Evaluation method of cigarette smoke component aroma contribution degree and application thereof

Abstract

The invention provides a cigarette smoke component aroma contribution degree evaluation method and application thereof, and the evaluation method comprises the following steps: (1) capturing a to-be-detected cigarette smoke gas phase component and / or particle phase component to obtain a smoke extraction liquid, then carrying out gas chromatography-tandem mass spectrometry detection, and analyzing to obtain an aroma compound and the content thereof; (2) grouping the aroma compounds to prepare a mixed standard solution and a gradient diluent thereof; and (3) performing GC-O sniffing analysis on the mixed standard solution and the gradient diluent, and recording the smell characteristics of each aroma compound and the dilution ratio of the corresponding gradient diluent when the smell characteristics are just not sniffed, namely the aroma contribution degree of the aroma compound. The method provided by the invention can effectively avoid the co-elution problem during direct GC-O sniffing of a complex flue gas system, and improves the accuracy and repeatability of evaluation; meanwhile, the method is suitable for evaluating the contribution degree of aroma in other complex systems except smoke, and has important significance in the field of evaluation of sensory quality.

Description

Technical Field

[0001] This invention belongs to the field of identification technology of active components in cigarette smoke, specifically relating to an evaluation method for the aroma contribution of cigarette smoke components and its application. Background Technology

[0002] The chemical composition of cigarette smoke is extremely complex. As of 2013, more than 6,000 chemical components had been identified in cigarette smoke. However, not all compounds are directly perceptible to smokers; only those components with concentrations above the olfactory threshold can contribute to the overall flavor profile. These components are commonly referred to as aroma-active compounds. The contribution of each aroma-active compound to the overall sensory quality of cigarette smoke varies, and evaluating the contribution of each aroma-active compound in cigarette smoke is crucial for cigarette smoke quality evaluation and formulation optimization.

[0003] Currently, there are two commonly used methods for evaluating aroma contribution. The first is to calculate the odor activity value (OAV) by the ratio of the absolute concentration of each aroma compound to its threshold. However, the threshold of each compound varies in different matrices, and the threshold of the same compound varies greatly in different reports, sometimes by hundreds or even thousands of times. Therefore, the accuracy of the OAV method is low. In recent years, the mainstream method for evaluating aroma contribution has been to perform gradient dilution analysis of sample extracts combined with gas chromatography-olfactometry (GC-O) to calculate the dilution factor (FD) of each aroma compound. However, smoke is different from common food systems, and its flavor is extremely complex. When directly performing GC-O analysis on smoke extracts, due to the limited separation capacity and sensitivity of gas chromatography and the limited peak capacity, problems such as co-elution of multiple compounds and overlapping chromatographic peaks often occur. This not only leads to inconsistencies between the odor characteristics detected by GC-O and the actual aroma performance of the target compound, but also significantly affects the accuracy and repeatability of the olfactometry results.

[0004] For example, Chinese invention patent CN102680627A describes a method for analyzing and identifying key aroma compounds in cigarettes. By directly diluting the tobacco extract in a gradient and combining it with GC-O olfactory analysis, it was found that the retention times (RT) of a large number of key aroma components differed by no more than 2 seconds, and some were even within one second. However, the co-eluting problem of these compounds was ignored, so the accuracy of the identification was difficult to guarantee.

[0005] Furthermore, the smoking process is done puff by puff, and the sensory experience of cigarettes depends on the flavor characteristics of each puff. Therefore, studies on the contribution of aroma-active compounds must be based on single-puff smoke samples. However, single-puff smoke is difficult to collect. Currently, commonly used smoke extracts are mostly derived from mixtures obtained from the combustion of multiple cigarettes. The concentrates are directly used for GC-O olfaction, which makes it difficult to truly reflect the types and content distribution of compounds in single-puff smoke.

[0006] On the other hand, when analyzing multiple groups of samples of the same type, the traditional gradient dilution analysis combined with GC-O sniffing method requires each group of samples to be diluted and sniffed separately in order to calculate the FD value of each group of samples, which greatly reduces the efficiency of the work.

