GB1566530A - Cheese manufacturing - Google Patents

Abstract

According to the method, the starting product is subjected to a mechanical treatment which enables the components to enter into intimate contact with each other, stabilising the mixture at high temperatures by microdispersion of the proteins coagulated in a stable dispersion phase. This method enables the mixture to withstand a stage of heating up without the structure and the quality of the cheese being adversely affected.

Description

(54) CHEESE MANUFACTURING (71) We, SOCIETE DES PRODUITS NESTLE S.A., a Swiss body corporate of Vevey, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a process for manufacturing cheese.

More particularly the invention relates to a modification or improvement in the process for manufacturing cheese described in our patent application 31277/77 (Serial No. 1,545,333).

The main patent concerns, among other things, a process for the production of cheese which comprises preparing a starting mixture the composition of which is substantially that of the cheese which it is desired to produce, subjecting this material to a thermal pasteurisation or sterilisation treatment, packaging the pasteurised or sterilised material under heat in a hermetic container or containers or in an impermeable coating, either at the same time as, or immediately after adding a fermentation agent to it and, finally, incubating the product thus packaged until fermentation is complete.

The present invention provides a process for the production of cheese which comprises preparing a starting material the composition of which is substantially that of the cheese which it is desired to produce, subjecting this starting material to a mechanical treatment which causes the constituent elements to become completely blended together, subjecting this material to a thermal pasteurisation or sterilisation treatment, packaging the pasteurised or sterilised material under heat in a hermetic container or containers or in an impermeable coating, either at the same time as, or immediately after adding a fermentation agent to it and, finally, incubating the product thus packaged until fermentation is complete.

In one preferred embodiment, while the initial mixture is being prepared, it is stabilised at high temperature by forming a stable microdispersion of coagulated proteins.

In order to prepare the fresh cheese according to the process of the main patent, the pH of the initial mixture is generally modified before any further treatment is contemplated. This is because the final product will not have the required homogeneous consistency for the taste to be good unless the pH is brought to a value of 5.9 to 6.2. The pH may be modified by means of a chemical agent, but these are not permitted in some countries and they cause the product to go down in the consumer's estimation.

According to the process described herein it becomes possible, if need be, to avoid recourse to chemical agents by treating the initial mixture mechanically. In this way, the constituent elements of the initial mixture become perfectly blended and the various stages of the process leading up to the finished product, as described in the main patent, are made possible.

In the process according to the invention of the parent patent, the manufacture of cheese is carried out as follows: I) Preparation of a milk extract, mainly protein, having a composition substantially that of the desired final product; 2) Mixing of this extract with cream, milk or other ingredients in order to obtain the desired characteristics and chemical composition; 3) Thermal stabilisation: 4) Addition of fermenting agents either at the same time as, or immediately before, packing; 5) Fermentation in definitive packing.

The further details contained herein relate to the first stage, when the preparation of the milk extract is carried out. In addition to what has already been described in the main patent, the preparation of the milk extract may be carried out as follows: fresh milk with a pH of 6.6 to 6.7 whole or skimmed, and irrespective of the fat content, is heated to 90"C maintained at this temperature until the caseins mix with the albumins (15 to 20 minutes) and then coagulated either by light acidification (pH 5.9 to 6.0) or by cooling to 40"C and the addition of rennet. Finally, the product is drained through cloth, or with a centrifuge at a temperature of from 60 to 90"C.

The preparation of the milk extract may also be carried out as follows, using pure whey, or whey mixed with variable amounts of milk or cream, so as to obtain a milk extract consisting entirely, or almost entirely. of proteinic whey (albumins and globulins). The curds are obtained by acidification (pH=5.9 to 6.0) at 900C and the draining is carried out through cloth or with a centrifuge until a dry product is obtained. The product manufactured from whey is included in the category of "cream cheese".

At this point the preparation of the initial mixture commences: to one of the lactic extracts mentioned above are added all the components of the cheese it is intended to manufacture, with the exception of the additives containing microorganism (for example lactic ferments) and enzymes (for example rennet). This basic mixture reproduces, more or less, the chemical composition of the cheese it is intended to make, and its physico-chemical characteristics should be such that they remain unharmed by the temperatures needed to destroy the enzymes and bacteria.

Cheese is made up mainly of coagulated proteins (caseins), fatty substances (butter) and whey (lactose, acids, salts, soluble or solubilised proteins and water). The mixture comprises, among other things, products derived from milk extracts: to them must be added the ingredients that are not already present and that must enter into the chemical composition of the final product.

In most cases, it is a matter of adding milk, cream, water, powdered milk, caseins or caseinates, salts and other additives; in some cases, the milk extracts may be prepared in such a way that it is not necessary to add any other ingredients.

For the invention it is important that the mixture should be capable of withstanding a considerable amount of heating without losing its qualities either of structure or as a cheese. The proteins, for instance, must be protected against coagulation and synaeresis, the fat content has to be thoroughly emulsified and protected against separation; the electrolytes have to guarantee the stability of the system.

As for the fat content of fresh cheese, to which the invention relates more particularly, there is no problem as far as the emulsifying is concerned, since the fat takes on the globular shape characteristics of milk. For the proteins and the electrolytes on the other hand, the problems are somewhat different and the means for solving them are given in the main patent.

Herein, it is proposed to form in the solutions already proposed a microdispersion of coagulated proteins in a stable, dispersion-forming state.

