FIELD OF THE INVENTION

The invention relates to a process for preparing a shaped, fryable cheese product and a shaped, fryable cheese product obtainable by such process.

BACKGROUND TO THE INVENTION

Cheese products are often used in cooking, typically because the cheese melts and provides a characteristic and attractive taste profile to a particular food product. There are also cheese products that can be fried or grilled without melting. A good example of such a cheese is halloumi cheese. Halloumi cheese was originally a cheese from Cyprus, but nowadays is prepared everywhere in the world. Whilst the traditional halloumi cheese was prepared from a mixture of unpasteurized goat’s and sheep milk, in today’s industrial halloumi cheese production cow’s milk is added as well. Halloumi cheese is white, has a distinctive layered texture similar to mozzarella cheese and has a salty taste. It also has a higher melting point than normal cheese which makes it particularly suitable for frying or grilling: it can be fried until brown or grilled.

The present invention aims to provide a cheese product which is based on cow’s milk and which, similar to halloumi cheese, can also be fried, grilled or otherwise subjected to a cooking treatment without melting.

This type of cheese product is, for instance, used in fast food restaurants, but also at home, to replace or supplement meat products. A fryable cheese is not an easy product to produce, because it should not melt when being subjected to a cooking treatment, but at the same time also not be too tough to chew after the cooking treatment. This requires a delicate balance between different structural and sensory properties, in particular flowability, meltability, rigidity, texture, mouthfeel and taste.

The present invention aims to provide a shaped, fryable cheese product which not only can be fried, grilled, oven-baked or heated in a microwave without melting and hence with retention of its shape, but after such cooking treatment also has an attractive taste and excellent textural properties. This is achieved by subjecting a suitable starting cheese to a multi-stage therm al/mechanical treatment.

WO 02/096209 Al discloses a process for making cheeses having a soft, flexible texture using a combined thermal and mechanical treatment. The process comprises as a first step preparing a cheese with a low calcium content and a soft, flexible, non-crumbly structure in a particular way involving acidifying milk to a certain pH and adding a coagulating enzyme. As a next step the resulting cheese base is thermally and mechanically treated at a temperature of 40 to 70 °C, after which the resulting cheese product is cooled by 8 to 20 °C, suitably to a temperature between 25 and 50 °C. If so desired, the cooled cheesed product can be moulded or shaped. WO 02/096209 Al is silent on any suitability of the cheese product prepared for frying or other cooking treatment.

US 2009/0324795 Al discloses cheese products with form stability and deep-frying stability based on cheese which further comprises maize flour and/or maize semolina as essential component as well as melting salts and possibly starch or other milled grain products. The maize-based component, melting salts and starch and/or other milled grain products may be combined into a stabilizing agent to be added to the cheese upon preparing the fryable cheese products. The process for producing the aforesaid fryable cheese product as disclosed in US 2009/0324795 Al comprises heating all components in a melting machine, while mechanically processing them, to a temperature of 70 to 140 °C, preferably 80 to 95 °C, thereby keeping the melting mass hot for 2-20 minutes, then pouring the hot mass into forms followed by cooling, hardening and cutting or processing into the desired shapes. The use of stabilizing components, either combined into a single stabilizer or added as individual ingredients, is essential to obtain a form stable, fryable cheese product. The present invention aims to provide a form stable, fryable cheese product that does not or hardly require the use of any stabilizing agents.

SUMMARY OF THE INVENTION

The present invention relates to a process for preparing a shaped, fryable cheese product from a starting cheese material comprising one or more starting cheeses of the hard or semi-hard type by a specific combination of thermal and mechanical treatment steps. The result is a unique, shaped, fryable cheese product with excellent structural and organoleptic properties, the shape and volume of which are stable during any frying or cooking treatment and hence do not significantly change as a result of any frying treatment.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, the present invention relates to a process for preparing a shaped, fryable cheese product from a starting cheese material comprising one or more starting cheeses of the hard or semi-hard type, which process comprises the steps of a) comminuting the starting cheese material at a temperature T1 below 40 °C; b) gradually heating the comminuted cheese material resulting from step a) under mechanical shear to a temperature T2 in the range of 60 to 80 °C to form a cheese dough; c) cooling the cheese dough to a temperature T3 in the range of 40 to 60 °C; d) shaping the cheese dough into the desired shape at T3; and e) further cooling the shaped cheese dough product obtained in step d) to a temperature T4 below 30 °C, preferably below 20 °C , to obtain the fryable, shaped cheese product.

