Microwave drying and grinding characteristics of gum karaya (Sterculia urens).

Walde, S. G. and Balaswamy, K. and Shivaswamy, R. and Chakkaravarthi, A. and Rao, D. G. (1997) Microwave drying and grinding characteristics of gum karaya (Sterculia urens). Journal of Food Engineering, 31 (3). 305-313, 12 ref..

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Abstract

Samples of gum karaya (Sterculia urens) of approximately 3.5 g each were dried in a domestic microwave oven for different time periods ranging from 10 to 90 s. The samples showed an average moisture loss of 7.5 x 10-j kg of water/kg of dy weight of solids per second. The dried samples were ground in a domestic dy grinder and the ground samples were subjected to sieve analysis to calculate the average final particle size. The grinding characteristics were evaluated bv calculating the Bond’s work index. The microwave-dried samples were crisp and consumed less energy for grinding compared to the control samples. This was evident from the bulk dying of gum samples of 1.5 kg (initial moisture content 16%) for 20 min. The Bond’s work index for this sample was 0.4786 compared to 0.7567 k Wh kg-’ for the control of the equal moisture content. Studies were also made on the effect of the microwave power supply on dying and grinding, and this was found to havIe no effect on the latter These studies have all indicated that microwave dying is a good candidate for dying of gum samples. The rheological studies were carried out with I % suspensions. They indicate non-Newtonian pseudoplastic flow behaviour and the data fit well to the power law fluid model. The effect of dying time on the ,flow behaviour index was assessed.

Item Type:	Article
Uncontrolled Keywords:	Gum Karaya microwave drying grinding
Subjects:	600 Technology > 09 Industrial oils, fats, waxes, gases > 06 Vegetable Gums 600 Technology > 05 Chemical engineering > 02 Drying, Dehydration
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	05 Aug 2008 06:51
Last Modified:	30 Dec 2016 12:36
URI:	http://ir.cftri.res.in/id/eprint/4640

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