Evaluation device and method for aroma retention capability of cigarette fixative

Abstract

The invention discloses a device and a method for evaluating the aroma retention capability of a cigarette fixative. The device comprises a sample reaction bottle, a discharge detection device and an optical detector, the discharge detection device comprises a metal cylinder serving as an outer electrode and forming a discharge cavity shell, a metal inner electrode arranged in the metal cylinder and a high-voltage alternating-current power supply connecting the metal cylinder and the metal inner electrode; the volatile matter outlet is communicated with the metal cylinder; the optical detector receives an internal optical signal; the evaluation method comprises the following steps: preparing a test sample added with the essence and the fixative, a blank control sample only added with the fixative and a reference sample only added with the essence; under temperature programming, the volatile matter is brought into a discharge detection device by carrier gas for ionization excitation, and a characteristic spectrum signal is collected; temperature intervals are divided, the signal intensity is extracted, the fragrance retention efficiency Ei of each interval is calculated, and the larger the value is, the stronger the fragrance retention capacity is. According to the method, objective, rapid and quantitative evaluation on the fragrance retention function of the fixative is realized, the test result is accurate and stable, and the repeatability is good.

Description

Technical Field

[0001] This invention belongs to the field of analytical testing technology, specifically relating to an evaluation device and method for the aroma retention ability of tobacco fixatives. Background Technology

[0002] Flavorings and fragrances are the core material basis for the style characteristics and quality stability of cigarette products. Throughout the production, storage, distribution, and final consumption of cigarettes, the volatile components in flavorings and fragrances continuously dissipate due to factors such as heat and contact with air, causing the original aroma characteristics of the cigarette product to gradually diminish. To inhibit the excessively rapid volatilization of aroma components and improve the stability of flavorings, fixatives are usually added to the flavoring formulation.

[0003] Flavor fixatives, also known as aroma retainers, are substances with low volatility that can slow down the evaporation rate of other flavoring agents through physical or chemical processes. Their core function is to ensure more even evaporation of the various flavoring components in a fragrance, preventing the rapid evaporation of key aroma components, thereby making the overall aroma of the fragrance more lasting and stable, and also modifying the aroma to create a smoother and more rounded flavor. There are many types of flavor fixatives suitable for tobacco products, mainly including plant-based flavor fixatives (such as Peruvian resin, benzoin esters, vetiver oil, etc.) and synthetic flavor fixatives (such as synthetic musk, vanillin, coumarin, and benzyl benzoate, etc.). The aroma retention ability of a flavor fixative directly determines the aroma persistence and stability of the flavored product throughout its use period. Therefore, accurately evaluating the aroma retention ability of a flavor fixative is crucial for the research and development, quality control, and product formulation optimization of tobacco flavorings.

[0004] Currently, the evaluation of fixative retention primarily relies on two methods: sensory evaluation and instrumental analysis. However, both of these approaches have inherent limitations. While sensory evaluation provides the most direct sensory feedback, its results are heavily dependent on the subjective judgment of the evaluators. Individual differences in olfactory sensitivity, sensory fatigue, and environmental factors can all lead to significant fluctuations in the evaluation results, making it difficult to guarantee the reproducibility and reliability of the data. Furthermore, this method requires a large number of well-trained evaluators, making the process complex, time-consuming, and labor-intensive. More importantly, it is difficult to establish quantifiable evaluation standards, hindering its standardized application in quality control.

[0005] On the other hand, while instrumental analysis methods, such as gas chromatography and its coupled techniques, can provide objective detection data, their analytical procedures are often cumbersome, especially in the sample pretreatment stage, where they face numerous challenges. For example, some methods require the addition of adsorbents and prolonged settling and filtration. These steps not only significantly extend the detection cycle, but more importantly, the irreversible adsorption of aroma components by the adsorbent and filter material can lead to the loss of target analytes, resulting in systematically lower measurement results. Furthermore, conventional chromatographic analysis mainly focuses on the qualitative and quantitative analysis of specific volatile components, making it difficult to intuitively and comprehensively reflect the inhibitory effect of fixatives on the overall volatility of fragrances, i.e., it is difficult to directly characterize the functional indicator of fragrance retention.

