Effect of cross-linking on the physicochemical and physiological properties of corn starch

Corn starch was chemically modified by cross-linking with STMP/STPP (99:1. w/w) and the physicochemical and physiological properties (in vitro and in vivo) of the cross-linked corn starch were investigated as a function of the degree of cross-linking. Cross-linking decreased the solubility, swelling factor, and paste clarity of corn starch. While the swelling factor was highly correlated with the degree of cross-linking (R-2 = 0.878), the X-ray diffraction patterns did not show any significant alteration in the crystallinity of corn starch. It was shown by SEM measurement that a black zone was observed on the surface of crossed-linked starch granules, which did not occur with native starch. When mice were fed the diets containing the corn starch with low (CLCS-5) and high (CLCS-12) degree of cross-linking (51.3 and 99.1%, respectively), significant effects on the final body weight, weight gain as well as perirenal weight of the mice (p < 0.05) were observed. Also, significant decreases in total lipid, triglyceride, and total cholesterol concentrations in serum were detected in CLCS-5 and CLCS-12 groups (p < 0.05). While total lipid level in the liver decreased with increasing degree of cross-linking, the triglyceride level was not affected by the supplementation with both of CLCS-5 and CLCS-12 corn starch samples. (C) 2010 Elsevier Ltd. All rights reserved.