摘要
研究在pH6.5、高离子强度(0.6mol/LKCl)下兔肌球蛋白热诱导凝胶过程中的物理化学特性的变化。α-螺旋含量从25℃开始缓慢减小,43℃后开始急剧减小,直到65℃左右后基本不发生变化;浊度从40℃左右开始增加,表明了凝集的开始,至65℃后不再变化。活性巯基含量40℃开始增加,65℃达到最大值;总巯基含量从30℃开始降低;疏水性在30～85℃间呈非线性增加趋势;G’(贮能模量)从48℃开始增加,在48～71℃间缓慢增加,71～82℃间急剧增加。表明肌球蛋白热变性从α-螺旋的解折叠开始,进而促进疏水基团和巯基基团的暴露;二硫键与疏水作用、分子间氢键等共同作用促进凝胶强度的增加。
The mechanism of heat-induced gelation of myosin was investigated by studying physico-chemical changes of rabbit myosin during at pH 6.5, high ionic strength of 0.6mol/L KCl. A slight decrease in a -helical content was observed at 25 ℃, then a rapid decrease from 43 to 65 ℃, followed by a plateau after 65℃. Turbidity increased at 40 ℃ which indicated the beginning of the aggregation, remaining constantly after 65 ℃. Reactive sulfhydryl content increased from 40 ℃, reaching a maximum at 65 ℃. Total sulphydryl content decreased from 30 ℃. Surface hydrophobicity increased non-linearly between 30-85 ℃. G＇ increased slowly between 48 and 71 ℃, sharply from 71 to 82 ℃. It was concluded that denaturation of myosin was initialized by unfolding of the a -helical and followed by the exposure of sulphydryl and hydrophobic residues. Disulfide linkages, hydrophobic interactions and hydrogen bonds could enhance the elasticity of the gelation of myosin together.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2008年第4期149-153,共5页
Food Science
基金
国家自然科学基金项目(30771526)
"973"计划课题(2006CB708212)
关键词
肌球蛋白
凝胶
物化特性
myosin
gelation
physico-chemical characteristics
