Morphological and Physicochemical Properties of Very Small Granules Starch from Agriophyllum squarrosum (L.) Moq. in Comparison with Maize Starch

Agriophyllum squarrosum (L.) Moq. (A. squarrosum) is an annual fast-growing psammophyte, producing large amounts of starchy seeds. To assess the potential application of this starch and increase the utilization of its flour, the composition, morphological, thermal, pasting, rheological, and textural properties of the starch are characterized by comparing with maize starch. The amylose content of the starch is 26.31%. Microscopy images reveal that the starch granules have a round shape and most of them are smaller than 1 mu m in diameter. The X-ray diffractogram exhibits a typical A-type pattern, and the crystallinity is 36.75%. The gelatinization temperature and enthalpy are 64.26-77.60 degrees C and 14.29Jg(-1), respectively. In contrast to maize starch, A. squarrosum starch has lower swelling power and solubility. RVA analysis shows a lower pasting viscosity and no break down at 95 degrees C. The starch has better cooking and shearing stability during heating and a lower tendency to retrograde during cooling and storage. Unique characteristics such as the extremely small size, and the excellent heating and shearing stability of the starch can contribute to special utilization in food or non-food industries.