Evaluation of new methods and measuring systems for characterisation of flow behaviour of complex foods
Författare
Summary, in English
Conventional methods often impose difficulties when measuring the viscosity of fluids containing particles or fibres, e.g. tomato paste or fruit preparations, mainly due to the narrow gaps of the viscometer. In order to solve these problems different geometries have been developed, e.g. different mixer systems and wide gap double concentric cylinders. However, these can not be evaluated assuming a constant shear rate throughout the fluid. In this study, three different kinds of mixer systems have been studied; a small and a large paddle and a helix. For the mixer systems an average shear rate must be determined and a quotient between torque and shear stress must be found. in addition, a wide gap double concentric cylinder (DCC) was examined and evaluated using two different methods. When evaluating the mixer systems a method based on the Couette analogy has been used successfully for a number of complex fluids, including prepared sauces and fruit samples containing particles of different size. The DCC has been evaluated using a numerical as well as an approximate method, both giving results of good accuracy. All systems had the limitation that no consistent results were obtained for tomato paste. However, when starch was added to the diluted tomato paste dispersion, satisfying results were once again obtained.
Avdelning/ar
- Department of Food Technology, Engineering and Nutrition
- Avdelningen för kemiteknik
Publiceringsår
2006
Språk
Engelska
Sidor
19-25
Publikation/Tidskrift/Serie
Applied Rheology
Volym
16
Issue
1
Dokumenttyp
Artikel i tidskrift
Förlag
De Gruyter
Ämne
- Food Engineering
- Chemical Engineering
Nyckelord
- food dispersions
- tomato paste
- rheology
- food
- double concentric cylinder
- Couette analogy
- mixer viscometer
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1430-6395