Absorption spectra for the complexes formed from vitamin-A and beta-lactoglobulin

The interactions between vitamin-A and beta-lactoglobulin have been investigated. We have found that two different complexes can be formed: one involving vitamin-A, and one involving a derivative of vitamin-A that most probably has a retro-beta-ionylidene structure. Room temperature absorption spectra for these complexes in phosphate buffer at pH 7.50 are reported and discussed.