Physical microdispersion, as hereinafter defined, of insolubilised and insoluble proteins at a colloidal level in a stable liquid state may be achieved by colloidal mills or homogenisers, or by both means at the same time, according to the physical characteristics of the product to be converted into a colloidal state, and according to whether the products contain water, or are in a dry powder state. As used herein, the term "physical microdispersion" means that the microdispersion is obtained by purely physical means and does not involve the use of chemicals.

Microdispersion may be used in the case of extracts that are either thoroughly decalcified or rich in coagulated proteins. In such an eventuality, the electrolytes have to be carefully adjusted so as to avoid the agglomeration of particles, especially during the stage of warming up.

Treatment carried out with a colloidal mill or a homogeniser, or with both systems combined, enables the products to withstand the thermal treatment without changing in structure.

The following example is an application of the process according to the main patent mentioned hereinbefore. The parts and percentages are expressed in values by weight.

A milk extract of the acid type is prepared from skim milk. The milk is warmed to 850C for 15 minutes, then cooled and left to ferment at 18 to 200 C, after 4% of a mixture of lactic ferments containing Str. lactis, Str.

cremoris, Str. diacetylactis and Leuc.

citrovorum has been added, as well as a small amount of rennet (2 to 3 cc of liquid rennet 1:10,000 per 100 litres of milk). The mixture is allowed to coagulate and then heated to 60"C and drained through cloth. This first extract is then dispersed in three parts of water and, after 15 to 20 minutes, drained a second time so that a washed extract is obtained, containing about 160/, dry residue total, of which proteins represent 80 to 85 -ó and lactose 7 to 8 , .

The milk extract is mixed with the other ingredients which may be the following: milk extract 16% D.R. 65.3 cream of milk 40On fat 29.1 powdered skim milk 5.2 kitchen salt 0.4 total 100.0 The mixture contains 10 to 1 11% proteins.

11.5 to 120, fat and 3.5 to 4 O lactose for a dry extract total of about 29%.

The mixture is then sent through a colloidal mill until the particles of milk extract have been reduced to colloidal size; then the mixture is pasteurised at 850C for 2 to 5 minutes; finally, the mix is put in a homogeniser at 50 atmosphere so as to make the particles impercentible to taste.

The process is then completed following the method outlined herein.

The products obtained frollowing the process of the present invention have been observed to contain a fresh cheese having a low cohesion factor and a fresh flavour.

WHAT WE CLAIM IS: 1. A process for the production of cheese which comprises preparing a starting material the composition of which is substantially that of the cheese which it is desired to produce, subjecting this starting material to a mechanical treatment which causes the constituent elements to become completely blended together, subjecting this material to a thermal pasteurisation or sterilisation treatment, packaging the pasteurised or sterilised material under heat in a hermetic container or containers or in an impermeable coating, either at the same time as. or immediately after adding a fermentation agent to it, and finally, incubating the product thus packaged until fermentation is complete.

2. A process as claimed in Claim 1, wherein while the initial mixture is being prepared, it is stabilised at high temperature by forming a stable microdispersion of coagulated proteins.

3. A process as claimed in Claim 1 or Claim 2 wherein the physical microdispersion as hereinbefore defined, is carried out to colloidal levels of insolubilised and insoluble proteins in a stable liquid state.

4. A process as claimed in Claim I or Claim 2 wherein the physical microdispersion as hereinbefore defined, is carried out by means of a colloidal mill.

5. A process as claimed in any of Claims 1 to 4, wherein a homogeniser under pressure is used as a supplementary means for obtaining the microdispersion.

6. A process for the production of cheese as claimed in Claim 1, substantially as herein described.

7. Cheese when produced by a process as claimed in any of Claims 1 to 6.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. milk extract 16% D.R. 65.3 cream of milk 40On fat 29.1 powdered skim milk 5.2 kitchen salt 0.4 total 100.0 The mixture contains 10 to 1 11% proteins. 11.5 to 120, fat and 3.5 to 4 O lactose for a dry extract total of about 29%. The mixture is then sent through a colloidal mill until the particles of milk extract have been reduced to colloidal size; then the mixture is pasteurised at 850C for 2 to 5 minutes; finally, the mix is put in a homogeniser at 50 atmosphere so as to make the particles impercentible to taste. The process is then completed following the method outlined herein. The products obtained frollowing the process of the present invention have been observed to contain a fresh cheese having a low cohesion factor and a fresh flavour. WHAT WE CLAIM IS:

1. A process for the production of cheese which comprises preparing a starting material the composition of which is substantially that of the cheese which it is desired to produce, subjecting this starting material to a mechanical treatment which causes the constituent elements to become completely blended together, subjecting this material to a thermal pasteurisation or sterilisation treatment, packaging the pasteurised or sterilised material under heat in a hermetic container or containers or in an impermeable coating, either at the same time as. or immediately after adding a fermentation agent to it, and finally, incubating the product thus packaged until fermentation is complete.

2. A process as claimed in Claim 1, wherein while the initial mixture is being prepared, it is stabilised at high temperature by forming a stable microdispersion of coagulated proteins.

3. A process as claimed in Claim 1 or Claim 2 wherein the physical microdispersion as hereinbefore defined, is carried out to colloidal levels of insolubilised and insoluble proteins in a stable liquid state.

4. A process as claimed in Claim I or Claim 2 wherein the physical microdispersion as hereinbefore defined, is carried out by means of a colloidal mill.

5. A process as claimed in any of Claims 1 to 4, wherein a homogeniser under pressure is used as a supplementary means for obtaining the microdispersion.

6. A process for the production of cheese as claimed in Claim 1, substantially as herein described.

7. Cheese when produced by a process as claimed in any of Claims 1 to 6.