Mechanism of Capsanthin Fadingin VitroInduced by Reactive Oxygen Species

Structural changes in capsanthin in the presence of exogenous reactive oxygen species such as , H2O2, and ·OH were analyzed by UV-visible spectroscopy, infrared spectroscopy, and mass spectrometry, which were used to explore the fading reaction mechanism of capsanthin. The results showed that reactive oxygen species could induce a blue shift in the maximum UV-visible absorption peak, as well as breakage of conjugated double bonds in capsanthin. Due to the direct oxidation or addition reactions in the presence of reactive oxygen species, the double bonds and carbonyl groups in capsanthin reacted with reactive oxygen species, generating alcohols such as C13H22O2, C15H24O2, and C10H18O in the presence of , C13H22O3, and C10H18O2 in the presence of H2O2 and C14H30O4 and C10H18O2 in the presence of ·OH. The rest of the products were small molecule compounds. These results suggested that reactive oxygen species could destroy the conjugated double bonds in capsanthin, which resulted in the color fading.