The present invention relates to a process for producing a dairy product, in particular intended for the production of a particular type of curd.

The production of pulled-curd cheeses (such as for example mozzarella), in countries with a deficit of milk production, is currently augmented by substituting liquid milk with substances chosen from among curds, actual liquid milk or liquid milk concentrate, and rennet caseins (milk proteins that favor coagulation).

Production through the use of rennet casein necessarily requires the addition of emulsifying salts (typically trisodium citrate), so as to impoverish the protein network of calcium, by virtue of their sequestrant action. Once the calcium has been eliminated, the protein acquires structural characteristics that are ideal for the production of pulled curds and other dairy products. If emulsifying salts are added, regulations require them to be indicated on the label, with consequent categorization of the product in categories other than natural cheeses. Furthermore the products obtained can be distinguished from natural products as regards the organoleptic and sensory characteristics, owing to the presence of the emulsifying salts and the“typical ^” taste of rennet casein in powder form.

Curds, instead, are the result of the decalcification of milk (achieved by lactic ferments or organic acids), their subsequent coagulation, pressing, and sending at a controlled temperature to a location for stretching.

This product, which typically has a 45% water content, is delicate insofar as it is very sensitive to the cold chain and has a limited shelf-life (90 days for the fresh product and 12 months for the frozen product).

During its useful life, fresh curd goes through a qualitative evolution of the product that brings it to its optimal condition for use in making dairy products within a limited time window, thus forcing the user to make continuous changes to the recipe as a consequence of the qualitative state of the raw material. For frozen curd, before it can be used, a defrosting procedure needs to be carried out, which takes between three and seven days (which generates real logistics problems for large-scale users). Once defrosted, the product must be used quickly because it begins the phase in which its quality deteriorates very quickly.

Some of the conventional solutions described above are illustrated in WO03069982, which makes it possible to produce a semi-finished product which however exhibits problems in terms of logistics (compliance with the cold chain and defrosting operations make it burdensome and complicated to use) and which comprises emulsifying salts that can partially compromise the organoleptic properties of the dairy product obtained using it.

The aim of the present invention is to solve the above mentioned drawbacks, by providing a process for producing a dairy product that does not entail the use of emulsifying salts.

Within this aim, an object of the invention is to provide a process for producing a dairy product that makes it possible to produce any type of cheese.

Another object of the invention is to provide a process for producing a dairy product that does not present problems of logistics and transport.

Another object of the invention is to provide a process for producing a dairy product that has a long shelf-life (a best-before date a long time after the date of production).

Another object of the present invention is to provide a process for producing a dairy product which is of low cost, easily and practically implemented and safe in use.

This aim and these and other objects which will become better apparent hereinafter are achieved by a process for producing a dairy product which consists in:

- selecting a raw material constituted by milk with a fat content comprised between 0% and 4.5%; - adding an acidifier to said milk, chosen preferably from among a mineral acid, an organic acid, lactic ferments and the like, until a pH comprised between 5.0 and 6.5 is reached for the obtained mixture;

- adding a coagulant to the obtained mixture, keeping said mixture at a temperature comprised between 20°C and 45°C for a period of time suitable for the coagulation of the curd;

- breaking up the curd inside syneresis tubes and separating the whey from it by way of an appropriate apparatus for separating the solid mass from the liquid mass;

- removing the whey proteins from the curd by way of at least one washing;

- separating the flakes of curd, obtained previously, from the residual liquid that is present, by way of a further apparatus for separating the solid mass from the liquid mass.

Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the process for producing a dairy product according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a functional block diagram of the process for producing a dairy product according to the invention.

With reference to such figure, the reference numeral 1 generally designates a process for producing a dairy product 9a, 10a according to the invention.

The process 1 according to the invention entails a sequence of operating steps.

A first step 2 entails selecting a raw material constituted by milk with a fat content comprised between 0% and 4.5%.

It should be noted that, for the use envisaged in the present process 1, the milk selected in step 1 is conveniently first subjected to a process of pasteurization.

