Dairy product and process

Abstract

A method for preparing a modified whey protein concentrate (WPC) or whey protein isolate (WPI) is described. It involves (a) providing an aqueous WPC or WPI solution having a protein concentration of 15-50% (w/v), at a pH of 4.7-8.5; (b) heat treating the solution to more than 50° C., for a time that allows protein denaturation to occur; the heat treating comprising heating the solution while under conditions of turbulent flow. At the end of the heat treatment, the heat treated material may be promptly transferred to a drier or to be mixed with other ingredients. The heat-treated WPC or WPI is not subjected to a mechanical shear process prior to the transfer other than where liquid is converted into droplets to facilitate drying. The modified WPC is useful in the manufacture of food and drinks where a high protein content is desired without undesirable changes in texture.

1 . A method as claimed in  claim 35 , wherein
 at the end of the heat treatment, the heat treated material is transferred directly to a drier.   
     
     
         2 . A method
 at the end of the heat treatment the heat treated material is directly transferred either to a drier to be dried or to a mixer to be mixed with other ingredients; and   
       wherein the heat treated WPC or WPI is not subjected to particle size reduction prior to step (c). 
     
     
         3 . A method as claimed in  claim 35 ,
 wherein at the end of the heat treatment, the heat treated material is promptly transferred to a drier; and   wherein the heat-treated WPC or WPI is not subjected to a mechanical shear process prior to drying other than where liquid is converted into droplets to facilitate drying.   
     
     
         4 . A method
 wherein at the end of the heat treatment, the heat treated material is directly transferred to a mixer to be mixed with at least one other ingredients, including at least one of the group consisting of milk, skim milk, fat, a carbohydrate, milk retentate, or skim milk retentate,   wherein the heat-treated WPC or WPI is not subjected to a mechanical shear process prior to mixing with other ingredients drying other than where liquid is converted into droplets to facilitate drying.   
     
     
         5 . A method as claimed in  claim 35 , wherein the pH of the WPC concentrate prior to heating is adjusted to between 5.0 and 8.5. 
     
     
         6 . A method as claimed in  claim 35 , wherein the protein concentration of the WPC concentrate prior to heating is 16-40%. 
     
     
         7 . A method as claimed in  claim 35 , wherein the heat treating occurs as the WPC or WPI solution passes along a heated flow path with an inside diameter greater than 5 mm and less than 150 mm. 
     
     
         8 . A method as claimed in  claim 35 , wherein the solution passes through a long tubular reactor and exits at a temperature between 60° C. and 110° C. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . A method for preparing a dried modified WPC or WPI with 50-95% of the total solids as whey protein, comprising:
 (a) preparing an aqueous WPC or WPI having 15-50% (w/v) whey protein,;   (b) using a high pressure pump to feed the protein concentrate at a pressure of between 3 to 1000 bars into a high pressure heater, the flow of the product is such that a turbulent flow is effected with a Reynolds number of at least 500;   (c) heat treating the solution obtained to more than 70° C. for a time that allows protein denaturation to occur;   (d) at the end of the heat treatment, promptly transferring the heat-treated material to a drier; and   (e) drying the heat-treated WPC or WPI,   
       wherein the treated WPC stream from the heat treatment arrangement (c) is not subject to a particle size reduction procedure prior to drying. 
     
     
         12 . A method as claimed in  claim 11  wherein the heat treatment zone is coupled directly to the inlet of the drier. 
     
     
         13 . A method as claimed in  claim 12  wherein the drying is by spray drying. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . A method as claimed in claim wherein the turbulent flow has a Reynolds number in the range 2,000-50,000. 
     
     
         17 . (canceled) 
     
     
         18 . A method of increasing the protein content of a foodstuff by including a WPC or WPI prepared by the method of  claim 35  in the ingredients of the foodstuff 
     
     
         19 . A method as claimed in  claim 18  wherein the foodstuff is a snack bar prepared by a method comprising melting fat, if melting is required, and mixing fat or oil with carbohydrate and WPC and allowing the mixture to set. 
     
     
         20 . A method of preparing a yoghurt comprising including a dried WPC or WPI prepared by the method as claimed in  claim 35  as an ingredient in yoghurt. 
     
     
         21 . A method as claimed in  claim 20  comprising preparing a yoghurt milk having at least 7% (w/v) protein by mixing the dried WPC or WPI with a milk comprising casein, and acidifying the yoghurt milk to a pH of 3.8-5.5 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . A method of preparing a yoghurt drink comprising 1.5-15% (w/v) protein comprising mixing a dried WPC or WPI prepared by the method as claimed in  claim 35  with a milk comprising casein, and acidifying to a pH of 3.8-5.5. 
     
     
         28 . (canceled) 
     
     
         29 . (canceled) 
     
     
         30 . A method for preparing a whey protein hydrolysate comprising preparing a heat-treated WPC or WPI by the method as claimed in  claim 35  and contacting the heat-treated WPC or WPI with a protease. 
     
     
         31 . (canceled) 
     
     
         32 . (canceled) 
     
     
         33 . (canceled) 
     
     
         34 . A method for preparing a processed cheese comprising preparing a whey protein ingredient by a method as claimed in  claim 35 , mixing the ingredient with other ingredients including cheese and water, cooking to form a molten processed cheese, and allowing to cool. 
     
     
         35 . A method for preparing a mixture comprising a liquid whey protein concentrate (WPC) or whey protein isolate (WPI), comprising:
 (a) providing an aqueous WPC or WPI solution having a protein concentration of 15-50% (w/v), at a pH of 4.7-8.5;   (b) heat treating the solution to more than 50° C., for a time that allows protein denaturation to occur; the heat treating comprising heating the solution while under conditions of turbulent flow; and   (c) at the end of the heat treatment,
 either (i) transferring the heat treated material directly to a mixer to be mixed with at least one other ingredients, including at least one of the group consisting of milk, skim milk, fat, a carbohydrate, milk retentate, or skim milk retentate, or 
 (ii) transferring the heat treat material promptly to a drier and drying the heat treated WPC or WPI 
 wherein the heat-treated WPC or WPI is not subjected to a mechanical shear process prior to drying or mixing with other ingredients other than where liquid is converted into droplets to facilitate drying.