The changed structures of Cyperus esculentus protein decide its modified physicochemical characters: Effects of ball-milling, high pressure homogenization and cold plasma treatments on structural and functional properties of the protein

Three physical treatments, including ball-milling (BM), high pressure homogenization (HPH) and cold plasma (CP) were applied to modify structural and functional properties of Cyperus esculentus protein (CEP). The results showed that three treatments significantly altered morphology and reduced particle size of CEP. Both primary and secondary structures of CEP were hardly changed, while disulfide bonds and hydrophobic forces between amino acid residues of CEP were interrupted by three treatments, releasing free sulfhydryls and hydrophobic groups. With the free moiety accumulation, the reformed interactions between them enhanced the crystallinity and thermostability of CEP. Besides, solubility and emulsifying properties of CEP were significantly improved within a certain range of treatment duration and intensity, and three treatments decreased water but increased oil holding capacity of CEP. Conclusively, the modified physicochemical properties of CEP were decided by the changed molecular structures of CEP, and different treatments may satisfy different processing requirements for the protein.