超声辅助核桃饼脱脂和多肽制备工艺的优化

Optimization of walnut cake defatting and walnut peptide preparation

采用超声辅助核桃饼脱脂,并以脱脂核桃粉为原料制备核桃蛋白,采用碱性蛋白酶酶解核桃蛋白制备多肽。通过单因素实验和正交实验对超声辅助核桃饼脱脂和核桃多肽制备工艺条件进行优化,并对最优条件下制备的核桃多肽的特性进行分析。结果表明:超声辅助核桃饼脱脂最优条件为料液比1∶20、超声功率500 W、超声时间140 min,在最优条件下脱脂率为91.23%,蛋白损失率为11.32%;酶解制备核桃多肽的最优工艺条件为酶解温度50℃、酶解pH 9、加酶量3.0%、酶解时间5.0 h,在最优条件下水解度达到22.63%,多肽得率为88.24%。核桃多肽粗蛋白质含量约为95%,相对分子质量小于1 000 Da的多肽占比达91.61%。

The walnut cake was defatted with ultrasound assist,and with defatted walnut powder as raw material,walnut protein was prepared. The peptide was prepared by alkaline protease hydrolysis from walnut protein. The defatting conditions of walnut cake and the preparation conditions of walnut peptide were optimized through single factor experiment and orthogonal experiment. In addition,the characteristics of walnut peptide prepared under the optimal conditions were analyzed. The results showed that the optimal defatting conditions were obtained as follows: ratio of material to solvent 1∶20,ultrasonic power 500 W,ultrasonic time 140 min. Under the optimal conditions,the defatting rate was 91. 23%,and the lost rate of walnut protein was 11. 32%. The optimal conditions of preparing walnut peptide were obtained as follows: enzymolysis temperature 50 ℃,enzymolysis pH 9,enzyme dosage 3. 0%,enzymolysis time 5. 0 h. Under the optimal conditions,the hydrolysis degree was 22. 63%,and the peptide yield was 88. 24%. The crude protein content in walnut peptide was about 95%,and 91. 61% of walnut peptides had a relative molecular weight less than 1 000 Da.