摘要
将鸡肉肌原纤维蛋白(myofibrillar protein,MP)-山茶油混悬液进行高速剪切均质(high-speed shear homogenization,HSSH)处理,制得9种不同剪切速率(11500、14500、20500 r/min)和剪切时间(3、5、7 min)的乳状液样品。研究HSSH对乳液中MP的乳化活性指数(emulsifying activity index,EAI)、乳化稳定性指数(emulsifying stability index,ESI)、溶解度、二级和三级结构的影响,同时研究HSSH对乳液液滴粒径的影响。结果表明:MP的EAI随剪切速率(11500~20500 r/min)增加和剪切时间(3~7 min)延长而增大,ESI在剪切速率为14500 r/min时几乎不受剪切时间影响且均获得>90%的高值;剪切速率14500 r/min乳液中MP溶解度最高,11500 r/min与14500 r/min组乳状液中MP的二级结构含量随时间延长变化趋势一致,即α-螺旋、β-转角含量随着时间延长逐渐下降,β-折叠和无规卷曲含量则显著升高(P<0.05);表征MP三级结构的表面疏水性和活性巯基含量均在20500 r/min、7 min剪切条件下出现最大值,此时MP的溶解度最小、乳液液滴粒径最大、乳液稳定性最差。因此,适当的HSSH能改变MP的二级和三级结构,并改善MP的乳化活性和乳化稳定性;但过度剪切却导致MP分子过度展开,并造成乳状液失稳。
Chicken myofibrillar protein(MP)suspended in camellia oil was processed by high-speed shear homogenization(HSSH)with different shear rates,(11500,14500 and 20500 r/min)and shear times(3,5 and 7 min).As a result,nine emulsion samples were obtained.The effects of HSSH treatment on the emulsifying activity index(EAI),emulsion stability index(ESI),solubility,secondary and tertiary structure of MP in emulsions and on emulsion droplet size were studied.The results showed that the EAI of MP increased with the increase in shear rate or shear time.At a shear rate of 14500 r/min,the ESI was hardly affected by shear time,and remained greater than 90%.The solubility of MP in the emulsion was the highest at a shear rate of 14500 r/min.For the emulsions with shear rates of 11500 and 14500 r/min,the secondary structure content of MP showed a consistent trend with increasing shear time.Specifically,the proportions ofα-helix andβ-turn gradually decreased,while the proportions ofβ-sheet and random coil increased significantly(P<0.05).The surface hydrophobicity and the reactive sulfhydryl group content,both representing the tertiary structure of MP,showed maximum values at 20500 r/min and 7 min.Under this condition,the solubility of MP was the lowest,the emulsion droplet size was the largest,and the emulsion stability was the worst.Therefore,appropriate HSSH treatment can change the secondary and tertiary structures of MP,and improve the EAI and ESI of MP.However,excessive HSSH treatment results in overunfolding of MP and emulsion instability.
作者
韩柯颖
杨玉玲
HAN Keying;YANG Yuling(Jiangsu Key Laboratory of Grains and Oils Quality Control and Processing,Jiangsu Collaborative Innovation Center for Modern Grain Circulation and Safety,College of Food Science and Engineering,Nanjing University of Finance and Economics,Nanjing 210023,China)
出处
《肉类研究》
2022年第12期1-6,共6页
Meat Research
基金
江苏高校优势学科建设工程资助项目(PAPD)
国家自然科学基金面上项目(31371798)。
关键词
高速剪切均质
肌原纤维蛋白
乳化特性
结构
山茶油
high-speed shear homogenization
myofibrillar protein
emulsifying properties
structure
camellia oil
