Mozzarella-Type String Cheese Product

Europäisches Patentamt *EP001576886A1* (19) European Patent Office

Office européen des brevets (11) EP 1 576 886 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication: (51) Int Cl.7: A23C 19/068 21.09.2005 Bulletin 2005/38

(21) Application number: 04006331.5

(22) Date of filing: 17.03.2004

(84) Designated Contracting States: • Cortes Martinez, Eduardo AT BE BG CH CY CZ DE DK EE ES FI FR GB GR 81667 München (DE) HU IE IT LI LU MC NL PL PT RO SE SI SK TR • Wolfschoon-Pombo, Alan Designated Extension States: 85354 Freising (DE) AL LT LV MK • Mehnert, David Lake Villa, IL 60046 (US) (71) Applicant: Kraft Foods R & D, Inc. 81737 München (DE) (74) Representative: Freiherr von Wittgenstein, Arved et al (72) Inventors: Abitz & Partner, • Schröder, Angela Poschingerstrasse 6 83714 Miesbach (DE) 81679 München (Bogenhausen) (DE) • Schmid, Thomas 27321 Thedinghausen (DE)

(54) Mozzarella-type string cheese product

(57) The invention relates to performed in a steam injection mixer/ cooker, - a process for manufacturing Mozzarella-type string cheese products comprising the steps of - and the Mozzarella-type string cheese products made according to this process. a) providing cheese curd, b) heating, kneading and stretching the cheese curd together with any desirable ingredients, c) extruding the cheese product, and d) cooling the cheese product in cold brine, characterized in that step b) is EP 1 576 886 A1

Printed by Jouve, 75001 PARIS (FR) 1 EP 1 576 886 A1 2

Description d) cooling the cheese product in cold brine,

FIELD OF THE INVENTION characterized in that step b) is performed in a steam injection mixer/cooker. [0001] The invention relates to a new process for 5 [0009] The invention also relates to Mozzarella-type manufacturing Mozzarella-type string cheese products string cheese products manufactured by the process as and to the cheese products made by this process. described above.

STATE OF THE ART DETAILED DESCRIPTION OF THE INVENTION 10 [0002] String cheese is a Mozzarella-type cheese [0010] The use of a steam injection mixer/cooker for product which is shaped by extrusion. the heating, kneading and stretching of the cheese curd [0003] The conventional process for manufacturing leads to a Mozzarella-type cheese product which has a Mozzarella-type cheese prodcuts, including string greatly improved texture which gives a much better cheese products, consists of pasteurizing cow or buffalo 15 mouthfeel and makes it much more attractive for direct milk, acidifying the milk to convert it to a cheese milk, consumption, which has been fully established by con- coagulating the cheese milk to obtain a coagulum com- sumer tests. prised of curd and whey, cutting the coagulum and drain- [0011] The use of steam injection is known in the pro- ing the whey therefrom, thereby leaving a cheese curd, duction of processed cheese where much higher tem- heating, kneading and stretching the cheese curd until 20 peratures are needed and where no extrusion of the final it is a homogeneous, fibrous mass of heated, unripened product is involved. It could not be foreseen that the use cheese, shaping the heated cheese, cooling the shaped of steam injection during heating, kneading and stretch- cheese in cold brine, and removing the cooled cheese ing of the cheese curd leads to a cheese mass which, from the brine. Such a process is known for example despite its extrusion, is no longer fibrous or rubbery. It from U.S. Patent 5,380,543 and WO 96/25051. 25 is believed that the fibrous texture of known extruded [0004] The heating, kneading and stretching of the Mozzarella-type cheese products is at least in part cheese curd is typically carried out in a piece of equip- caused by the extrusion step. Therefore, it is very sur- ment called a hot water mixer/cooker. The temperatures prising that the extrusion step within the process of the used for heating, kneading and stretching of the cheese present invention does not cause the undesired fibrous curd are quite low. Example 1 of WO 96/25051 mentions 30 texture of the Mozzarella cheese and it is further sur- a temperature of 49°C. prising that the string cheese product is no longer rub- [0005] The texture of the extruded Mozzarella-type bery. cheese products is fibrous and somewhat rubbery. How- [0012] An additional advantage of the process of the ever, the texture of Mozzarella-type cheese products is present invention is brought about by the possibility of not of concern because Mozzarella cheese is mostly 35 adding a much greater variety of different ingredients used for baking purposes, for example for producing piz- during the heating, kneading and stretching step, which zas where high baking temperatures are used and was not possible with the known use of a hot water mix- where the structure and texture of the Mozzarella er/cooker without steam injection. cheese is completely altered. [0013] The process for manufacturing Mozzarella- [0006] Extruded Mozzarella-type cheese products 40 type cheese products is well-known as mentioned are not very attractive for direct consumption because above and the steps of making cheese curd, heating, of their fibrous and somewhat rubbery texture. kneading and stretching the cheese curd in a commonly [0007] It is the object of the present invention to pro- used mixer/cooker, shaping and especially extruding vide a process for manufacturing extruded Mozzarella- the cheese product, and cooling the cheese product in type cheese products, i.e. string cheese products, which 45 cold brine are well described in the above-mentioned U. have an improved mouthfeel and are more attractive for S. Patent 5,380,543 and WO 96/25051, both of which direct consumption. are hereby incorporated by reference. [0014] The use of a steam injection mixer/cooker in SUMMARY OF THE INVENTION the heating, kneading and stretching step b) will now be 50 described in more detail. [0008] The invention relates to a process for manu- [0015] In the conventional process for making Moz- facturing Mozzarella-type string cheese products com- zarella-type cheese in a hot water mixer/cooker using prising the steps of hot water as heat provider, pieces of cheese curd and other ingredients are introduced into a container provid- a) providing cheese curd, 55 ed with paddles or stirring arms. A volume of hot water b) heating, kneading and stretching the cheese curd having a temperature in the range of 60° to 90°C, typi- together with any desirable ingredients, cally 80°C, is added, covering the raw material. The c) extruding the cheese product, and components of the raw material are kneaded by the ac-

