卷烟主流烟气中吲哚和3-甲基吲哚的香气作用分析

Impacts of indole and 3-methylindole on aroma of mainstream cigarette smoke

为考察卷烟主流烟气中吲哚和3-甲基吲哚的香气作用,建立了卷烟主流烟气粒相物中吲哚和3-甲基吲哚的GC/MS定量分析方法,测定了其在14个品牌卷烟主流烟气粒相物中的质量分数以及在乙醇和三乙酸甘油酯中的嗅觉阈值和嗅觉特征转变时的浓度;计算了14个品牌卷烟烟气粒相物中吲哚和3-甲基吲哚的香气活性值(OAV)。结果表明:①在乙醇和三乙酸甘油酯中,3-甲基吲哚的嗅觉阈值均远低于吲哚,而在粒相物中二者的质量分数无数量级差异,因此3-甲基吲哚的OAV远大于吲哚。②二者在乙醇中的嗅觉阈值均明显低于各自在三乙酸甘油酯中的阈值,其嗅觉特征均随浓度升高由花香变为粪臭气息。③吲哚、3-甲基吲哚对卷烟烟气香气均具有重要影响,且以3-甲基吲哚作用最明显。④吲哚、3-甲基吲哚在所考察卷烟主流烟气粒相物中的质量分数远高于嗅觉特征转变时的浓度,但由于烟熏香的掩盖作用,烟气中二者的粪臭气息并不易被卷烟消费者感受到,其在口腔内的累积可能是造成卷烟长期消费者口腔具有异味的重要原因。

To investigate the impacts of indole and 3-methylindole on the aroma of mainstream cigarette smoke,a quantitative GC/MS method was developed for analyzing the indole and 3-methylindole levels in total particulate matter(TPM)of mainstream cigarette smoke.The contents of the two analytes in TPMs of mainstream smoke of 14 cigarette brands were determined.The olfactory thresholds of indole and 3-methylindole,as well as the concentrations at which their olfactory characteristics changed,were determined in ethanol and triacetin separately.Their odor activity values(OAVs)in TPMs were also calculated.The results showed that:1)The olfactory threshold of 3-methylindole was much lower than that of indole,irrespective of ethanol or triacetin.However,the difference between their contents in TPMs was less than one order of magnitude,therefore the OAVs of 3-methylindole were much higher than those of indole.2)The olfactory thresholds of indole and 3-methylindole in ethanol were much lower than those in triacetin,and their olfactory characteristics changed from floral to fecal with increasing concentrations.3)Indole and 3-methylindole had important effects on the aroma of cigarette smoke,especially 3-methylindole.4)The contents of indole and 3-methylindole in all investigated TPMs were much higher than the concentrations at which their olfactory characteristics changed,but the fecal odor of indole and 3-methylindole in cigarette smoke could not be sensitively felt due to the masking effect of smoky aroma in cigarette smoke.Their accumulation in buccal cavity might be the reason for the unique smell in the breath of long-term cigarette consumers.