Abstract
The sizes and shapes of lutein aggregates in acetone aqueous solution were examined by spectroscopic analyses and electron microscopic observation, since lutein dispersed into acetone aqueous solution and provided a much simpler system than others. This system is suitable for basic research on lutein aggregates. The lutein aggregate gave maximum molar ellipticity in acetone concentrations from 35 to 45% aqueous solution. When the acetone concentration increased, CD spectra were reversed in 45% concentration from a negative exciton chirality to the positive. Since the aggregates were most slender in these acetone concentrations, it was found that the length of the lutein aggregate was closely related to the molar ellipticity. The apparent widths of the aggregates became large with increases of the acetone concentration after the reversion of CD spectra, where the molar ellipticities were diminished. These results are similar to those for the lutein aggregates in dilute surfactant solution, and this system is clearer and simpler for electron microscopic observation than those in surfactant solutions.
