Cherry-red tobacco has aroused significant interest in both the academic and industrial fields due to its unique aroma style. In order to analyze the aroma characteristics of Cherry-red tobacco and the intrinsic aroma substance basis, the aroma compounds were analyzed by gas chromatography-mass spectrometry (GC-MS), the aroma characteristics were verified by sensory evaluation, and a correlation analysis was further conducted. The sensory evaluation suggested that Cherry-red tobacco was significantly richer in aroma, containing a total of 11 aromas, among which nutty, bean, herbal, and spicy were the characteristic aromas. The analysis of aroma compounds indicated that there were 88 differentiating aroma compounds between Cherry-red tobacco and Yunyan 87. The correlation analysis revealed that the glutinous sweet aroma of Cherry-red tobacco was strongly correlated with phenols, aromatic hydrocarbons, and aldehydes, while the fresh sweet aroma of Yunyan 87 was strongly correlated to ketones and nitriles. There were 24 characteristic aroma substances with strong correlations with the glutinous sweet aroma of Cherry-red tobacco. Furthermore, based on the odor and OAV analysis results, 2-vinylpyridine, 2,6-dimethylpyridine, scopoletin, 4-methylphenol, and eugenol were the key aroma compounds that highlighted the characteristic aroma of Cherry-red tobacco.

The low temperature catalytic pyrolysis performances of heated tobacco sheets by alkali/alkaline earth metal were investigated by TG-FT-IR and Py-GC-MS. Thermogravimetric analysis showed that the maximum weight loss rate temperature of the heated tobacco sheets significantly reduced from 328 degrees C to 292 degrees C catalyzed by alkali metal Na or K catalysts, and the weight loss between 100 and 300 degrees C increased by 48.83% and 40.05% respectively. While alkaline earth metal Mg or Ca catalysts exerted less influence on the maximum weight loss rate temperature and the weight loss between 100 and 300 degrees C reduced slightly. The online infrared absorption band of pyrolysis gas shifted to lower temperature and the concentration of pyrolysis gas increased over Na catalysts, which matched well with TG results. Moreover, the concentration of carbonyl compounds and compounds containing C-O bonds in pyrolysis gas increased significantly. The content of 2-furanmethanol, butyrolactone and megastigmatrienone in pyrolysis gas increased under the assistance of alkali metal Na or K. Model compounds research confirmed that alkali metal could catalyze low temperature pyrolysis of cellulose in heated tobacco sheets. These results demonstrated that the pyrolysis of heated tobacco sheets could be catalyzed by alkali metal catalysts at low temperature, increasing the concentration of pyrolysis gas and aroma substance. This research provided a new idea for the study of aroma and concentration enhancement of heated cigarettes through catalytic technology.

It is well known that 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) is usually formed in the Maillard reaction and it contributes to the antioxidant properties of Maillard reaction intermediates. A series of hydroxyl group protected DDMP derivatives were synthesized to further understand the source of antioxidant activity. Antioxidant abilities of the DDMP derivatives were evaluated by scavenging the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS˙+), 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and galvinoxyl radical, respectively. It was found that the introduction of protecting groups to the free hydroxyl groups of DDMP decreases their reducing abilities. In particular, the hydroxyl group at the olefin position exhibited a remarkable impact on the antioxidant activity of DDMP, indicating that the unstable enol structure in the DDMP moiety is the key factor for its antioxidant activity.

2,3-Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) exists in many foods, and its effect on taste is controversial. The aim of this study was to clarify whether DDMP has bitter taste or not. For this purpose, DDMP was synthesized from maltol instead of from glucose for the first time. In contrast, DDMP derived from glucose was also prepared and further purified. Their structures were identified by NMR and MS, and considered to be the same substance. The sensory analysis showed that DDMP derived from maltol was tasteless. Further studies indicated that some impurities in Maillard reaction made DDMP derived from glucose taste bitter.

