtained by the reduction of the applied content and / or the reduction in the area applied.

For CO ₂ permeability coefficient measurements only, it is also possible to apply the flame ionization detection method on gas chromatograph with injection valve and sampling loop according to ISO 15 105-2. : 2003 Annex B.

The permeable material constituting all or part of the packaging according to the invention is a material generally having gaseous diffusion properties. It does not generally include the materials sought for their porosity and / or microporosity properties, that is to say those that are said porous or microporous because they contain open pores (opening). According to a preferred embodiment, the permeable material is not microporous, in particular is not a microporous material having a pore size of 0.05-5 μm, in particular 0.1-2 μm, with a pore density of 30% or more.

• un conditionnement comprenant au moins un matériau dont la surface est telle que le rapport S/M est d'au moins 3 et dont le coefficient de perméabilité à l'O₂ est comprise entre 800 et 4000 cm³/m².24h.bar. Le coefficient de perméabilité au CO₂ est préférentiellement compris entre 3000 et 15000 cm³/m².24h.bar. De manière particulièrement avantageuse, un tel conditionnement convient particulièrement pour le conditionnement d'une levure liquide ayant une teneur classique en matières sèches, comprise entre 15 et 24% en masse.
• selon un mode de réalisation préféré, un conditionnement comme ci-dessus comprenant au moins un matériau dont la surface est telle que le rapport S/M est compris entre 4 et 10, et dont le coefficient de perméabilité à l'O₂ est compris entre 800 et 2000 cm³/m².24h.bar, préférentiellement entre 1000 et 2000 cm³/m².24h.bar. De manière particulièrement avantageuse, un tel conditionnement convient particulièrement pour le conditionnement d'une levure liquide ayant une teneur classique en matières sèches, comprise entre 15 et 24% en masse et offre les avantages de limiter les odeurs éventuellement perçues de manière désagréable par le consommateur telles que les odeurs d'alcool et certaines notes aromatiques en particulier notes soufrées et phénolées, de permettre une meilleure conservation en terme de stabilité et une remise en suspension facilitée. Le développement des contaminants est en outre réduit avec ce conditionnement.

The Applicant has discovered in a particularly unexpected manner that the following packages are particularly suitable for the packaging of liquid product containing yeast, preferably fresh, and in particular the cream of liquid yeast, preferably bakery:

• a package comprising at least one material whose surface is such that the S / M ratio is at least 3 and whose coefficient of permeability to O ₂ is between 800 and 4000 cm ³ / m ² .24 hr. . The coefficient of permeability to CO ₂ is preferably between 3,000 and 15,000 cm ³ / m ² .24 hrbar. Particularly advantageously, such a packaging is particularly suitable for packaging a liquid yeast having a conventional solids content of between 15 and 24% by weight.
• according to a preferred embodiment, a packaging as above comprising at least one material whose surface is such that the S / M ratio is between 4 and 10, and whose coefficient of permeability to O ₂ is between 800 and 2000 cm ³ / m ² .24 hrbar, preferably between 1000 and 2000 cm ³ / m ² .24 hrbar. Particularly advantageously, such a packaging is particularly suitable for the packaging of a liquid yeast having a conventional solids content, of between 15 and 24% by weight and offers the advantages of limiting the odors possibly perceived in an unpleasant manner by the consumer. such as alcohol smells and some aromatic notes especially sulfur and phenol notes, to allow a better conservation in terms of stability and a facilitated resuspension. The development of contaminants is further reduced with this conditioning.

• un conditionnement comprenant au moins un matériau dont la surface est telle que le rapport S/M est d'au moins 6 et dont le coefficient de perméabilité à l'O₂ est compris entre 400 et 4000 cm³/m².24h.bar, préférentiellement 400 et 1000 cm³/m².24h.bar.
• un conditionnement comprenant au moins un matériau dont la surface est telle que le rapport S/M est d'au moins 1,2, préférentiellement 1,3 et dont le coefficient de perméabilité à l'O₂ est compris 1000 et 8000 cm³/m².24h.bar, de préférence entre 3000 et 7000 cm³/m².24h.bar, plus préférentiellement 4000 et 6500 cm³/m².24h.bar. Le coefficient de perméabilité en CO₂ est préférentiellement compris entre 4000 et 24000 cm³/m².24h.bar. De manière particulièrement avantageuse, un tel conditionnement convient particulièrement pour le conditionnement d'une levure liquide à teneur en matières sèches plus élevée, c'est-à-dire d'au moins 25% en masse, en particulier les crèmes de levure de boulangerie dite à haute densité (teneur en matières sèches comprise entre 25 à 46% en masse) contenant un ou plusieurs agents osmotiques, tels que par exemple les composés polyhydroxy alimentaires et les sels alimentaires.

