title: Effect of ultrasonic homogenization on the Vis/NIR bulk optical properties of milk.
abstract: The size of colloidal particles in food products has a considerable impact on the product's physicochemical, functional and sensory characteristics. Measurement techniques to monitor the size of suspended particles could, therefore, help to further reduce the variability in production processes and promote the development of new food products with improved properties. Visible and near-infrared (Vis/NIR) spectroscopy is already widely used to measure the composition of agricultural and food products. However, this technology can also be consulted to acquire microstructure-related scattering properties of food products. In this study, the effect of the fat globule size on the Vis/NIR bulk scattering properties of milk was investigated. Variability in fat globule size distribution was created using ultrasonic homogenization of raw milk. Reduction of the fat globule size resulted in a higher wavelength-dependency of both the Vis/NIR bulk scattering coefficient and the scattering anisotropy factor. Moreover, the anisotropy factor and the bulk scattering coefficients for wavelengths above 600 nm were reduced and were dominated by Rayleigh scattering. Additionally, the bulk scattering properties could be well (R(2) ≥ 0.990) estimated from measured particle size distributions by consulting an algorithm based on the Mie solution. Future research could aim at the inversion of this model to estimate the particle size distributions from Vis/NIR spectroscopic measurements.
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium. Electronic address: Ben.Aernouts@kuleuven.be.
authors.forename: Ben
authors.initials: B
authors.lastname: Aernouts
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Robbe
authors.initials: R
authors.lastname: Van Beers
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Watté
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Tjebbe
authors.initials: T
authors.lastname: Huybrechts
authors.affiliation: KU Leuven, Department of Chemical Engineering, ProcESS, Willem de Croylaan 46, 3001 Leuven, Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Jordens
authors.affiliation: KU Leuven, Department of Biosystems, Livestock-Nutrition-Quality, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Daniel
authors.initials: D
authors.lastname: Vermeulen
authors.affiliation: KU Leuven, Department of Chemical Engineering, ProcESS, Willem de Croylaan 46, 3001 Leuven, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Van Gerven
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Lammertyn
authors.affiliation: KU Leuven, Department of Biosystems, MeBioS, Kasteelpark Arenberg 30, 3001 Leuven, Belgium.
authors.forename: Wouter
authors.initials: W
authors.lastname: Saeys
mesh_terms: D000818:Animals; D007834:Lasers; D008892:Milk / Q000737:chemistry*; D055620:Optical Phenomena; D010316:Particle Size; D013056:Spectrophotometry, Ultraviolet; D019265:Spectroscopy, Near-Infrared; D013499:Surface Properties; D014465:Ultrasonics
keywords: Fat globule size distribution; Food emulsion; Light scattering; Milk; Ultrasonic homogenization; Vis/NIR spectroscopy