• An ultrasound treated corn ACE inhibitory peptide-ferrous chelate was developed. • CP-Fe possessed ferrous content of 66.39% and ACE inhibition activity of 82.21%. • CP-Fe was formed by binding peptide amino, carbonyl and carboxyl groups with Fe²⁺. • CP-Fe was stable at various temperatures, pH and gastrointestinal environments.

• Combined polyphenol and ultrasound modification was incorporated into TSC-CTS film. • GA-UT modification increased tensile strength of the TSC-CTS film by 47.03%. • GA-UT modification improved antioxidant activity of the TSC-CTS film by 24.16 folds. • GA-UT modification reduced transmittance and permeability of the film by 29.26% and 15.70%. • GA-UT modified TSC-CTS films possessed improved antibacterial activity.

• An effective film preparation method by sweep frequency pulsed ultrasound was developed. • Significant increases were observed in the mechanical properties of film by sonication. • Sonication achieved more a ordered and compact structure and a higher thermostability of film. • Ultrasonic treated film presented good antioxidant and antibacterial activities.