FR2750015A1 - Production of dry expanded cheese based snack food product - Google Patents

Abstract

Process for preparing a dry expanded cheese based product comprises subjecting a cheese based starting material having a water content of 25-65 wt. % to a drying and expansion treatment by passage through a microwave oven under vacuum at a temperature of below 40 deg C to give a final moisture content of less than 10 wt. %.

Description

 The present invention relates to a process for manufacturing dry and expanded cheese products, of the "snack" type.

 The term “snack” is understood to mean food products which allow food to be eaten quickly and conveniently, and which provide pleasure and nutritional benefits; these products are considered as appetite suppressants, snacks and even meal replacements. Currently, the market for dry and expanded snacks is represented by products of mainly vegetable origin based on seeds, cereals (corn), potatoes (chips), etc. They are advantageously in the form of crisps, sticks, popcorn or any other form suitable for this market. These products are essentially low mass products representing an individual portion, sometimes even a bite (10 to 50 g, possibly 100 g) grouped by several in a sachet or a box.

 The processes for manufacturing dry and expanded cheese products, described in the state of the art, for the most part use chemical agents, which are increasingly challenged by legislation and which, moreover, can be taste modifiers . A solution to these drawbacks has been provided in patent FR-A-2 582 192 which describes a process for the preparation of expanded products based on casein, in which the expansion is carried out by subjecting a product to subatmospheric pressure beforehand. extruded by heat treatment at a temperature between 30 and 100 OC under sufficient pressure to make it plastic.

 The authors of the present invention have now developed a process which makes it possible to transform materials of cheese origin into expanded snacks, using as a means of drying and expansion, a treatment by microwave under vacuum.

 The subject of the present is therefore a process for manufacturing a dry and expanded cheese product, consisting in subjecting a material of cheese origin having a water content of 25 to 65% by weight to an expansion drying treatment by passing through a vacuum microwave oven at a temperature below 400C, up to a water content of less than 10% by weight.

 The expansion drying treatment according to the process of the present invention is carried out in a microwave oven under vacuum (at a pressure of less than 0.9 bars, preferably between 0.4 and 0.9 bars), generally for 20 seconds to 10 minutes.

The optimal duration of treatment depends on the initial water content of the product to be treated; the higher the water content, the longer the treatment time.

 A vacuum microwave treatment as carried out in the process of the present invention has the advantage of not causing any deterioration of the treated product, since the treatment is carried out at a temperature below 400C (generally between 20 and 400C), which does not cause any alteration of the protein network unlike more drastic expansion processes.

 The products obtained after the drying treatment will be conditioned after possibly coating with a salty or sweet layer if necessary, and cooling to around 6-100C. In fact, packaging the product hot, as soon as it leaves the expansion treatment, leads to rehydration of the product by the water of condensation and therefore less conservation. Preferably, the packaging of the products will be done under neutral gas for better conservation. They will be packaged in flow-pack type bags, in boxes or any other suitable packaging.

 In addition, the products obtained, which are not very humid, will have a fairly long shelf life; the shelf life will be at least four months at 50C or out of the cold in the case of packaging in a modified atmosphere or vacuum.

 In a first embodiment of the invention, the starting material of cheese origin consists of curds, refined or not, and the process makes it possible to obtain puffed grains appearing as real "popcorn" .

 According to another embodiment, the material of cheese origin is a cheese cut into pieces. In the case of cheeses cut into strips, the process makes it possible to obtain expanded products in the form of "chips".

 For a good understanding of the invention, the main stages in the manufacture of cheeses and derivatives will be briefly recalled.

 The cheese is obtained by solidification (gelling) of the milk using a coagulating agent to result in a coagulum which will then be drained or not, pressed or not, refined or not. The curd obtained has specific characteristics which depend on the nature of the coagulating agent used. Thus, the lactic curd is firm, brittle, porous, not very contractile, while the rennet curd is flexible, elastic, compact, waterproof and contractile.

