Structural and rheological characterization of liquid egg white modified with phospholipase A(2) enzyme

The objective of this research was to evaluate the efficiency of phospholipase A(2) (PLA) enzyme treatments (0.1%, 0.2%, and 0.3% by -v/v) on liquid egg white (LEW). The rheological behaviors and physico-functional characteristics such as foam capacity (FC), foam stability, turbidity, color parameters, and pH-values were evaluated during the 27 days at 4 degrees C. The correlation coefficient (R-2) were best fitted for the Herschel-Bulkley model in all LEW samples. The PLA increased FC compared to nontreated LEW. The use of PLAs were also significantly (p < .05) decreased turbidity, control, 0.1%, 0.2%, and 0.3% of PLA with 0.76 +/- 0.07, 0.64 +/- 0.06, 0.57 +/- 0.04, and 0.62 +/- 0.04, respectively. Significant changes in L* (lightness) was observed, while 0.1% treated LEW showed lower L* and higher a* (redness and greenness) values than the control (p < .05). The b* (yellowness and blueness) color of the treated samples remained stable except for the untreated samples (12.65 +/- 0.14 to 5.71 +/- 1.01). A considerable (p < .05) increase was observed in b* values, while lowest turbidity (0.57 +/- 0.04) was obtained 0.2% treatment, while the best treatment was the 0.3% PLA with higher FC and lower foam stability. The effect of enzyme treatment concentrations was statistically nonsignificant (p > .05) on the pH values before and after the treatment.