These above packages are suitable for application in the form of sponges, preferably skins containing less than 100 g, in particular between 20 and 80 g of liquid product containing fresh yeast.

• a packaging comprising at least one material whose surface is such that the S / M ratio is at least 6 and whose coefficient of permeability to O ₂ is between 400 and 4000 cm ³ / m ² .24 hr. preferably 400 and 1000 cm ³ / m ² .24 hrbar.
• a packaging comprising at least one material whose surface is such that the S / M ratio is at least 1.2, preferably 1.3, and whose permeability coefficient at O ₂ is between 1000 and 8000 cm ³ / m ² .24 hrbar, preferably between 3000 and 7000 cm ³ / m ² .24 hrbar, more preferably 4000 and 6500 cm ³ / m ² .24 hrbar. The coefficient of permeability of CO ₂ is preferably between 4000 and 24000 cm ³ / m ² .24 hrbar. Particularly advantageously, such a packaging is particularly suitable for packaging a liquid yeast with a higher solids content, that is to say at least 25% by weight, in particular creams of baker's yeast. said high density (solids content between 25 to 46% by weight) containing one or more osmotic agents, such as for example polyhydroxy food compounds and food salts.

This packaging immediately above is suitable for application in the form of stains, preferably of the skins containing at least 100 g, in particular between 200 and 1200 g of liquid product containing fresh yeast, more particularly about 500 g.

The packs that are the subject of the invention exhibit improved preservation, especially during cold chain break in the order of 2 to 8 hours.

According to a first embodiment, the packaging according to the invention is entirely flexible and / or deformable. This is an undeniable advantage of the present invention because the problem of the diffusion of CO ₂ with risk of deformation or bursting of the packaging is maximum in this form. Indeed, a flexible and / or deformable packaging lacks strength, changes shape during handling, and thus exposes a larger surface in contact with the liquid product containing yeast, which can then suddenly change the diffusion properties packaging and the storage conditions of the product. A planar shape also offers a large exchange surface with the ambient atmosphere and therefore with air containing oxygen and maximizes the risks of poor conservation. A packaging according to the invention, by its permeability coefficients and its S / M ratio, then allows good preservation of the liquid product containing yeast, preferably fresh.

The packaging according to the invention is preferably in the form of a known.

By way of example according to the invention, one can envisage a knowledge for a content of liquid product containing the yeast of about 500 g, and whose dimensions (excluding welds) would be about 15 cm x 23 cm. The invention therefore relates to these sheets having dimensions (excluding welds) 12-18cmx18-25cm.

By way of example again, it is possible to envisage a solution for a content of about 40 g of liquid product containing yeast, and whose dimensions (excluding welds) would be about 7.5 cm × 12.5 cm. The invention therefore relates to these bags having dimensions (excluding welds) 6-9cmx1 1-14cm.

According to a second embodiment, the packaging according to the invention is rigid on a part of its surface exposed in contact with the liquid product containing yeast, preferably fresh. The exchange surface defined by the material may for example be fixed above to form a flexible seal, in particular an opening cap. This embodiment corresponds to the presentation of a unit dose or a multi-dose packaging of cream for example to form a pot with a lid. This mode corresponds for example to a pot having a cylindrical shape of inner diameter of 5 to 15cm and a height of 2 to 5cm.

According to a preferred embodiment, the packaging comprises the permeable material over its entire exchange surface. According to an alternative embodiment, the packaging, preferentially flexible and / or deformable consists of two or more materials of different types, and possibly different permeability coefficients, that is to say that the exchange surface comprises two or several parts of distinct surfaces. We can then define a mean permeability coefficient as the surface average of the permeability coefficients of the different parts. By way of example for two surfaces S1 and S2 having two coefficients CP1 and CP2, the average coefficient will be defined as (CP1S1 + CP2S2) / (S1 + S2).

