滚筒分段变温干燥方式下烤烟叶丝质量的变化特征

为分析滚筒分段变温干燥方式下叶丝含水率变化、物理特性及叶丝香味成分变化规律,考察了100、120、130、140、150℃滚筒恒温干燥后,150/100、140/100、130/100、120/100℃滚筒分段变温干燥后,以及140/100℃分段变温干燥条件下分别在叶丝含水率为19%、17%、15%时改变筒壁温度进行干燥后叶丝填充值、弹性的变化情况,并对比了两种干燥方式下叶丝石油醚提取物及香味成分的变化规律。结果表明:①采用第一阶段高温第二阶段低温的变温干燥方式,通过提高脱水前期的筒壁温度,能够明显提升叶丝干燥效率;②与高温恒温干燥过程相比,采用第一阶段高温第二阶段低温的变温干燥方式有利于提高叶丝弹性、填充值,叶丝中棕色化反应产物、类胡萝卜素降解产物等香味成分含量也明显升高;③变温干燥方式下,变温点处烟丝含水率从19%降低至15%时,叶丝填充值呈降低趋势,弹性呈增大趋势,叶丝中香味成分总量也呈降低的趋势。 

Quality Variation Characteristics of Cut Strips of Flue-cured Tobacco During Dual-temperature Drying

In order to analyze the changes of physical properties of,moisture content and aroma components in cut strips in dual-temperature cylinder drying,the filling values and elasticity of cut strips dried in cylinder at constant temperatures of 100,120,130,140,150℃ and at temperature combinations of 150/100(first section temperature/second section temperature),140/100,130/100 and 120/100℃ were determined,and the contents of petroleum ether extracts and aroma components in cut strips dried at constant and varied temperatures were compared.For the temperature combination of 140/100℃,experiments were conducted by changing cylinder wall temperature when tobacco moisture contents reached 19%,17%,15% separately.The results showed that:1) Under high/low temperature combination conditions,the drying efficiency of cut strips was obviously promoted by rising cylinder wall temperature at earlier drying stage.2) Comparing with constant high temperature drying,high/low temperature combination was helpful to improving the elasticity and filling value of cut strips,meantime,the aroma components,such as brown reaction products and carotenoids degradation products,increased obviously.3) Under dual-temperature drying,the filling value of and total aroma component content in dried cut strips would decrease,while its elasticity would increase when temperature transition point was the moisture content reached 15% instead of 19%.