[0007] Therefore, how to provide a highly efficient and accurate method for evaluating the contribution of aroma has become an urgent problem to be solved. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a method for evaluating the aroma contribution of cigarette smoke components and its application. The method provided by this invention can effectively avoid the co-elution problem during direct GC-O olfaction of complex smoke systems, improving the accuracy and repeatability of the evaluation. Furthermore, the method proposed in this invention is also suitable for evaluating the aroma contribution in other complex systems besides cigarette smoke, possessing a certain degree of universality and significant importance in the field of sensory quality evaluation.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] On the one hand, the present invention provides a method for evaluating the aroma contribution of cigarette smoke components, the evaluation method comprising the following steps:

[0011] (1) Collect the gas phase components and / or particulate components of the cigarette smoke to be tested to obtain the smoke extract, and then mix it with the internal standard and the protective agent and perform gas chromatography-tandem mass spectrometry to analyze the aroma compounds and their contents in the cigarette smoke to be tested.

[0012] (2) Based on the concentration and retention time of each aroma compound, the aroma compounds obtained in step (1) are grouped to prepare mixed standard solutions, and then gradient diluted to obtain gradient dilution solutions;

[0013] (3) Perform GC-O olfactory analysis on the mixed standard solution obtained in step (2) and the gradient dilution solution, record the odor characteristics of each aroma compound and the dilution factor of the corresponding gradient dilution solution when it is just not smelled, which is the theoretical dilution factor (FD) and aroma contribution of the aroma compound.

[0014] The above method, by rationally grouping aroma compounds, can effectively avoid the co-elution problem during direct GC-O olfaction of complex flue gas systems, thereby improving the accuracy and repeatability of the evaluation. At the same time, the method proposed in this invention is also suitable for evaluating the aroma contribution in other complex systems besides flue gas, and has a certain degree of universality, which is of great significance in the field of sensory quality evaluation.

[0015] The present invention does not impose too many restrictions on the gas chromatography-mass spectrometry detection conditions in step (1). Any conditions that can achieve quantitative and qualitative analysis of the gas phase components and / or particulate components of the cigarette smoke to be tested can be applied.

[0016] For example, the present invention can perform gas chromatography-mass spectrometry detection under the following conditions:

[0017] The following chromatography methods were employed: DB-5MS UI flexible quartz capillary column (60 m × 0.25 mm × 0.25 μm); injection port temperature: 280 ℃; initial temperature 40 ℃, held for 3 min, then increased to 75 ℃ at 5 ℃ / min, followed by increases to 120 ℃ at 1 ℃ / min, then to 160 ℃ at 2 ℃ / min, and finally to 290 ℃ at 5 ℃ / min, held for 10 min; splitless injection, splitless time 1 min; carrier gas: helium (99.999% purity), constant flow mode, flow rate 1.5 mL / min; injection volume: 0.8 μL; or DB-624 flexible quartz capillary column (60 m × 0.25 mm × 1.4 μm); injection port temperature: 235 ℃; initial temperature 40 ℃, held for 5 min, then increased to 160 ℃ at 2 ℃ / min, held for 1 min. The temperature was increased to 235℃ at 5℃ / min and held for 20 min; the sample was injected without splitting for 1 min; the carrier gas was helium (99.999% purity), in constant flow mode at a flow rate of 1.5 mL / min; the injection volume was 0.8 μL.

[0018] Preferably, the internal standard in step (1) includes acetophenone-d8, styrene-d8 and benzophenone-d10.

[0019] Preferably, the protective agent in step (1) comprises 3-methoxy-1,2-propanediol, 1,2-octanediol, 1,2-decanediol and 1,2-tetradecanediol, wherein the mass ratio of 3-methoxy-1,2-propanediol, 1,2-octanediol, 1,2-decanediol and 1,2-tetradecanediol is (0.8-1.2):(0.8-1.2):(0.8-1.2):(1-2.5).

[0020] Preferably, the grouping in step (2) is based on the fact that the retention time of aroma compounds in the same group differs by more than 30 s and the content differs by no more than 10 times, preferably no more than 5 times.

[0021] Preferably, after grouping in step (2), the number of aroma compounds in each mixed standard solution does not exceed 30.

[0022] The aforementioned specific parameter control can more effectively distinguish different aroma compounds and group them appropriately, thus effectively improving the accuracy and repeatability of the evaluation.

[0023] Preferably, the content of aroma compounds in the mixed standard solution in step (2) is consistent with its content in the cigarette smoke to be tested.

[0024] Preferably, the mixed standard solution in step (2) also includes a protective agent.

[0025] Preferably, the olfactory analysis in step (3) is performed by at least three professional sensory evaluators, and the aroma compounds smelled by at least two professional sensory evaluators are recorded and statistically analyzed.