Particularly advantageously, the material is chosen from the class of synthetic polymers, in particular polyolefins and PET and organic films.

Of the synthetic polymers, the most suitable materials are polyolefins, in particular polypropylene, which is preferentially oriented, polyethylene which is preferentially uncoated, linear low density PE (LDPE), linear or not, high density PE (HDPE), linear or otherwise. and polymers selected from certain PET polyester grades and / or in low thicknesses.

By organic films is meant according to the invention in particular the biodegradable polymers. Examples are cellulose films, starch-based films, protein-based films, optionally supplemented with plasticizer and synthetic polymers. These biodegradable materials are preferably used in complexes, in combination with a material which gives the packaging impermeability to water and / or water vapor.

The coefficient of permeability can be adjusted according to the nature of the polymer used (or a mixture of polymers or several layers of polymers where appropriate) and the thickness of the polymer film, the diffusion being a function of the film thickness, process parameters (for example corona treatment or not). A conventional thickness is between 5 and 100 μm, typically about 10 to 50 μm.

Advantageously, the permeable material is in film form and / or in complexed form.

The packaging according to the invention may comprise an impression on its outer face and / or on one side of an inner film; the coefficient of permeability is determined for conditioning in its final form, with printing (taking into account the totality of the surface and determining an average coefficient).

According to a preferred embodiment, the material is complexed with other materials whose permeabilities with O ₂ and CO ₂ are greater than those of the material and whose function is to bring additional qualities to the complex, such as for example to improve the behavior of the packaging, in particular its rigidity, its machinability, its feel, its ability to open, and to provide a more suitable printing medium including varnishes.

The material may be disposed at any layer, i.e. at the inner surface in contact with the yeast-containing liquid product, at the intermediate layer or at the level of the layer external.

The material can be combined with other materials by conventional calendering, complexing, coextrusion and plaxing techniques known to those skilled in the art.

Examples of preferred carriers are papers such as Kraft paper, other polyolefins such as polyethylene, polypropylene, or porous / microporous materials.

A particularly interesting material according to the invention consists of a multilayer OPP / Kraft / PE paper laminate, the OPP material being the material having the lowest coefficient of permeability.

According to an advantageous embodiment, the packaging is provided with means for closing it after use and use the product later. In particular, a resealable package can be provided. In this case, the operculum contains a pressure-sensitive adhesive which is discovered during the first use by tearing along the weld seam. This type of packaging is known for example from the patent WO-A-9719867 and patent applications on behalf of Soplaril citing this application. The package may also be provided with a slide strip.

Preferably, the packaging according to the invention does not comprise a vent.

The present invention also relates to the use of a packaging as defined above to maintain a liquid product containing yeast, preferably fresh. Such a packaging is more particularly used at temperatures below 15 ° C, preferably between 4 ° C and 15 ° C and allows good storage for at least 4 weeks, preferably at least 6 weeks, and still preferably 8 weeks or more.

Under these conditions of preservation, such a packaging can, in addition, be used with a potential temperature variation of up to 35 ° C for a maximum period of 8 hours, and preferably for 4 hours, and even more preferably up to 20 ° C for a maximum period of 2h.

• conditionnement du produit liquide contenant de la levure dans le conditionnement selon l'invention, préférentiellement 5 jours ou moins après sa production, puis
• conservation dudit conditionnement de produit liquide contenant de la levure jusqu'à son utilisation à une température de conservation égale ou inférieure à 15°C, préférentiellement égale ou inférieure à 10°C, puis
• optionnellement exposition à une variation de température pouvant aller jusqu'à 35°C pendant une durée pouvant aller jusqu'à 4h, préférentiellement pouvant aller jusqu'à 20°C pendant une période maximale de 2h, puis
• utilisation du produit liquide contenant de la levure.

The subject of the invention is also a process for preserving and using a liquid product containing yeast, preferably fresh and preferentially baked, comprising the following steps:

• conditioning of the liquid product containing yeast in the packaging according to the invention, preferably 5 days or less after its production, then
• maintaining said yeast-containing liquid product package until it is used at a storage temperature of 15 ° C or less, preferably 10 ° C or less, and then
• optionally exposure to a temperature variation of up to 35 ° C for a duration of up to 4h, preferably up to 20 ° C for a maximum period of 2h, then
• use of the liquid product containing yeast.

