Processed cheese with improved firmness using cross-linking enzymes

Abstract

A method of making a processed cheese with improved firmness comprises mixing a protein cross-linking enzyme and optionally first other ingredients with a cheese material having a pH of less than 5.6, a moisture content of less than 60% and preferably containing one or more coagulating agents, to form a mixture; providing temperature and pH conditions and allowing time for the enzyme to react with protein in the mixture to cross link at least a portion of the protein; and combining one or more emulsifying agents and optionally second other ingredients with the mixture and heating the combination to thereby produce processed cheese from the combined cheese material contain cross-linked proteins, emulsifying agents and optional first and second other ingredients.

1 - 31 . (canceled)  
   
   
       32 . A method of making a processed cheese comprising: 
 a) producing cheese curds;    b) mixing transglutaminase with the cheese curds;    c) packing the mixture of cheese curds and transglutaminase to form cheese;    d) allowing the cheese to age for a period of at least 24 hours, the transglutaminase reacting with protein in the curds to cross link the protein while the cheese is aging, and    e) mixing the transglutaminase-treated cheese with other processed cheese ingredients and heating and mixing the combination to produce the processed cheese.    
   
   
       33 . The method of  claim 32  wherein the other processed cheese ingredients comprise one or more emulsifying agents.  
   
   
       34 . The method of  claim 33  wherein the other processed cheese ingredients also include cheese made by ultrafiltration and diafiltration of milk.  
   
   
       35 . The method of  claim 32  wherein the transglutaminase is mixed with the curds, at a level of between about 0.2 units per gram of protein in the curds and about 5 units per gram of protein in the curds.  
   
   
       36 . A method of making processed cheese comprising: 
 a) ultrafiltering and diafiltering milk to produce a retentate;    b) fermenting the retentate;    c) adding transglutaminase to the retentate;    d) removing water from the fermented retentate;    e) providing temperature and pH conditions and allowing a period of time for the transglutaminase to cross link at least a portion of proteins in the retentate; and    f) combining the fermented dewatered retentate with cross-linked proteins therein with other processed cheese ingredients, and heating and mixing the combination to produce the processed cheese.    
   
   
       37 . The method of  claim 36  wherein the transglutaminase is added to the retentate after fermentation and before removal of water.  
   
   
       38 . The method of  claim 36  wherein the period of time for cross linking comprises at least 24 hours and is between when water is removed and when the fermented, dewatered retentate is combined with other processed cheese making ingredients.  
   
   
       39 . The method of  claim 36  wherein a starter culture is added to the retentate to start fermentation and the transglutaminase is mixed with the retentate prior to or when the starter culture is added.  
   
   
       40 . A method of making processed cheese comprising: 
 a) providing cheese material and other ingredients used to make the processed cheese;    b) mixing transglutaminase with the cheese material and providing temperature and pH conditions and allowing time for the transglutaminase to cross link at least a portion of proteins in the cheese material; and    c) heating and mixing the cheese material, transglutaminase and other processed cheese ingredients to form the processed cheese.    
   
   
       41 . The method of  claim 40  wherein the cheese material and transglutaminase are mixed in a blender and later placed in a cooker.  
   
   
       42 . The method of  claim 41  wherein water is added with the cheese material and transglutaminase in the blender.  
   
   
       43 . The method of  claim 42  wherein water is also added in the cooker in the form of steam.  
   
   
       44 . The method of  claim 41  wherein the cheese material and transglutaminase are heated to a temperature of between about 50° F. and about 120° F. in the cooker.  
   
   
       45 . The method of  claim 44  wherein the cheese material and transglutaminase are mixed in the cooker for a period of between about 1 hour and about 3 hours while being heated, thus providing said time for cross linking.  
   
   
       46 . The method of  claim 45  wherein the other processed cheese ingredients comprise one or more emulsifying agents and the one or more emulsifying agents are added to the cooker after said period of between about 1 hour and about 3 hours.  
   
   
       47 . The method of  claim 46  wherein the cheese material, transglutaminase and one or more emulsifying agents are heated to a temperature of between about 170° F. and about 210° F. in the cooker.  
   
   
       48 . The method of  claim 40  wherein the other processed cheese ingredients comprise one or more emulsifying agents and the one or more emulsifying agents are mixed with the cheese material and transglutaminase prior to allowing said time for cross-linking.  
   
   
       49 - 56 . (canceled)  
   
   
       57 . A processed cheese made by the method of claim  1 .  
   
   
       58 . The processed cheese of  claim 57  having an Instron firmness, corrected to 40% moisture, of at least 1 kgf.  
   
   
       59 . The processed cheese of  claim 57  having a Mettler melt temperature of between about 120° F. and about 200° F.  
   
   
       60 . The processed cheese of  claim 57  having a Schreiber melt score of at least 3.  
   
   
       61 . The processed cheese of  claim 60  also having an Instron firmness, corrected to 40% moisture, of at least 1.5 kgf.  
   
   
       62 . A mixture of a cheese material and a protein cross-linking enzyme comprising: 
 a) a cheese material selected from the group consisting of comminuted natural cheese, conventional cheese curds and fermented UF retentate, and    b) transglutaminase, wherein the transglutaminase is present at a level of between about 0.2 units and about 10 units of transglutaminase per gram of protein in the mixture.    
   
   
       63 . The mixture of  claim 62  wherein the mixture is essentially free of emulsifying agents.  
   
   
       64 . The mixture of  claim 62  wherein the cheese material has not been melted.  
   
   
       65 . A process of adding a protein cross-linking enzyme to a cheese material so as to allow the enzyme to cross link protein in the cheese material comprising the steps of: 
 a) ultrafiltering and diafiltering milk to produce a UF retentate;    b) adding transglutaminase to the retentate at a level of between about 0.2 units and about 10 units of transglutaminase per gram of protein in the UF retentate; and    c) evaporating water from the retentate to produce a UF cheese containing active transglutaminase.    
   
   
       66 . The process of  claim 65  wherein the transglutaminase is allowed to cross link protein in the UF cheese for at least 24 hours before the transglutaminase is deactivated.  
   
   
       67 . A process of adding a protein cross-linking enzyme to a cheese material so as to allow the enzyme to cross link protein in the cheese material comprising the steps of: 
 a) producing conventional cheese curds;    b) mixing transglutaminase with the cheese curds at a level of between about 0.2 units and about 10 units of transglutaminase per gram of protein in the curds; and    c) packing the mixed curds and transglutaminase into a container.    
   
   
       68 . The process of  claim 67  wherein the transglutaminase is allowed to cross link protein in the curds for at least 24 hours before the transglutaminase is deactivated.