Study on the extraction of wheat germ protein by subcritical water and its functional properties

The extraction condition of wheat germ protein by subcritical water was optimized using single factor and response surface methodology and the functional characteristics of wheat germ protein were studied. The results showed that under the optimum extraction parameters obtained from response surface analysis,the yield of protein in the extracts was 42.25% at p H9.4,130 ℃ for 15 min with the solid-liquid ratio of 1 ∶ 20 g / m L. In addition,the emulsion activity index of wheat germ protein extracted by subcritical water was 113.63 m~2/ g,and the emulsion stability indicator was 82.16%; the foamability and the foam stability were 71.45% and 36.05%,respectively; the water / oil absorption and the solubility were respectively 4.21%,4.49% and 60.93%. Compared with traditional alkaline-soluble acid precipitation method,subcritical water extracting wheat germ protein has obvious advantages in saving time,extraction yield.