海湾扇贝多肽提取工艺优化及其结构鉴定

The Optimization of Extraction Technology and Structural Identification of Polypeptide from Bay Scallop

以海湾扇贝为原料，优化酶法水解工艺，获得海湾扇贝多肽（PBS），鉴定其进行结构，研究其体外抗氧化活性。在单因素和正交试验的基础上选取试验因素和水平，以DPPH自由基清除率为衡量指标，根据Box—Behnken设计原理．采用响应面分析法对关键参数——固液比、pH值及加酶量进行酶解优化研究。采用串联飞行时间质谱方法鉴定海湾扇贝多肽的结构。结果显示：最佳酶解条件：固液比1：6．25，pH3．53，加酶量1312．82U幢。此条件下，DPPH自由基清除率为91．59％，与模型理论值91．66％的相对误差在±l％内。实测值与理论值基本一致．预测模型能较好地反映实际情况。经串联飞行时间质谱鉴定。海湾扇贝多肽含有5个分子质量为700～1000L1的多肽组分及其氨基酸序列。这为海湾扇贝多肽的功能机理研究及产品开发提供了理论依据。

With Bay scallop as raw material, polypeptide from Bay scallop （PBS） was obtained by the optimized en- zymatic hydrolysis. In addition, the structure and in vitro antioxidant activity of the PBS were evaluated. Taking the scavenging rate of DPPH radical as measurement index, the proper test levels were selected by single factor experiment and orthogonal experiment, then the ratio of solid to liquid, pH and enzyme quantity were further optimized using a Box-Behnken design and response surface analysis. Finally, the structure of the PBS was evaluated by 4800 Plus MALDI TOF / TOF mass spectrometer. The results showed that the optimized hydrolytic conditions were as follows： the ratio of solid to liquid 1：6.25, pH 3.53, enzyme quantity 1 312.82 U/g. Under this condition, the scavenging rate of DPPH radical was 91.59%, the relative error with the theoretical value of the model （91.66%） was within 1%. It indicated that the measured data agree well with the theoretical values. It was found that the PBS contained five polypeptide components which molecular weight were 700- 1 000 u, and the amino acid sequences were measured too. This study aims to provide the theory basis for the mechanism research of function and products development of PBS.