木薯叶片多肽的制备与抗氧化功能研究  

Preparation and antioxidant function of polypeptide from cassava leaf

作　　者：张作达 王琴飞[2] 吴若娜 牛晓磊[1] 张振文[2] ZHANG Zuoda;WANG Qinfei;WU Ruona;NIU Xiaolei;ZHANG Zhenwen(College of Tropical Crops,Hainan University,Haikou 570228,China;Institute of Tropical Crop Variety Resources,Chinese Academy of Tropical Agricultural Sciences,Haikou 571101,China)

机构地区：[1]海南大学热带作物学院,海南海口570228 [2]中国热带农业科学院热带作物品种资源研究所,海南海口571101

出　　处：《食品与发酵工业》2022年第7期146-153,共8页Food and Fermentation Industries

基　　金：国家重点研发计划项目(2081YFF0213505);国家木薯产业技术体系项目(CARS-11-HNZZW);科技部对发展中国家援助项目(KY202002005)。

摘　　要：以木薯叶片为材料,采用碱溶酸沉法对木薯叶片蛋白质进行提取,通过正交法优化提取工艺,采用响应面法优化3种蛋白酶酶解条件,并对酶解所得多肽进行抗氧化功能验证。结果表明,木薯叶片蛋白质最佳提取条件为:温度60℃、碱溶pH 11.0、提取时间2 h;酸沉pH 4.6,每克叶片鲜样的蛋白质最高得率为11.73%,所得蛋白质的纯度为92.57%。响应曲面分析结果表明,利用碱性蛋白酶、中性蛋白酶和胰蛋白酶酶解木薯叶片蛋白质,其酶解最佳条件分别为:酶解温度36.74、35.00、36.45℃,pH值8.76、6.31、8.00,反应时间2.44、2.18、3.82 h,其中胰蛋白酶多肽得率最高,为41.89%。酶解所得多肽溶液中游离氨基酸含量均极低,仅检测到酪氨酸,其质量浓度为9.90μg/mL。抗氧化功能分析发现,中性蛋白酶酶解所得多肽抗氧化活性均较高,在其多肽质量浓度为1.5 mg/mL时,其DPPH自由基清除率、·OH清除率和总还原力分别为91.83%、79.3%、0.558。因此,中性蛋白酶酶解所得多肽抗氧化活性最强,最适合制备木薯叶抗氧化肽。In this experiment,cassava leaf protein was extracted by alkali solution and acid precipitation,and the extraction process was optimized by orthogonal method.The hydrolysis conditions of three proteases were optimized by response surface methodology,and the antioxidant function of the peptides was verified.The results showed that the optimum extraction conditions of cassava leaf protein were as follows:extraction with alkali soluble(pH 11.0)for 2 h at 60℃,acid precipitation at pH 4.6.Under these conditions,the highest yield of protein per gram of fresh leaves was 11.73%and the purity of protein was 92.57%.The results of response surface analysis showed that the optimum conditions for enzymatic hydrolysis of cassava leaf protein by alkaline protease,neutral protease and trypsin were as follows:enzymatic hydrolysis temperature 36.74℃,35.00℃,36.45℃,pH value 8.76,6.31 and 8.00,reaction time 2.44 h,2.18 h and 3.82 h,respectively.The yield of trypsin polypeptide was the highest(41.89%).The content of free amino acids in the peptide solution obtained by enzymatic hydrolysis was very low,only tyrosine could be detected,and its concentration was 9.90μg/mL.The antioxidant function analysis showed that the antioxidant activities of the peptides hydrolyzed by neutral protease were high.When the polypeptide concentration was 1.5 mg/ml,the DPPH radical clearance,hydroxyl radical clearance and total reducing power were 91.83%,79.3%and 0.5584,respectively.Therefore,the peptides hydrolyzed by neutral protease had the strongest antioxidant activity.Among the three enzymes,neutral protease is the most suitable for the preparation of cassava leaf antioxidant peptides.

关 键 词：木薯叶片 酶解 多肽 抗氧化 蛋白质 

分 类 号：TS201.2[轻工技术与工程—食品科学]