Quality assurance is one of the key issues in tobacco industry and many efforts have been put on the quality control. This paper introduces a new chemometrics technique to estimate the "quality similarity rate", which is used for quality control. The value of the quality similarity rate represents the similarity degree between the products and the standard reference samples, which is a global parameter that can be generated by either human assessors or machine learning. Supervised similarity regression models are built to automatically estimate the quality similarity rate value from NIRS data of tobacco leaf and smoke. For the similarity regression learning, the metric matrix is generated by a novel method which calculates the Mahalanobis distance from the segmented near infrared spectroscopy (NIRS). The results show the similarity regression learning can predict the quality similarity score well in high speed and can be improved with lasso (least absolute shrinkage and selection operator) related feature selection algorithms such as sRDA (sparse redundancy analysis) and glmnet.

为区分不同浓香型烟叶风格特征的差异,对96种烟草重要香气成分的作用阈值进行了评价,以GC-MS法测定了其在许昌、郴州和潍坊烤烟烟气中的释放量,获得了香气活性值,将属于同一香韵的化合物的香气活性值加和得到10种香韵活性值并进行对比分析,揭示了不同浓香型烟叶的香韵特点.结果表明:①96种香气成分的作用阈值介于8.68×10-14和12.3μg/g之间.②郴州C3F、潍坊C3F和许昌C3F浓香型烟叶主流烟气中,乙酸的释放量最高,分别达475.103、551.326和455.425μg/g,其次为十六酸和油酸;坚果香、膏香、脂蜡香、甜香和烤甜香5种香韵香气成分总释放量存在差异.③香气活性值可用于判别3种浓香型烟叶的风格特征差异,其中,许昌C3F的烘焙香、膏香和烤甜香香韵相对突出,郴州C3F的甜香香韵最为突出,潍坊C3F脂蜡香香韵更为突出.

[目的]研究滤嘴参数(滤棒压降、滤嘴通风率)对细支烟香味成分释放的影响.[方法]按单因素设计制备60个卷烟样品,采用CH2Cl2浸提、GC/MS分析测定滤片捕集的代表性香味成分.在此基础上,建立并筛选了滤嘴参数对香味成分释放量的预测模型.[结果]①细支烟主流烟气中代表性碱性、中性、酸性和香味成分总释放量与滤棒压降和滤嘴通风率均呈显著负相关;②滤棒压降对细支烟主流烟气香味成分释放量的影响高于常规烟,而滤嘴通风则相反.③外部验证结果显示,4个预测模型的平均预测偏差在4.23％～5.95％之间,所建立的模型预测精度良好.

In order to study the influences of filter parameters on the mainstream smoke pH and sensory quality of slim cigarettes, 60 slim cigarettes with different tow specifications, different filter rod pressure drops and different filter ventilation rates were prepared, and their mainstream smoke pH and sensory quality were analyzed. The results showed that: 1) Tow specification had no significant influence on both mainstream smoke pH and sensory quality. 2) Mainstream smoke pH increased with the increase of pressure drop of filter rod. For the slim cigarettes with the same tow specifications, the mainstream smoke pH increased with the increase of filter ventilation rate; for the slim cigarettes with different tow specifications, the mainstream smoke pH presented a decrease trend with the increase of denier per filament. 3) The score of sensory evaluation decreased with the increase of pressure drop of filter rod. The scores of sensory evaluation of slim cigarettes with tow specifications of 6.7Y/17 000 decreased gradually with the increase of filter ventilation rate, and those of the slim cigarettes with the other four tow specifications in the suitable pressure drop range of filter rod increased first and then decreased with the increase of filter ventilation rate. 4) Correlation analysis indicated that the pressure drop of filter rods significantly positively correlated to the mainstream smoke pH, while significantly negatively correlated to the sensory evaluation score. Filter ventilation rate extremely significantly positively correlated to the mainstream smoke pH. No statistically significant correlation with sensory evaluation score was found. Filter ventilation rate extremely significantly negatively correlated to aroma, while extremely significantly positively correlated to irritation among sensory evaluation indexes.

