Cottonseed proteins from meals with high yield for plasticizer-free biofilms with good mechanical properties.

We report a green, non-destructive, and highly effective extraction, dissolution, film casting and solidification technology for cottonseed proteins from cottonseed meals. Although cottonseed meals are protein-rich, with about 40 % of proteins, they are cheap with a price 20 % to 50 % lower than soybean meals due to their poor performance as feed and bioplastics and due to the limited efforts from the academia and industries. Our green and protective protein extraction technology provided an extraction yield of 89 % and purity of 92 % with minimal destruction to the protein backbones, better than those reported previously. Our green dissolution/casting technology provided proteins with maximized unfolding and entanglement. When cottonseed proteins were solidified to form bioplastics, our technology also enabled substantial recovery of cystine crosslinkages between protein molecules to maximize the properties of the final products. Using our technologies, cottonseed protein films from cottonseed meals have toughness higher than what have been reported in literature without adding plasticizers or reinforcement materials, therefore better property stability or shelf life. Our technology is also cost-effective and can potentially add values to the cotton industry.