• conditionnement du produit liquide contenant de la levure, préférentiellement fraîche, de préférence 5 jours ou moins après sa production, puis
• conservation dudit conditionnement de produit liquide contenant de la levure pendant son transport à une température comprise entre 0 et 15°C, préférentiellement environ 4°C, puis
• conservation à une température comprise entre 0 et 15°C, préférentiellement entre 8 et 10°C pendant au moins 2 semaines, préférentiellement de 4 à 8 semaines, et encore de préférence de 4 à 6 semaines depuis le conditionnement du produit contenant de la levure puis
• optionnellement exposition à une variation de température pouvant aller jusqu'à 35°C pendant une durée pouvant aller jusqu'à 4h, préférentiellement pouvant aller jusqu'à 20°C pendant une période maximale de 2h puis
• utilisation du produit liquide contenant de la levure, de préférence au plus tard à 8 semaines depuis le conditionnement du produit contenant de la levure.

According to an embodiment of said method, said method comprises the following steps:

• conditioning the liquid product containing yeast, preferably fresh, preferably 5 days or less after its production, then
• preservation of said liquid product package containing yeast during its transport at a temperature between 0 and 15 ° C, preferably about 4 ° C, and then
• storage at a temperature between 0 and 15 ° C, preferably between 8 and 10 ° C for at least 2 weeks, preferably from 4 to 8 weeks, and more preferably from 4 to 6 weeks from the packaging of the product containing yeast then
• optionally exposure to a temperature variation of up to 35 ° C for a duration of up to 4 hours, preferably up to 20 ° C for a maximum period of 2 hours then
• use of the liquid product containing yeast, preferably no later than 8 weeks since the packaging of the product containing yeast.

Preferably, after exposure to a temperature variation of up to 35 ° C for a duration of up to 4 hours, preferably up to 20 ° C for a maximum period of 2 hours, the conditioning of liquid product containing yeast, preferably fresh is stored again until use at a temperature between 0 and 15 ° C, preferably between 6 and 10 ° C.

The liquid product containing baker's yeast is used for the production of a bread-making product. It can be directly in flour bakery products, in short or long baking scheme. It is thus used for making pizzas, French type breads, Viennese pastries, etc ...

The liquid product containing yeast, brewery and / or distillery can be used for seeding the fermentation and / or propagation medium.

The invention also allows the realization of specific association. Indeed, consumers appreciate that products are available in a pre-cooked way, to facilitate the preparation of the dish. The invention thus also offers the combination of a packaging according to the invention with one or more of the other ingredients of the food preparation, including bread improvers, a certain amount of flour and other pre-cooked ingredients. The following examples are provided to illustrate the invention and should in no way be considered as a limit to the scope of the invention.

EXAMPLES • Trial 1: Monitoring of different yeast cream packs at 8-10 ° C for 8 weeks 1. Material:

Preservation in different types of packaging was followed for 8 weeks at a fixed temperature of 8 to 10 ° C.

• souples sous forme de saches de dimensions (8.5cm-0.8cm correspondant au retrait des soudures)x(13cm-0.8cm correspondant au retrait des soudures)x 2 faces soit une surface hors soudure de 187.9cm²
• rapport S/M = 4.7
• crème de levure de boulangerie stabilisée à 19% MS dosée à 40g par sache conditionnée 4jours après sa fabrication et conservée à 8-10°C pendant 4 semaines

All yeast cream packs tested have the following characteristics:

• flexible in the form of stains of dimensions (8.5cm-0.8cm corresponding to the withdrawal of welds) x (13cm-0.8cm corresponding to the withdrawal of welds) x 2 faces or a solderless surface of 187.9cm ²
• S / M ratio = 4.7
• 19% MS stabilized baker's yeast cream dosed at 40g per sachet packaged 4 days after manufacture and stored at 8-10 ° C for 4 weeks

By internal layer in the multilayer complexes is meant the layer exposed in contact with the yeast cream.

