Designing New Materials from Wheat Protein

Abstract

We recently discovered that wheat gluten could be formed into a tough, plasticlike substance when thiol-terminated, star-branched molecules are incorporated directly into the protein structure. This discovery offers the exciting possibility of developing biodegradable high-performance engineering plastics and composites from renewable resources that are competitive with their synthetic counterparts. Wheat gluten powder is available at a cost of less than dollars 0.5/lb, so if processing costs can be controlled, an inexpensive alternative to synthetic polymers may be possible. In the present work, we demonstrate the ability to toughen an otherwise brittle protein-based material by increasing the yield stress and strain-to-failure, without compromising stiffness. Water absorption results suggest that the cross-link density of the polymer is increased by the presence of the thiol-terminated, star-branched additive in the protein. Size-exclusion high performance liquid chromatography data of molded tri-thiol-modified gluten are consistent with that of a polymer that has been further cross-linked when compared directly with unmodified gluten, handled under identical conditions. Remarkably, the mechanical properties of our gluten formulations stored in ambient conditions were found to improve with time.

Production of renewable polymers from crop plants

“…Plastics can be produced from zein (the major corn protein; Lawton, 2002;Shukla and Cheryan, 2001), soy protein (Mohanty et al, 2005) and wheat gluten (Pallos et al, 2006;Woerdeman et al, 2004) by cross-linking with glutaraldehyde, formaldehyde or other chemicals. In 1950, about 2700 tonnes year )1 of zein plastic, a glossy, scuff-proof, grease-proof material for coatings, was produced along with 2200 tonnes year )1 of Vicara Ò , a fiber that is also based on zein.…”

Novel Protein Fibers from Wheat Gluten

“…Wheat gluten and PLA fibers were heated in water at 90°C for 60 min in various pH (3,5,7,9, and 11) conditions to test their stability. The hot water treated fibers were tested and compared to the untreated controls for the changes in tensile properties.…”

“…With a selling price of less than $0.50 per pound, and a worldwide availability of 500 000 tons every year, wheat gluten is a cheap, abundant, and renewable source for producing protein fibers. [1][2][3] In addition, wheat gluten has good stability to water and heat, excellent elasticity, and easy degradability, properties that are desirable for fibers. [3][4][5] The annual world fiber market is about 67 million tons including about 2.3 million tons of the two natural protein fibers, wool and silk.…”

The composition and extractability of thermo - molded wheat gluten bio-plastics

“…The need for environmentally friendly, renewable and biodegradable plastics is increasing due to pollution and long term health impacts of synthetic polymers (Zhang et al, 2010;Sun et al, 2008); possess suitable gas barrier properties and nutritional value (Lagrain et al, 2010;Cao et al, 2007); poor moisture barrier properties due to its hygroscopic nature; binds with water through hydrogen bridges modified by thermal and chemical treatments (Sun et al, 2008;Carvalho et al, 2008;Brauer et al, 2007;Dicharry et al, 2006;Gallstedt et al, 2004;Domenek et al, 2004;Woerdeman et al, 2004). The effect of processing on gluten network formation is determined by the SDS extractability which measures the degree of polymerization: the lower the extractability the higher the degree of polymerization (Sun et al 2008;Gallstedt et al, 2004;Domenek et al, 2004;Pommet et al, 2003;Micard et al, 2001;Cuq et al, 2000).…”

“…The effect of processing on gluten network formation is determined by the SDS extractability which measures the degree of polymerization: the lower the extractability the higher the degree of polymerization (Sun et al 2008;Gallstedt et al, 2004;Domenek et al, 2004;Pommet et al, 2003;Micard et al, 2001;Cuq et al, 2000). Besides process conditions, the presence of additives influences extractability (Lagrain et al, 2010;Sun et al, 2007;Dicharry et al, 2006;Gallstedt et al, 2004;Woerdeman et al, 2004).…”