Optimization of Extracting Jujube Kernel Protein by Ultramicro Freezing Grinding

In this paper,the residue of jujube kernel was treated by superfine grinding and freezing grinding. On the basis of single factor experiment,solid-liquid ratio,pH,extraction temperature,extraction time as test factors,using the response surface method,the extraction method of Zizyphus jujube kernel protein was optimized. The results showed that the extraction rate of jujube kernel protein was significantly higher under the conditions of ultramicro grinding and freezing comminution than under the conditions of ordinary comminution(P<0.05). The four factors had the greatest influence on the protein extraction rate from large to small:pH,solid-liquid ratio,extraction time,extraction temperature. The optimum technological conditions for extracting jujube kernel protein based on ultramicro freezing comminution were as follows:Solid-liquid ratio 32∶1,pH11.4,temperature 51 ℃,extraction time 58 min. Under the condition of the protein extraction yield optimization predictive value of 78.50%,the actual protein extraction rate was 78.47%±0.17%. The results of protein extraction were predicted by the regression model,which provided a good reference for the reuse of waste from jujube kernel processing.