Professional paper
Use of low-intensity ultrasound for foreign bodies determination in food systems
Mladen Brnčić
; Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
Damir Markučič
orcid.org/0000-0001-6310-1325
; Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
Miroslav Omelić
; Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
Branko Tripalo
; Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
Damir Ježek
orcid.org/0000-0002-1952-8310
; Faculty of Food Technology and Biotechnology, University of Zagreb, Zagreb, Croatia
Abstract
Ultrasound waves are mechanical vibrations in a solid or fluid with frequencies above 20 kHz. Ultrasound has been used in a many different technologies for a various industry applications and more and more in food industry, as an analytical tool, or for the raw material modification before, during and after the manufacturing of food products.
The use of ultrasound in food technology can be globally divided as low-intensity (< 1 Wcm-2), and hi-intensity (> 1 Wcm-2). Hi-intensity ultrasound is used to enhance, promote or change physical or chemical properties of foods. Low-intensity ultrasound is non-destructive method that enables data about physicochemical properties of food components and products such as structure, flow rate, thickness, composition, particle size and attendance of foreign bodies.
A “foreign body” is any unwanted piece of solid matter present in foodstuffs. It can be piece of wood, glass, rubber, stone, metal, plastic, fibre, dirt, nail or thin hair. Foreign bodies are significantly dissimilar from foodstuffs in terms of acoustic impedance and ultrasonic velocity, consequently a certain ultrasound response is to be registered.
Foreign bodies can be detected by registering the reflected, refracted or scattered acoustic signals. In practical applications for detection of
foreign bodies in foodstuffs frequency is usually above 50 kHz. In this work theoretical and practical approach for this technology is presented.
Keywords
ultrasound; frequency; foreign bodies
Hrčak ID:
49938
URI
Publication date:
1.7.2009.
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