The term “shaped, fryable cheese product” as used herein refers to a cheese product of particular shape that can be subjected to a typical frying treatment (such as pan frying, deep -frying or air frying) or to a dry cooking treatment (such as grilling, oven-baking or heating in a microwave) to prepare the cheese product for consumption without significant loss of such shape. The term “frying” or “frying treatment” as used herein, accordingly, refers to any cooking treatment that involves heating the cheese product to prepare it for consumption and hence includes the typical frying treatments and dry cooking treatments mentioned above. Typical temperatures applied during such frying treatments will be at least 150 °C and will usually not exceed 220 °C. Frying temperatures between 160 and 210 °C are most commonly applied. Obviously conditions (e.g. temperature, duration) during frying vary depending on the specific frying treatment used, but such conditions are well known and for the purpose of the present invention would be those that are conventionally applied in the specific frying treatment in question. The shape of the cheese product essentially could be any desired shape of any desired size, for example the shapes and sizes one would typically see in fast food restaurants. Accordingly, typical shapes and sizes include those of a burger (essentially round or oval), square shaped, cylinder-shaped or nugget-shaped. A key characteristic of the shaped, fryable cheese product of the invention is that the frying treatment to which the cheese product is subjected does not essentially change its shape, unless external pressure is applied onto the cheese product, e.g. by a pressing plate. This implies that the cheese product has a sufficiently high melting point and a sufficiently strong internal structure to ensure it does not melt or hardly melts when subjected to a frying treatment.

The starting cheese material to be used in the process of the present invention comprises one or more starting cheeses of the hard or semi-hard type. Suitable starting cheeses will typically have a moisture content, expressed in grams of moisture per gram of fat-free dry matter in the cheese (g/g ffdm), in the range of 1.0 to 2.2 g/g ffdm, preferably 1.2 to 1.9 g/g ffdm. Based on total weight of cheese, so including the amount of fat in the cheese, this could correspond with a moisture content in the range of 35 to 65% by weight based on total weight of cheese, preferably between 40 and 60% by weight. A preferred starting cheese is a cheese selected from a Gouda type cheese, an Edam type cheese, a Swiss type cheese, a Cheddar cheese and mozzarella cheese. A preferred starting cheese material accordingly comprises a Gouda type cheese, an Edam type cheese, a Swiss type cheese, a Cheddar cheese, mozzarella cheese or a combination of two or more of such cheeses. Such cheeses and their preparation processes are well known. As a mozzarella cheese preferably a low moisture mozzarella cheese is used, that is, a mozzarella cheese of which the moisture content is below 50% by weight and typically between 40 and 50% by weight, based on total weight of cheese. Conventional mozzarella has a moisture content between 50 and 60% by weight, but by either removing moisture from such conventional mozzarella by pressing or by removing more moisture after the stretching step in the preparation process, a low moisture mozzarella can be obtained. It is preferred to use a starting cheese material that comprises a single starting cheese, preferably from the types mentioned above. Best results are obtained when using Gouda type cheese or Edam type cheese as the starting cheese.

The starting cheese(s) used may have conventional calcium contents, expressed in milligrams calcium per gram of fat-free dry matter in the cheese (mg/g ffdm), of at least 25 mg/g ffdm, typically in the range of 25 to 35 mg/g ffdm. Based on total weight of cheese, so including the amount of fat in the cheese, conventional calcium content would typically be above 700 mg/100 g cheese, with most cheeses having calcium contents between 720 and 1200 mg/100 g cheese. For example, Gouda cheese, Edam cheese, Cheddar cheese and mozzarella cheese all have a typical calcium content between 700 and 850 mg/100 g cheese, whilst Swiss type cheese typically has a slightly higher calcium content between 900 and 1200 mg/100 g cheese. It was, however, found that very good results are also obtained when using a starting cheese having a calcium content of less than 25 mg/g ffdm, preferably in the range of 15 to 20 mg/g ffdm. This covers low calcium cheeses that have a calcium content of less than 700 mg/100 g cheese, preferably in the range of 400 to 600 mg/100 g cheese. Methods to prepare such low calcium cheeses are known in the art, e.g. from WO 02/096209 Al described hereinbefore. Another known method, e.g. applied in preparation of Mozzarella cheeses, is pre-acidifying the cheese milk. Such pre-acidification leads to solubilization of the calcium and phosphate, which then end up in the whey. The result is a curd, and eventually a cheese, having a lower calcium content. When using a combination of starting cheeses as the starting cheese material, a combination of a starting cheese with a conventional calcium content and a low calcium starting cheese is also possible.

