Mechanistic insight into the regulation of gelatin hydrogels structure and gel-forming properties by reactive species in plasma-activated water.

This study established a refined plasma activated water (PAW) system to distinguish the effects of acidification and H2O2 from the broader effects of PAW-derived reactive species on gelatin gelation. Acidification altered surface charge and resulting in an increased in β-turn content (38.90%) and ionic bonding (15.23%). H2O2 treatment induced oxidative modification, leading to sulfhydryl oxidation, increased hydrophobic interactions and decreased gelation temperature, but partially disrupted triple-helix-based crosslinking. Notably, PAW exerted unique enhanced effects, significantly enhancing gelling properties by strengthening hydrogen bonding and lowering the eutectic point. Molecular docking further suggested that PAW-derived reactive species promoted hydrogen bonding and hydrophobic interactions with gelatin. These improvements highlight the potential of PAW-modified gelatin for functional gelled foods and gelatin-based packaging requiring enhanced structural and moisture stability, although validation in complex food matrices and practical processing systems remains necessary.