Defatted corn protein extraction: Optimization by response surface methodology and functional properties

Abstract

A number of operating parameters including temperature, pH, solvent/flour ratio and time influence the yield of protein during extraction. In order to effectively identify the good combinations of the extraction conditions, Response Surface Methodology (RSM) was employed to determine optimum conditions for extraction of protein from defatted corn. The coefficient of determination (0.9789) was good for the second-order model. Protein extraction from defatted corn was mainly affected by pH and solvent/flour ratio. From RSM-generated model, the optimum extraction conditions were 54°C, 11.55, 1:18 and 33 min for temperature, pH, solvent/flour ratio and time, respectively. Under these conditions, the experimental protein content was 69.25 mg mL -1 which agreed closely with the predicted value 71.23 mg mL -1. To ensure that the protein extract could be utilized for food application, some functional properties such as water holding capacity, oil holding capacity, emulsifying capacity, foaming capacity and foaming stability were evaluated. Defatted corn protein had a good water holding and foaming capacity. Thus, it can be used in food formulation systems. © 2011 Academic Journals Inc.