The amylose and lipid contents, dimensions, and gelatinisation characteristics of some wheat starches and their A- and B-granule fractions

Authors

  • Amjad B. Soulaka,

    1. Food Science Division, Department of Bioscience and Biotechnology, University of Strathclyde, 131 Albion Street, Glasgow GI ISD
    Current affiliation:
    1. Food Technology Department, College of Agriculture and Forestry, Mosul University, Hamam Al-Alil, Mosul, Iraq
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  • William R. Morrison

    1. Food Science Division, Department of Bioscience and Biotechnology, University of Strathclyde, 131 Albion Street, Glasgow GI ISD
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Abstract

Starches isolated from 23 bread wheats (Triticum aestivum) and 26 durum wheats (T. durum) contained 26.3-30.6% (mean 29.1%) total amylose, 19.3–25.1% (mean 22.9%) apparent amylose and 783–1144mg 100g−1 (mean 977 mg 100g−1) lysophos-pholipids. Gelatinisation temperatures were 57.3–64.9°C (mean 61.8°C) and enthalpies 6.4–11.8 Jg−1 (mean 9.7Jg−1) in excess water, measured by differential scanning calorimetry. There were no correlations between any of these parameters. Starch granule size distributions were determined with a Coulter Counter and 100–channel analyser. A-granule mean volumes were 1235–2585μm3 (av. 1778), modal volumes 863–1804μm3 (av. 1264), mean diameters 13.9–16.0μm (av. 13.99), and specific surface areas 0.236–0.302m2g−1. B-granule mean volumes were 35.4–100.4μm3 (av. 55.9), modal volumes 16.5–54.5μm3 (av. 27.7), mean diameters 3.66–5.07μm (av. 4.09), and specific surface areas 0.684–0.920m2g−1. The B-granule contents of the starches were 12.8–34.6% (av. 27.3) by weight (sedimentation method) and 13.0–37.3% (av. 24.0) by volume (Coulter method), the latter being the more accurate method.

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