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The physicochemical properties of starch isolated from Yullmoo (Coix lachryma-jobi var. mayuen stapf.) and Yeomjoo (Coix lachryma-jobi L.) were investigated. The average diameters of starch granules of Yullmoo and Yeomjoo were 12.0 microns, bath of all, and the shape of these starch granules were hexagon, octagon and round. X-ray diffraction patterns of two samples were A-types and amylose contents of Yullmoo and Yeomjoo starch were 0% and 23%, respectively, iodine affinities of these were 0.08% and 4.2%, respectively, blue values and alkali numbers of these were 0.13 and 0.43, 2.4 and 7.2, and raising power of these were 280 and 20, respectively. Yullmov starch had higher swelling power than Yeomjoo starch. The increase in optical transmittance of 0.1% suspensions of Yullmoo and Yeomjon starches occurred at 60℃ and continued up to 75℃ for Yullmov, 85℃ for Yeonajoo. Amylogram data on 5% of Yullmoo and Yeomjoo starch suspensions showed that gelatinization temperatures and maximum peak heights of Yullmoo and Yeomjoo were 68.5℃ and 78℃, 920 and 310 B.U., respectively. Intrinsic viscosities of Yullmoo and Yeomjoo starches were 1.49 and 1.77, respectively, and interaction coefficients of the two starches were 0.57 and 0.56, respectively. The extent of retrogradation determined at 2℃ showed that retrogradation occurred slowly with Yeomjoo starch paste but little with Yullmoo.
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