Physicochemical properties of high pressure treated wheat gluten

Hydrated wheat gluten samples with moisture contents of about 62.5% ww were subjected to high pressure treatment. The experiments followed a three way factorial design which treated pressures at 200, 400, 600 and 800 MPa, temperatures at 20, 40 and 60°C and times of 20 and 50 minutes as the variables. The treated gluten samples were analysed for structural modifications by texture profile analysis (TPA) to measure hardness, initial moduli and solubility in sodium dodecyl sulphate and sodium dodecyl sulphate plus 2-mercaptoethanol. There was a strong correlation between hardness and the elastic modulus at (55%) strain (r = 0.98). Results obtained revealed that, at 20 °C and 40 °C, pressure could alter gluten structure but at these temperatures disulphide cross-linking only became significant when samples were held at 800 MPa for 50 minutes. Treatments at the highest temperature (60 °C) markedly increased hardness and the degree of disulphide bonding, especially in the pressure range of 400 to 800 MPa (p ≤ 0.001).