 In the latter case, the curd left to stand does not spontaneously drip unlike the lactic curd; to eliminate the whey impregnating the gel, it is necessary to subject the curd to a certain number of mechanical actions. Among the most frequently used means, one can cite cutting and mixing.

 The cutting constitutes the "breaking", the first object of which is to break the integrity of the almost impermeable film which forms on the surface of the coagulation tanks by the gathering of certain constituents of milk, and the second object is to multiply the whey exudation surface, thus promoting its evacuation by cutting the curd into "grains" by increasing the exudation surface.

 This cutting is followed by stirring in order to renew the exudation surfaces and prevent the grains from adhering to each other. The drained grains are then placed in molds for cheese formation and pressing, an operation which promotes the exudation of the residual whey and the compaction of the curd grains therebetween, so as to form a compact curd cake. The cake obtained will then undergo the stages of brining, drying, refining to result in a cheese with physicochemical and organoleptic characteristics of the desired cheese.

 According to a first embodiment of the invention, dry and expanded products are produced from curd grains prepared according to conventional cheese-making processes.

 For this, a milk is made to coagulate by adding coagulating enzymes and is applied to the coagulum obtained slicing / cutting / stirring treatments in order to obtain curd grains and to avoid re-cohesion. Depending on the slicing / cutting treatment used, we obtain curds of the desired size for the finished product. The size of the latter is advantageously between 2 and 30 mm.

As a starting raw material, cow's milk will advantageously be used, but milk from other mammals such as sheep or goats may also be used. The milk can be skimmed, semi-skimmed or whole and it will advantageously be pasteurized and matured with lactic ferments before adding rennet or other coagulating enzyme. It is also possible and advantageously to use as starting material a milk concentrate, more specifically a retentate obtained by ultrafiltration of milk. It may be lean, standardized in fat and / or enriched in protein.

 As the proteolytic coagulation enzyme, rennet will advantageously be used, but any enzyme may be used such as, for example, enzymes of microbial origin or other animal species such as calves. The rate of rennet used will advantageously be between 15 and 50 ml per 100 l of milk. The curd's pH will be between 5.20 and 6.50.

 As soon as solidification or gelation, the coagulum will be cut using a traditional cheese curd cutter to obtain curds of determined size. Preferably, we will use curds of the size of a grain of rice or wheat, but we may prefer for later use grains of larger size, the size of a cherry or a hazelnut. , for example. In order to avoid any recohesion of the grains between them, it will be necessary to mix the curd grain / whey mixture. We will then proceed to the elimination of the whey by drawing off directly from the tank or by any other suitable means and delactosing by adding water followed by a new drawing to remove the residual lactose and water.

 According to a first variant, the curd grains will undergo an expansion treatment during which their volume will be multiplied by a coefficient between 1.5 and 4.

 Before expansion, the grains will generally be drained, then undergo partial drying by passage through a traditional dryer, in a ventilated tunnel or fluidized bed or any other suitable means, this in order to remove part of the water from the grains and result in a residual water content of about 25 to 40% by weight.

 Preferably, partial drying is carried out in order to bring the dry extract content of the curd grains to a value greater than 60% by weight, generally between 60 and 80% by weight.

 The expansion treatment which is then carried out makes it possible to obtain products similar in size, shape, presentation and density to the traditional "popcorn" based on corn kernels.

 The method according to the present invention is preferably carried out on curd grains whose wall is hardened.

 These are curd grains which contain residual whey but which have a relatively dry and hardened surface. Such curd grains have a limited ability to agglomerate with one another, due to a stiffening of their wall.

 The hardening of the wall of these grains can be obtained by subjecting the grains to a heat treatment carried out at a temperature between 38 and 450C for two to thirty minutes, followed by a cooling phase at a temperature between 10 and 150C. This cooling step can be carried out by adding cold water, which is then removed by drawing off.

