Effects of roasting conditions on major aroma components in Burley tobacco
The contents of proline-glucose Amadori compounds and thirteen kinds of alkaline aroma components in burley tobacco were determined after roasting under different conditions, including roasting temperature, air humidity and ending moisture content in tobacco. The roasting conditions were optimized by comparing the contents of said aroma components before and after roasting, and the results of sensory evaluation. The results showed that: 1) The contents of proline-glucose Amadori compounds increased to different extent under various roasting conditions, which indicated that roasting was beneficial to the formation of Amadori compounds. 2) With the increase of air moisture, the total contents of alkaline aroma components decreased at a lower temperature (100 °C), while increased at a higher temperature (140 °C). 3) The results of sensory evaluation agreed with the determined total content of alkaline aroma components and Amadori compounds. The optimal roasting conditions were: temperature 120 °C, air humidity 400 g/kg and ending moisture content in tobacco 8 %. The total content of aroma components was higher and the aroma quality of tobacco was markedly improved after being roasted under such conditions.