Abstract:

Effects of factors including pH, NaCl, protein concentration on solubility and foaming properties of flaxseed protein isolate were investigated in this study. Results indicated that the influence of pH on solubility of protein isolate showed a typical V-shaped curve pattern. Significant salt-in and salt-out effects were observed when NaCl concentration was lower than 0.4 mol/L or higher than that. Within the range of 0.1% to 0.8%, an increment in protein concentration resulted in enhancements in foaming capacity and foaming stability. Lower foaming capacity was found at isoelectric point (pI), which proved to be higher foaming stability. NaCl concentration displayed the similar pattern in influencing foaming properties and solubility of protein isolate. Addition of sugar could increase foaming stability of flaxseed protein isolate while reduce its foaming capacity at the concentration above 5%. 

Key words: flaxseed, protein isolate, solubility, foaming capacity, foaming stability