In order to investigate the effects of cigarette material parameters (including filter ventilation, filter rod pressure drop, cigarette paper grammage, air permeability of cigarette paper, combustion improver content in cigarette paper, and K/Na ratio in combustion improver) on the deliveries of tar, nicotine, the 7 harmful smoke components, and the hazard index (H) of cigarette mainstream smoke, 50 cigarette samples were prepared according to a central composite design combined with orthogonal design methods. Ten multi-factor prediction models based on cigarette material parameters were established by linear regression and stepwise regression methods, and the optimal models were selected according to the statistical principle of minimum RMSECV (Root mean squares error of cross validation). The results showed that the ten models had good prediction accuracies, with the average relative deviations of prediction between 3.11% and 8.10% . The models were well adaptive for different cigarette material parameters.

In order to investigate the effects of filter parameters on the quality of slim cigarettes (circumference=17.0 mm), five acetate tows with the specifications of 6.0Y/17 000, 6.7Y/17 000, 8.0Y/15 000, 9.5Y/12 000, and 11.0Y/15 000 were shaped into slim filter rods with different pressure drops and then made into slim cigarettes at filter ventilation level of 0, 20% , 40% , 60% . The effects of filter parameters on the draw resistance, nicotine filtration efficiency and routine smoke components of the slim cigarettes were investigated. The results showed that: 1) Draw resistance significantly differed and nicotine filtration efficiency extremely significantly differed among cigarettes with different tow specifications, while the releases of routine smoke components were not significantly different. 2) The releases of tar and nicotine negatively correlated to the filter rod pressure drop and the filter ventilation rate. The release of CO did not correlate to the filter rod pressure drop, but negatively correlated to the filter ventilation rate. 3) The influences of the filter parameters on the nicotine filtration efficiency and the releases of routine smoke components of slim cigarettes were less than those on conventional cigarettes. 4) The regression equations for cigarette draw resistance, nicotine filtration efficiency, releases of routine smoke components with filter parameters were established, and the calculated values by the regression equations well agreed with the measured values (all R2 were greater than 0.95).

建立了测定5种烤甜香味成分逐口释放量的分析方法,采用相同烟丝配方卷制细支和常规卷烟,考察细支和常规卷烟主流烟气常规与5种关键烤甜香味成分逐口释放量差异.结果表明:①分析方法重复性、灵敏度和准确度较好,适合于卷烟逐口烟气中5种烤甜香味成分的定量分析;②细支卷烟常规成分逐口释放量均低于常规卷烟,总粒相物(TPM)、焦油、水分的逐口释放变化幅度大于常规卷烟,烟碱变化幅度小于常规卷烟;③细支卷烟糠醇、5-甲基糠醛和3-甲基-2-环戊烯-1-酮的逐口释放量高于常规卷烟(除第1口外),4-羟基-2,5-二甲基-3(2H)呋喃酮(呋喃酮)和麦芽酚的逐口释放量略低于常规卷烟;抽吸中段细支卷烟糠醇和5-甲基糠醛的逐口释放稳定性优于常规卷烟,3-甲基-2-环戊烯-1-酮劣于常规卷烟,呋喃酮和麦芽酚差异不大;细支卷烟5种香味成分总量中糠醇和5-甲基糠醛所占比例高于常规卷烟,3-甲基-2-环戊烯-1-酮、呋喃酮和麦芽酚低于常规卷烟.

