Abstract: A process for extraction of absolute oil from Sichuan 'paste' tobacco was optimized through single factor test and orthogonal test with n-hexane as extraction solvent.In addition,the effect of various factors on the decolorization and wax removing efficiency was investigated with activated clay as decoloring agent and anhydrous ethanol as wax removing agent.Eventually,volatile components of ‘paste’ tobacco absolute oil were analyzed using GC-MS.The results showed that the optimal conditions were:solid to liquid ratio of 1:10,extraction temperature of 55 ℃,extraction duration of 0.5 h and extracting for 2 times;the optimal conditions of decoloration were:150 g/L of activated clay,35 ℃ of temperature,mixing and adsorption time for 3 h;the optimal conditions of wax removing were:anhydrous alcohol 1:10 (g/mL),wax removing temperature 0 ℃ and wax removing time for 4 h.Fifty-two volatile components were detected in the absolute oil of ‘paste’ tobacco,in which irone,ocimene,alloocimene, trans-isllimonene,dextro-terpadiene,α-bisabolene and natural vitamin E were firstly reported in the volatile components of tobacco absolute oil.The result of this study will provide some technical references for the development and application of the ‘paste’ tobacco absolute oil or essential oil products.

Key words: 'paste' tobacco absolute oil, extraction, purification, volatile components