Abstract:

Lignin was extracted from carrot root with high boiling solvent(HBS) 80% ethylene glycol aqueous solution as solvent. Results show that the optimum conditions were as follows:the mass ratio of raw solid materials to solvent was 1∶6, temperature was 210 ℃, reaction time was 2 h, the maximum yield was 17.79%. The chemical structure of the carrot lignin has been characterized by FTIR, UV, and 1H NMR. The chemical composition of HBS lignin from carrot root was determined by elemental analysis, and the content of methoxyl was tested with Viebock′s methods. The C9 structure of lignin from carrot was estimated as C9H9.62O1.99(OCH3)0.96. The elimination efficiency of ·OH free radical by lignin from carrot was studied. The results show that carrot lignin can inhibit the activity of ·OH free radical at low concentrations（50 mg/L）with a maximum inhibition efficiency of 64.9%.

Key words: HBS solvent, glycol, carrot, lignin, antioxidant