烟叶自然陈化过程中高级脂肪酸及有关生化特性动态变化的研究

Changes in Higher Fatty Acids and Relative Biochemical Characteristics of Flue-cured Tobacco during Aging

烟叶陈化（aging）过程中，脂质总量逐渐下降。其中，豆寇酸（C14：0）含量呈上升趋势，硬脂酸（C18：0）和油酸（C18：1）含量在陈化前期有所增加，陈化1年时达最高，而后又逐渐下降；棕榈酸（C16：0）、亚油酸（C18：2）和亚麻酸（C18：3）含量在新烟（未经陈化）中最高，在陈化过程中均持续下降，其中以亚麻酸含量下降幅度最大；同时，不饱和高级脂肪酸总量（C18：1＋C18：2＋C18：3）与饱和高级脂肪酸总量（C14：0＋C16：0＋C18：0）之比值持续下降。烟叶陈化过程中，脂氧合酶活性、过氧化值（POV）、酸值（AV）及丙二醛（MDA）含量的变化均表现为前期升高而后期下降的单峰曲线。而烟叶挥发性酸在陈化过程中持续增加。

The concentration of total lipids in flue-cured tobacco decreased gradually duringnatural aging. But the principal higher fatty acids in flue-cured tobacco have been showndifferent changing orders during aging. Myristic acid(C14: 0) increased constantly during the whole aging course. While stearic acid (C18: 0) and oleic acid (C18: 1) increased at the initial stages of aging and reached their maximum contents after one yearof aging, but decreased thereafter. Palmitic acid(C16: 0), linoleic acid (C18: 2) andlinolenic acid (C18: 3) decreased constantly throughout the aging. Especially, thelinolenic acid content decreased drastically. Furthermore, the ratio of unsatuated fattyacids (C18: 1 +C18: 2+C18: 3) and satuated fatty acids (C14: 0+C16: 0+C18: 0)decreased continuously during aging, from 1.00 at the initial stage to 0. 43 at the end ofaging, when it seemed to be stabilized, but the maximum rate of decrease of the ratiowas at the stage from 12 months to 18 months during the aging. Relatively, the activityof lipoxygenase and peroxidation value (POV) initially increased and reached their highest levels after 6 months of aging, but steadily decreased thereafter. The acid value andmalondialdehyde (MDA) content increased constantly during 12 months and 18 monthsof aging respectively, and decreased rapidly in subsequent stages, while a continuous increase of total volatile acids in flue-cured tobacco was observed throughout the aging.