Such process of pasteurization, in a particularly advantageous implementation of the present process, is carried out at a temperature comprised between 70°C and 80°C (preferably between 73°C and 75°C), for a treatment duration of less than 40 seconds (preferably between 15 and 25 seconds).

The process according to the invention is particularly efficient if the milk selected in the first step 2 is fully skimmed milk, i.e. which has a fat content lower than 0.1%.

In a subsequent step 3 an acidifier 3a is added to such milk, which is preferably selected from among a mineral acid, an organic acid, lactic ferments and the like. The addition of an acidifier must be such as to bring the mixture obtained to reach a pH value comprised between 5.0 and 6.5 for the mixture obtained.

The pH values that can be obtained can vary within the indicated range and depend on the type of acidifier used: purely for the purposes of example it should be noted that, in the specific case where the chosen acidifier is citric acid, the ideal pH value of the mixture will preferably be comprised between 5.6 and 6.3.

The next step 4 entails the addition of a coagulant 4a to the mixture obtained previously.

Such operation needs to be carried out while keeping the mixture at a temperature comprised between 20°C and 45°C for a period of time suitable for the coagulation of the curd.

It should be noted that it is possible to obtain excellent results in terms of quality of the curd and yield of the coagulation by keeping the mixture at a temperature of around 30°C.

Once coagulation is complete and consequently the formation of the curd is complete, it will be possible to proceed to step 5, which entails breaking up the curd inside syneresis tubes and then separating the whey 5a from it by way of an appropriate apparatus for separating the solid mass from the liquid mass.

At this point it will be possible, in step 6, to remove the whey proteins 6a from the curd by way of at least one washing (repeating the washing operation enables a greater efficiency of such operation).

Such washing in a generic form thereof will be carried out using water.

Then comes a separating step 7 of the flakes of curd, obtained previously, from the residual liquid 7a that is present, by way of a further apparatus for separating the solid mass from the liquid mass, making it possible to obtain a substance 8.

In order to produce a semi-finished product 9a that is suitable for commercial distribution to dairy product processing facilities, it should be noted that the present process 1 can profitably comprise a further drying step 9 of the substance 8, i.e. the flakes of curd free from residual liquids. The semi-finished product 9a will then be a dried skim curd (DSC).

As an alternative to what is explained in the foregoing paragraph, again for the purpose of producing a semi-finished product 10a that is suitable for commercial distribution to dairy product processing facilities, it should be noted that the present process 1 can comprise a further freezing step 10 of the substance 8, i.e. the flakes of curd free from residual liquids. The semi-finished product 10a will then be a frozen wet skim curd (WSC).

The process according to the invention also allows for the possibility of carrying out optional steps, intended to increase the yield of the process 1 itself and/or to improve the quality of the semi-finished product 9a, 10a obtained via the process.

In particular, an intermediate step 11 is envisaged, of adding at least one acid substance chosen from among organic acids and mineral acids between the adding step 4 of a coagulant 4a and the breaking up step 5 of the curd in syneresis tubes. In this case too, purely for the purposes of non-limiting example, it is possible to use citric acid as the acid substance.

With particular reference to an embodiment of the present process 1 which is particularly advantageous on a practical level and on an implementation level, the apparatuses for separating the solid mass from the liquid mass can advantageously be constituted by decanters.

Decanters for industrial use are generally of the rotating type, the centrifugal type, the type using a screw feeder, gravity decanting or other type (for the process 1 according to the invention it is possible to use any type of decanter) and their purpose is to separate the solid phase of a mixture from the liquid phase: the efficiency of the separation depends on the type of decanter selected.

It should furthermore be noted that the washing step 6, to remove the whey proteins 6a from the curd, can profitably be carried out in a washing tower using a washing liquid that has a pH comprised between 3 and 7.

The aforementioned washing towers are of the standard type envisaged for these devices in industries for producing dairy products. It should be noted therefore that the process according to the invention, while being intended for the production of curd, also uses techniques and machines that are typical of the industrial processes for the production of rennet casein, by combining techniques and technologies that to date have always been kept separate.

