Abstract: Food safety problem of genetically modified crops have aroused public concern day by day. As crop seed is one of the most important source of food, the research on safety of genetically modified crop seeds need to be strengthened. The present work applied cotton and corn seeds, Bt modified varieties and non-genetically modified varieties, to treat with high temperature（55-130℃）, and then detected the dynamic digestion process of Bt protein with sandwich enzyme link immunoassay（ELISA）. The result of the assay showed that the Bt protein in different crops have different degree of tolerance to high temperature. The capacity of enduring heat stress of Bt protein in cotton seed is better than that in corn seed; the toxin protein significantly decreased within 10 min in the high temperature treatment, followed by slow degradation; all Bt protein in transgenic corn and cotton seeds can obviously inactivation treated with 130℃ or higher temperature.

Key words: High temperature, Bt protein, Seed, Sandwich enzyme link immunoassay