[0006] To address the above problems, this invention is proposed. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide an evaluation device and method for the aroma retention ability of tobacco fixatives, so as to overcome the defects of sensory evaluation method, which is highly subjective and difficult to quantify, and traditional instrumental analysis method, which is cumbersome in pretreatment, has a long cycle, and cannot intuitively reflect the inhibitory effect of fixatives on the overall volatilization behavior of fragrances.

[0008] Specifically, this invention aims to provide an objective, rapid, and directly quantifiable solution for evaluating fragrance retention. By constructing a combined technology system of programmed temperature evaporation, discharge plasma excitation, and optical spectroscopy detection, the detection process is first instrumented and standardized, fundamentally avoiding interference from human sensory factors and ensuring the objectivity and reproducibility of the evaluation results. Based on this, the invention strives to simplify or even eliminate complex sample pretreatment steps, achieving continuous online monitoring of fragrance evaporation behavior, thereby significantly improving analytical efficiency. Ultimately, the core objective of this invention is to acquire and compare the evaporation signals of fragrances in different characteristic temperature ranges by simulating temperature changes in actual use through programmed temperature rise. Then, by applying specific data processing algorithms (such as the signal inhibition rate Ei calculation formula), the inhibitory ability of fixatives on fragrance evaporation at each stage is directly and quantitatively characterized, thereby providing an accurate and intuitive quantitative evaluation of the fragrance retention index of fixatives.

[0009] The technical solution adopted in this invention is as follows:

[0010] The first aspect of this invention provides a device for evaluating the aroma retention ability of tobacco fixatives, comprising:

[0011] The sample reaction bottle 10 is provided with a carrier gas inlet 11 and a volatile matter outlet 12;

[0012] The discharge detection device 20 includes a metal cylinder 21 that serves as an outer electrode and forms the shell of the discharge cavity, a metal inner electrode 22 disposed inside the metal cylinder 21, and a high-voltage AC power supply 23. The two output terminals of the high-voltage AC power supply 23 are electrically connected to the metal cylinder 21 and the metal inner electrode 22, respectively.

[0013] First optical detector 30;

[0014] The volatile outlet 12 is connected to the metal cylinder 21, and the detection end of the first optical detector 30 is configured to receive light signals from inside the metal cylinder 21.

[0015] Preferably, the metal cylinder 21 is made of stainless steel, and the metal inner electrode 22 is made of tungsten wire or stainless steel.

[0016] Preferably, the inner metal electrode 22 is fixed inside the metal cylinder 21 by an insulating support 26, and the discharge portion of the inner metal electrode 22 is spaced apart from the inner wall of the metal cylinder 21. To ensure that the carrier gas can carry the volatiles unimpeded through the entire discharge region and be effectively excited, the insulating support 26 is designed as a large-area perforated mesh or frame structure. For example, it can be a ring or bracket made of an insulating material (such as ceramic or polytetrafluoroethylene) with multiple through holes. This design, while firmly supporting the inner metal electrode 22 and ensuring the insulating distance between it and the metal cylinder 21, minimizes its obstruction of the gas flow path, ensuring smooth and uniform gas flow through the discharge region, thereby ensuring sufficient interaction between the volatiles and the plasma.

[0017] Preferably, one end of the metal cylinder 21 is provided with a first optical observation window 25, and the other end of the metal cylinder 21 or the cylinder wall is provided with a volatile inlet 24; the volatile outlet 12 is connected to the internal cavity of the metal cylinder 21 through the volatile inlet 24; the detection end of the first optical detector 30 is aligned with the first optical observation window 25 to receive the light signal from the discharge region of the metal inner electrode 22.

[0018] Preferably, the sample reaction flask 10 comprises:

[0019] Bottle body 110;

[0020] A jacket 120 is wrapped around the outer peripheral wall of the bottle body 110. The jacket 120 and the bottle body 110 form an annular sealed cavity for the flow of heat exchange medium. The jacket 120 is provided with a medium inlet 121 and a medium outlet 122.

[0021] A porous baffle 130 is supported within the cavity of the bottle body 110;

[0022] The carrier gas inlet 11 and the volatile matter outlet 12 are disposed on the bottle body 110.

[0023] Preferably, the volatile inlet 24 and the first optical observation window 25 are respectively disposed at both ends of the axial direction of the metal cylinder 21, so that the carrier gas flow path passes through the discharge area of ​​the metal inner electrode 22, and the first optical detector 30 can observe the discharge area along the axial direction.