Step (a) of the present process involves comminuting the starting cheese material at a temperature T1 below 40 °C. Comminuting the cheese should take place at a temperature which is well below the temperature at which the cheese starts to melt in order to avoid changing the fat and protein structure of the cheese. T1 suitably is above the temperature at which the cheese would become hard and hence more difficult to cut into smaller pieces. Preferably, T1 is in the range of 8 to 35 °C, more preferably 10 to 30 °C. Comminuting the cheese can take place by ways known in the art and by cutting or grating equipment available on the market. If actually starting from a piece of cheese that is comminuted by cutting, the size of the comminuted cheese parts or particles should be such that they can be conveniently handled in the equipment used. Typically, the average size of the cheese particles may vary from the size of grated cheese to small blocks, chunks, balls or other shapes of cheese. Such cheese particles will have volumes that may range within wide limits, but typically the average volume of a cheese particle in the comminuted cheese will be up to 10 cm ³ , preferably up to 8 cm ³ , more preferably in the range of 0.1 to 4.5 cm ³ and most preferably in the range of 0.1 to 2 cm ³ . For example, cheese blocks having an average size between 0.2 cm x 0.2 cm x 0.2 cm and 1 cm x 1 cm x 1 cm or cheese balls having an average diameter between 0.5 and 1 cm could be suitably used. If, on the other hand, comminuting the starting piece of cheese takes place by grating the cheese, then the resulting grated cheese is anyhow suitable as comminuted cheese for step (b). If multiple starting cheeses are used as the starting cheese material, step (a) suitably comprises the steps of al) comminuting each starting cheese separately and then a2) combining the comminuted starting cheeses into a single comminuted cheese material for use in step (b).

In step (b) the comminuted cheese material resulting from step (a) is gradually heated under mechanical shear to a temperature T2 in the range of 60 to 80 °C to form a cheese dough. Average heating rate can vary within wide limits and will depend on amount of cheese to be melted, shear forces deployed and type of equipment used. Typically, the average heating rate will be in the range of 0.5 to 5 °C/min, suitably between 1 and 4 °C/min. The cheese will melt within this temperature range and as a result of the mechanical shear combined with the increasing temperature phase inversions occur and it is observed that larger fat and protein domains are formed. This has an impact on the structure of the cheese dough obtained. When using a starting cheese material comprising one or more starting cheeses having a calcium content of less than 25 mg/g ffdm, T2 preferably is in the range of 60 to 75 °C. When using a starting cheese material comprising one or more starting cheeses having a calcium content of at least 25 mg/g ffdm, T2 preferably is in the range of 65 to 80 °C. When using a starting cheese material comprising at least one cheese having a calcium content of less than 25 mg/g ffdm and at least one cheese having a calcium content of at least 25 mg/g ffdm, then T2 preferably is in the range of 65 to 75 °C. This latter range of T2 is also the overall most preferred range to be applied in step (b) regardless of the exact composition of the starting cheese material. Simultaneous heating and exertion of shear can, for example, be conducted in so called thermoblenders, cooking processors or powerblenders and other mixing/heating devices available on the market. For example, mixing machines ex Stephan Machinery GmbH, such as UM44 (pilot scale) or the Combitherm 800 (factory scale) could be used, or ex GE A. For small scale testing, cooking machines, such as those sold under the brand name Thermomix®, could be suitably used.

