Abstract: It was found that only fewer isomerizations take place during the melting of β-carotene. When heating β-carotene solution at 40 ℃ for one week,products with molecular weight (MW) from 251 to 5283 are created,and when solid β-carotene was heated at 40℃ for one week,products with MW from 431 to 11511 are produced by serious oxidation and polymerization. In a sense polymerization might be dominant path of β-carotene producing byproducts during thermal processing according to analysis of functional groups of the byproducts,while the mechanism should be researched further.

Key words: &beta, -carotene； gel permeation chromatography； 1H nuclear magnetic resonance spectra； fourier transform infrared spectrometry； polymerization；