MSc. Thesis Evaluation of Enzymatic Hydrolysis of Wheat Gluten at Different Protein Concentrations

................................................................................................................................ 3 Introduction ........................................................................................................................... 6 1 Theoretical Background .................................................................................................. 7 1.1 Wheat gluten ........................................................................................................... 7 1.1.1 Wheat gluten proteins ...................................................................................... 7 1.1.2 Properties of wheat gluten ................................................................................ 8 1.1.3 Wheat gluten extraction .................................................................................... 9 1.2 Hydrolysis ..............................................................................................................10 1.2.1 Types of hydrolysis .........................................................................................11 1.2.2 Hydrolysis at high concentrations ....................................................................13 1.2.3 Effect of hydrolysis on solubility .......................................................................13 1.2.4 Gluten hydrolysis .............................................................................................14 2 Materials and Methods ..................................................................................................15 2.1 Raw material ..........................................................................................................15 2.2 Methods .................................................................................................................16 2.2.1 Hydrolysis .......................................................................................................16 2.2.2 Degree of Hydrolysis .......................................................................................20 2.2.3 Solubility ..........................................................................................................21 2.2.4 Peptide size distribution ..................................................................................22 3 Results and Discussion .................................................................................................23 3.1 DH at different protein concentrations ....................................................................23 3.2 Effect of NaCl on hydrolysis ...................................................................................26 3.3 DH and solubility ....................................................................................................29 3.4 Influence of water holding capacity and protein content on hydrolysis. ...................30 3.4.1 Influence of water holding capacity on hydrolysis ............................................30 3.4.2 Influence of protein content on hydrolysis ........................................................32 3.5 Effect of hydrolysis on protein-starch separation ....................................................33