College of Food Science and Technology and MOE Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China; The Sub Center (Wuhan) of National Technology and R&D of Staple Freshwater Fish Processing, Wuhan 430070, China.
College of Food Science and Technology and MOE Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Wuhan 430070, China; The Sub Center (Wuhan) of National Technology and R&D of Staple Freshwater Fish Processing, Wuhan 430070, China.
Int J Biol Macromol. 2014 Mar;64:17-24. doi: 10.1016/j.ijbiomac.2013.11.019. Epub 2013 Dec 1.
The effects and mechanism of cassava starch (CS), hydroxypropylated cassava starch (HCS) and cross-linked hydroxypropylated cassava starch (CHCS), on gel properties of myofibrillar protein (MP) from grass carp were investigated using texture analyzer, dynamic rheometer, scanning electron microscopy (SEM) and circular dichroism (CD). Water holding capacity (WHC) of MP gels increased from 70% to ca. 90% with an increase in additive amount of modified starches (MS) and HCS improved WHC most effectively. The MS (HCS and CS) at proper additive amount (1.5 wt%) improved the textural properties of MP gels significantly (P<0.05). In rheological test, all MS-MP solutions showed viscoelastic nature of MP, but adding MS resulted in much higher G', suggesting the effect of MS (especially 2.5 wt% CHCS) was considerable and equal to increasing protein concentration. The SEM photographs showed the MP gel with 2.5 wt% CHCS or 0.5 wt% HCS formed compact and homogeneous network, while the gel with CS agglomerated and the agglomerate phenomenon occurred more obviously with increasing additive amount. The addition of MS, especially CHCS, promoted the heat-induced conformational transition from the α-helix companied with β-turn to β-sheet, leading to the MP molecules stretching out.
研究了木薯淀粉（CS）、羟丙基木薯淀粉（HCS）和交联羟丙基木薯淀粉（CHCS）对草鱼肌原纤维蛋白（MP）凝胶特性的影响及作用机制，采用质构仪、动态流变仪、扫描电子显微镜（SEM）和圆二色性（CD）进行了研究。随着改性淀粉（MS）添加量的增加，MP 凝胶的持水力（WHC）从 70%增加到约 90%，其中 HCS 对 WHC 的改善效果最显著。在适当添加量（1.5wt%）下，MS（HCS 和 CS）显著改善了 MP 凝胶的质构特性（P<0.05）。在流变学测试中，所有 MS-MP 溶液均表现出 MP 的粘弹性，但添加 MS 导致 G'显著升高，表明 MS（尤其是 2.5wt%CHCS）的作用相当，相当于增加蛋白质浓度。SEM 照片显示，添加 2.5wt%CHCS 或 0.5wt%HCS 的 MP 凝胶形成了紧密均匀的网络，而 CS 则导致 MP 凝胶团聚，且随着添加量的增加团聚现象更加明显。MS 的添加，特别是 CHCS 的添加，促进了热诱导构象转变，从α-螺旋伴有的β-转角转变为β-折叠，导致 MP 分子伸展。