Step (b) does not need to immediately follow step (a). It is very well possible that the preparation of the comminuted cheese material in step (a) takes place well before step (b) and even at a different location, so that the comminuted cheese is first stored and possibly transported to another location before it is used in step (b). This makes the present process flexible in that the comminuted cheese could come from a different location (or even from multiple locations if a combination of cheeses is used as starting cheese material) and/or from a stock of comminuted cheese which has been prepared earlier.

In step (c) the cheese dough is cooled to a temperature T3 in the range of 40 to 60 °C. It was found that cooling to a temperature within this range on the one hand fixates the structure with the larger fat and protein domains, thus creating a stable product, but on the other hand still leaves the cheese dough sufficiently soft for it to be shaped in step (d) in the desired shape. Such cooling can take place gradually in a single step, in distinct successive steps or using a combination of both. It can be achieved in ways known in the art, e.g. by air cooling.

Once the cheese dough has been cooled to T3 it is brought into the desired shape in step (d). At T3 the cheese dough is still sufficiently flexible to be shaped, but at the same time sufficiently rigid to retain such shape. As mentioned hereinbefore, typical shapes and sizes include those of a burger (essentially round or oval), square shaped, cylinder-shaped or nugget-shaped, but other shapes are of course possible too.

Finally, in step (e), the shaped cheese dough product obtained in step (d) is further cooled to a temperature T4 below 30 °C, preferably below 20 °C , to obtain the fryable, shaped cheese product. By cooling to T4 the internal structure of the shaped cheese product is fixated, thus resulting in a fryable cheese product which is stable during the frying treatments (i.e. it does not completely melt at typical frying temperatures) whilst having an excellent taste, attractive appearance, pleasant mouthfeel and good texture. Cooling to T4 can be achieved by common cooling means, for example by allowing the shaped cheese product to cool at ambient conditions or by placing the shaped cheese product in a refrigerator.

If so desired, other ingredients could be included as well into the shaped cheese product. Such other ingredients include, for example, flavouring agents and colouring agents. Those ingredients would typically be added during steps (b), (c) and/or (d). The advantage of adding the further ingredients during step (b) is that such ingredients will be well distributed through the cheese dough before it is cooled and shaped into the desired shape in steps (c) and (d).

Although other ingredients as mentioned hereinbefore could be added, there is hardly any and typically no need to add stabilizing agents or other ingredients for providing stability to the fryable cheese product obtained by the process of the present invention. If used at all, any stabilizing agents, such as any melting salts and milled maize or grain products as mentioned in US 2009/0324795 Al, are used in amounts of at most 8% by weight (in total), preferably 0-5% by weight, based on total weight of the cheese dough. Most preferably, however, no stabilizing agents or other ingredients for providing stability to the fryable cheese product are used at all. The process of the present invention, and in particular the temperature profile applied in preparing the shaped fryable cheese product, makes the use of stabilizing agents (including melting salts) redundant, as the specific sequence of steps and temperature profile applied provides sufficient processability and stability to the end product. The invention further relates to a fryable, shaped cheese product obtainable by the process described above, wherein surface area ratio RSAIS in the range of 0.8 to 1.2, preferably 0.9 to 1.1, more preferably 0.95 to 1.05, with

RSA = surface area of the shaped cheese product after frying surface area of the shaped cheese product before frying

The surface area is the total surface of the shaped cheese product either before frying or after frying at typically frying temperatures of between 160 and 210 °C , typically expressed in cm ² . If the surface area of the shaped cheese product does not materially change as a result of the frying treatment, then this is an indication that the shaped cheese product does not shrink or expand during frying and hence that the shape and size of the cheese product of the invention does not significantly change as a result of the frying treatment (provided no external pressure is applied onto the cheese product during frying, e.g. by a pressing plate) and hence is illustrative of the stable structure of the cheese product when applying the method of the invention, which structure increases the melting temperature of the cheese considerable, whilst maintaining an attractive product.

The invention is further illustrated by the following examples without limiting the invention to these specific embodiments

EXAMPLES

Methods used

Dry matter content is determined in accordance with standard method ISO 5534 for cheese and processed cheese products. Moisture content is calculated from the dry matter content as the balance up to 100 wt%.

Fat content is determined in accordance with standard method ISO 1735 for cheese and processed cheese products.

