Abstract:In this study, the spectral characteristics of C-phycocyanin (C-PC) from Spirulina platensis were studied, and the changes of its solution stability and fluorescence characteristics under the environmental factors such as temperature, pH, light (intensity, time, light source), protein denaturants. The results showed that the color stability and fluorescence characteristics of C-PC were affected by factors such as pH, light, temperature, and protein denaturants. Under the conditions of dark, pH 6~7, and temperature ranged 4~30 ℃, the pigment retention rate and blue value b* of C-PC solution were less than 4.93%, which has good stability. C-PC was sensitive to light, of which the red and blue band light sources have the greatest influence (p<0.05). In the solution of protein denaturants, certain concentrations of guanidine hydrochloride (≥2 mol/L), ethanol (≥50%, V/V), and sodium lauryl sulfate SDS (≥0.05%, m/V) could make C-PC seriously unstable and discolored, and quenched its fluorescence peak. Correlation analysis showed that the color change of C-PC caused by temperature and light intensity was significantly correlated with the peak of its fluorescence characteristics (p<0.05). However, the color change caused by pH or protein denaturants has no significant correlation with the peak of its fluorescence characteristics (p>0.05), indicating that the fluorescence characteristics of C-PC were not completely consistent with the changes in its color stability. The results provided references for the application of C-PC in natural pigments, fluorescent reagents or further research on the mechanism of instability.
