Structure characteristics of Coix seeds prolamins and physicochemical and mechanical properties of their films

The structure characteristics of three Coix seed (BCS, SCS, and TCS) prolamins were studied and their pure films properties compared. The three prolamins showed different amino acid composition, and hydrophobicity, and the results of LC-MS/MS exhibited their peptide sequence differences. Their aggregates were rodlike structures, formed very a fine meshwork and had self-assembly properties, which was the basis of their film-forming, similar to zeins. The SCS and TCS prolamins showed better thermal stability than that of BCS prolamins, and their films had better water resistance, puncture, and tensile strengths than those of pure zein film. The SCS film displayed better water absorption and higher elongation than those of the TCS film. Although some properties of the films, such as flexibility and thermal stability, still need to be improved, these results have proven that Coix seed prolamins have potential as biodegradable films for use in the food industry.