2 3 EP 1 576 886 A1 4 tion of the paddles until they melt and aggregate to each ment in all respects compared with conventionally pro- other and finally create a homogeneous elastic mass. duced string cheese. The various properties improved An alternative to the batch production is the use of a by 13 to 34%, the overall acceptance improved by 22%. continuous hot water cooker. In this system, the cheese The most striking improvement is the much more pleas- does not remain in a specific location while being knead- 5 ant texture which is no longer fibrous and rubbery. ed, but is transported through the hot water by means [0023] The following example illustrates the process of screws along a pipe. The melting/stretching/homog- according to the invention and is not limiting. enisation of the mass is done during the time the cheese needs to reach the exit of the cooker. Example [0016] In the process of the present invention the in- 10 gredients are charged into a batch mixer/cooker which [0024] Cheese curd is cut into pieces by means of a is preferably provided with a double-screw system. The dicer, and loaded into the double-screw direct steam in- ingredients are pieces of fresh or up to 28-days-old jection cooker/mixer (Inotec ISM-250DV, total capacity: cheese curd and emulsifying salts such as sodium cit- 250 1). The remaining ingredients (dairy proteins con- rate in an amount of up to 1% by weight. Other optional 15 centrate powder, calcium milk powder, sodium citrate, ingredients are dairy ingredients such as milk protein, colouring agents and water) are weighed separately. SMP, etc., as well as non-dairy ingredients such as col- The powders are then introduced into the cooker/mixer ouring agents, flavouring agents, meat pieces, nuts, together with the cheese pieces, and dry-mixed for 1 etc., and water. The ingredients are then mixed until they minute at 40% speed (30 rpm). After that, water and col- reach a homogeneous distribution. 20 ouring agents are added and mixing is continued for an- [0017] Steam is then directly applied to the mass by other minute at the same speed (wet mix). The total means of injectors which are preferably positioned at the batch was 175 kg. bottom of the cooker. The steam together with the me- [0025] Immediately after mixing, steam is directly ap- chanical effect of the screws starts melting and emulsi- plied to the mass by means of 4 injectors which are po- fying the cheese mass while preventing the degradation 25 sitioned at the bottom of the cooker. The steam, together of the fresh protein. The cheese mass should not reach with the mechanical effect of the screws, starts melting/ a temperature of 70°C. The cheese mass preferably emulsifying the cheese mass. Heating and mixing is reaches a temperature of 60 to 67°C, typically about continued until the cheese mass reaches 65°C. 64°C. The steam is injected at a pressure of preferably [0026] When the cheese reaches 65°C, mixing is con- about 2 bar abs., a pressure range of 1.5 to 2.5 bar abs. 30 tinued (without steam) for another 1.5 minutes (55 rpm) being possible. The temperature of the steam is prefer- in order to complete homogenisation in the cooked ably in a range of 120°Cto150°C, preferably about cheese mix. At this point, the cheese mix is ready to start 130°C. the shaping and cooling process steps. [0018] The mixing speed or mixing energy input [0027] The cheese mass is downloaded into a double- should be relatively high during the time of steam injec- 35 jacketed (40°C water temperature) extruder, which ap- tion in order to avoid local overheating. The steam in- plies a pressure to the cheese mass (0.8 - 1 bar), forcing jection must be terminated when the cheese mass it to go through double-jacketed extruder head (70°C) reaches the above-mentioned temperature range of 60 with 15 mm diameter nozzles, to create a continuous to 67°C in order to avoid degradation. cheese rope, which falls into a channel with a flow of [0019] After further mixing and stretching the cheese 40 cold brine (18% salt content, 5°C) and is transported as mass for several minutes without steam injection, the far as the cutting system (knives activated by an optic cheese mass can be transferred to a conventional ex- sensor) which cuts the cheese sticks (11 cm long). truder to produce the desired string cheese product. [0028] The product then falls into a brine bath to com- [0020] The string cheese products made according to plete the cooling (down to 7°C) and salting (to 1.6% Na- the process of the present invention have a texture 45 Cl in the final product) during 8 minutes of residence which is particularly pleasant, melts in mouth and is not time, proceeding finally to the packaging machine and fibrous. This is a very surprising and striking result which storage under refrigeration. makes the products according to the invention much [0029] The obtained string cheese product had a more acceptable for direct consumption. It is no longer pleasant texture. It was not fibrous or rubbery. fibrous and not rubbery. 50 [0021] Moreover, the use of steam injection increases the possibility of using many more ingredients which Claims were unable to be introduced into Mozzarella-type cheese products up to now. This leads to an added in- 1. A process for manufacturing Mozzarella-type string crease of consumer acceptance. 55 cheese products comprising the steps of [0022] Consumer tests which were performed in Great Britain with respect to aroma, appearence, tex- a) providing cheese curd, ture, taste and aftertaste revealed a significant improve- b) heating, kneading and stretching the cheese

