大豆蛋白热诱导聚集体和κ-卡拉胶混合体系相行为及微观结构的研究  

Phase Separation Study of Soy Protein Aggregates and κ-Carrageenan Mixtures

作　　者：李向红[1] 华欲飞[2] 刘展 李伟 

机构地区：[1]长沙理工大学化学与生物工程学院,长沙410076 [2]江南大学食品学院食品科学与技术国家重点实验室,无锡214122 [3]宁波中普检测技术服务有限公司,宁波315192

出　　处：《中国粮油学报》2009年第9期12-18,共7页Journal of the Chinese Cereals and Oils Association

基　　金：国家自然科学资金项目(20476040);长沙理工大学博士启动基金(521)

摘　　要：研究了室温下,NaC l浓度0.1 mol/L,pH 7.0时不同大小大豆蛋白热聚集体和κ-卡拉胶混合物的相分离行为,并以天然大豆蛋白和κ-卡拉胶混合体系作为对照体系。通过离心、化学分析和目测建立了相图,结果表明:较大的聚集体和κ-卡拉胶的混合体系具有较窄的均相区域。采用共聚焦激光扫描显微镜(CLSM)观察了相分离体系的微观结构,结果显示出相分离后蛋白质聚集结构间存在交联。对共聚焦图像进行灰度水平变化方差分析表明,不同的混合物间微观结构上具有显著性差异。流变研究进一步证明相分离体系形成了相互交联的网状微观结构。上述研究结果表明,大豆蛋白聚集体和卡拉胶的相分离是由于排空相互作用(depletion interaction)。Heat - induced aggregates of different size and κ - carrageenan （ κ -- car） mixed systems were investigated in 0.1 mol/L NaCl with pH 7.0 at room temperature （25 ℃） with native soy protein/κ -car system as comparison. Phase diagrams were established by centrifugation, chemical assays and visual observation and it was found that the larger aggregate/κ - car system had narrower stable region. The microstruetures of the phase - separated mixtures were described using a confocal laser scanning microscope （CLSM） , which revealed the association of protein aggregate structures after phase separation. The image analysis based on the CLSM images of different mixtures showed that the variances of the grey values were different significantly. The association of protein parts was also verified by small deformation rheology observation （G′, G″）. The above results indicate that depletion interaction induces the phase separation of soy protein aggregates and κ - car.

关 键 词：相分离 微观结构 聚集体 共聚焦显微镜 交联 排空相互作用 

分 类 号：TS201.21[轻工技术与工程—食品科学]