It should be noted that the liquid used to carry out the washing in the washing towers just illustrated is preferably chosen from among water, water acidified with organic acids, water acidified with mineral acids, and corresponding combinations.

In particular it will be advantageous for the washing liquid used in step 6 to have a pH value comprised between 3 and 7.

It should furthermore be noted that between the washing step 6 to remove the whey proteins 6a from the curd and the step separating 7 of the flakes of curd (constituted by the substance 8) from the residual liquid 7a that is present, there is an intermediate step 12, during which a further washing can be carried out in a second washing tower (although the possibility is not ruled out of using the same washing tower mentioned previously again, when step 6 is not being carried out). In this case too, a washing liquid will preferably be used which is preferably chosen from among water, water acidified with organic acids, water acidified with mineral acids, and corresponding combinations, which will need to have a pH value preferably comprised between 3 and 7.

The step 12 will also involve a corresponding separation of the solid mass from the liquid mass by way of a further separation apparatus (which, in this case too, can be constituted by an industrial decanter of the type usually used in the dairy industry).

It should be noted that the process 1 according to the invention can conveniently comprise a last mixing step of the flakes of curd free from residual liquids (substance 8), in a form chosen from between dried 9a and frozen 10a, with ingredients chosen from among water, fats, flavoring agents, salts, and spices for producing natural cheeses.

The possibility also exists of implementing an additional, and alternative, last step of providing a dairy preparation by way of an apparatus for stretching an aggregate constituted by the flakes of curd free from residual liquids (substance 8), in a form chosen from between dried 9a and frozen 10a, and ingredients chosen from among water, fats, flavoring agents, salts, and spices for producing natural cheeses.

Such step of providing a dairy preparation entails the preliminary heating of the ingredients, the stretching of the flakes of curd free from residual liquids (in its dried form 9a or frozen form 10a) and the incorporation of the preheated ingredients therein during the stretching.

It should be noted that lastly there is a possible concluding step of mixing the flakes of curd free from residual liquids (substance 8) in dried form 9a with anhydrous fats of a type preferably chosen from among butter, fats of animal origin, fats of vegetable origin, fats derived from animal fats and/or vegetable fats and the like.

Through this mixing it will be possible to obtain an anhydrous curd (also known as full fat curd or FFC) intended for the production of natural cheeses, dairy preparations and the like.

This product too (anhydrous curd), by virtue of the semi-finished product 9a contained in it and the low water content, can combine the advantages derived from a formula that is ready to use (it does not require preliminary operations such as defrosting) and is stable at non-freezing thermal conditions (positive temperatures). This makes it possible to save considerably on transport costs and avoid the problems deriving from the cold chain (which is usually mandatory for semi-finished products produced with conventional techniques) which very often cause great qualitative fluctuations of traditional curd and as a consequence of the products obtained therewith.

The semi-finished products 9a and 10a will be free from additional chemical substances (such as, for example, emulsifying salts) and this will be evident from the associated identifying label: this will translate to a definite greater appreciation thereof by end customers. For the reasons given above, the cheese obtained using the semi-finished product 9a (or the semi-finished product 10a) can be defined as a natural cheese (in conformity with the current regulations in this area).

Furthermore the semi-finished product 9a will ensure a considerable energy saving during the stages of production and distribution (transport), thus ensuring that the entire process and the associated logistics can be deemed "ecological" (the reduced energy consumption determines a lower environmental impact than conventional techniques).

The semi-finished product 9a will furthermore be more stable than the curds obtained with conventional industrial methods, as it is much less sensitive to the variations of temperature that can occur during storage and transport, and therefore its quality will be considerably higher than that of the alternative semi-finished products currently present on the market.

A similar advantage can also be ascribed to the semi-finished product 10a.

