超声波辅助高效提取辣木籽中的蛋白质

Ultrasonic-assisted highly efficient extraction of proteins from Moringa oleifera seeds

以脱脂辣木籽粉为原料,采用超声辅助法提取蛋白质,研究超声功率、液料比、NaCl浓度等因素对蛋白质提取率的影响。当NaCl浓度从0增大至0. 250 mol/L时,辣木籽蛋白质的提取率从7. 78%迅速增大至70. 68%,说明辣木籽蛋白质主要为盐溶蛋白质。通过响应面分析得到影响提取率的主次因素为:液料比> pH>NaCl浓度;当超声功率为120 W、超声时间为15 min、液料比为60∶1、pH为6. 30、NaCl浓度为1. 10 mol/L时,重复2次提取,辣木籽蛋白质的提取率高达88. 09%。将此条件下所得的上清液在pH为10. 00,NaCl浓度为4. 27mol/L的盐析条件下盐析,沉淀率达86. 80%,透析纯化后蛋白质纯度为96. 22%。因此,超声辅助能高效提取辣木籽蛋白质。

Proteins from Moringa oleifera seeds have high nutritional value. This study aimed to investigate the effects of ultrasonic power, liquid-solid ratio, and NaCl concentration on ultrasonic-assisted extraction of proteins from defatted Moringa oleifera seeds. When the concentration of NaCl increased from 0 to 0.250 mol/L, the protein extractability increased rapidly from 7.78% to 70.68%, indicating that Moringa seed proteins were mainly salt-soluble proteins. The response surface analysis showed that liquid-solid ratio affected the protein extractability the most, followed by pH and NaCl concentration. The maximal protein extractability (88.09%) was achieved under the following condition: conducted an ultrasonic treatment at 120 W for 15 min with a liquid to solid ratio of 60∶ 1 and 1.10 mol/L NaCl, and at pH of 6.30, repeated this procedure for twice. The supernatant obtained under this condition was salted out with 4.27 mol/L NaCl at pH=10.00, which resulted 86.80% precipitation rate, and the purity of proteins reached 96.22%. Therefore, highly efficient extraction of proteins from Moringa oleifera seeds could be achieved using an ultrasonic-assisted approach, which provides theoretical and technical supports for developing and using Moringa oleifera seeds′ proteins.