Scientific journal

53 2014

Journal of Food and Nutrition Research
Summary No. 1 / 2014

Nowak, E. – Krzeminska-Fiedorowicz, L. – Khachatryan, G. – Fiedorowicz, M.
Comparison of molecular structure and selected physicochemical properties of spelt wheat and common wheat starches
Journal of Food and Nutrition Research, 53, 2014, No. 1, s. 31-38

Maciej Fiedorowicz, Department of Chemistry and Physics, University of Agriculture, 122 Balicka Str., 30-149 Cracow, Poland.
Tel: 48126624139, fax: 48126634336, e-mail: rrfiedor@cyf-kr.edu.pl

Summary: Molecular weight (Mw) and radii of gyration (Rg) of starch polysaccharide chains, distribution of amylopectin structural units, crystallinity, thermal properties, pasting viscosity profiles, susceptibility to alpha-amylolysis, swelling power and solubility of spelt and wheat starches isolated from commercially available spelt and wheat flours were studied. Average molecular weight Mw of polysaccharide chains eluted under the whole complex peak from high-performance size exclusion chromatography (HPSEC) column was found to be 0.829 × 107 g·mol-1 for spelt starch and 2.307 × 107 g·mol-1 for wheat starch. Significant differences in amylopectin chain length distribution between spelt and wheat starch were found. Shortest A type chains with Mw = 3.418 × 103 g·mol-1 and Rg = 65.4 nm constituted 88.2% of total mass of debranched spelt starch, whereas mass ratio of respective chains of wheat starch with Mw = 5.277 × 103 g·mol-1 and Rg = 88.2 nm was found to be 32.7%. Wheat starch was more susceptible to alpha-amylolysis than spelt starch. Enzymatic hydrolysis, rate constant for the first stage of hydrolysis (k1 = 4.5 × 10-3 mg·ml-1min-1) and final hydrolysis extent (42.5%) for wheat starch were significantly higher than the respective values for spelt starch (k1 = 2.3 × 10-3 mg·ml-1min-1; 35%).

Keywords: amylopectin; molecular weight; polysaccharides; spelt

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