Effects of microfluidization time on the structural, physiochemical and functional properties of walnut protein

Abstract

The effect of microfluidization treatment time under a pressure of 1 MPa on the structural, physiochemical and functional properties of walnut protein (WP) were evaluated. The results showed that the particle size of WP was significantly reduced by 102.10 % and the absolute zeta potential, solubility, water holding capacity, foaming capacity and stability increased by 336.41 %, 170.69 %, 27.67 g/g, 302.07 % and 334.23 %, respectively, when the microfluidization treatment time was 15 min (P < 0.05). And the oil holding capacity, emulsion capacity and stability of the WP increased from 1.19 g/g to 1.81 g/g, from 34.48 % and 78.82 % to 57.52 % and 98.86 %, respectively. With the extend of microfluidization treatment time, the secondary structure percentages of WP were altered. The WP after microfluidization treatment had optimal gastric digestion, while the intestine digestion was the worst. The amino acid results indicated the microfluidization treatment time did not affect the nutritional quality of WP.