Process for producing beta-lactoglobulin isolates and related methods and uses

Abstract

The present invention pertains to novel beta-lactoglobulin (BLG) isolates as well as to a method of producing such isolates and to uses of the powders, e.g. in beverage applications.

1 .- 18 . (canceled) 
     
     
         19 . A beta-lactoglobulin (BLG) isolate powder, preferably prepared by spray-drying, having a pH in the range of 2.5-4.9 and comprising:
 total protein in an amount of at least 30% w/w,   BLG in an amount of at least 85% w/w relative to total protein   water in an amount of at most 10% w/w,   said BLG isolate powder having one or more of the following:   a bulk density of at least 0.2 g/cm3,   an intrinsic tryptophan fluorescence emission ratio (I330/I350) of at least 1.11,   a degree of protein denaturation of at most 10%,   a heat-stability at pH 3.9 of at most 200 NTU, and   at most 15000 colony-forming units/g.   
     
     
         20 . The BLG isolate powder according to  claim 19 , comprising total protein in an amount of at least 40% w/w, preferably at least 50% w/w, at least 60% w/w, more preferably at least 70% w/w, even more preferably at least 80% w/w, even more preferably at least 90% w/w, and most preferably at least 92% w/w. 
     
     
         21 . The BLG isolate powder according to  claim 19 , comprising BLG in an amount of at least 88% w/w relative to total protein, preferably at least 90% w/w relative to total protein. 
     
     
         22 . The BLG isolate powder according to  claim 19 , wherein the powder comprises lipid in an amount of at most 10% w/w, preferably at most 5% w/w, more preferably at most 2% w/w, and even more preferably at most 0.1% w/w. 
     
     
         23 . The BLG isolate powder according to  claim 19 , having a bulk density of at least 0.20 g/cm3, preferably at least 0.30 g/cm3. 
     
     
         24 . The BLG isolate powder according to  claim 19 , having an intrinsic tryptophan fluorescence emission ratio (I330/I350) of at least 1.11. 
     
     
         25 . The BLG isolate powder according to  claim 19 , having a degree of protein denaturation of at most 10%. 
     
     
         26 . A liquid beta-lactoglobulin (BLG) isolate having a pH in the range of 2-4.9 and comprising:
 total protein in an amount of at least 10% w/w,   BLG in an amount of at least 85% w/w relative to total protein   said BLG isolate powder having one or more of the following:   an intrinsic tryptophan fluorescence emission ratio (I330/I350) of at least 1.11,   a degree of protein denaturation of at most 10%,   a heat-stability at pH 3.9 of at most 200 NTU, and   at most 15000 colony-forming units/g, preferably at most 1000 colony-forming units/g.   
     
     
         27 . A method of producing a dried beta-lactoglobulin (BLG) isolate powder according to  claim 19  containing BLG in an amount of at least 85% w/w relative to total protein, the method comprising the steps of:
 a) providing a liquid BLG isolate having a pH in the range of 2-4.9, said liquid BLG isolate containing BLG in an amount of at least 85% w/w relative to total protein, 
 b) optionally, subjecting the liquid BLG isolate to a physical microbial reduction, 
 c) drying the liquid BLG isolate by spray-drying. 
 
     
     
         28 . The method according to  claim 27 , wherein the liquid BLG isolate comprises a total solids content in an amount in the range of 5-50% w/w. 
     
     
         29 . The method according to  claim 27 , wherein the protein fraction of the liquid BLG isolate has an intrinsic tryptophan fluorescence emission ratio (I330/I350) of at least 1.11. 
     
     
         30 . The method according to  claim 27 , wherein the protein of liquid BLG isolate has a degree of protein denaturation of at most 10% w/w. 
     
     
         31 . The method according to  claim 27 , wherein the provision of the liquid BLG isolate involves isolating BLG from whey protein feed, and optionally subjecting the resulting BLG-enriched composition to one or more steps selected from the group of:
 demineralisation,   addition of minerals,   dilution,   physical microbial reduction,   concentration, and   pH-adjustment.   
     
     
         32 . The method according to  claim 27 , wherein the liquid BLG isolate is subjected to physical microbial reduction, which preferably involves or even consists of heat-treatment. 
     
     
         33 . The method according to  claim 27 , wherein the liquid BLG isolate is a liquid BLG isolate according to claim  8 . 
     
     
         34 . Use of the BLG isolate powder according to  claim 19  or the liquid BLG isolate according to  claim 26  as an ingredient for the production of a food product, e.g. a beverage or an instant beverage powder, having a pH in the range of 2-4.7 and furthermore having one or more of the following:
 a reduced level of drying mouthfeel, 
 improved transparency, and/or 
 increased content of protein, preferably heat-treated beverages containing a protein content in an amount of at least 3-45% w/w, more preferably 11-40% w/w, even more preferably 15-38% w/w and most preferably 20-36% w/w.