【摘要】 对膜技术在花生蛋白酶解液分离纯化应用的工艺进行了研究。考察了超滤膜截留相对分子质量(1、3、5 kDa)、超滤压力(0.086、0.121、0.157、0.193 MPa)、超滤温度(30、35、40、45℃)、超滤加水量(0.5~5.5倍)对超滤效果的影响,以及考察加水次数(1~12次)对纳滤脱盐效果的影响。结果表明:超滤操作的最适工艺为用截留相对分子质量为1 kDa的超滤膜,在超滤压力0.193MPa、超滤温度45℃的条件下进行恒体积超滤,加水量以加入3倍水为最适,此时短肽透过率可达65.01%,透过液中短肽的相对分子质量主要分布在283~402 Da之间;纳滤操作在纳滤温度为常温(20℃)、纳滤压力为1.5 MPa的条件下进行,采用间歇式恒容纳滤方式,最适加水次数为10次,此时Na+脱除率为(69.78±0.69)%,短肽损失率仅为2.00%。采用最适的先超滤、后纳滤联用工艺制备的花生短肽液经冻干后,冻干粉对ACE的IC50为0.78 mg/mL,体外抗氧化活性为ORAC值(以Trolox计)(2 359.50±40.43)μmol/g,表明短肽同时具有较强的ACE抑制活性和体外抗氧化活性。更多还原

【Abstract】 The application of membrane technique in separation and purification of peanut protein enzymatic hydrolysate was studied. The impacts of retention relative molecular weight of ultrafiltration membrane( 1 kDa,3 kDa,5 kDa),ultrafiltration pressure( 0. 086 MPa,0. 121 MPa,0. 157 MPa,0. 193 MPa),ultrafiltration temperature( 30 ℃,35 ℃,40 ℃,45 ℃) and water dosage( 0. 5-5. 5 times of peanut protein enzymatic hydrolysate) on ultrafiltration effect were discussed,and the influence of water addition times( 1-12 times) on desalination effect of nanofiltration was also discussed. The results showed that the optimal ultrafiltration conditions were obtained as follows: retention relative molecular weight of ultrafiltration membrane 1 kDa,ultrafiltration pressure 0. 193 MPa,ultrafiltration temperature45 ℃,water dosage 3 times of peanut protein enzymatic hydrolysate with constant volume ultrafiltration. Under these conditions,the transmittance rate of short peptides was up to65. 01%,and the distribution of relative molecular weight of short peptides in the permeate was in the range of 283-402 Da. The optimal nanofiltration conditions were obtained as follows: nanofiltration temperature room temperature( 20 ℃),nanofiltration pressure 1. 5 MPa,water addition times10 times with interval constant volume nanofiltration. Under these conditions,the removal rate of Na+was( 69.78 ±0.69) %,while the loss rate of short peptides was only 2.00%. The short peptides prepared by the process of first ultrafiltration then nanofiltration were freeze-dried into peptides powder,the IC50 value to angiotensin-converting enzyme( ACE) and oxygen radical absorbance capacity( ORAC) value of the peptides powder were 0. 78 mg /mL and( 2 359. 50 ± 40. 43) μmolTrolox /g respectively,which indicated that the short peptides had good ACE inhibitory activity and in vitro antioxidant activity.更多还原