PAN Chuang1，Shoichiro Ishizaki2，JI Hong-wu1，PAN Guang-kun1
1.Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China；2.Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477,Japan
Abstract: Circular dichroism spectroscopy was used to investigate the physicochemical properties of β crustacyanin extracted from shells of Pacific white leg shrimpLitopenaeusvannamei. The β crustacyanin with molecular weight of 75 000 and λmax580 nm consists of carotenoprotein and carotenoids, mainly in α helix form and contains more than 60% of α helices. 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 of α helix, nearly 50% when it was heated for 30 min. Addition of salt resulted in formation of the irreversible protein，with inverse proportion to salt concentrations. There were significant differences in the physicochemical properties including absorbance spectra and the affinity to ionic column of β crustacyanin extracted from Pacific white leg shrimp and American losterHomarusspecies. It is concluded that the complex showing water soluble,thermal unstable and coloring on heating has a potential as food colorant or temperature indicator.
2014, Vol. 29 