[0026] Step (3) after the olfactory analysis also includes comparing the recorded odor characteristics of the aroma compounds with the odor characteristics of their standards to confirm the accuracy of the olfactory results.

[0027] On the other hand, the present invention also provides the application of the evaluation method for the aroma contribution of cigarette smoke components as described above in the evaluation of cigarette smoke quality.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention provides a method for evaluating the aroma contribution of cigarette smoke components. By rationally grouping aroma compounds, it can effectively avoid the co-elution problem during direct GC-O olfaction of complex smoke systems, thereby improving the accuracy and repeatability of the evaluation. At the same time, the method proposed in this invention is also suitable for evaluating the aroma contribution in other complex systems besides cigarette smoke, and has a certain degree of universality, which is of great significance in the field of sensory quality evaluation. Attached Figure Description

[0030] Figure 1 This is the total ion chromatogram obtained from the detection of sample 1 in Comparative Example 1. Detailed Implementation

[0031] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0032] Example 1

[0033] This embodiment provides a method for evaluating the aroma contribution of cigarette smoke components, and the specific steps are as follows:

[0034] (1) In accordance with the requirements of GB / T 16447—2004, cigarette samples were equilibrated in an environment of (22±1) ℃ and (60±3)% relative humidity for 48 h. Cigarettes with an average mass of ±0.020 g and an average draw resistance of ±30 Pa were selected as test samples. Using the ISO suction mode, particulate matter in the mainstream smoke of 5 cigarettes was captured with a Cambridge filter. Two 500 mL absorption bottles were connected after the Cambridge filter. 20 mL of dichloromethane solution was added to each absorption bottle and the bottles were placed in a low-temperature (dry ice) environment to capture the gaseous phase of the mainstream cigarette smoke.

[0035] After smoking the cigarette, fold the Cambridge filter in half and place it in a 12 mL sample vial. Add 10 mL of dichloromethane and 50 μL of an internal standard (acetophenone-d8, styrene-d8, benzophenone-d10, mass ratio 1:1:1) at a concentration of 0.12 mg / mL. Extract the solution by sonication for 30 min. Take the extract and filter it through a disposable filter (the syringe contains an organic phase filter membrane). Collect the filtrate and take 1 mL of the smoke solution in a chromatographic vial. Add 50 μL of analyte preservative (3-methoxy-1,2-propanediol + 1,2-octanediol + 1,2-decanediol + 1,2-tetradecanediol; concentrations of 1, 1, 1, and 2 mg / mL, respectively) for later use. Quickly remove the absorption bottle containing the gaseous phase from the dry ice, aspirate the liquid in the bottle with a syringe bulb to mix, and then add 50 μL of an internal standard with a concentration of 0.12 mg / mL (acetophenone-d8, styrene-d8, benzophenone-d10, mass ratio 1:1:1). Take 1 mL of the solution, add 50 µL of the above analyte preservative, mix with the particulate phase test solution 1:1, and then analyze using GC-MS / MS.

[0036] GC-MS / MS analysis was performed using two instruments equipped with different columns, under the following conditions:

[0037] Column 1 parameters:

[0038] DB-5MS UI flexible quartz capillary column (60 m × 0.25 mm × 0.25 μm); Injector temperature: 280 ℃; Temperature program: Initial temperature 40 ℃, hold for 3 min, then increase to 75 ℃ at 5 ℃ / min, then increase to 120 ℃ at 1 ℃ / min, then increase to 160 ℃ at 2 ℃ / min, and finally increase to 290 ℃ at 5 ℃ / min, hold for 10 min; Splitless injection, splitless time 1 min; Carrier gas: Helium (purity 99.999%), constant flow mode, flow rate 1.5 mL / min; Injection volume: 1 μL.

[0039] Column 2 parameters:

[0040] DB-624 flexible quartz capillary column (60 m × 0.25 mm × 1.4 μm); injection port temperature: 235℃; temperature program: initial temperature 40 ℃, hold for 5 min, then increase to 160 ℃ at 2 ℃ / min, hold for 1 min, then increase to 235℃ at 5℃ / min, hold for 20 min; splitless injection, splitless time 1 min; carrier gas: helium (purity 99.999%), constant flow mode, flow rate 1.5 mL / min; injection volume: 1 μL.