为降低再造烟叶中的果胶含量,采用单因素试验和正交试验对微紫青霉产果胶酶降解果胶的工艺条件进行优化,分析了酶解前后样品的热裂解产物,并将酶解后样品抄造制丝添加至卷烟中进行感官评价,结果表明:微紫青霉产果胶酶降解果胶的最佳反应条件为酶活力3000 U/mL,高浓混合浆干重与粗酶液体积的料液比1∶1,反应温度50℃,处理时间3h.在此条件下果胶降解率达到最大,为28.63％,相对分子量由341 kDa减小到55 kDa.酶解后样品裂解产物的组成和含量发生明显变化,除醇类物质外,其他香味物质酚类、醛酮类、酯类、杂环类减少.将酶解后的样品抄造制丝添加于卷烟中,香气质丰满细腻,透发性、甜润感增强,刺激性减小,余味纯净舒适,吸食品质得以改善,但劲头略有不足.

为探索卷烟烟气中彰显香气风格的关键中性香气成分,采用烟用香料作用阈值感官评价方法,评定了32种重要中性香气成分（中性成分）的作用阈值,同时以GC-MS技术测定了其在卷烟烟气中的释放量,获得活性阈值并进行数据分析。结果表明:（1）32种中性成分的作用阈值介于7.04×10 -14 和6.76×10 -7 μg/支之间,戊酸乙酯和β-二氢大马酮的作用阈值最小,糠酸甲酯等6种中性成分的作用阈值较大,作用阈值最高相差约7个数量级。（2）主流烟气中32种中性成分的总质量分数为11.320μg/支;其中,5-甲基糠醛的质量分数最高（5.881μg/支）,占总量的52.0%;β-大马酮和苯乙醇的质量分数较高,其值之和占总量的14.5%。（3）32种中性成分的活性阈值范围为2.45×10~4~2.77×10 12 ,总活性阈值为6.38×10 12 ;戊酸乙酯等7种中性成分活性阈值之和占总活性阈值的96.5%,表明在彰显卷烟香气风格时此7种成分作为关键香气成分起着决定性作用。

2-L-Aspartic acid-2-deoxy-D-glucose was synthesized from D-fructose and L-aspartic acid monopotassium salt,and it was characterized by Fourier transform infrared spectroscopy,1H nuclear magnetic resonance (NMR),13C NMR and high resolution mass spectroscopy.The thermogravimetdc behavior,thermal pyrolysis behavior and antioxidant activity of 2-L-aspartic acid-2-deoxy-D-glucose was investigated using thermo gravimetry-derivative thermo gravimetry (TG-DTG),on-line pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS),and 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging and reducing capacity assays,respectively.The results showed that the synthetic product was confirmed to be the target compound.The target compound has a pyrolysis temperature of 187.8 ℃ and a total weight loss of 91.26％ at 700 ℃.The number of pyrolysis products from the compound increased with reaction temperature.The pyrolysis products included heterocyclic hydrocarbons,ketones,carboxylic acids,aldehydes,phenols,olefins,alcohols and aromatic hydrocarbons and other compounds,which had baking,sweet aroma,burnt-sweet,cocoa-like incense,floral and milky aroma notes.The synthetic product possessed strong DPPH free radical scavenging and reducing capacity and could be regarded as a potential antioxidant.

为给细支卷烟[圆周为(17.0±0.1)mm]滤嘴设计开发提供更多参考,按照单因素设计了5种丝束规格、每个丝束3个滤棒压降梯度、4个滤嘴通风梯度,共15个滤棒样品,卷接为60个卷烟样品,考察了不同滤嘴参数对细支烟烟碱过滤效率的影响.结果表明:对于不同丝束规格成型的细支滤棒卷烟,①在滤棒压降相同条件下,细支烟烟气烟碱过滤效率与滤嘴通风率显著正相关;随着滤棒压降增大,滤嘴通风率对烟碱过滤效率的影响幅度先增加后降低,滤嘴通风率每增加10％,烟碱过滤效率增加0.64％～1.00％;②在相同滤嘴通风率条件下,烟碱过滤效率与滤棒压降显著正相关,滤棒压降每增加100 Pa,烟碱过滤效率增加1.20％～1.40％;③丝束单旦增加、总旦降低,所成型的细支滤棒对主流烟气烟碱的过滤效率呈降低趋势.

