Leibniz-Institut für Lebensmittel-Systembiologie
an der Technischen Universität München

Programmbereich IIBiopolymers

Working Group II. Biopolymers

Head: Dr. Katharina Scherf (until 31 March 2017: Prof. Dr. Peter Köhler)

Research:

The research activities of PB II focus on answering the following key questions:

  • Why does the prevalence of (wheat-)hypersensitivities such as celiac disease, wheat allergy and non-celiac (wheat) gluten sensitivity (NCGS) increase within the population?
  • How do different factors (e.g. raw materials, environmental conditions, processing) influence structural and functional interactions within proteins, flours and their products?

Studies on fundamental mechanisms in celiac disease, wheat allergies and NCGS

Recent scientific studies provide mounting evidence for an increasing prevalence of (wheat) hypersensitivities such as celiac disease, wheat allergy and NCGS within the population. As with other allergies, the underlying reasons are still not entirely clear. Different factors such as changes in the composition of cereal proteins due to breeding, agricultural practices and processing are being discussed. Multidisciplinary cooperation is essential for this research area, because the expertise from plant genetics, bioinformatics, gastroenterology, immunology, nutrition and cereal science needs to be combined synergistically to elucidate fundamental pathomechanisms and develop novel treatment and prevention strategies. In cooperation with globally leading research groups, the studies of PB II aim at:

  • Elucidation of fundamental mechanisms of wheat-dependent exercise-induced anaphylaxis (WDEIA) 
  • Development of sensitive methods (ELISA, LC-MS/MS) to detect gluten and gluten peptides in physiological samples 
  • Providing well-characterized reference materials for clinical studies and challenge tests 
  • Identification of isopeptide-crosslinks between gluten peptides and transglutaminase 2, the key enzyme in the pathomechanism of celiac disease
  • Evaluating the impact of wheat breeding on the immune activity of wheat cultivars and identification of cultivars with low immune activity for NCGS patients
  • Characterization of the wheat components responsible for triggering NCGS 

Improvement of cereal protein analysis

Combined with classical extraction and purification methods, modern proteomics techniques enable structure elucidation and quantitation of cereal proteins and peptides. The main goals are:

  • Ensuring the safety of gluten-free foods with improved analytical methods to detect gluten from wheat, rye, barley and oats (ELISA, LC-MS/MS)
  • Enhancement of reproducibility and comparability of different gluten detection methods through provision of improved reference materials (in cooperation with international stakeholders such as the Prolamin Working Group, the MoniQA Association, the AOAC International and the AACC International)
  • Development of new methods to quantitate further immunoactive cereal proteins such as amylase-trypsin inhibitors and puroindolines 
  • Prevention of (wheat) hypersensitivities through removal of immunoactive cereal proteins using appropriate processing 

Structural and functional interactions within proteins, flours and their products

Research in this field comprises studies on the influence of different factors (e.g. raw materials, environmental conditions, processing) on structural and functional interactions within proteins, flours and their products. Key objectives are:

  • Improvement of sensory and technological-functional properties through targeted texture analysis and modification in cereal products
  • Securing biodiversity by increasing the utilization of alternative plant species
  • Sustainable cereal production to guarantee feeding the world population in times of climate change and dwindling natural resources 
  • Valorization of by-products from cereal processing
  • Answering current issues related to food legislation 
  • Fundamental understanding of interactions between proteins as well as between proteins and small molecules 

Methods

  • Different extraction and purification techniques (dialysis, size exclusion filtration, SPE)
  • Gel electrophoresis (SDS-PAGE)
  • Reversed-phase HPLC, gel permeation HPLC (analytical and preparative scale, detection: UV, DAD, fluorescence, ELSD) 
  • LC-MS: untargeted (peptides and intact proteins)
  • LC-MS: targeted (stable isotope dilution assay for specific peptides)
  • NMR (1H, 13C, two dimensional experiments)
  • Immunological techniques (ELISA, Western Blot)
  • Enzyme assays
  • Milling: cryogenic mill, ball mill, ultra centrifugal mill, roller mill (Quadrumat Junior)
  • Classical methods of flour analysis: content of water, ash, protein, fat, sedimentation value
  • Rheology: farinograph (10 g, 50 g, 300 g), measurement of bread volume and texture, gluten index, gluten peak test, dynamic stress rheometry, microscale extension tests
  • Microscale baking tests (10 g of flour, automated baking line)