摘要
研究谷氨酸螯合钙可以实现食盐部分替代的内在原因。以兔腰大肌肌原纤维蛋白为研究对象,对比钙盐组(1.25%谷氨酸螯合钙+1.20%食盐,质量分数)和对照组(常规食盐添加量组,添加3%食盐,质量分数)的盐溶性蛋白溶解度、溶解和未溶解组分中的蛋白组成(十二烷基硫酸钠-聚丙烯酰胺凝胶电泳SDS-PAGE)、热凝胶形成前后的蛋白分子高级结构(拉曼光谱)和水分子存在状态(低场核磁共振NMR)变化以及凝胶微结构差异。结果表明:钙盐组的蛋白溶解度为24.24%,显著低于对照组(P<0.05),但是加热前后体系中α-螺旋含量和β-折叠含量均与对照组差异不显著;热凝胶T22b弛豫时间由对照组的305.39 ms下降至钙盐组的285.50 ms,说明不易流动水的结合程度增强;虽然该组凝胶微结构与对照组差异显著,凝胶网络线也稍粗于对照组,但其微结构细腻规则且凝胶孔径均匀一致。结论:以谷氨酸螯合钙替代部分食盐,肌原纤维蛋白体系中蛋白分子-水分子、蛋白分子-蛋白分子间有较好的交联平衡,加热后可以形成规则均匀并具有高保水性的三维一体凝胶网络结构。
Excessive sodium intake had became a global issue in recent years,and more and more people paid their attentions to it. The studies showed that reducing the intake of sodium was good for human＇s health. NaCl could be substituted partially by calcium diglutamate in order to reduce sodium contents of the gel-type meat products,but the mechanism was unclear. In this paper,we wanted to find the underlying reasons of calcium diglutamate partially substituting NaCl. In this study,the salt mixture comprised of 70% NaCl and 30% KCl. The differences of salt soluble protein solubility,proteins content of the supernatant and precipitate（SDSPAGE）,secondary structures of protein molecules before or after heat-induced gel-forming（Raman spectroscopy）,changes of water molecules existing state（NMR） and gel microstructures between calcium diglutamate substitute samples（1. 25% calcium diglutamate and 1. 20% salt,m/m） and the control（conventional salt dosage group,3% salt,m/m） were investigated,and the myofibrillar proteins from Pasoas major（PM） were used as experimental object. PM was taken from the 3-month-old male New Zealand white rabbits（weight 2. 0-2. 5 kg）. Experiments were repeated three times and new myofibrils were extracted each time. The results showed that the protein solubility of treatment group was 24. 24%,which was significantly lower than that of the control（P〈0. 05）. We found from the comparison of dissolved protein fractions that,contents of α-actinin and actin showed no significant difference（P〉0. 05）,however,contents of the dissolved myosin heavy chain from treatment group decreased by 51. 80%（P〈0. 05）,and content of C-protein increased by 143. 30%（P〈0. 05）. Before or after heating,contents of α-helix and β-sheet in the system showed no significant difference with the control; T22brelaxation time of thermal gels decreased from 305. 39 ms of control to 285. 50 ms of treatment,indicating the degree of immobilized water combination increased; the gel microst
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2014年第3期159-166,共8页
Journal of Nanjing Agricultural University
基金
国家自然科学基金项目(31171707)
关键词
谷氨酸螯合钙
低钠
肌原纤维蛋白
理化特性
兔
calcium diglutamate
low sodium
myofibrillar proteins
physicochemical properties
rabbit
