Viscous properties of microparticulated dairy proteins and sucrose.
Slurries of whey protein concentrate (WPC) or sodium caseinate (Na-CN) mixed with sucrose (36% T.S.) were subjected to microparticulation by a high shear homogenizer operated at 27,000 rpm for 2, 4, and 6 min to facilitate gel formation. After microparticulation treatment, the milk protein and sucrose slurries were evaporated at 85 degrees C for 60 min under a partial vacuum (20 to 45 mm of Hg) to form composite gels. Particle sizes and viscoelastic properties were determined before microparticulation treatment. Microparticulation reduced the particle size of WPC-sucrose slurries from an average size of 330 to 188 nm after 4 min and NaCN-sucrose slurries from 270 to 35 nm after 2 min. The WPC-sucrose composites were gel-like, but NaCN-sucrose composites did not gel. Viscoelastic properties of heated WPC-sucrose composites were liquid-like, exhibiting significant reduction in storage modulus and complex viscosity. Microparticulation reduced particle sizes, which resulted in softer gels as time of shearing increased.
US Department of Agriculture, ARS, Eastern Regional Research Center, Wyndmoor, PA 19038, USA. Conulata@arserrc.gov
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Onwulata
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D000818:Animals; D002364:Caseins / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D005524:Food Technology; D005782:Gels; D008855:Microscopy, Electron, Scanning; D008894:Milk Proteins / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012212:Rheology; D013395:Sucrose / Q000737:chemistry*; D014783:Viscosity
D002364:Caseins; D002614:Chelating Agents; D005782:Gels; D008894:Milk Proteins; D013395:Sucrose