Modification of Wheat Gluten

Biorelated Polymers Sustainable Polymer Science and Technology Edited by Chiellini et al., Kluwer Academic/Plenum Publishers, 2001 

The efficiency of cross-linking wheat gluten with EDC/NHS was evaluated by measuring  

---

Lens, J.-P., Mulder, W. J., and Kolster, P., 1999, Modification of wheat gluten fi>rnonfi)od applications. Cereal Foods WorU 44 5-9. 

Chemical modification is a powerful tool to improve protein properties. There are different ways to modify proteins. Cross-linking, which is the covalent linking of protein chains, decreases the water sensitivity of wheat gluten. This may lead to improved water stability and to an increased strength of protein based products. The present work opens new outlets for... 

Gennadios, A., Weller, C.L., and Testing, R.F. (1993). Modification of physical and barrier properties of edible wheat gluten-based films. Cereal Chem., 70 426-429. 

P. Tosi, A. Giovangrossi, R. D Ovidio, F. Bekes, O. Larroque, J. Napier, and P. Shewry, Modification of the low molecular weight (LMW) glutenin composition of transgenic durum wheat effects on glutenin polymer size and gluten functionality. Mol. Breed. 16(2), 113-126 (2005). 

In order to optimise the process parameters (temperature, plasticiser content, residence time and so on), during the transformation of material proteins, the specific characteristics of each protein should be determined (thermal, mechanical and chemical sensitivities, and high viscosities of the rubbery phases above the Tg) for these new raw materials. However, the physico-chemical factors involved in these processes are unclear because very little is currently known about protein modifications that take place when processing at high temperature under low hydration conditions [182]. This has mainly been determined for wheat gluten-based materials [71,74,75]. 

For example, succinylated wheat gluten is quite soluble at pH 5 (cf. Fig. 1.40). This effect is related to disaggregation of high molecular weight gluten fractions (cf. Fig. 1.41). In the case of succinylated casein it is obvious that the modification shifts the isoelectric point of the protein (and thereby the solubility minimum) to a lower pH (cf. Fig. 1.42). Succinylation of leaf proteins improves the solubility as well as the flavor and emulsifying properties. 

Domenek S., M., M. H., Guilbert, S. Wheat gluten based agromaterials Environemental performance, biodegradability and physical modifications The Royal Society of Chemistry Cambridge, 2004. 

Proteins valorization as thermoplastic or thermosetting materials has been performed by chemical modifications [212]. Improved functional properties can be obtained by esterification of protein carboxyl and amide groups by fatty alcohol that lead to a protein-derivative with improved functional properties which would result into a lower water sensitivity. For example sunflower and wheat gluten have been esterified by octanol in the presence of an acid catalyst. Esterified protein result less soluble at basic pH compared to native proteins, indicating a hydrophobation effect [213]. 

---