Pasting and swelling properties of wheat flour and starch in relation to amylose content

The influence of the content of total amylose, free amylose and lipid-complexed amylose, and amylopectin chain length distribution, on swelling behavior and pasting properties of wheat (Triticum aestivum L.) flour and starch from varieties with increased amylose content was investigated. These wheat starches displayed pasting properties that featured decreasing peak, breakdown and final viscosities with increasing total amylose content. Swelling power of flour was found to be a useful predictive tool of amylose content and pasting characteristics of the wheat starches. Amylopectin chains with degree of polymerization greater than 36 were correlated with increasing peak, minimum and final viscosities of starch pastes. No significant correlations were found between amylopectin chain length distribution and swelling behavior of flours and starches. The results are discussed in relation to the principles underlying swelling tests and pasting behavior of wheat starches.