Studies On The Degradation Technology Of β-carotene And The Mechanism Of Degradation

Carotenoids widely exist in nature, andβ-carotene is the most active of its various isomers. The special structures of isoprenoid compounds are sensitive to light, heat, oxygen and other factors, which are easy to occur isomerization and oxidation reaction.β-Carotene is related to the quality of tobacco. It determines the colour of the modulated tobacco leaf, and the flavor substances in the products of its degradation affect the aroma and quality.The purpose of this paper is to acquire the best technology for β-carotene degradation, which is through the methods of chemical degradation. And during the process of producing tobacco, these degradation products are used to be added as a new idea for a cigarette flavoring.The main works of this paper are shown as follows. Based on lots of documents, it is compared the advantages and disadvantages between ethanol and n-hexane as solvent in gradating β-carotene, and then the experimental scheme is established. During the experiments, spectrophotometric method is used to determine the maximum absorption wavelength of β-carotene and β-ionone, which is the main product of degradation. The wavelengths are450nm and285nm respectively, the standard working curves are also obtained. The effects of heating time, heating temperature, amount of catalyst and oxidant for β-carotene degradation reaction are investigated, which is based on the absorbance at450nm of degradation as the main index. It confirms the effects of various factors on the degradation of β-carotene, and selects these four factors above as the main influencing factors for the next step of investigation.L9(34) orthogonal experiment method is used to screen and optimize the process of P-carotene degradation. And the optimum technology condition for the degradation is in the following. The hydrogen peroxide content is70mL, and the copper sulfate is0.100g, when the reaction time is2.0h, with the reaction temperature at70℃. Confirming the conditions above, the results are stable and reliable and this method is feasible. Finally, combining with the related literatures, the products ofβ-carotene degradation by GC-MS analysis conditions is confirmed, and the composition is also determined. The effects of different experimental conditions on the β-carotene degradation reaction are studied through comparing and analysis. According to the data of quality,β-carotene degradation mechanism was inferred.