Lastly it must not be forgotten that the cheeses obtained using the semi-finished product 9a and with the semi-finished product 10a will have superior organoleptic properties to those obtained with conventional methods (which, in particular, entail the use of rennet casein which affects the taste and flavor of the finished product.

It should be noted that the anhydrous curd (full fat curd or FFC) obtained using the semi-finished product 9a ensures the same advantages that can be ascribed to that semi-finished product and which are mentioned previously: by not comprising additional chemical substances (such as for example emulsifying salts) it will be better appreciated by the end customer (such absence is made clear in fact by the information present on the attached sales label); the finished product produced using it can be called natural cheese; all logistics and transport operations will imply lower costs than similar conventional raw materials; the quality will be appreciably higher and more stable than similar conventional raw materials; the finished products produced using it will offer superior organoleptic properties to similar conventional products which entail the use of rennet casein; it can be used immediately for the production of natural cheese (no preliminary preparatory operations are necessary), therefore behaving like a natural curd.

Advantageously the present invention solves the above mentioned problems, by providing a process 1 for the production of a dairy product 9a, 10a that does not entail the use of emulsifying salts.

Conveniently the process 1 according to the invention makes it possible to produce any type of cheese, in particular including cheeses that current regulations classify with the designation "natural cheese".

Advantageously the process 1 according to the invention does not exhibit problems of logistics and transport; this is particularly evident with reference to the semi-finished product 9a, which does not necessitate any refrigeration operation and which does not require preliminary preparatory operations in order to be used.

Positively the process 1 according to the invention makes it possible to produce a semi-finished product that has a long shelf-life (a best-before date a long time after the date of production).

Positively the process 1 for the production of a dairy product 9a, 10a is easily and practically implemented and is of low cost: such characteristics demonstrate how the process 1 according to the invention is an innovation that is proper to be applied.

Traditional curd production attracts a considerable consumption of energy along the whole production chain, from the provisioning of raw materials up to the use of the finished product.

The energy consumption occurs during the various stages, which consist of: the conversion process, conservation at the place of production, distribution at controlled temperatures, conservation on distributor premises, and/or retail sale.

It is therefore evident that controlling (and containing) the overall energy demand is difficult to achieve and is closely linked to the geographic distances between the regions of production and the regions of consumption, as well as to the climate conditions of such places.

In the production flow of skim curd in dried form 9a, the energy demand required by the conversion process is comparable to that required for traditional curd production, to which must be added the energy necessary for the drying step.

On its own this last step of production can consume significant amounts of energy, but it is limited to the final step of preparation before packaging. When it leaves the factory the product needs no further energy to maintain its organoleptic and food safety characteristics. Skim curd in dried form 9a is a product that is commercially defined as“ambient”, i.e. it can be stored, transported and distributed, while reducing the causes of alteration and contamination and strict controls of ambient temperatures.

It is noted that this aspect is a great innovation in terms of overall energy saving. In fact the concentration of the energy demand in the production stage alone makes it possible to pursue strategies for procuring sustainable energy, such as procuring electricity generated by renewable sources (by virtue of the assured location of the regions where the energy will be consumed).

Unlike conventional production techniques, therefore, the production of skim curd in dried form 9a makes it possible to avoid parceling out energy consumption (which in conventional processes is distributed, first at the production stage, then in the distribution under controlled temperatures and subsequently in refrigerated storage), makes it easier to suppress energy requirements, and makes it simpler to conserve product quality from production to consumption (problems that afflict conventional products and the corresponding production/distribution processes).

Conservation of the skim curd product in dried form 9a at ambient temperature enables a considerable reduction in the consumption of energy for conservation in refrigerated compartments and the possibility of distributing the product to any latitude, even reaching countries afflicted by logistics problems at low cost.

The possibility of having a product available with greater stability in quality over time (skim curd in dried form 9a) will further make it possible to optimize transport, by minimizing the logistical limitations imposed by production rhythms: in other words, by using skim curd in dried form 9a, customers can import and store more product, as they can conserve it for longer (at reasonable cost). The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. 102019000000541 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs