【作者】 王珊珊； 黄素艳； 孙永； 刘楠； 曹荣； 周德庆；

【Author】 Wang Shanshan;Huang Suyan;Sun Yong;Liu Nan;Cao Rong;Zhou Deqing;Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences;

【机构】 中国水产科学研究院黄海水产研究所；

【摘要】 目的:探究两种提取方法对微拟球藻蛋白结构及功能的影响。方法:分别采用冻融盐沉法与碱溶酸沉法制备冻融蛋白(Nannochloropsis freeze-thawed extraction protein,NFP)和碱提蛋白(Nannochloropsis alkali extraction protein,NAP),并对其营养性、结构与功能特性进行对比研究。结果:碱溶酸沉法使蛋白提取率上升到18.70%,比冻融盐沉法高7%。NFP与NAP中均含有人体所需8种必须氨基酸,分别占总氨基酸含量的38.25%与39.48%。傅里叶变换红外光谱显示NFP与NAP具有典型的蛋白吸收峰,但二级结构发生变化,碱提法使NAP中α-螺旋与β-转角相对含量降低至21.09%与20.25%,β-折叠相对含量增加至35.09%(P <0.05),这与亚基的空间结构紧密度降低及亲水基团的暴露有关。功能特性分析显示NFP与NAP的溶解性、起泡性、乳化性及乳化稳定性随pH值的变化趋势相似。在中性条件下,NAP起泡性优于NFP,持油性及乳化性低于NFP(P <0.05)。结论:不同提取方法能够对微拟球藻蛋白的结构性质产生影响,可以根据应用目的选择处理方式。研究结果为微藻蛋白资源在食品领域的开发利用提供了一定的理论依据。更多还原

【Abstract】 Objectives:This study was aimed to investigate the effect of preparation methods on the nutritional and physicochemical properties of Nannochloropsis protein.Methods:Nannochloropsis freeze-thawed extraction protein(NFP) and alkali-extracted protein(NAP) were prepared by using freeze-thawed and alkali-dissolution acid-precipitation method,respectively.Their nutritional,structural and functional properties were compared.Results:Both NFP and NAP contained all eight of the essential amino acids(EAAs),accounting for 38.25% and 39.48% of total amino acids,respectively.Fourier transform infrared(FTIR) spectroscopy indicated that both NFP and NAP displayed typical protein absorption peaks,however,the secondary structure was changed.The proportions of α-helix and β-turn in NAP decreased to 21.09% and20.25%,respectively,whereas the β-sheet content increased to 35.09%(P <0.05),which implied the reduction of spatial structure density and the exposure of hydrophilic groups due to the alkali treatment.The solubility,foaming capacity,emulsifying capacity and emulsifying stability of NFP and NAP exhibited similar variation trend with pH.NAP showed obviously higher foaming capacity,lower oil-holding and emulsifying capacity(P <0.05) at natural pH as compared to NFP.Conclusion:The structure and properties of Nannochloropsis protein can be significantly influenced by extraction treatments,and these processing methods can be selected according to the application purpose.These findings provide a theoretical basis for the application of microalgae protein resources in food industry.更多还原