Physicochemical Properties of Water-soluble Polysaccharide Enriched Fractions of Adlay and Their Hypolipidemic Effect in Hamsters
YEN-TSUN YU1, TING-JANG LU1, MENG-TSAN CHIANG2 AND WENCHANG CHIANG1*
1. Graduate Institute of Food Science and Technology, National Taiwan University, 1, Sec. 4, Roosevelt Rd., Taipei City 106, Taiwan, R.O.C.
2. Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Rd., Keelung City 202, Taiwan, R.O.C.
(Received: May 19, 2005; Accepted: July 19, 2005)
ABSTRACT
To investigate the physicochemical propertites of the water-soluble polysaccharide enriched fractions of adlay (Coix lachrymajobi L. var. ma-yuen Stapf) and their hypolipidemic effects, we fed the enriched fraction adlay water-soluble dietary polysaccharide (AWSP) to hamsters to evaluate the effects of AWSP on serum and hepatic cholesterol and triglyceride levels. The AWSP used was extracted from dehulled adlay and its high- and low-molecular weight fractions (AWSPH and AWSPL, respectively) and prepared by 40% ethanol concentration fractionation. Hamsters fed with AWSP showed serum / hepatic total cholesterol, triglyceride and serum LDL cholesterol levels significantly lower than those in the cellulose control group. We found higher serum hypolipidemic activities associated with AWSPH than with AWSPL, which were correlated with AWSPH's higher molecular weight and water-holding capacity. Fecal lipids data supported our theory that the hypolipidemic activities of AWSPH decrease cholesterol absorption in the intestines. We found ASDFL to be relatively more fermentable in cecum and to have higher hepatic hypolipidemic activities than AWSPH, which correlated with the amount of short-chain fatty acid in cecum. The apparent molecular-weights of AWSPH and AWSPL were 14.5 and 8.7 × 104 Daltons, respectively.
Key words: adlay, water-soluble polysaccharide, physicochemical property, hypolipidemic effect, hamster