title: Continuous hydrolysis of modified wheat gluten in an enzymatic membrane reactor.
abstract: BACKGROUND
  The low solubility of wheat gluten is one of the major limitations to its use in food processing, and enzymatic hydrolysis has been found to be an effective way to prepare more soluble bioactive peptides from gluten. The aim of this study was to prepare bioactive peptides from modified wheat gluten (MWG) in a continuous enzymatic membrane reactor (EMR) that allowed rapid separation of low-molecular-weight peptides from hydrolysates, thus avoiding the disadvantages of batch reaction such as inefficient use of enzymes, inconsistent products due to batch-to-batch variation, substrate-product inhibition, low productivity and excessive hydrolysis.
  
  
  RESULTS
  Wheat gluten was modified to decrease its lipid and starch contents in order to prevent membrane fouling. The optimal working conditions for Alcalase to hydrolyse MWG in the EMR were a substrate concentration of 20 g L(-1) , an enzyme/substrate ratio of 0.03, an operating pressure of 0.04 MPa, a temperature of 40 °C and a pH of 9. The operating stability of the EMR (including residual enzyme activity, productivity and capacity) was high. The permeate fractions showed antioxidant activities that were mostly due to low-molecular-weight peptides. A simple theoretical kinetic model was successfully applied to the enzymatic hydrolysis of MWG in the EMR.
  
  
  CONCLUSIONS
  Modification of wheat gluten made the continuous enzymatic membrane reaction more efficient and the EMR proved to be an effective means of producing peptides with particular properties and bioactivities. The permeate fractions (mainly < 1000 Da) were homogeneous and stable and also showed strong antioxidant activities.
authors: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, Jiangsu, China.
authors: Jie
authors: J
authors: Cui
authors: Xiangzhen
authors: X
authors: Kong
authors: Yufei
authors: Y
authors: Hua
authors: Huiming
authors: H
authors: Zhou
authors: Qing
authors: Q
authors: Liu
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D019149:Bioreactors; D004798:Enzymes / Q000378:metabolism; D005511:Food Handling / Q000379:methods*; D005983:Glutens / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D050356:Lipid Metabolism; D008566:Membranes / Q000378:metabolism; D008954:Models, Biological; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D011312:Pressure; D013213:Starch / Q000378:metabolism; D013696:Temperature; D014908:Triticum / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004798:Enzymes; D010455:Peptides; D010940:Plant Proteins; D005983:Glutens; D013213:Starch