• conditionnement 1 : complexe tricouche contenant une feuille d'aluminium, étanche, comparable à ceux utilisés pour le conditionnement de levure sèche en vermicelles.
• conditionnement 2 : sache constituée d'un matériau polymère présentant un débit d'air supérieur à 0,1 Nlitre/heure/cm² sous une ΔP de 12mbar.
• conditionnement 3 selon l'invention : sache constituée d'un matériau en complexe bicouche, constitué d'une couche externe en papier Kraft 45g/m2 collée à une couche interne polypropylène (PP cast) d'épaisseur 25µm ; coefficient de perméabilité O₂ de 380 cm³/m².24h.bar.
• conditionnement 4 selon l'invention : sache constituée d'un matériau de polyèthylène PE d'épaisseur 40µm; coefficient de perméabilité O₂ de 3500 cm³/m².24h.bar; coefficient de perméabilité CO₂ de 25 400 cm³/m².24h.bar.
• conditionnement 5 selon l'invention : sache entièrement constituée d'un complexe bicouche constitué d'une couche externe Kraft 60g/m² enduit d'une couche interne de polyéthylène PE 20g/m² ; coefficient perméabilité O₂ de 8 400 cm³/m².24h.bar; coefficient perméabilité CO₂ de 45 000 cm³/m².24h.bar.
• conditionnement 6 selon l'invention : sache entièrement constituée d'un complexe bicouche constitué d'une couche externe de polypropylène orienté coextrudé OPP d'une épaisseur de 20µm collée à une couche interne de polyéthylène PEBD linéaire d'épaisseur 20µm ; coefficient de perméabilité O₂ de 1570 cm³/m².24h.bar; coefficient de perméabilité CO₂ de 7600 cm³/m².24h.bar.
• conditionnement 7 selon l'invention : sache entièrement constituée d'un complexe multicouche constitué d'une couche externe de polypropylène orienté OPP d'une épaisseur de 20µm collé à une couche intermédiaire de papier Kraft 22g/m² enduit d'une couche interne de polyéthylène PE 6g/m²; coefficient de perméabilité O₂ de 1600 cm³/m².24h.bar; coefficient de perméabilité CO₂ de 5 400 cm³/m².24h.bar
• conditionnement 8 selon l'invention : sache entièrement constituée d'un complexe multicouche constitué d'une couche externe de polypropylène orienté OPP d'une épaisseur de 20µm collé à une couche intermédiaire de papier Kraft 45g/m² enduit d'une couche interne de polyéthylène PE 15g/m² ; coefficient de perméabilité O₂ de 1630 cm³/m².24h.bar.
• conditionnement 9 selon l'invention : sache entièrement constituée d'un complexe multicouche constitué d'une couche externe de polypropylène orienté OPP d'une épaisseur de 20µm collé à une couche intermédiaire de papier Kraft 40g/m² collé à une couche interne de polyéthylène PEBD 20 µm; coefficient de perméabilité O₂ de 1350 cm³/m².24h.bar.

The following packages have been tested:

• packaging 1: three-layer complex containing an aluminum foil, waterproof, comparable to those used for the packaging of dry yeast in vermicelli.
• conditioning 2: made of a polymer material having an air flow rate greater than 0.1 Nlitre / hour / cm ² under a ΔP of 12mbar.
• packaging 3 according to the invention: made of a bilayer complex material, consisting of an outer layer of 45g / m2 Kraft paper bonded to a polypropylene inner layer (PP cast) 25μm thick; coefficient of permeability O ₂ of 380 cm ³ / m ² .24 hrbar.
• packaging 4 according to the invention: made of a polyethylene PE material of thickness 40 .mu.m; coefficient of permeability O ₂ of 3500 cm ³ / m ² .24 hrbar; CO ₂ permeability coefficient of 25 400 cm ³ / m ² .24 hrbar.
• packaging 5 according to the invention: entirely composed of a bilayer complex consisting of an outer layer Kraft 60g / m ² coated with an inner layer of polyethylene PE 20g / m ² ; permeability coefficient O ₂ of 8 400 cm ³ / m ² .24 hrbar; CO ₂ permeability coefficient of 45,000 cm ³ / m ² .24 hrbar.
• packaging 6 according to the invention: entirely composed of a bilayer complex consisting of an outer layer of OPP coextruded oriented polypropylene of a thickness of 20 .mu.m glued to an inner layer of linear LDPE polyethylene of thickness 20 .mu.m; coefficient of permeability O ₂ of 1570 cm ³ / m ² .24 hrbar; CO ₂ permeability coefficient of 7600 cm ³ / m ² .24 hrbar.
• packaging 7 according to the invention: entirely composed of a multilayer complex consisting of an outer layer of OPP oriented polypropylene of a thickness of 20 .mu.m glued to an intermediate layer of Kraft paper 22g / m ² coated with an inner layer of polyethylene PE 6g / m ² ; O ₂ permeability coefficient of 1600 cm ³ / m ² .24h.bar; CO ₂ permeability coefficient of 5 400 cm ³ / m ² .24 hr.
• packaging 8 according to the invention: entirely composed of a multilayer complex consisting of an outer layer of OPP oriented polypropylene of a thickness of 20 .mu.m glued to an intermediate layer of 45g / m ² Kraft paper coated with an inner layer of polyethylene PE 15g / m ² ; O ₂ permeability coefficient of 1630 cm ³ / m ² .24h.bar.
• packaging 9 according to the invention: entirely composed of a multilayer complex consisting of an outer layer of polypropylene oriented OPP of a thickness of 20 .mu.m glued to an intermediate layer of 40g / m ² Kraft paper bonded to an inner layer of polyethylene LDPE 20 μm; coefficient of permeability O ₂ of 1350 cm ³ / m ² .24 h.bar.

