Cereal Biochemistry

Cereals are the most important staple food in many parts of the world and it is the main source of nutrients, a.o., protein, fibre and minerals in the human diet (Weegels 2019). To feed future generations better, it is of paramount importance that food safety and security of cereal-based foods is enhanced and food waste is reduced.
“To explore the potential of nature to improve the quality of life” is the mission of WUR. Sustainable production and processing of food, food safety, food security and health aspects of food belong to the focus areas to achieve this mission. Since starchy staple foods nourish the world population and because of the complexity of nutritional quality, cereal breeding and processing, Cereal Biochemistry aims to enlarge the scientific fundament to develop more nutritious cereal staple foods by bioprocessing to feed the future generations better and to increase its safety and security.

1. Coeliac disease has not been solved and patients have limited acces to palatable high quality gluten free food
2. Non gluten wheat intolerances seem to be increasing, causing a decrease in consumption of cereal based products. Thus, consumers are missing out on an important and cheap source of nutrients (Weegels 2019).
3. The control of digestibility of cereal based products and its effect on nutritional status (undernutrition, obesity) is still limited.

Description of theme

The research on Cereal Biochemistry will focus on three main issues:

1.Anti nutritional factors in cereals, especially amylase trypsin inhibitors (ATI), affecting digestibility

2.Safety and quality of gluten free foods

3.Starch digestibility in intermediate moisture foods

1. Anti nutritional factors in cereals, especially amylase trypsin inhibitors, affecting digestibility

Anti nutritional factors (ANF) play an important role in cereals to protect against infestation and animal consumption. From an agronomic point of view these pest barriers are beneficial as the required pest control measures (chemical pesticides, storage facilities) is relatively limited.

From a health point of view ATI’s are of special attention for human health (First International Workshop on ATIs, February 3-5, 2020; Geisslitz et al 2021):

  • Their enzyme inhibition can reduce digestibility of food directly, which can be either beneficial (weight reduction) or negative (pathological effects, undernutrition and food insecurity). They can increase the load of allergenic peptides presented to the small intestine, thus increasing the allergenic and inflammation reactions
  • Complexation behavior may strongly interact with the small intestine epithelium that can cause inflammation by itself
  • the not yet completely understood cause of Bakers asthma, the major labour related allergy (Stobnicka and Górny, 2015)

·increase of the load of non-digested peptides and carbohydrates especially of non-starch polysaccharides (FODMAPS) that are a major cause of Irritable Bowel Syndrome (IBS) which affects 7% to 21% of the general population (Chey et al 2015)

Understanding the role of ATI in cereals food processing and food digestion and mitigation of the negative effects is therefor of prime importance for food safety, security and sustainability. To establish the in vivo effects of ATIs on the human gut for the first time, the project AF 18019 was initiated (In vivo effects of Amylase Trypsin Inhibitors from wheat in the human gut: proof of cause of non-celiac wheat sensitivity in irritable bowel syndrome? 2018-2022; consortium WUR FCH and PRI, Maastricht University, 9 industrial partners and 4 societal organisations; budget

An interesting way to mitigate the effect of ATI could be by altering its molecular structure that is stabilised by the large number of disulphide bonds (5-6 on ca. 14 kDa; Buchanan et al 1997). Therefore, a project was initiated to investigate this in detail (LWV20.187ATI-DETOX Modification of functional properties of Amylase Trypsin Inhibitors by REDOX reactions to mitigate pathogenic effects. 2021-2025; consortium WUR FCH, FBR and PRI, Maastricht University, 4 industrial partners and 3 societal organisations;

2. Safety and quality of gluten free foods

This theme is principally concerned with:

  • Improving the safety and safe use of cereals in relation to celiac disease, by improved analytical methods to detect toxic epitopes (van den Broeck et al 2010)
  • Enabling the development of gluten-free bread by replacing gluten with other ingredient functionalities (van Riemsdijk, 2015)

3. Starch digestibility in intermediate moisture foods

Starch structuring during processing and storage is key to food structure, its digestibility and palatability. the changes in crystallinity in starch during and after processing are another important factor determining the digestibility of cereal foods. These changes are depending on several factors:

  • Processing (time, temperature, heat transfer)
  • Food composition (a.o. presence of proteins, non-starch polysaccharides and components forming molecular complexes with starch like lipids)
  • Moisture content
  • Storage time and temperature after preparation

The speed of digestion of starch is linked to blood glucose levels and satiety and probably other health aspects, like obesity and cardiovascular diseases. It is, therefore, important to understand the effect of processing conditions on starch crystallinity and consequently the speed of digestion.

Most starchy staple foods are produced under low or medium moisture contents, such as baking, cooking, frying, extrusion, moulding, drying/puffing. Therefor focus will be on intermediate moisture foods.

References:

  • van den Broeck, H.C., de Jong, H.C., Salentijn, E.M.J., Dekking, L., Bosch, D., Hamer, R.J., Gilissen, L.J.W.J., van der Meer, I.M., and Smulders, M.J.M. 2010. Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease.Theoretical and Applied Genetics121:1527-1539.
  • Buchanan, B. B., Adamidi, C., Lozano, R. M., Yee, B. C., Momma, M., Kobrehel, K., Ermel, R. and Frick, O. L. 1997. Thioredoxin-linked mitigation of allergic responses to wheat.Proceedings of the National Academy of Sciences,94: 5372-5377.
  • Chey, W.D., Kurlander, J. and Eswaran S. 2015. Irritable Bowel Syndrome. A Clinical Review.Journal of the American Medical Association313:949-958
  • Geisslitz, S., Shewry, P., Brouns, F., America, A. H., Caio, G. P. I., Daly, M., D’Amico, S., De Giorgio, R., Gilissen, L., Grausgruber, H., Huang, X., Jonkers, D., Keszthelyi, D., Larré, C., Masci, S., Mills, C., Møller, M.S., Sorrells, M.E., Svensson, B., Zevallos, V.F. & Weegels, P. L. (2021). Wheat ATIs: characteristics and role in human disease. Frontiers in Nutrition, 8, 265-281.
  • Stobnicka, A. and Górny R.L., 2015. Exposure to flour dust in the occupational environment,International Journal of Occupational Safety and Ergonomics21: 241-249.
  • van Riemsdijk, L. E., van der Goot, A. J., Hamer, R. J. and Boom, R. M. 2011. Preparation of gluten-free bread using a meso-structured whey protein particle system.Journal of Cereal Science,53: 355-361.
  • Weegels, P.L. 1994. Depolymerisation and re-polymerisation of wheat glutenin during dough processing and effects of low Mr wheat proteins, PhD Thesis, University of London, UK.
  • Weegels, P. L. (2019). The future of bread in view of its contribution to nutrient intake as a starchy staple food. Plant Foods for Human Nutrition, 74(1), 1-9.
  • Zevallos, V. F., Raker, V., Maxeiner, J., Khan, M., Steinbrink, K., & Schuppan, D. 2014. A diet containing wheat alpha-amylase/trypsin inhibitors (ATIs) promotes allergic airway inflammation in mice.Zeitschrift für Gastroenterologie52(08), FV44.