Effect of variety and growing environment on pasting and thermal properties of wheat starch

Abstract

The objective of this study is to increase our understanding of the heritability of starch quality characteristics, and of their sensitivity to effects of the growing environment. To this end, variability of pasting, thermal and gel properties of starch was examined using grains of five varieties of wheat (Triticum aestivum L.), grown in commercial cropping systems in five locations in Australia in 2 years. About 60–70% of the variability of DSC thermal properties and hardness of starch gels kept at 4°C for 24 h was contributed by factors related to growing conditions. Starch pasting properties had a higher degree of heritability (30–35%), although environmental conditions also contributed significantly to variability. A key effect of the growing environment appeared to be on the stability of the crystallites in the starch granules. While the results obtained are characteristic of the varieties used in this study, and of the specific environmental factors that influenced crop growth, the results nevertheless indicate that atmospheric and soil conditions can affect functional properties of starch that are important in foods and other applications. The finding that pre-anthesis conditions seem to affect the structure of starch raises interesting questions about the mechanism of starch biosynthesis in wheat grains.