重组米曲霉中性蛋白酶(rNpI)水解大豆蛋白苦味及其抗氧化性研究  

Research on hydrolysis of soy protein by Asperigillus oryzae recombinant neutral protease(rNpI) and its hydrolysates' bitterness and antioxidant activity

作　　者：游子娟 钟丽芬[1] 黄伟谦[1] 马纳纳 罗晓春[1] 

机构地区：[1]华南理工大学生物科学与工程学院,广东广州510006

出　　处：《广东农业科学》2015年第10期84-88,共5页Guangdong Agricultural Sciences

基　　金：广东省科技计划项目(2012B02031100;2013B010404003)

摘　　要：为探讨重组中性蛋白酶rNpI对大豆蛋白的水解、水解产物的苦味及产物抗氧化性的影响,进行水解度测定、水解产物苦味值感官评定,以及水解产物清除DPPH自由基能力、还原能力、和氧自由基清除能力测定。结果表明,重组米曲霉rNpI对大豆蛋白有较高的水解度,当酶与底物比（E/S）为1000、4000、8000U/g时,水解度分别为7.8%、11.5%和16.0%。对其水解产物进行苦味评价,结果发现,r Np1大豆蛋白水解产物苦味值明显比Alcalase的水解产物低。不同的抗氧化方法测定水解产物的抗氧化活性表明,r Np1对大豆蛋白的水解产物具有较高的清除DPPH自由基能力、还原能力和氧自由基清除能力。通过超滤的方法对E/S为4000U/g的水解产物进行分离,得到分子量〉10ku、3-10ku和〈3ku的组分,分别测定其抗氧化性,发现抗氧化性能力与肽的分子量大小有关。重组米曲霉rNpI对植物蛋白有很高的水解效率,其水解产物苦味值低且具有较高的抗氧化性,在食品、饲料等行业有很好的应用前景。To study the applications of recombinant neutral protease（rNpI）in Soy Protein Isolate（SPI）hydrolysis,the hydrolysis degree,bitterness and antioxidant activity of SPI hydrolysates（SPIH）were evaluated.After protease digestion,the DH and bitterness of SPIH were assessed.Further more,three different in vitro methods were used to evaluate the antioxidant activities of SPIH,including DPPH radical scavenging activity assay,reducing power assay and Oxygen Radical Absorbance Capacity（ORAC）assay.The results showed that rNpI had relative high efficiency in SPI hydrolysis,the hydrolysis degrees were 7.8%,11.5% and 16.0%,under the E/S ratio of 1 000 U/g,4 000 U/g and 8 000 U/g.For the bitterness evaluation,results showed that the bitterness of SPIH of rNpI was significantly lower than hydrolysates of Alcalase.The antioxidant activities of SPIH were determined by different assays,and the results showed that these SPIH of rNpI had high antioxidant activities.When the E/S ratio was 4 000 U/g,SPIH had high antioxidant activities,the reducing power of 1.0 mg/m L SPIH was 0.34,its DPPH free radical scavenging activity was 80% and the ORAC value was 455 μmol TE/g protein.Ultrafiltration membrane was used to separate SPIH components,and their antioxidant activities were analyzed.Results showed that SPIH-I（molecular weight above 10 ku）had the highest DPPH radical scavenging activity（82.7%）,while SPIH-III（molecular weight below 3 ku）had the highest ORAC value（722 μmol TE/g protein）.rNpI had high efficiency in SPI hydrolysis.Its SPIH had low bitterness and high antioxidant activity.All these results indicated that the rNpI had good application potentials in food production.

关 键 词：重组中性蛋白酶 水解度 苦味值 抗氧化性 

分 类 号：S188[农业科学—农业基础科学]