为全面理解兔肉品质的形成过程,利用偶氮二异丁脒盐酸盐(2,2’-azobis(2-amidinopropane)dihydrochloride,AAPH)的热分解作用生成过氧自由基(ROO·)诱导兔肉肌浆蛋白氧化,通过AAPH处理后兔肉肌浆蛋白中高铁肌红蛋白相对含量、超铁...为全面理解兔肉品质的形成过程,利用偶氮二异丁脒盐酸盐(2,2’-azobis(2-amidinopropane)dihydrochloride,AAPH)的热分解作用生成过氧自由基(ROO·)诱导兔肉肌浆蛋白氧化,通过AAPH处理后兔肉肌浆蛋白中高铁肌红蛋白相对含量、超铁肌红蛋白浓度、羰基含量、总巯基含量以及肌浆蛋白表面疏水性、粒度、浊度和溶解性测定,肌浆蛋白十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)和内源荧光光谱分析,研究ROO·胁迫肌浆蛋白氧化聚集机制。结果表明,随着AAPH浓度的升高,高铁肌红蛋白和超铁肌红蛋白相对含量显著增加(P<0.05),蛋白质羰基含量显著增加(P<0.05),总巯基含量显著下降(P<0.05)。内源荧光光谱和表面疏水性分析结果表明ROO·可以引起肌浆蛋白的去折叠和疏水基团暴露。SDS-PAGE分析结果表明ROO·可以导致肌浆蛋白二硫键交联。此外,随着AAPH浓度的增大,肌浆蛋白粒度和浊度呈现出逐渐增大的趋势,表明ROO·可以引发肌浆蛋白的聚集。疏水相互作用和二硫键交联是ROO·胁迫肌浆蛋白聚集的主要作用力。ROO·不仅可以直接引发肌浆蛋白聚集,还可以通过影响肌红蛋白诱导氧化体系促进肌浆蛋白交联聚集。展开更多
The interactions of carotenoids (bixin, β-carotene and lycopene) with CCl3OO. in aqueous and i-propylalcohol solution saturated with air have been studied by pulse radiolysis. For bixin and β-carotene reaction produ...The interactions of carotenoids (bixin, β-carotene and lycopene) with CCl3OO. in aqueous and i-propylalcohol solution saturated with air have been studied by pulse radiolysis. For bixin and β-carotene reaction products from forming process, absorbing in the region of 650 nm, is observed with concomitant carotenoid bleaching (bixin at 500 nm, β-carotene at 450 nm). Their rate constants from forming process are 1.78 ×108 and 7.8 ×107 mol-1 · L · s-1 respectively. However, in the case of lycopene, no such a forming process of reaction as bixin and β-carotene can be observed although there is the bleaching reaction (rate constant 4 ×107 mol-1 · L · s-1). The results suggest that the carotenoid radical cation and an additional radical are produced in the case of bixin and β-carotene, whereas lycopene undergoes electron transfer with CCl3OO., forming cation radical.展开更多
文摘为全面理解兔肉品质的形成过程,利用偶氮二异丁脒盐酸盐(2,2’-azobis(2-amidinopropane)dihydrochloride,AAPH)的热分解作用生成过氧自由基(ROO·)诱导兔肉肌浆蛋白氧化,通过AAPH处理后兔肉肌浆蛋白中高铁肌红蛋白相对含量、超铁肌红蛋白浓度、羰基含量、总巯基含量以及肌浆蛋白表面疏水性、粒度、浊度和溶解性测定,肌浆蛋白十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)和内源荧光光谱分析,研究ROO·胁迫肌浆蛋白氧化聚集机制。结果表明,随着AAPH浓度的升高,高铁肌红蛋白和超铁肌红蛋白相对含量显著增加(P<0.05),蛋白质羰基含量显著增加(P<0.05),总巯基含量显著下降(P<0.05)。内源荧光光谱和表面疏水性分析结果表明ROO·可以引起肌浆蛋白的去折叠和疏水基团暴露。SDS-PAGE分析结果表明ROO·可以导致肌浆蛋白二硫键交联。此外,随着AAPH浓度的增大,肌浆蛋白粒度和浊度呈现出逐渐增大的趋势,表明ROO·可以引发肌浆蛋白的聚集。疏水相互作用和二硫键交联是ROO·胁迫肌浆蛋白聚集的主要作用力。ROO·不仅可以直接引发肌浆蛋白聚集,还可以通过影响肌红蛋白诱导氧化体系促进肌浆蛋白交联聚集。
文摘The interactions of carotenoids (bixin, β-carotene and lycopene) with CCl3OO. in aqueous and i-propylalcohol solution saturated with air have been studied by pulse radiolysis. For bixin and β-carotene reaction products from forming process, absorbing in the region of 650 nm, is observed with concomitant carotenoid bleaching (bixin at 500 nm, β-carotene at 450 nm). Their rate constants from forming process are 1.78 ×108 and 7.8 ×107 mol-1 · L · s-1 respectively. However, in the case of lycopene, no such a forming process of reaction as bixin and β-carotene can be observed although there is the bleaching reaction (rate constant 4 ×107 mol-1 · L · s-1). The results suggest that the carotenoid radical cation and an additional radical are produced in the case of bixin and β-carotene, whereas lycopene undergoes electron transfer with CCl3OO., forming cation radical.
