Physicochemical characterization and utilization of Cyperus rotundus starch

Starch was isolated from the subterraneous swollen tuberous bases and nodules of Cyperus rotundus by a wet-milling process with a yield of 24.1% on a dry weight basis. The white starch was characterized in terms of granule size, specific gravity, amylose content, cold water extracts, moisture and ash contents, paste stability, clarity, viscosity at 20°C, adhesive strength and line-spread at 50°C. Starch noodles were prepared and the quality assessed by tensile strength and solid loss during cooking. A textile sizing solution was formulated with the starch and the tensile strength of yarns sized with the solution examined. The starch granules were large-sized and comparable to the potato types, and had an appreciable amylose content, 26.73%. Solutions of the starch showed a high pasting temperature, viscosity and adhsive strength. The C. rotundus starch noodles and the sized yarns both elicited fairly good tensile strengths, comparable to standards.