foams suitable for such uses as landfill coverage , frost protection , volatile emission control , gas control in mining , are composed of a hydrolyzable protein and a pre - gelatinized cationic modified starch along with other ingredients . the foam concentrate can be made at ambient temperature , is stable over time , can be easily tailored to achieve a desired foam stiffness and drain time characteristic over wide ranges , and can be easily diluted at ambient temperature to produce a foamable composition .