The glass-transition behaviour of wheat gluten proteins.
The glass-transition behaviour of four hydrated wheat gluten proteins (alpha-gliadin, gamma-gliadin, omega-gliadin and high-molecular-weight (HMW) subunits of glutenin) was studied using differential scanning calorimetry (DSC). By fitting the data to the Gordon-Taylor equation, which has previously been used to describe the plasticization of polymers by diluents, the glass-transition temperatures (Tg) for the dry proteins were found by extrapolation. The values for Tg were within the range 397-418 K. Values for the heat capacity increment delta Cp at Tg for the plasticized proteins were also determined and ranged from 0.29-0.47 J g-1 K-1 with no dependence on water content. The differences in glass-transition behaviour of the proteins are discussed in relation to their secondary structure.
Noel
T R
TR
Institute of Food Research, Norwich Laboratory, Norwich Research Park, UK.
Parker
R
R
Ring
S G
SG
Tatham
A S
AS
D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography; D005903:Gliadin / Q000737:chemistry*; D005983:Glutens / Q000031:analogs & derivatives* / Q000737:chemistry; D017433:Protein Structure, Secondary; D013696:Temperature; D013816:Thermodynamics; D014908:Triticum / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D014867:Water; D005983:Glutens; D005903:Gliadin; C037302:glutenin