title: BETA-CAROTENE: THERMAL DEGRADATION.
abstract: Thermal treatment of crystalline beta-carotene (240 degrees C in a vacuum) results in the formation of a volatile fraction containing chiefly aromatic hydrocarbons such as toluene, m- and p-xylene, 2,6-dimethylnaphthalene, and ionene. These compounds have been identified by means of gas-liquid chromatography, infrared spectroscopy, and, in the case of ionene, by additional nuclear magnetic resonance and mass spectroscopy. The principal degradation product is a yellowish-brown, glutinous mass which can be separated by means of preparative thin-layer chromatography in a number of fractions different in molecular weight. The structure of these fractions is not yet clear.
mesh_terms: D002338:Carotenoids; D002623:Chemistry Techniques, Analytical; D002845:Chromatography; D006358:Hot Temperature; D006841:Hydrocarbons, Aromatic; D013058:Mass Spectrometry; D009281:Naphthalenes; D012106:Research; D014050:Toluene; D014992:Xylenes; D019207:beta Carotene
chemical_list: D006841:Hydrocarbons, Aromatic; D009281:Naphthalenes; D014992:Xylenes; D019207:beta Carotene; D002338:Carotenoids; D014050:Toluene; C031286:4-xylene; C028519:2,6-dimethylnaphthalene
keywords: CAROTENE; CHEMISTRY, ANALYTICAL; CHROMATOGRAPHY; EXPERIMENTAL LAB STUDY; HEAT; NAPHTHALENES; TOLUENE; XYLENE