裸藻蛋白泡沫分离的工艺优化及功能特性分析

Process optimization and functional characteristics analysis of euglena protein foam separation

摘要:

以裸藻蛋白液为原料，通过泡沫分离法提取裸藻蛋白，以回收率和富集比为指标，通过单因素和响应面设计探究pH、装液量、温度、稀释倍数对裸藻蛋白的回收率和富集比的影响。同时研究了裸藻蛋白的功能特性，又采用傅里叶红外光谱和双光束紫外-可见分光光度计对蛋白进行结构分析，通过Peakfit Version软件对蛋白的二级结构进行鉴定，并通过氨基酸分析仪测定了裸藻蛋白的氨基酸组成。结果表明：裸藻蛋白泡沫分离的最佳条件为： pH5.5，装液量300 mL，温度30 ℃，稀释倍数15 倍，在此条件下的蛋白回收率为94.27%，富集比为4.18。蛋白的持水量在60 ℃最大，为7.27 g/g，持油量在40 ℃最大，为14.74 g/g。裸藻蛋白的乳化能力、乳化稳定性、起泡性、泡沫稳定性均随着质量分数的增大呈现先增加后减小的趋势。FT-IR和UV显示裸藻蛋白有典型的蛋白峰，它的二级结构表示裸藻蛋白以β-折叠为主。蛋白中必需氨基酸含量和疏水性氨基酸含量为35.28%和50.81%。

Abstract:

In this study, euglena protein solution was used as raw material, and euglena protein was extracted by foam separation method. With the recovery and enrichment ratio as indexes, the effects of pH, liquid volume, temperature and dilution ratio on the recovery and enrichment ratio of euglena protein were investigated by single factor and response surface design. At the same time, the functional characteristics of euglena protein were studied, and the structure of the protein was analyzed by Fourier transform infrared spectroscopy and dual-beam ultraviolet-visible spectrophotometer. The secondary structure of the protein was identified by Peakfit Version software, and the amino acid composition of euglena protein was determined by amino acid analyzer. The results showed that the optimum conditions for foam separation of Euglena protein were as follows: pH5.5, liquid volume 300 mL, temperature 30 ℃, and 15 times of dilution. Under these conditions, the protein recovery rate was 94.27% and the enrichment ratio was 4.18. The maximum water holding capacity of protein was 7.27 g/g at 60 ℃, and the maximum oil holding capacity was 14.74 g/g at 40 ℃. The emulsifying ability, emulsifying stability, foaming property and foam stability of euglena protein increased at first and then decreased with the increase of mass fraction.. FT-IR and UV showed that euglena sp. protein had a typical protein peak, and its secondary structure indicated that euglena sp. protein was mainly β-folded. The contents of essential amino acids and hydrophobic amino acids in protein are 35.28% and 50.81%. The results provide experimental basis for the study of euglena protein.