高密度CO_2处理提取鲵皮胶原蛋白的工艺优化

为研究高密度CO_2(dense phase carbon dioxide,DPCD)前处理对鲵皮胶原蛋白提取率的影响,以冻干鲵皮为原料,采用DPCD对鲵皮进行前处理,酶法提取鲵皮胶原蛋白,设计单因素试验和响应面试验,以胶原蛋白提取率为评价指标,优化DPCD处理鲵皮的工艺条件。结果表明,DPCD处理鲵皮的最适温度32℃、压强30 MPa、时间6 h;在该处理条件下,模型预测鲵皮胶原蛋白的提取率为39.70%,验证值为(39.48±0.74)%,无显著性差异(P0.05);与原料未经DPCD处理胶原蛋白提取率((20.63±0.46)%)相比,提取率提高了18.85%;微观结构显示,鲵皮经DPCD处理后的组织疏松、胶束纤维有规则排列被破坏并呈现多孔状态;电泳图谱显示鲵皮经DPCD处理后,胶原蛋白保持典型的Ⅰ型胶原蛋白结构特征。DPCD处理鲵皮,在保持鲵皮胶原蛋白结构特征的同时,显著提高了胶原蛋白提取率。

Optimization of Processing Parameters for Collagen Extraction from Chinese Giant Salamander (Andrias davidianus) Skin after Dense Phase Carbon Dioxide Pretreatment

In this study, the effect of pretreatment with dense phase carbon dioxidense (DPCD) on improving the enzymatic extraction of collagen from Chinese giant salamander skin was investigated. For collagen extraction, lyophilized Chinese giant salamander skin was pretreated with DPCD under different operating conditions of pressure and temperature, and then hydrolyzed by pepsin for different time periods. The optimization of these three parameters for improved extraction yield was performed using a combination of one-factor-at-a-time method and response surface methodology. The optimal enzymatic extraction conditions were found to be 6 h hydrolysis after DPCD pretreatment at 32 ℃ and 30 MPa. The model-predicted extraction yield under these optimized conditions was 39.70%, and it was not significantly different from the experimental value, (39.48±0.74)% (P > 0.05), 18.85% higher than that obtained without any pretreatment, (20.63±0.46)%.It was observed with a scanning electron microscope (SEM) that the microstructure of the skin became more loose, and collagen fibrils were damaged and became more orderly arranged and porous after DPCD treatment. The SDS-PAGE patterns showed that the typical characteristics of type I collagen was retained after DPCD treatment. Meanwhile, DPCD treatment significantly increased the extraction yield of collagen.