Use of Ultrasound for Characterizing Dairy Products

• Published in: Journal of dairy science Vol. 88; no. 4; pp. 1320 - 1334
• Main Authors: Dukhin, A.S., Goetz, P.J., Travers, B.
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.04.2005; Am Dairy Sci Assoc; American Dairy Science Association
• Subjects: Acoustics; Animal productions; Animals; Biological and medical sciences; Dairy Products - analysis; droplet size distribution; fat content; Fats - analysis; Food Handling - methods; Food industries; Food Technology; Fundamental and applied biological sciences. Psychology; Milk - chemistry; Milk - diagnostic imaging; Milk and cheese industries. Ice creams; Particle Size; process control; Spectrum Analysis - methods; Temperature; Terrestrial animal productions; Ultrasonics; Ultrasonography; ultrasound; Vertebrates; fat content; process control; ultrasound; droplet size distribution; Dairy product; Ultrasound; Dairy industry
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(05)72798-3

It has been known for a long time that acoustic measurements offer some unique features for characterizing liquid food products in their intact state, without any preparation or destruction of the product sample. Acoustic characterization can yield information about fat content, droplet size distribution, and kinetics of product variation with time. Furthermore, acoustic methods are very attractive for on-line process control. This paper addresses several questions: Why does ultrasound attenuate when propagating through a heterogeneous system? What properties of dairy products can be extracted from such ultrasound measurements? Which measurement is better for product characterization: attenuation or sound speed? What measurement precision is required to adequately characterize product properties? What frequency range is of most value for determining these product properties? It is possible to provide answers to many of these questions using experimental data, thereby avoiding, for the moment, any complex mathematical analysis. We present several applications of acoustic spectroscopy for characterizing dairy products, including characterization of the fat content in a wide variety of dairy products; calculation of the fat droplet size distribution in milk without dilution; and calculation of water droplet size in butter, without dilution or melting.