Review: bio-based films from zein, keratin, pea, and rapeseed protein feedstocks

The development of bio-based films from proteins for their utilization as packaging materials and composites has gained popularity due to the availability, renewable nature, and biodegradability of proteins. The most studied of these polymers is sourced from soy. However, other sources of proteins show great commercial potential when transformed into films. As such, zein from corn and keratin from low-value chicken feather can be plasticized into films which exhibit good mechanical properties. Films derived from pea proteins can resist UV light transmission due to the presence of disulfide bonds within the network and the presence of amino acids such as tyrosine, tryptophan, and phenylalanine. Proteins from rapeseed have not been extensively studied as feedstocks for bio-based films but show great potential since their amino acid composition is similar to soy proteins. This review aims at combining and condensing the body of research performed on the synthesis of zein-, keratin-, pea-, canola-, and rapeseed-based films. The structural diversity of these proteins highly influences their processing methods and the physical properties of the resulting films. The potential applications of these bio-based materials are also highlighted.