小球藻多肽的制备、表征及抗氧化活性研究

Preparation, characterization and antioxidant activity of Chlorella pyrenoidosa polypeptides

中文关键词:  小球藻  蛋白  多肽  结构  抗氧化

英文关键词:Chlorella pyrenoidosa  polypeptide  structure  antioxidant activity

中文摘要:

      目的 优化蛋白核小球藻多肽的提取工艺, 探究蛋白与多肽的结构差异及多肽的抗氧化活性。方法 主要采用热碱法提取小球藻蛋白; 并结合酶解和发酵的方法对小球藻多肽的提取工艺进行优化; 采用扫描电镜、红外光谱等仪器分析手段表征蛋白与多肽的结构; 采用1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl radical, DPPH·)、2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐阳离子自由基[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt radical , ABTS+·]和羟基自由基(hydroxyl radical,·OH)清除能力法研究多肽的抗氧化活性。结果 热碱法提取蛋白质效果最好, 多肽的最佳提取工艺为发酵温度37℃、初始pH 5.0、发酵时间24 h、菌接种量为3%; 蛋白的粒径为(54.13±0.57) μm, 多肽的粒径为(15.60±0.74) μm; 蛋白呈现大碎片状, 多肽呈现小碎片状; 蛋白的Zeta电位为(-25.27±0.23) mV, 多肽的Zeta电位为(-23.10±0.30) mV; 蛋白与多肽的二级结构具有显著性差异, 多肽的结构更无序; 多肽对DPPH·、ABTS+·、·OH的半抑制浓度(half maximal inhibitory concentration, IC50)分别为(3.84±0.03)、(3.58±0.03)、(2.78±0.01) mg/mL。结论 采用酶解和发酵相结合的方法能制备高产量的小球藻多肽, 小球藻多肽具有较好的抗氧化活性, 在功能性食品领域具有开发潜力。

英文摘要:

      Objective To optimize the extraction process of peptides from Chlorella pyrenoidosa, the structural differences between proteins and peptides and the antioxidant activity of peptides were investigated. Methods Chlorella pyrenoidosa protein was extracted by the hot alkali method. The extraction process of Chlorella polypeptide was optimized by enzymolysis and fermentation. Characterization methods such as scanning electron microscopy and infrared spectroscopy were utilized to determine the structure of proteins and peptides. The antioxidant activity of the polypeptide was studied using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·), 2,2’-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) ammonium salt radical (ABTS+·) and hydroxyl radical(·OH) scavenging ability. Results The most effective extraction method of protein was hot alkali method. The optimal extraction process of polypeptide was fermentation temperature 37℃, initial pH 5.0, fermentation time 24 h, and inoculation amount of 3%. The particle size of protein was (54.13±0.57) μm, and the particle size of polypeptide was (15.60±0.74) μm. The protein showed large fragments and the polypeptide showed small fragments. The Zeta potential of protein was (?25.27±0.23) mV and that of polypeptide was (?23.10±0.30) mV. The secondary structure of protein and polypeptide was significantly different, and the structure of polypeptide was more disordered. The half maximal inhibitory concentration (IC50) of polypeptide on DPPH·, ABTS+· and ·OH were (3.84±0.03), (3.58±0.03) and (2.78±0.01) mg/mL, respectively. Conclusion Chlorella polypeptides with high yield can be prepared by combining enzymatic hydrolysis and fermentation. Chlorella polypeptides have good antioxidant activity and have potential in the field of functional food.