The quality of the yeast cream is determined after 8 weeks of storage at 8-10 ° C by observing the appearance of the cream, its microbiology and its weight.

The performances correspond to fermentative force measurements on normal and sweet dough (application in breadmaking on French bread and brioche), changes in dry matter content, ethanol and trehalose dosage.

The other parameters of use correspond to the evaluation of the swelling, the odor, the decantation and the emptying capacity of the cream apart from its packaging.

2. Results:

Conditioning Quality of the cream performances Other usage parameters comments 1 witness ND ND o (bursting) 2 witness o (parched) ND o (very difficult draining) 3 invention x x o (slight swelling) 4 invention x x x alcohol odors (phenol notes) Invention x x o (slight settling) alcohol odors (phenolic notes) no swelling 6 invention x x x 7 invention x x x 8 invention x x x 9 invention x x x ND = not determinable
o = unsatisfactory results
x = satisfactory results

With regard to packaging 1, it should be noted that the bursting of the skins was also observed at storage temperatures of 4 ° C. and 20 ° C. The internal pressure caused by the accumulation of the gases produced by the yeast (CO ₂ and ethanol) causes in less than 2 weeks the rupture of the welds of the stains.

With regard to the packaging 2, a loss of 80% of the initial mass is obtained after 2 weeks of storage. The loss of biomass is such that no measure of performance is possible.

With regard to the packaging 3, a slight swelling was observed.

The packages according to the invention have acceptable performance in terms of fermenting force tested on baking dough. The loss of fermenting force after 6 weeks with the packs according to the invention is less than or equal to 50% of normal paste, and remains acceptable for use in sweet dough. In addition, irrespective of the breadmaking scheme used, the liquid products preserved in the packages according to the invention gave very satisfactory bread-making products.

3. Conclusion:

Packs 1 and 2 can not be stored under consumer market conditions, particularly at 8-10 ° C. The packs according to the invention are the only ones which allow a conservation of the qualities during the conservation phase at 8 ° -10 ° C., that is to say in accordance with the conditions of the general public market without breaking the cold chain. . Such packaging after 8 weeks of preservation without breaking the chain of cold therefore make it possible to restore to the consumer the qualities of the yeast cream in a very acceptable manner. The packages 6 to 9 are those that give the best results especially because they limit the settling and allow a good emptying of the cream during use. In addition, no smell of alcohol is perceptible by the consumer with these packaging. The packages 6, 8 and 9 are those which also have the best machinability (weld strength).

• Test 2: Variation of S / M ratio and storage conditions

Under the conditions of the aforementioned test 1, the S / M ratio was varied for 3 packages, the packages 3, 4 and 9. The storage conditions were also varied.

The results are shown in the table below, a slight swelling or medium swelling still being acceptable, although it is preferred to avoid such swelling. Swelling S / M Type of complex 3 weeks at 4 ° C 10 ° C (*) 20 ° C (**) 1.61 4 no way way 3.22 4 no no no 3.22 9 no no way 4.7 4 no no no 4.7 9 no no no 9.9 4 no no no 9.9 9 no no no 9.9 3 no no way (*): Heat treatment applied: 2 weeks at 4 ° C + 1 week at 10 ° C OR 1 week at 4 ° C + 2 weeks at 10 ° C
(**): Heat treatment applied: 1 week at 4 ° C + 2 weeks at 20 ° C OR 1 week at 4 ° C + 1 week at 10 ° C + 1 week at 20 ° C

• Trial 3: Monitoring of various yeast cream packs at 8-10 ° C with a consumer market simulation for 8 weeks

The examples according to the invention 4 and 9 are compared. The S / M ratio is always 4.7.

