Manuscripts has been accepted online, under examination by three international reviewers, It will be accepted and published likely for the next issues 2010.
Physico-chemical properties of a purified konjac flour washed with multi-level ethanol solutions by ultrasound-assisted extraction
Simon Bambang Widjanarko1, Anni Faridah2 and Aji Sutrisno1
1) Department of Food Technology, Faculty of Agricultural Technology, University of Brawijaya, Malang Indonesia
2) Ph.D. student, Postgraduate Programme, Faculty of Agricultural Technology, University of Brawijaya, Malang Indonesia
Physico-chemical properties of a purified konjac flour extracted with ethanol solutions at multi-level concentrations (40, 60 and 80%), at different extraction cycles (1, 2 and 3) and extraction times (5, 15 and 25 minutes) using an ultrasonic baths were investigated. The results showed that crude konjac flour which was extracted three periods for 25 minutes showed the highest content of glucomanan, its viscosity, the degree of whiteness and it had the lowest calcium oxalate content. Calcium oxalate reduced significantly and the degree of whiteness increased due to multi-level ethanol washing treatments assisted by ultrasonic. Levels of extraction periods and extraction times on ultrasonic-assisted extraction did not significantly effect on its moisture content and total yield of treated konjac flour. Moisture content of treated flours were slightly higher than control, and total yield of treated flours were almost the same amongst treatments used.
Keywords: Physico-chemical properties, multi-level ethanol extraction, konjac flour, ultrasonic.