According to another advantageous variant, the curd grains, preferably with a hardened wall, will be flavored before expansion. They will be flavored in several ways
- for salted flavorings, the grains can be brined before draining by soaking in a brine of specified salt concentration and optionally flavored, or dusting after partial drying of the grains with salted or flavored powders, or with salted ingredients (aromatic herbs, spices )
- for sweet flavorings, the grains will advantageously be sprinkled after partial drying with sweet powders based on fruits or sweet ingredients.

 The flavored grains will then undergo an expansion treatment according to the methods described above. The products obtained similar to traditional popcorn will then be packaged in an appropriate packaging and preferably under neutral gas for better conservation.

 According to another advantageous variant, the curd grains will be ripened before expansion in order to give them the organoleptic characteristics of traditional ripened cheeses.

For the production of the products according to this variant, the curd grains advantageously with hardened wall will be put in a thin layer in a device allowing good aeration and seeded using different flora usually used in the ripening of the surface of rind cheeses. natural as for example: P. Candidum, G. Candidum, yeast,
B. linens, micrococci and / or any flora usually used in cheese making. Refining can be carried out at a temperature between 10 and 200C, preferably at a temperature between 12 and 140C.

The large contact surface and the grain size allow rapid ripening and therefore rapid development of aromas; usually, the ripening time can be between 3 and 7 days.

Advantageously, the grains can be seeded with different strains, so as to obtain grains with different characteristics such as, for example, grains with a "blue-veined paste" flavor, grains with a "camembert" flavor, etc.

 Once the aromatic characteristics have been obtained, the ripening will be stopped by inhibiting the development of the seeds sown by, for example, passage of the grains in the microwave or any other suitable means. The grains will then undergo an expansion treatment according to the methods described in the first variant. The product obtained according to this variant will have a completely original presentation and organoleptic characteristics.

 As in the previous case, it will consist of grains similar to popcorn grains, with a traditional cheese flavor and having all the organoleptic and nutritional qualities of dairy products, as well as a longer shelf life of up to at least four months, or more if the packaging is carried out under a modified atmosphere or under vacuum.

 Whatever the variant used, the products obtained from curd grains have an original texture, thanks to which they can be used as they are, incorporated into cheese pastes to create contrasts in texture or to serve as decor for cheeses or other food products.

 According to a second embodiment of the invention, expanded cheese products are produced from cheeses. Preferably, the cheeses used comprise a dry matter content of 50 to 75%% by weight and for organoleptic reasons, mature cheeses will be used. A particularly suitable example of cheese capable of being treated according to the method of the present invention is represented by the mimolette. It is also possible to apply the process of the invention to other cheeses, the level of dry extract of which is lower.

In this case, prior to the expansion step, these products will undergo partial drying by passage through a dryer, a ventilated tunnel, a fluidized bed, or any other suitable means.

 The expansion drying treatment will then be carried out on cheeses previously peeled and cut into pieces, in particular in strips. These strips which may for example have a thickness of 0.2 to 4 mm will be subjected to a microwave treatment under vacuum, in particular for a period varying from 20 seconds to 10 minutes, in particular at a temperature between 20 and 400C. As previously indicated, the duration of treatment is a function of the dry extract content of the product, the treatment being shorter the higher the content.

 After this step, the product is cooled and then preferably packaged under neutral gas to improve conservation.

 The products obtained have a crisp and dry texture and have the original taste of the starting cheese. These "cheese chips" are perfectly suited to new consumption occasions of the "snacking" type.

 Because of the great variety of starting raw materials existing on the market, the skilled person will be able to grasp all the possibilities offered by the process to create an original and new range of products adapted to the new behavior of the consumer, which bring to this last all the nutritional characteristics of cheese products.

 The following examples illustrate the present invention.

Example 1
Example of a popcorn type product obtained from curds.

 We start with a milk standardized to 35 g / l of fat to which we add a sufficient amount of rennet to ensure solidification or gelation of the milk. For this, add 25 to 30 ml of rennet per 100 1 of milk at a temperature of 30 plus or minus 10C. The clotting time is approximately 40 minutes. The coagulum is then "broken" using a curd slice; curd breaking is carried out slowly to ensure better regularity of the curd grains. Parallel to the "breaking" of the curd, the latter is stirred to avoid the recohesion of the grains between them.

