Bioaccessibility and transformation of cadmium in different tissues of Zhikong scallops (Chlamys farreri) during in vitro gastrointestinal digestion

•A significant organ-specific total cadmium distribution in Zhikong scallops (Chlamys farreri)•The bioaccessibility of total Cd ranged from 44.0% (kidney) to 90.2% (gonad) for different tissues of C. farreri.•Steaming decreased the total Cd bioaccessibility in the mantle, gill, gonad, digestive gland and muscle.•The reactive cadmium ions (Cd2+) could be detected in the digestive juice of five tissues except for the muscle.•The bioaccessible Cd2+ content in the digestive gland, gill and gonad tissues all significantly increased after steaming.