Original Research Article
Year: 2018 | Month: February | Volume: 5 | Issue: 2 | Pages: 36-40
The Correlation of Colour and Viscosity Changes of Rice Flour with Gelatinization Percentage under Infrared Heating
Gunaratnam Abhiram
Department of Agricultural Engineering, Faculty of Agriculture, University of Peradeniya, Sri Lanka.
Department of Export Agriculture, Faculty of Animal Science and Export Agriculture, Uva Wellassa University, Sri lanka.
ABSTRACT
The study was conducted with the objective of finding out the correlation of colour and viscosity changes with gelatinization percentages of rice flour during gelatinization using far-infrared heating. The rice flour was roasted or heated with three far-infrared panel each having 500 W and degree of gelatinization, viscosity and colour changes were measured. The gelatinization percentage, viscosity and browning reaction increases with the far-infrared intensity and exposure time. When the combination of far-infrared intensity and exposure time was higher, a higher gelatinization percentage, viscosity changes and brown colour development were observed. The viscosity changes increased linearly, whiteness reduction (ΔL*) increased exponentially and total color change (ΔE*) increased linearly with the degree of gelatinization. Maximum gelatinization (100%) could be achieved by exposing rice flour to 9000 W/m2 for 6 minutes. Therefore it can be concluded that there is a strong positive relationship for viscosity and colour development against degree of gelatinization of rice flour gelatinized with far-infrared radiation.
Key words: colour changes, correlation, far-infrared, rice flour gelatinization, viscosity.
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