 The curd grains obtained, the size of a grain of wheat, then undergo a wall hardening operation by heat treatment at 38-400C for 30 minutes and cooling to 120C by adding cold water directly to the tank. The grains are then drained and then dried by passage through a ventilation tunnel, which results in a loss of grain weight of 50% to reach a total dry extract equal to 50% by weight.

 The capped and partially dried grains are then subjected to an expansion treatment by passage through a microwave oven under vacuum for 5 minutes (power = 600 watts continuously; temperature: 350C; pressure = 0.6 bar). During this treatment, the volume of the grains is multiplied by 4 and their dry extract content reaches 96%.

 The expanded grains are then cooled to 100C by passage through a cooling tunnel, ventilated to dryness and packaged in "flow-pack" bags and under neutral gas.

 The product obtained, similar to popcorn, will keep for about 4 months. It can be eaten as an aperitif or in the form of snack snacks.

Claim 2
Example of a flavored "popcorn" type product.

 Curd grains are prepared according to Example 1 and are sprinkled with an aromatic cumin-based composition after drying and before expansion.

 The grains obtained are flavored with cumin and can for example be used to flavor a salad.

Example 3
Example of a "popcorn" type product obtained from skim curd grains.

 Curd grains are prepared by coagulation using calf rennet from a retentate obtained by ultrafiltration of milk at 0% fat and cutting / mixing of the curd obtained.

The curd-sized grains of cherry are heat treated as in Example 1 to harden their walls, then drained and brined. They are then dried by passage over a fluidized bed in order to obtain a water removal of 55%.

 The heat treated and dried grains are then expanded by passage through a microwave oven under vacuum for 6 minutes (power = 600 watts continuously; temperature: 300C; pressure = 0.6 bar) to obtain a residual water content of 5% .

They are then cooled to 10 OC and packaged in a cardboard box; they will advantageously be used as snacks as an aperitif.

Example 4
Example of a "chips" type product.

 We use a mimolette made according to current technologies (VeisseyreX: Milk technology - La Maison Rustique, Paris).

 This peeled mimolette having a dry extract of 69% is cut into thin strips 1 mm thick on a rotary cutting machine.

 These strips are then expanded by passing through a microwave oven under vacuum for 35 seconds (power = 600 watts continuously temperature: 350C; pressure = 0.6 bar) so as to obtain a residual water content of less than 5%. .

 They are then cooled by passage through a drying tunnel, dry ventilated to 100C. They are then packaged in a "flow-pack" under neutral gas to be consumed as snacks.

Claims (9)

 1. A method of manufacturing a dry and expanded cheese product, consisting in subjecting a material of cheese origin having a water content of 25 to 65% by weight to an expansion drying treatment by passage through a microwave oven under vacuum at a temperature below 400C, up to a water content of less than 10% by weight.  2. Method according to claim 1, in which the material of processed cheese origin consists of curds having a size of 2 to 30 mm.  3. The method of claim 2, wherein the curd grains are hard wall grains.  4. Method according to claim 3, in which the curd grains with hardened wall are curd grains which have undergone a heat treatment carried out at a temperature of 38 to 450C for 2 to 30 minutes and then have been cooled to a temperature between 10 and 150C.  5. Method according to claim 4, in which the curd grains with hardened walls are dried to a dry extract content of between 60 and 80% by weight before the expansion drying treatment.  6. Method according to any one of claims 2 to 5, in which the curd grains undergo a refining treatment by sowing using a traditional refining flora before the expansion drying treatment.  7. The method of claim 1, wherein the material of processed cheese origin consists of a cheese cut into pieces.  8. The method of claim 7, wherein the pieces of cheese are strips.  9. Method according to any one of claims 1 to 8, in which the products are packaged under neutral gas.