Fat-free dry matter content is calculated as the difference between dry matter content and fat content.

Protein content is determined in accordance with standard method ISO 8968-1 (as %N*6.38). Calcium content is determined in accordance with standard method ISO 11885 (ICP-OES method).

Example 1

750 grams of a Edam 40+ cheese of room temperature (18 °C), having the properties as listed in Table 1, was put in a Thermomix® TM6 kitchen machine having a heating plate that was initially set a temperature of 37 °C. Stirring speed was initially set at approximately 1100 rpm (rotations per minute) for 1 minute and then reduced to approximately 500 rpm. After 5 minutes all cheese was chopped into pieces that, on visual inspection, all had a diameter below 0.5 cm. During the chopping the temperature of the cheese increased and when all cheese was chopped the temperature had raised to 28 °C (Tl).

When all cheese was chopped into pieces, the mechanical shear exerted by the kitchen machine was continued at the same level and the temperature was step-wise increased: first to 50 °C, then to 60 °C and finally to 70 °C by setting the kitchen machine’s heating plate at this temperature. The temperature of the cheese material was continuously measured. Once the cheese material reached the temperature set, the temperature was increased to the next level. When the cheese material reached a temperature of 70 °C (T2), mechanical shear continued for 5 minutes. Total heating time of the chopped cheese amounted to 45 minutes. A warm cheese dough was obtained.

The cheese dough was removed from the cutting machine and allowed to cool in air. When its temperature had decreased to 52 °C (T3) two small balls were formed by hand from the dough and the balls were flattened into hamburgershaped cheese products.

These hamburger-shaped cheese products were allowed to cool to room temperature (18 °C, T4 ). One hamburger-shaped cheese product was then fried for 6 minutes in an airfryer at 175 °C. The resulting fried cheese product still had about the same shape as before frying and had a slightly brown outer surface. The other hamburger-shaped cheese product was pan fried in a baking pan with a nonstick coating layer for 3 minutes, 1.5 minute on each side. Both fried products had a brownish and crispy outer surface, whilst the inside was smooth and had a soft mouthfeel.

Surface area (SA) of the hamburger-shaped cheese products was determined before and after frying by measuring diameter d (in cm) and height h (in cm) and calculating the surface area using the formula:

The results are indicated in Table 2.

The results show that for both cheese products surface area only slightly increased as a result of the frying treatment.

Table 1 - Cheese base properties ^y y weight percentages (wt%) based on total weight of cheese

²⁾ FFDM = fat-free dry matter

Table 2 - Results Example 1 Example 2

750 grams of the same Edam 40+ cheese as used in Example 1 having a temperature of 10 °C was put in the Thermomix® TM6 kitchen machine. Stirring speed was initially set at about 1100 rpm (rotations per minute), the heating plate was set at 65 °C. After 1 minute at stirring speed 1100 rpm, the stirring speed was reduced to about 500 rpm. After 5 minutes all cheese was chopped into pieces smaller than 0.5 cm (on visual inspection). Temperature of the chopped cheese at this point was 25 °C (Tl).

Whilst stirring continued at the same speed the temperature of the cheese increased to 65 °C (T2) in 40 minutes. Stirring continued for another 5 minutes at the same stirring speed and temperature. A warm cheese dough was obtained.

The cheese dough was removed from the cutting machine and allowed to cool in air. When its temperature had decreased to 51 °C (T3) two balls were formed by hand from the dough and the balls were flattened into hamburger-shaped cheese products having a diameter of about 7 cm and a height between 0.7 and 1.0 cm. The remaining cheese dough was further cooled to 39 °C and an attempt was made to form a ball from this cheese. This was not successful, as the dough was no longer sticky enough to form a ball.

The hamburger-shaped cheese products were placed in a refrigerator for 2 hours and cooled to 12 °C, T4 ). Both hamburger-shaped cheese product were subsequently pan fried in a baking pan with a non-stick coating layer for 3 minutes, 1.5 minute on each side. Both fried products had a brownish and crispy outer surface, whilst the inside was smooth and had a soft mouthfeel.

Surface area of the hamburger-shaped cheese products were determined before and after pan frying in the same way as described in Example 1.

Results are indicated in Table 3. Table 3 - Results Example 2