of the microporous amylase treated starch granules although the partially hydrolyzed starch granules have been found to have surprising mechanical strength in the dry state and significant structural integrity in water dispersion a greater degree of structural integrity can be introduced by treating the microporous granules with an effective amount of a bifunctional starch reactive chemical cross linking agent any of a variety of art recognized starch cross linking agents including those recognized as food acceptable by the food and drug administration can be used suitable cross linking agents include phosphates such as sodium trimetaphosphate dicarboxylic acids derivatives particularly c 2 c 6 dicarboxylic acids including maleic and glutaric acid phosphorous oxychloride epichlorohydrin and u03b2 u03b2 dichlorodiethyl ether microporous starch granules become more and more resistant to mechanical damage and to swelling and dissolution with increased degree of cross linking starch cross linking agents are described in my book starch chemistry and technology second edition 1984 academic press inc new york new york the capacity of microporous starch granules prepared in accordance with this invention to absorb functional substances is dependent upon the compatibility of the surfaces of the starch matrix with the intended absorbate thus the partially hydrolyzed microporous granules can be treated with surface modifying agents to enhance granule absorptivity if the substance to be absorbed onto and into the starch matrix has a predominant lipid character the starch matrix can be treated to render the pore surfaces more lipophilic the partially hydrolyzed starch granules can be treated with solutions.