Figure 4. Normalized absorbance spectra of astaxanthin and astaxanthin H-aggregates.

The UV-Vis spectra of astaxanthin dissolved in methanol and astaxanthin dissolved in methanol in the presence of distilled water in a ratio of 1∶3 was recorded. The absorbance peak of astaxanthin dissolved in methanol and mixed with water resulted in a blue spectral shift which is indicative of the formation of H-aggregates [14], [35].