• 8 semaines à 8-10°C avec application d'un choc thermique de température de 35°C pendant 4 heures à 4 semaines. L'analyse est ainsi effectuée 8 semaines après le conditionnement de la crème de levure.

The storage conditions after conditioning of the baker's yeast cream are as follows:

• 8 weeks at 8-10 ° C with application of a temperature shock of 35 ° C for 4 hours to 4 weeks. The analysis is thus carried out 8 weeks after the conditioning of the yeast cream.

• la perte en matière sèche (en pourcentage par rapport à la valeur initiale lors du conditionnement).
• la teneur en alcool (teneur en g/l en éthanol).
• la teneur en tréhalose (teneur en pourcentage de matières sèche en tréhalose).
• la force fermentaire (application en panification sur pain de type français et brioche).
• les autres paramètres d'utilisation (l'évaluation du gonflement, de l'odeur, de la décantation et des capacités de vidange de la crème en dehors de son conditionnement).

The following parameters were then evaluated:

• the dry matter loss (as a percentage of the initial value during conditioning).
• the alcohol content (g / l content in ethanol).
• the trehalose content (percentage content of dry matter in trehalose).
• fermentary strength (application in breadmaking on French type bread and brioche).
• the other parameters of use (the evaluation of the swelling, the odor, the decantation and the emptying capacity of the cream apart from its packaging).

The packaging 4 does not show any swelling of the bag, but there is an odor of alcohol (a lower ethanol content than the packaging 9 being noted in the liquid product, difference of about 32%), a loss of biomass more important than conditioning 9, higher loss of trehalose (greater trehalose loss in package 4 than in packaging 9, difference of about 15%), and greater contamination (non-baker type yeast contaminants) and / or bacteria). The stability of fermentary performance is slightly higher with the packaging 9 compared with the packaging 4.

These results show that these two packages are suitable for general public use, the packaging 9, however, having better results than the packaging 4.

Claims (36)

