Radiative and nonradiative deexcitation of pigments from natural oils

The absorption, steady state photoacoustic, fluorescence emission and excitation spectra of unbleached oils obtained by pressing the seeds of: evening primrose, borage, rape and viper's burgloss have been taken. Results obtained for samples under air and washed by nitrogen have been compared. In order to establish the occurrence of the slow thermal processes usually related to very photochemically active triplet states, the thermal deactivation in the absorption regions of carotenoids and the pheophytins has been observed at various frequencies of acting light modulations. The interactions between oil pigments are discussed. The generation of triplet states of dyes and singlet oxygen production in oils with different content of carotenoids and pheophytins is evaluated.