中国农业科学 ›› 2010, Vol. 43 ›› Issue (1): 164-170 .doi: 10.3864/j.issn.0578-1752.2010.01.019

• 贮藏·保鲜·加工 • 上一篇    下一篇

pH对肌原纤维蛋白二级结构及其热诱导凝胶特性的影响

费英,韩敏义,杨凌寒,周光宏,徐幸莲,彭增起

  

  1. (南京农业大学食品科技学院/农业部农畜产品加工与质量控制重点开放实验室)
  • 收稿日期:2009-05-21 修回日期:2009-07-03 出版日期:2010-01-10 发布日期:2010-01-10
  • 通讯作者: 周光宏

Studies on the Secondary Structure and Heat-Induced Gelation of Pork Myofibrillar Proteins as Affected by pH

FEI Ying, HAN Min-yi, YANG Ling-han, ZHOU Guang-hong, XU Xing-lian, PENG Zeng-qi
  

  1. (南京农业大学食品科技学院/农业部农畜产品加工与质量控制重点开放实验室)
  • Received:2009-05-21 Revised:2009-07-03 Online:2010-01-10 Published:2010-01-10
  • Contact: ZHOU Guang-hong

摘要:

【目的】研究pH对猪肉肌原纤维蛋白二级结构α-螺旋及其热诱导凝胶硬度、保水性及微观结构的影响。【方法】采用圆二色谱(circular dichroism, CD)测定不同pH下,猪肉肌原纤维蛋白α-螺旋含量的变化;用物性测试仪测定相应pH下肌原纤维蛋白热诱导凝胶的硬度,用离心法测定其保水性,同时利用扫描电镜拍摄其微观结构。【结果】随着pH偏离肌原纤维蛋白等电点(pI)向中性范围靠近,其α-螺旋含量及其热诱导凝胶的保水性都逐渐增大;而凝胶硬度在pH 6.0时达最大值;在远离等电点的中性条件下,肌原纤维蛋白凝胶具有较高有序性的微观结构,而且结构均匀,酸性条件下凝胶的微观结构有序性低,不均匀,且存在聚合物。【结论】猪肉肌原纤维蛋白α-螺旋含量与其热诱导凝胶保水性呈正相关关系;蛋白含天然结构α-螺旋较多时,凝胶微观结构比较有序,反之,凝胶微观结构比较粗糙。

关键词: 猪肉肌原纤维蛋白, pH, α-螺旋, 硬度, 保水性, 微观结构

Abstract:

【Objective】 The objective is to study the effect of pH on the secondary structure, α-helix of pork myofibrillar protein, and the hardness, water holding capacity (WHC) and microstructure of its heat-induced gel. 【Method】 The α-helix of pork myofibrillar protein under different pH were measured by circular dichroism (CD), and the hardness, WHC and microstructure of the heat-induced gel were determined by texture analyzer, centrifugation method and scanning electron microscope (SEM), respectively. 【Result】 The α-helix of pork myofibrillar protein and WHC of its heat-induced gel increased with pH away from pI, the hardness reached its maximum when pH was 6.0, the gel had a uniform and orderly microstructure in neutral, while it had disorderly and uneven microstructure with polymer in the acidic. 【Conclusion】 The α-helix of myofibrillar protein is positive correlated with the WHC of its heat-induced gelation, and the gel has an orderly microstructure with more α-helix, while rough microstructure with less α-helix.

Key words: pork myofibrillar protein, pH, α-helix, hardness, water holding capacity, microstructure