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curd together with any desirable ingredients, c) extruding the cheese product, and d) cooling the cheese product in cold brine, characterized in that step b) is performed in a steam injection mixer/cooker. 5

2. Process according to claim 1, characterized in that the steam is injected at a pressure of 1.5 to 2.5 bar. 10 3. Process according to claim 2, characterized in that the steam is injected at a pressure of about 2 bar.

4. Process according to any one of claims 1 to 3, char- 15 acterized in that the steam is injected until the cheese mass has reached a temperature in the range of 60° to 67°C.

5. Process according to claim 4, characterized in 20 that the steam is injected until the cheese mass has reached a temperature of about 64°C.

6. Process according to any one of claims 1 to 5, characterized in that the steam is injected at a pressure 25 of 1.5 to 2.5 bar abs., preferably about 2 bar abs.

7. Process according to any one of claims 1 to 6, characterized in that the steam is injected at a temperature in the range of 120°C to 150°C, preferably 30 about 130°C.

8. A Mozzarella-type cheese product manufactured by the process comprising the steps of 35 a) providing cheese curd, b) heating, kneading and stretching the cheese curd together with any desirable ingredients, c) extruding the cheese product, and d) cooling the cheese product in cold brine, 40

characterized in that step b) is performed in a steam injection mixer/cooker.

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