title: Enhanced creaming of milk fat globules in milk emulsions by the application of ultrasound and detection by means of optical methods.
abstract: The effects of application of ultrasonic waves to recombined milk emulsions (3.5% fat, 7% total solids) and raw milk on fat destabilization and creaming were examined. Coarse and fine recombined emulsions (D[4,3]=9.3 μm and 2.7 μm, respectively) and raw milk (D[4,3]=4.9 μm) were subjected to ultrasound for 5 min at 35°C and 400 kHz or 1.6 MHz (using a single transducer) or 400 kHz (where the emulsion was sandwiched between two transducers). Creaming, as calculated from Turbiscan measurements, was more evident in the coarse recombined emulsion and raw milk compared to that of the recombined fine emulsion. Micrographs confirmed that there was flocculation and coalescence in creamed layer of emulsion. Coalescence was confirmed by particle size measurement. These results imply that ultrasound has potential to pre-dispose fat particles in milk emulsions to creaming in standing wave systems and in systems with inhomogeneous sound distributions.
authors.affiliation: CSIRO Food and Nutritional Sciences, Werribee, VIC 3030, Australia. pablo.juliano@csiro.au
authors.forename: P
authors.initials: P
authors.lastname: Juliano
authors.forename: A
authors.initials: A
authors.lastname: Kutter
authors.forename: L J
authors.initials: LJ
authors.lastname: Cheng
authors.forename: P
authors.initials: P
authors.lastname: Swiergon
authors.forename: R
authors.initials: R
authors.lastname: Mawson
authors.forename: M A
authors.initials: MA
authors.lastname: Augustin
mesh_terms: D000818:Animals; D003611:Dairy Products / Q000032:analysis*; D004655:Emulsions / Q000737:chemistry / Q000528:radiation effects; D005223:Fats / Q000737:chemistry* / Q000528:radiation effects*; D005511:Food Handling; D008892:Milk / Q000737:chemistry* / Q000528:radiation effects*; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D011829:Radiation Dosage; D013010:Sonication / Q000379:methods*; D014783:Viscosity
chemical_list: D004655:Emulsions; D005223:Fats