Packaging liquid product containing yeast comprising at least one permeable material whose exchange surface S is such that the S / M ratio is at least 1.2, with S expressed in cm ² and M the mass of the product liquid expressed in g and whose coefficient of permeability CP at O ₂ is between 200 and 9000 cm ³ / m ² .24 hrbar, and / or the coefficient of permeability CP at CO ₂ is between 800 to 45000 cm ³ / m ² .24h.bar. Packaging according to claim 1 wherein the coefficient of permeability CP to TO ₂ is between 800 and 2000 cm ³ / m ² .24h.bar. Packaging according to claim 1 or 2 wherein the coefficient of permeability CP to CO ₂ is between 2400 and 8000 cm ³ / m ² .24h.bar. Packaging according to one of claims 1 to 3 wherein the S / M ratio is at least 1.3 preferentially 1.4. Packaging according to one of claims 1 to 4 wherein the S / M ratio is at least 3, preferably between 4 and 12, more preferably between 4 and 10. Packaging according to one of claims 1 to 5 wherein the product (S / M) xCP O ₂ is between 4000 and 20000, preferably between 5000 and 10000. Packaging according to one of claims 1 to 6 wherein the product (S / M) xCP CO ₂ is between 15000 and 80000, preferably between 20000 and 40000. Packaging according to one of claims 1 to 7 wherein the S / M ratio is at least 3 and the coefficient of permeability to O ₂ is between 800 and 4000 cm ³ / m ² .24h.bar. Packaging according to the preceding claim, wherein the coefficient of permeability to CO ₂ is between 3000 and 15000 cm ³ / m ² .24h.bar. Packaging according to one of claims 1 to 7 wherein the S / M ratio is between 4 and 10, and the coefficient of permeability to O ₂ is between 800 and 2000 cm ³ / m ² .24h.bar, preferably between 1000 and 2000 cm ³ / m ² .24 hrbar. Packaging according to one of claims 1 to 7 wherein the S / M ratio is at least 6 and the coefficient of permeability to O ₂ is between 400 and 4000 cm ³ / m ² .24h.bar, preferably 400 and 1000 cm ³ / m ² .24h.bar. Packaging according to one of claims 1 to 7 wherein the S / M ratio is at least 1.2, preferably 1.3 and the coefficient of permeability to O ₂ is 1000 and 8000 cm ³ / m ² .24 hrbar, preferably between 3000 and 7000 cm ³ / m ² .24 hrbar, more preferably 4000 and 6500 cm ³ / m ² .24 hrbar, and / or advantageously the coefficient of permeability of CO ₂ is preferably between 4000 and 24000 cm ³ / m ² .24 hrbar. Packaging according to one of claims 1 to 12 characterized in that it is flexible and / or deformable. Packaging according to claim 13, in the form of a know. Packaging according to claim 14, in the form of a size know welds 12-18cmx18-25cm. Packaging according to claim 14, in the form of a non-weld dimensional note 6-9cmx1 1-14cm. Packaging according to one of claims 1 to 12 characterized in that it is rigid and comprises a flexible cover fixed on it. Packaging according to Claim 17, characterized in that it has a cylindrical shape with an inside diameter of 5 to 15 cm and a height of 2 to 5 cm. Packaging according to one of the preceding claims wherein the packaging comprises said permeable material over its entire exchange surface. Packaging according to one of the preceding claims wherein the permeable material is in film form and / or in complexed form. Packaging according to one of the preceding claims wherein the permeable material has a thickness between 5 and 100μm, preferably about 10 to 50μm. Packaging according to one of the preceding claims wherein the permeable material is selected from synthetic polymers and organic films. Packaging according to claim 22 wherein the synthetic polymer is a polyolefin, such as polypropylene, preferably oriented, preferentially uncoated polyethylene, low density PE (LDPE), linear or not, high density PE (HDPE), linear or not, and polymers selected from polyester such as PET. Packaging according to one of the preceding claims wherein the permeable material is not microporous. Packaging according to one of the preceding claims which does not comprise vent. Packaging according to one of the preceding claims wherein the permeable material is impermeable to liquid water and preferably to steam water. Use of a package according to one of the preceding claims for containing a liquid product containing yeast. Use of a packaging according to the preceding claim wherein the liquid product containing yeast contains at least 10 ⁵ units forming colonies (CFU) of yeast per gram. Use of a packaging according to claim 27 or 28 wherein the yeast-containing liquid product has a content of at least 0.03% by weight of yeast solids dry matter, and still more preferably at least 0.1% by weight. %. Use of a package according to one of claims 27 to 29 wherein the yeast is a baker's yeast. Use of a packaging according to one of claims 27 to 30 wherein the liquid product containing yeast is selected from yeast cream and liquid leaven. A method of preserving and using yeast-containing liquid product comprising the steps of: - Packaging the liquid product containing yeast in a package according to one of claims 1 to 26; storage of said liquid product package containing yeast until it is used at a storage temperature of 15 ° C. or less, preferably 10 ° C. or less, and then - optionally exposure to a temperature variation of up to 35 ° C for a period of up to 4 hours, then - use of the liquid product containing yeast. A method of preservation and use according to claim 32 wherein the liquid product containing yeast is characterized according to one of claims 29 to 31. A method of conservation and use according to one of claims 32 to 33 comprising the following steps: - Packaging the liquid product containing yeast after its packaging according to one of claims 1 to 26; - Preservation of said liquid product packaging containing yeast during transport at a temperature between 0 and 15 ° C, preferably about 4 ° C, and then - Preservation at a temperature of between 0 and 15 ° C, preferably between 8 and 10 ° C for at least 4 weeks, preferably from 4 to 8 weeks, and more preferably from 4 to 6 weeks from the packaging of the product containing the yeast then - optionally exposure to a temperature variation of up to 35 ° C for a period of up to 4 hours, then use of the liquid product containing yeast, preferably no later than 8 weeks since the packaging of the product containing yeast. A method of preservation and use according to one of claims 32 to 34 comprising the following steps: - exposure to a temperature variation of up to 35 ° C for a period of up to 4 hours, then - Preservation until use at a temperature between 0 and 15 ° C, preferably between 6 and 10 ° C. A method of preservation and use according to one of claims 32 to 35 wherein the yeast-containing product is used for the production of a bread-making product.