Mechanistic and conformational studies on the interaction of food dye amaranth with human serum albumin by multispectroscopic methods

► We investigate the interaction of amaranth with HSA by multispectroscopic methods. ► The florescence of HSA is quenched by amaranth through a static quenching mechanism. ► The surface hydrophobicity of HSA increases upon interaction with amaranth. ► Amaranth is located in subdomain IIA (Site I) of HSA. ► The binding of amaranth to HSA can induce changes in the secondary structure of HSA.