香气活力值(odor activity value,OAV)从浓度和阈值两个维度揭示了香气成分对食品香气体系的贡献,是表征关键香气成分的一种有效技术手段,在食品关键香气成分表征中得到了广泛应用.本文系统阐述了OAV在发酵制品、水果、植物油等食品中的应用研究进展,同时探讨了当前OAV研究中存在的问题和解决思路,展望了OAV相关技术在食品关键香气成分表征和调香技术中的应用前景.

In order to investigate the contribution of important basic aroma components in mainstream cigarette smoke to cigarette style characteristics,the activity thresholds of 25 important basic aroma components (pyrazines and pyridines) were obtained from their functional thresholds. The evaluation was conducted by sensory evaluation of functional thresholds for tobacco flavors and their releases in mainstream cigarette smoke as determined by GC/MS. The activity threshold data of 25 basic components were analyzed to pinpoint the important basic components in cigarette smoke demonstrating characteristic cigarette styles. The results showed that:1)The functional thresholds of the 25 basic components ranged from 1.00×10-13 to 2.74×10-5 μg·cig-1;the levels of 2-methylpyridine,2,6-dimethylpyridine,3-ethylpyridine and 2-vinylpyridine were lower,while those of 2-methylpyrazine and 2-acetylpyridine were higher. The maximum difference of functional threshold between these basic components reached eight orders of magnitude. 2)The total content of the 25 basic components inparticulate matter of mainstream smoke was 11.130 μg·cig-1,the contents of 3-vinylpyridine and 3-methylpyridine were higher (2.784 and 2.476 μg·cig-1,and accounted for 25.0% and 22.2% of the total content,respectively). The contents of six basic components,such as 2,3-dimethylpyrazine,were lower,and the sum of their contents only accounted for 4.0% of the total content. 3) The activity thresholds of the 25 basic components ranged from 1.20 × 104 to 2.34 × 1012,which was 6.51 × 1012 in total. The activity thresholds of 3-ethylpyridine,2-methylpyridine,2,6-dimethylpyridine and 2-vinylpyridine were up to 3.05×1011-2.34×1012,and the sum of which accounted for 99.9% of the total activity thresholds. These indicated that as key aroma components,the above four components played a decisive role in demonstrating the toasted aroma note of cigarette smoke.

Sweetpotato processing food is greatly popular with large customers because of its rich and attractive flavor, sweet and palatable taste.The article summarized the recent domestic and international researches about the effect of processing methods on sugar, aroma and sweetness of sweetpotato. And it mainly introduced forma-tionmechanism of the aroma and sweetness of sweetpotato processing food, as well as analyzed the relationship between the change of sugar and its aroma and sweetness.

A method for determination of the content of neutral aromatic components from cigarette mainstream smoke by semi-preparative high performance liquid chromatography (semi-preparative HPLC) coupled with gas chromatography-mass spectrometry (GC-MS) was developed:the fraction collection time was determined to three time periods by optimizing the conditions of semi-preparative HPLC in order to ensure that the compounds to be measured don’t cross in the fractions.The selected ion chromatogram showed that all target compounds could be separated completely in three fractions and the method could satisfy the demands of quantitative analysis.Quantitative analysis was performed by establishing a GC-MS internal standard curve.The analysis results showed that the correlation coefficients were greater than 0.999 0,the limits of detection (LOD) were 0.55 ～ 13.06 μg/kg and the limits of quantitation (LOQ) were 1.85 ～ 43.55 μg/kg.It showed that the method has high sensitivity.The results of sample determination and recovery experiment showed that the average added standard recovery of the neutral aromatic components from cigarette mainstream smoke was in the range of 64.39％ ～93.57％ and the relative standard deviations were less than 10％.It showed that the method could satisfy the requirement of quantitative analysis of trace compounds,with good reproducibility.