CAJ | 학술논문

采用远紫外圆二色光谱法对提取自南美白对虾Litopenaeus vannamei壳中的β虾青蛋白的理化性质进行了研究。结果表明：该蛋白是一种以α螺旋(含量为69%)为主要二级结构存在的二聚物,相对分子质量约为75000,最大吸收波长为580 nm；在40℃以下加热以及外加盐未加热时,该蛋白会出现可逆变性,升温至40℃以上、改变溶液pH均会对二级结构造成破坏,引起蛋白不可逆变性；加热30 min时,α螺旋损失率最大,约为50%；外加盐在升温时会加速蛋白的不可逆变性,其加速能力与盐浓度成反比；从南美白对虾壳与美国龙虾壳中提取的虾青蛋白在吸收光谱、离子柱亲合力等上有明显区别。研究表明,南美白对虾壳中的虾青蛋白具有水溶性、热不稳定性和遇热显色等性质,可作为食品着色剂或温度敏感指示剂。
채용원자외원이색광보법대제취자남미백대하Litopenaeus vannamei각중적β하청단백적이화성질진행료연구。결과표명：해단백시일충이α라선(함량위69%)위주요이급결구존재적이취물,상대분자질량약위75000,최대흡수파장위580 nm；재40℃이하가열이급외가염미가열시,해단백회출현가역변성,승온지40℃이상、개변용액pH균회대이급결구조성파배,인기단백불가역변성；가열30 min시,α라선손실솔최대,약위50%；외가염재승온시회가속단백적불가역변성,기가속능력여염농도성반비；종남미백대하각여미국룡하각중제취적하청단백재흡수광보、리자주친합력등상유명현구별。연구표명,남미백대하각중적하청단백구유수용성、열불은정성화우열현색등성질,가작위식품착색제혹온도민감지시제。
Circular dichroism spectroscopy was used to investigate the physicochemical properties ofβcrustacyanin extracted from shells of Pacific white leg shrimp Litopenaeus vannamei. Theβcrustacyanin with molecular weight of 75 000 andλmax 580 nm consists of carotenoprotein and carotenoids, mainly inαhelix form and contains more than 60% ofαhelices. This large molecule subunit showed a reversible denaturation exposed to conditions of heat below 40 ℃ and addition of saline before heating. The complex was thermal unstable at over 40 ℃, and the pH change led to the protein denaturation and irreversible. The complex showed the maximal loss ratio ofαhelix, nearly 50%when it was heated for 30 min. Addition of salt resulted in formation of the irreversible protein,with inverse propor-tion to salt concentrations. There were significant differences in the physicochemical properties including absor-bance spectra and the affinity to ionic column ofβcrustacyanin extracted from Pacific white leg shrimp and Ameri-can loster Homarus species. It is concluded that the complex showing water soluble,thermal unstable and coloring on heating has a potential as food colorant or temperature indicator.