[0041] Tandem mass spectrometry ionization mode: Electron impact (EI); Ionization energy: 70 eV; Filament current: 35 μA; Ion source temperature: 280 ℃; Quadrupole temperature: 150 ℃; Transfer line temperature: 280 ℃; Collision gas: Nitrogen (99.999%), flow rate 1.5 mL / min; Quenching gas: Helium (99.999%), flow rate 2.25 mL / min; Scanning mode: Multiple reaction monitoring (MRM) mode.

[0042] The analysis results are shown in Table 1: A total of 193 aroma compounds were identified in the cigarette samples to be tested, with the equivalent single-puff release ranging from 0.73 to 27140.35 ng and the retention time spanning from 10.15 to 101.12 min.

[0043] (2) The 193 aroma compounds obtained in step (1) were grouped to prepare mixed standard solutions (each group contained no more than 30 compounds). The retention times of the compounds in the same group differed by more than 30 s, and the concentrations differed by no more than 5 times, as shown in Table 1. The 193 compounds were divided into 10 groups according to the above requirements and were subjected to gradient dilution to obtain gradient dilution solutions. n (n=1, 2, 3…) gradient dilution;

[0044] (3) The mixed standard solution obtained in step (2) and the gradient dilution solution were subjected to GC-O olfactory analysis. The column effluent was introduced into the mass spectrometer end and the olfactory end at a ratio of 1:1. The temperature of the olfactory instrument transfer line was 280 ℃ and the temperature of the olfactory port was 160 ℃. To prevent nasal dryness during olfactory smelling, moist nitrogen gas was introduced into the olfactory port at a flow rate of 15 mL / min. The olfactory smelling was performed by three professional sensory evaluators. The compounds and their odor characteristics smelled by two or more sensory evaluators were recorded and statistically analyzed. The olfactory accuracy was calculated by comparing them with the standard odor characteristics of the compound. The dilution factor of the gradient dilution solution corresponding to each aroma compound that was just not smelled was recorded. This is the theoretical dilution factor of the aroma compound. The aroma contribution can be obtained by sorting according to the FD value. The results are shown in Table 1.

[0045] A total of 75 odor-active compounds were detected using this method. Comparing the detected odor characteristics with the standard odor characteristics of the compounds, 69 compounds were found to be correctly matched, resulting in an olfactory accuracy of 69 / 75 × 100% = 92%. Furthermore, dilution analysis of the 69 odor-active compounds revealed that furfuryl mercaptan (FD = 8192) had the highest dilution factor (FD), followed by fenugreek lactone (FD = 4096) and pineapple ketone (FD = 4096), indicating that these compounds contributed the most to the overall flavor characteristics of the flue gas.

[0046] Table 1. Grouping of compounds in Example 1 and identification results of aroma-active compounds.

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] Example 2

[0057] This embodiment provides a method for evaluating the aroma contribution of cigarette smoke components. In the specific steps, except that in step (2), the retention time of each compound in the same group of mixed standards differs by more than 20 s and the concentration differs by no more than 5 times, the rest is the same as in Example 1. The grouping and GC-O olfactory results are shown in Table 2:

[0058] Of the 193 compounds, 70 were detected, and 57 of them matched their standard odor characteristics. The accuracy of the detection was calculated to be 57 / 70 × 100% = 81.4%.

[0059] Table 2. Grouping of compounds and identification results of aroma-active compounds in Example 2

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] Example 3

[0070] This embodiment provides a method for evaluating the aroma contribution of cigarette smoke components. In the specific steps, except that in step (2), the retention time of each compound in the same group of mixed standards differs by more than 30 s and the concentration differs by no more than 10 times, the rest is the same as in Example 1. The grouping and GC-O olfactory results are shown in Table 3.

[0071] Of the 193 compounds, 72 were detected, and 60 of them matched the standard odor characteristics. The accuracy of the detection was calculated to be 60 / 72×100%=83.3%.

[0072] Table 3. Grouping of compounds and identification results of aroma-active compounds in Example 3

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080] Example 4

[0081] This embodiment provides a method for evaluating the aroma contribution of cigarette smoke components. Except for step (2), in which each group of mixed standards does not exceed 40, the specific steps are the same as in Example 1. The grouping and GC-O olfactory results are shown in Table 4.

[0082] Of the 193 compounds, 71 were detected, and 60 of them matched the standard odor characteristics. The accuracy of the detection was calculated to be 60 / 71×100%=84.5%.

