  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
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Characterization of different starches oxidized by hypochlorite. D. KUAKPETOON (1) and Ya-Jane Wang (1,2). (1) Department of Food Science, University of Arkansas, Fayetteville, AR 72704; (2) Corresponding author, Email: yjwang@comp.uark.edu, Phone: 501-575-3871, Fax: 501-575-6936.
The effects of starch origin (potato, corn, and rice starches) and hypochlorite level (NaOCl, 0.8% and 2% w/w) on the structures and physicochemical properties of oxidized starches were investigated. Carboxyl and carbonyl contents of oxidized starches increased with increasing NaOCl, with potato starch having the highest and corn starch having the lowest carboxyl content at both NaOCl levels. Oxidation generally reduced the pasting temperature and viscosity of native starches as demonstrated by using a Rapid Visco-Analyzer. The peak viscosities of oxidized rice and corn starches were higher than those of their native counterparts at 0.8% NaOCl. The morphology of starches was not altered and X-ray diffraction patterns of all the starches remained unchanged after oxidation. Oxidized starch batters exhibited greater adhesions than did native starch batters with rice starch batter exhibiting the greatest adhesion. Carbohydrate profiles by high-performance size-exclusion chromatography indicated that both amylopectin and amylose were degraded during oxidation. The level of oxidation was largely dependent on the degree of crystallinity of starch and the degree of polymerization of amylose, whereas adhesion property of oxidized starch was mainly attributed to its granular size and shape.
Copyright 2001
The American Association of Cereal Chemists