动态高压微射流协同糖基化对β-乳球蛋白乳化性和结构的影响  

Effect of Glycosylation Treatment Coupled with Dynamic High Pressure Microfluidization on Emulsifying Properties and Structure of β-Lactoglobulin

作　　者：钟俊桢[1] 涂越[1] 刘伟[1] 刘成梅[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《食品科学》2014年第1期7-11,共5页Food Science

基　　金：国家自然科学基金地区科学基金项目(21366021);食品科学与技术国家重点实验室目标导向项目(SKLF-MB-201004);教育部高等学校博士学科点专项科研基金项目(20103601110002)

摘　　要：采用动态高压微射流(dynamic high pressure microfluidization,DHPM)协同糖基化处理β-乳球蛋白,研究改性β-乳球蛋白乳化性、乳化稳定性和结构的变化。研究发现DHPM协同糖基化处理过程中β-乳球蛋白结构变化与其乳化性能可能存在关联;DHPM协同糖基化处理能显著提高β-乳球蛋白的乳化性和乳化稳定性。0、40、120 MPa糖基化处理后β-乳球蛋白的乳化活性指数(emulsifying activity index,EAI)分别为136.3、168.1、177.9 m2/g。0 MPa协同糖基化处理后β-乳球蛋白的乳化稳定指数(emulsifying stability index,ESI)为52.3 min;随着压强逐渐增加至40 MPa和120 MPa,协同糖基化处理后ESI值分别升高为56.4 min和59.0 min。通过表征分析β-乳球蛋白结构变化发现:不同压力DHPM协同糖基化处理后,β-乳球蛋白分子质量升高;巯基含量升高;表面疏水性降低;二级结构变化以及氨基酸三维空间构象暴露程度发生变化。这些变化说明β-乳球蛋白与低聚半乳糖发生共价交联时改变了蛋白质结构,造成β-乳球蛋白表面亲水基团的增加,从而导致其乳化性能显著提高。The effect of glycosylation treatment coupled with dynamic high-pressure microfluidization （DHPM） on emulsifying properties and structure change of β-lactoglobulin （β-Lg） was investigated. The results showed that glycosylation treatment coupled with DHPM obviously improved the emulsifying capacity and emulsion stability of β-Lg. The emulsifying activity index （EAI） of β-Lg subjected to glycosylation treatment in the presence of high pressure at 0, 40 and 120 MPa were 136.3, 168.1 m2/g and 177.9 m2/g, respectively. The emulsifying stability index （ESI） of β-Lg subjected to glycosylation treatment was 52.3 min. With increasing the pressure up to 40 MPa and 120 MPa, the ESI of β-Lg treated by glycosylation were increased to 56.4 min and 59.0 min, respectively, indicating the structural change of β-Lg due to the combinatorial treatment of DHPM and glycosylation. This structural change was characterized as increased molecular weight, sulphydryl （-SH） content, reduced surface hydrophobicity （Ho）, changed secondary structure, and unmasked amino acids in the tertiary structure after the combinatorial treatment of DHPM and glycosylation. These results revealed that the conjugation with galacto-oligosaccharides （GOS） changed the structure of β-Lg, which contributed to the increase of surface hydrophilic groups of β-Lg and resulted in the improvement of emulsifying properties.

关 键 词：Β-乳球蛋白 动态高压微射流 糖基化 乳化性 结构 

分 类 号：TS252[轻工技术与工程—农产品加工及贮藏工程]