Synergistic modification of starch-based active films by citric acid and chlorogenic acid: Interactions,...

Poor properties have limited starch film application in food packaging. This study investigated citric acid (ca) and chlorogenic acid (CGA) effects on structural and functional enhancements of starch films. Microrheology demonstrated that ca and CGA suppressed starch long-term reaggregation during film-forming. SEM, LF-NMR, and WVP results confirmed compact morphology, increased immobile water content, and reduced WVP values (from 3.82 × 10^-10 to 2.06 × 10^-10 (g/(m·s·Pa)) of starch films with ca and CGA. Molecular docking and FTIR revealed hydrogen and ester bonding interactions in the composite, with a higher binding affinity for CGA-starch (-4.59 kcal/mol) than CA-starch (-3.48 kcal/mol). The film with 4% ca and 15% CGA exhibited the lowest minimum inhibitory concentration of 12.5 mg/mL against S. aureus, and high DPPH• scavenging activity (91%), which extended fresh-cut cherry tomato shelf life. These findings establish a viable strategy for developing functional starch-based packaging.