Optimization of processing time, amplitude and concentration for ultrasound-assisted modification of whey protein using response surface methodology.

Response surface methodology was used to optimize processing variable for ultrasound-assisted modification of whey protein. The process was optimized employing Box-Behnken Design with three independent variables i.e. amplitude (20-40%), time (10-20 min) and concentration (10-15%). A second order model was employed to generate response surfaces. Experimental results revealed that analyzed model solutions exhibited the significant influence on various responses signified that the applied statistical model fitted well. The optimized independent variables were found to be 19.77 min time, 20.02% amplitude and 12.78% concentration of feed. The modified whey protein had the solubility, 78.52%; heat stability, 1076.19 s; water solubility index, 92.30%; water holding capacity, 0.469; oil absorption capacity, 1.709; foaming capacity 92.27; foam stability, 27.71 and firmness, 1692.09 g. Analytical response revealed that solubility of modified whey protein exhibited significant positive correlation with water solubility index, emulsion stability index and firmness.