烘烤中的膜脂过氧化作用及其对烟叶内在质量的影响

采用自行设计的温湿度自控电热烤烟箱研究了烘烤过程中烟叶的膜脂过氧化作用及烟叶内在品质的变化。结果表明,随烘烤时间发展,超氧化物歧化酶(SOD),过氧化物酶(POD)活性减小,丙二醛(MDA)含量增加,烘烤72h后SOD和POD活性消失;60h后,MDA积累达到最大值。烟叶的内在品质与膜脂过氧化水平呈负相关。高温快烤条件下,烟叶的膜脂过氧化水平最高,低温慢烤则降低;与此相反,低温慢烤条件下,烟叶的化学成分含量适宜,各成分间比例协调,叶内主要致香物质数量多,含量高,香气质好量足。高温变黄或快速升温定色,烤后烟叶内在质量都有不同程度的下降,且变黄温度对膜脂过氧化水平和烟叶内在质量的作用较定色升温速度对二者的影响要大。 

Characteristics of membrane lipid peroxidation in tobacco leaves during curing and its effect on quality

Studies on the membrane lipid peroxidati0n and the change 0f interior quality of tobacco leaf during curing wereconducted by using self-made temperature and moisture automatic control electric-heated curing barn- The resultsshowed that as the curing process procecding, the activity of superoxide dismutase (SOD) and peroxidase (POD) de-creased gradually and the c0ntent of mal0ndialdehyde (MDA) increased. 72 hours later, the activity of superoxidedismutase (SOD) and peroxidase (POD) disappearsed. 60 hours later, the content 0f malondialdehyde (MDA) got tothe highest level. The relation between tobacc0 leaf interior quality and the membrane peroxidation is minus. The de-gree of membrane peroxidation reached the highest under the condition of high temperature yellowing and high speedcolorfixing and the l0west under the condition of low temperature yell0wing and low speed color-fixing on the con-trary, the content of chemical components was appropriate and the ratio among different composition was compatib1eunder the condition of the latter. The content of main aromatic matter in tobacco 1eaf was high and the quality andvolume of aroma were well. Under the condition of high temperature yell0wing or high speed col0rfixing, the tobaccoleaf quality decreased'at diffrent degree. The effect of yellowing temperature on the membrane perxidation degree andtobacco leaf interior quality was larger than the effect of the speed of temperature rising in color-fixing stage.