Effect of temperature and high pressure on the foaming properties of beta-lactoglobulin salted out at pH 2.
Heat treatment and pressurization affected the foaming capacity and stability of beta-lactoglobulin--stabilized foams. The foaming capacity of heated beta-lactoglobulin (beta-Lg) was lower than of the non-heated protein by 9-30%, depending on the medium acidity. At pH 5.0 and 7.0, the stability of beta-Lg-stabilized foams was 3-fold lower and at pH 6.0 it was 3-fold higher than the stability of foams stabilized by the non-heated protein. Pressurization at 300 MPa/10 min increased the protein foaming capacity by about 25% and the foam stability almost 3-fold, comparing with the non-pressurized protein. Longer (20-30 min) pressurization at 300 MPa did not affect the foaming capacity of beta-Lg, slightly increasing the foam stability. Pressurization at 600 and 900 MPa did not change the foaming capacity, but decreased drastically the foam stability. Beta-Lg pressurized at 300 MPa/10 min had the foaming capacity and foam stability better at pH 6.0 and 7.0, whereas beta-Lg pressurized at 600 MPa/10 min had those properties better at pH 5.0, as compared with the non-pressurized protein.
J
J
Leman
T
T
Doga
D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007782:Lactoglobulins / Q000737:chemistry*; D011312:Pressure
D007782:Lactoglobulins