2003 Fiscal Year Final Research Report Summary

Effects of tyrosine residues on the rheological properties of wheat dough

Research Project

Project/Area Number	14580162
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	食生活
Research Institution	Tokyo Metropolitan College
Principal Investigator	TAKASAKI Sadako Tokyo Metropolitan College, Food Science and Human Nutrition, Associate Professor, 健康栄養学科, 助教授 (50171434)
Project Period (FY)	2002 – 2003
Keywords	wheat / dough / tyrosine residue / dityrosine / rheological property / peroxidase / hydrogen peroxide
Research Abstract	There are some cross linkages involving the tyrosine residues, which are expected to be utilized in the rheological development of breadmaking. One is the combination of tyrosine and tyrosine residues, another is the combination of tyrosine and cysteine residues, and another is the combination of tyrosine residues and ferullic acid. The formation of dityrosine and the changes of rheological properties of wheat dough were investigated. 1 Dityrosine was identified in hydrolysates of gluten prepared from bread dough (flour : 250, salt : 5, yeast : 5, sugar : 12.5, water : 170) by HPLC and LC-MS. The amounts of dityrosine increased when hydrogen peroxide or peroxidase/hydrogen peroxide was added to the dough. 2 Doughaph was used to analyze the dough mixing characteristics. The mixing curve was changing with addition of hydrogen peroxide and peroxidase/hydrogen peroxide changed. The mixing curve, peak time, development time and softening time were extended. A remarkable change was not observed depending on addition of peroxidase. 3 Addition of hydrogen peroxide and peroxidase/hydrogen peroxide didn't affect the amount of total generation gas and internal gas of dough. The volumes of bread adding peroxidase/hydrogen peroxide became small compared with control. Further study is necessary to elucidate the mechanisms and contribution of dityrosine and rheological properties.