[0083] Table 4. Grouping of compounds and identification results of aroma-active compounds in Example 4

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] Comparative Example 1

[0095] This comparative example provides a method for evaluating the aroma contribution of cigarette smoke components. The specific steps are consistent with Example 1, except that in step (2), no grouping is performed and the gaseous and particulate smoke extract samples are directly analyzed by GC-O. The GC-O olfaction results are shown in Table 5.

[0096] Of the 193 compounds, 65 were detected, and 42 of them matched their standard odor characteristics. The olfactory accuracy was calculated to be 42 / 65 × 100% = 64.6%. This accuracy is significantly lower than that of Examples 1-4, and the compounds that did not match the actual odor were mostly affected by interference from other compounds within ±0.5 min of their retention time. This is further supported by the total ion chromatogram results. Figure 1 This study confirms that the co-eluting of multiple compounds in GC-O olfaction leads to a decrease in olfaction accuracy.

[0097] Table 5. Grouping of compounds in Comparative Example 1 and identification results of aroma-active compounds

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] As can be seen from the above methods, the method provided by the present invention can effectively avoid the co-elution problem in GC-O olfaction of complex flue gas systems, and improve the accuracy and repeatability of the evaluation. Comparing Examples 1-4 and Comparative Example 1, it can be found that the present invention, by adopting a grouping method and controlling the grouping parameters, can more effectively distinguish different aroma compounds and further improve the accuracy of the evaluation and analysis.

[0107] The applicant declares that this invention illustrates the method for evaluating the aroma contribution of cigarette smoke components and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials in the product of this invention, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

[0108] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0109] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A method for evaluating the aroma contribution of cigarette smoke components, characterized in that, The evaluation method includes the following steps: (1) Collect the gas phase components and / or particulate components of the cigarette smoke to be tested to obtain the smoke extract, and then mix it with the internal standard and the protective agent and perform gas chromatography-tandem mass spectrometry to analyze the aroma compounds and their contents in the cigarette smoke to be tested. (2) Based on the concentration and retention time of each aroma compound, the aroma compounds obtained in step (1) are grouped to prepare mixed standard solutions, and then gradient diluted to obtain gradient dilution solutions; (3) Perform GC-O olfactory analysis on the mixed standard solution obtained in step (2) and the gradient dilution solution, record the odor characteristics of each aroma compound and the dilution factor of the corresponding gradient dilution solution when it is just not smelled, which is the theoretical dilution factor and aroma contribution of the aroma compound.

2. The method for evaluating the aroma contribution of cigarette smoke components according to claim 1, characterized in that, The internal standard in step (1) includes acetophenone-d8, styrene-d8 and benzophenone-d10.

3. The method for evaluating the aroma contribution of cigarette smoke components according to claim 1 or 2, characterized in that, The protective agent in step (1) includes 3-methoxy-1,2-propanediol, 1,2-octanediol, 1,2-decanediol and 1,2-tetradecanediol, wherein the mass ratio of 3-methoxy-1,2-propanediol, 1,2-octanediol, 1,2-decanediol and 1,2-tetradecanediol is (0.8-1.2):(0.8-1.2):(0.8-1.2):(1-2.5).

4. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-3, characterized in that, The grouping in step (2) is based on the fact that the retention time of aroma compounds in the same group differs by more than 30 s and the content differs by no more than 10 times, preferably no more than 5 times.

5. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-4, characterized in that, After grouping in step (2), the number of aroma compounds in each mixed standard solution shall not exceed 30.

6. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-5, characterized in that, The content of aroma compounds in the mixed standard solution in step (2) is consistent with its content in the cigarette smoke to be tested.

7. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-6, characterized in that, The mixed standard solution in step (2) also includes a protective agent.

8. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-7, characterized in that, The olfactory analysis in step (3) is conducted by at least three professional sensory evaluators, and the aroma compounds smelled by at least two professional sensory evaluators are recorded and statistically analyzed.

9. The method for evaluating the aroma contribution of cigarette smoke components according to any one of claims 1-8, characterized in that, Step (3) after the olfactory analysis also includes comparing the odor characteristics of the smelled aroma compounds with the odor characteristics of its standard to confirm the accuracy of the olfactory results.

10. The application of an evaluation method for the aroma contribution of cigarette smoke components according to any one of claims 1-9 in the evaluation of cigarette smoke quality.

Images