Technology Description: The invention involves starch-based microcellular foams that have a solid matrix with a network of small open cells or pores. The foams have high pore volume, low density, and a high surface area. The foams are made using a process where an aqueous gel prepared from gelatinized starch is treated to exchange the water in the gel with air, while maintaining the integrity of the network of open cells or pores. The starch-based microcellular foams are particularly useful for encapsulation and later release of a substance. Reference: Please refer to USPN 5,958,589 (Docket #0160.97), "Starch-Based Microcellular Foams," which issued on September 28, 1999, and is a division of USPN 5,595,595 (Docket #0165.95), "Aquagel-Based Lightweight Concrete," which issued on January 21, 1997. Inventors: Gregory M. Glenn Western Regional Research Center Cereal Product Utilization Research Albany, CA 94710 (510) 559-5677 / Fax: (510) 559-5936 gmg@pw.usda.gov Donald J. Stern (Same as first inventor)