Cereal protein technology
Cereals like wheat, corn and rice are so-called staple foods. They fulfill an important role in our diet as a source of nutrients and are consumed all over the world, every day. Cereals are at the core of our life: The cultivation of cereals ca 10,000 years ago marked the start of civilization. The availability of cereals and quality of cereal products is key to the social stability of communities. This important role is reflected even today in strict regulations with respect to bread.
Description of theme
However, cereals are not cereals. Within cereals, the bread-making properties of wheat are really unique (see Figure 1). Also, within wheat a wide range of varieties exist and different crops can vary widely in yield and quality. Effects of abiotic stresses (drought/rainfall, heat/cold), but also varietal differences are not always understood and still require continuous research. The endowed chair “Technology of Cereal Proteins” therefore focuses on two main aspects:
- Cereal Technology for product and process improvements
- Cereal Technology for Health
Cereal Technology for product and process improvements
Cereal grains mainly consist of starch and protein. With wheat the protein is often referred to as gluten. From a technological point of view the variation in gluten properties causes the largest problems. This is why cereal chemists have dedicated their efforts in unraveling the links between gluten protein structure and composition on the one hand and technological properties (related to mixing, dough rheology, loaf volume) on the other. Within this topic our research is based on the breakthrough finding that gluten proteins in wheat are stored in protein bodies that during wheat maturation can fuse into larger protein particles. Thus, the polymeric glutenin fraction of gluten is shaped into large (10-50 µm) spherical particles that persist in wheat flour (see figure 2). In the past years we discovered that this feature of gluten provides a complete new avenue to study and understand gluten structure-function relations. In a number of patents and publications we have demonstrated this importance and provided examples of its use.
Cereal Technology for Health
Again, gluten proteins play a central role in this topic. In celiac disease (gluten intolerance affecting ca 1-2 % of the population) specific sequences of the gluten cause damaging immunological responses. Our work is helping to develop wheat varieties that have a minimum amount of such CD-toxic proteins, while maintaining technological properties. In another line of research, we are developing new protein structures to successfully replace gluten in gluten-free products. Here, we use our knowledge of gluten structure to build gluten analogs from non-cereal proteins.
Wheat is an excellent source of fibers. Increasing the level of fiber in bakery products however goes at the expense of product quality. We specifically study the interaction of fibers with gluten formation in order to solve this problem. Finally, we recently started to study the interaction of wheat proteins and starch with the aim of better controlling starch digestion.
The general aim of this endowed chair is to understand structure and function of cereal proteins with the aim of improving the use of cereals in terms of better processes and better and more healthy food products.
- Understanding the fracture mechanical properties of baked and fried products. Eva Castro-Prado MSc, prof.dr. R.J. Hamer, dr.ir. Ton van Vliet
- Modifying the properties of baked or fried crusted products. Jendo Visser MSc, prof. dr. R.J. Hamer, dr. Ton van Vliet
- The effect of crust morphology on water sorption properties. Anita Hirte, prof. dr. R.J. Hamer
- The fate of fat in the intestinal tract. Anne Helbig MSc, prof.dr.ir. H. Gruppen, prof.dr. R.J. Hamer
- The role of interactions in the digestibility of starch. Salomeh Ahmadi-Abhari, prof.dr. K. Loos (Groningen University)
Some Key References
- Enzymes in Food Processing, I and IInd ed. Editors: Tucker, G. A., Woods, L. F. J., Blackie Academic & Professional, Glasgow
- Interactions: the Keys to Cereal Quality, Hamer, Rob J, Hoseney, C. eds. Eagan press, Eagan, USA, 1998, 184 pages.
- Wheat Gluten Protein Analysis, Edited by Peter R. Shewry and George L. Lookhart
- 2003; 198 pages
- Wheat: Chemistry and Technology, Fourth Edition, Khan, K and Shewry P. eds. Hamer R.J. et al. Chapter 6. Structure and Functional properties of Gluten. Eagan Press, Eagan, USA, 2009, 480 pages.
- Hamer,R.J. 2005. Coeliac Disease: Background and biochemical aspects. Biotechnology Advances 23:401-408.
- Peighambardoust,S.H., van der Goot,A.J., Hamer,R.J., and Boom,R.M. 2005. Effect of simple shear on the physical properties of glutenin macro polymer (GMP). Journal of Cereal Science 42:59-68.
- Don,C., Lookhart,G., Naeem,H., MacRitchie,F., and Hamer,R.J. 2005. Heat stress and genotype affect the glutenin particles of the glutenin macropolymer-gel fraction. Journal of Cereal Science 42:69-80.
- Don,C., Lichtendonk,W.J., Plijter,J.J., Van Vliet,T., and Hamer,R.J. 2005. The effect of mixing on glutenin particle properties: aggregation factors that affect gluten function in dough. Journal of Cereal Science 41:69-83.
- Primo-Martin,C., Hamer,R.J., and de Jongh,H.H.J. 2006. Surface layer properties of dough liquor components: Are they key parameters in gas retention in bread dough? Food Biophysics 1:83-93.
- Don,C., Mann,G., Bekes,F., and Hamer,R.J. 2006. HMW-GS affect the properties of glutenin particles in GMP and thus flour quality. Journal of Cereal Science 44:127-136.
- Spiertz,J.H.J., Hamer,R.J., Xu,H., Primo-Martin,C., Don,C., and van der Putten,P.E.L. 2006. Heat stress in wheat (Triticum aestivum L.): Effects on grain growth and quality traits. European Journal of Agronomy 25:89-95.
- Peighambardoust,S.H., van der Goot,A.J., Boom,R.M., and Hamer,R.J. 2006. Mixing behaviour of a zero-developed dough compared to a flour-water mixture. Journal of Cereal Science 44:12-20.
- van Herpen,T.W.J.M., Goryunova,S.V., van der Schoot,J., Mitreva,M., Salentijn,E., Vorst,O., Schenk,M.F., van Veelen,P.A., Koning,F., van Soest,L.J.M. et al 2006. Alpha-gliadin genes from the A, B, and D genomes of wheat contain different sets of celiac disease epitopes. Bmc Genomics 7.
- Primo-Martin,C., van Nieuwenhuijzen,N.H., Hamer,R.J., and Van Vliet,T. 2007. Crystallinity changes in wheat starch during the bread-making process: Starch crystallinity in the bread crust. Journal of Cereal Science 45:219-226.
- van Herpen,T.W.J.M., Cordewener,J.H.G., Klok,H.J., Freeman,J., America,A.H.P., Bosch,D., Smulders,M.J.M., Gilissen,L.J.W.J., Shewry,P.R., and Hamer,R.J. 2008. The origin and early development of wheat glutenin particles. Journal of Cereal Science 48:870-877.
- van Nieuwenhuijzen,N.H., Primo-Martin,C., Meinders,M.B.J., Tromp,R.H., Hamer,R.J., and Van Vliet,T. 2008. Water content or water activity: What rules crispy behavior in bread crust? Journal of Agricultural and Food Chemistry 56:6432-6438.