EP0695124A1

EP0695124A1 - Cast cheese and a method of producing

Info

Publication number: EP0695124A1
Application number: EP94916198A
Authority: EP
Inventors: Janos Unilever Res.Vlaardingen Lab. Bodor; Maria Anna Unilever Res.Vlaardingen Lab. Bodor
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 1993-04-27
Filing date: 1994-04-27
Publication date: 1996-02-07
Also published as: WO1994024879A1; ZA942962B; CA2161450A1; AU6795794A

Abstract

Cast cheese is made by renneting concentrated milk at temperatures between 45 °C and 55 °C and preferably between 46 °C and 52 °C. The rennet activity in the cheese is less than 0.001 % calculated on a rennet strength of 1:10800.

Description

CAST CHEESE AND METHOD OF PRODUCING

The invention relates to cast cheese and a method of producing it. Cast cheese is a product obtained by adding rennet and optionally a starter or acidulent to concentrated milk and immediately filling this mixture into the final packages saving as moulds where this mixture is allowed to curdle without cutting or any other disturbance or damaging of the curd structure in order that little or no whey separation occurs.

A usual method of producing cast cheese comprises providing concentrated milk, e.g. ultrafiltrating skim-milk to a solids content of about 20% (roughly corresponding with a concentration factor of 5) , optionally adding flavouring matter, salt, fat, preservative and similar additives, homogenising at a temperature above 50°C, .pasteurising and cooling down again, adding sufficient rennet for clotting, for instance about 0.2 g of rennet having a strength of 1:10000 per kg concentrated milk having a temperature of 27 to 35°C, filling the renneted concentrated milk immediately into a package where it curdles, leaving it undisturbed until the curd or fresh cheese has totally set, usually taking one hour or more, and distributing and selling the set product in said package.

The invention aims at reducing the amount of rennet to be used and reducing the time required for setting the cheese and reducing the rennet activity remaining in the final product.

For achieving this the invention provides a method as defined in claim 1. Preferred embodiments thereof being defined in claims 2 to 5 and products obtainable thereby in claims 6 and 7. Cast cheese is preferably made at moderate pH values usually between 5.0 and 6.7 more preferably between 6.0 and 6.7 and in particular between 6.3 and 6.7. The latter ranges being increasingly preferred for taste reasons and also for preventing wheying off problems.

In this specification and claims rennet is intended to comprise both calf rennet and similar milk coagulants, e.g. chymosin, microbial rennet.

It does not need explanation that the salt balance and the lactose level may be adjusted by suitable methods like dia- filtration.

As is well known the keepability of cheese can be improved by lowering the pH value from the usual value of natural milk. In the above method this may be achieved by incorporating suitable acids, e.g. lactic acid and citric acid, food acid precursors, e.g. glucono delta lactone (GDL) or food acid producing cultures to milk, resulting in a lowering of the pH value. The addition of GDL is preferably made after the final heating step but before adding rennet.

The invention also provides a cast cheese which is characterised by its low level of post clotting rennet activity, i.e. less than 1 x 10^~5 of 1:10800 or a corresponding amount of another activity. The strength or activity of rennet is defined in The Merck Index 10th Ed. (1983) monograph 8033.

Having generally described the invention a preferred embodiment and some alternatives thereof will be described in detail for elucidation.

In the present specification and claims parts and percentages refer to weights unless otherwise indicated. Example I

Skim-milk is pasteurised for 14 seconds at 72°C and thereafter ultrafiltrated at 50°C to a concentration factor of 5. Fat is added in an amount of 18% and salt of 1.5% after which a homogenisation treatment at 55°C is effected. The homogenised concentrated milk is pasteurised again for 15 seconds at 74°C and thereafter cooled down to 48°C. At this temperature 0,01 g rennet having a strength of 1:10800 is added per kg concentrated milk and thoroughly distributed therein. The resulting mixture is immediately filled into tubs of 100 ml. These tubs are stored without disturbance in an at 48°C thermostated room for 1 hour whereby the temperature of the product is at any time kept above 45°C. Thereafter the tubs with the set cheese are stored at chill, e.g. 5°C. Determination of the rennet activity in the resulting cast cheese reveals about 1% of post clotting activity, as compared with the original rennet activity in the cheese milk for making cast cheese. The enzymatic activity is likewise very low when compared with the original one.

Example II

The process of Example I is repeated with the only difference that the skim-milk which initially has a pH value of 6.7 is acidified with sufficient citric acid for reducing the pH value to 6.3.

Example III

The process of Example I is repeated with the only difference that GDL is added to the concentrated milk after the final heating treatment but before the addition of rennet. GDL is added in an amount sufficient to reduce the pH value to 6.0.

Example IV

The process of Example I is repeated with the only difference that 0.005 g rennet per kg concentrated milk is used. A fresh cheese having a slightly less rigidity 1 day after renneting is obtained.

Example V The process of Example I is repeated using milk with a milk fat content of 3.5% for the ultrafiltration step. The ultrafiltration is continued until 40% dry matter content is reached. Thereafter no fat is added.

Example VI

The process of Example I is repeated, except that the cheese milk after homogenising and pasteurising is cooled down to 50°C. After renneting this temperature is maintained for 1 hour without fluctuations of more than 1°C plus or minus. Similar results are obtained.

Claims

1. Method of producing cast cheese wherein a concentrated milk is pasteurised by heating and thereafter cooled down, the pH value of the milk is controlled, renneting is effected after cooling down and the resulting mixture is directly filled into the final packages, characterised in that renneting is effected at a milk temperature of from 45 to 55°C.

2. Method according to claim 1, characterised in that renneting is effected at a milk temperature of 46° to 52°C and particularly of 46°C to 51°C.

3. Method according to claim 1 or 2, characterised in that rennet is mixed in at a level of 0.03-0.2 g per kg of concentrated milk.

4. Method according to any one of claims 1-3, characterised in that the pH value is controlled at a value between 6.7 and 5.0, more preferably between 6.7 and 6.0 and in particular between 6.7 and 6.3.

5. Method according to any one of claims 1-4, characterised in that the concentrated milk is obtained by ultrafiltration.

6. Cast cheese having a rennet activity less than 0.001% calculated on a rennet strength of 1:10800.

7. Cast cheese according to claim 6 having a pH value between 6.7 and 5.0, preferably between 6.7 and 6.0 and in particular between 6.7 and 6.3.