[0024] Preferably, it also includes a control and data processing unit;

[0025] The control and data processing unit is connected to the media supply system of the jacket 120, the high-voltage AC power supply 23, and the first optical detector 30.

[0026] A second aspect of the present invention provides a method for evaluating the aroma retention ability of tobacco fixatives, using the apparatus described in the first aspect, comprising the following steps:

[0027] Step (1): Prepare the first sample, the second sample, and the third sample;

[0028] The first sample is a tobacco sample with the target flavoring and the fixative to be evaluated added; the second sample is a blank control sample of tobacco with the same matrix as the first sample, but with an equal amount of the fixative to be evaluated added and no target flavoring added; the third sample is a reference sample of tobacco with the same matrix as the first sample, but with an equal amount of the target flavoring added and no fixative added.

[0029] Step (2): Under the same test conditions, the first sample, the second sample, and the third sample are subjected to the following operations in sequence: the sample is placed in the sample reaction bottle 10, heated by programmed temperature rise, and carrier gas is introduced through the carrier gas inlet 11, so that the volatilized substances enter the discharge detection device 20 through the volatile substance outlet 12; the high-voltage AC power supply 23 is turned on, so that a discharge is generated between the metal inner electrode 22 and the metal cylinder 21, and the volatilized substances are ionized and dissociated; at the same time, the first optical detector 30 is used to collect the continuous optical signals generated by ionization and dissociation during the entire programmed temperature rise process.

[0030] Step (3): Based on the time-temperature relationship of the programmed heating process, the acquired optical signal is divided into multiple data segments corresponding to different temperature ranges; for the characteristic spectral signals representing key aroma components in the target fragrance, the signal intensity values ​​of the first sample, the second sample, and the third sample in each temperature range are extracted respectively; the signal intensity value of the first sample in the i-th temperature range is Xi, the signal intensity value of the second sample in the i-th temperature range is Yi, and the signal intensity value of the third sample in the i-th temperature range is Zi.

[0031] Step (4): For each temperature range i, calculate the evaluation parameter Ei of the fragrance retention effect of the fixative to be evaluated on the target fragrance. The calculation formula is as follows:

[0032] Ei = 1 - [(Xi - Yi) / Zi]

[0033] In the formula:

[0034] (Xi-Yi) characterizes the actual net volatile signal intensity of the target fragrance in the presence of the fixative in the first sample after subtracting the background of the matrix and fixative;

[0035] Zi characterizes the intensity of the original volatile signal of the target fragrance in the third sample without a fixative;

[0036] The ratio (Xi-Yi) / Zi represents the relative volatility of the fragrance in the presence of a fixative.

[0037] Ei represents the signal inhibition rate of the fixative on the volatilization of the fragrance;

[0038] The value of Ei serves as the basis for evaluating the fragrance retention ability of the fixative under evaluation within the corresponding temperature range. The larger the value of Ei, the stronger the ability to inhibit fragrance volatilization and the better the fragrance retention ability.

[0039] Preferably, the specific conditions for the programmed temperature rise are: heating from 50°C to 120°C at a temperature rise rate of 3°C / minute to 8°C / minute.

[0040] Preferably, the temperature range in step (3) includes a first range of 50-70℃, a second range of 90-110℃, and a third range of 115℃ to 125℃.

[0041] The temperature range division of the programmed heating process described in this invention is not arbitrarily set, but is based on the simulation of typical temperature scenarios in actual cigarette consumption and consideration of the staged volatilization characteristics of aroma components. The specific basis and technical purpose of the division are as follows:

[0042] The first temperature range (50-70℃) simulates the environment of cigarettes during storage at room temperature, handling, and initial smelling. At this relatively low temperature, the main volatile components are the top notes with the lowest boiling point and the highest volatility in the flavoring. Examining the fixative's retention efficiency (E1) in this range can evaluate its ability to maintain the initial aroma of the product upon opening and the persistence of the aroma at room temperature.

[0043] The second temperature range (90-110℃) simulates the temperature range at the front of the cigarette combustion cone and in the mainstream smoke generation area. This is the most active and crucial stage for the release of aroma substances during inhalation. At this temperature, most of the medium-boiling-point core aroma components in the flavoring are volatilized. Examining the fixative's retention efficiency (E2) in this range is a core indicator for evaluating its ability to maintain aroma fullness, stability, and effectively deliver key aroma notes during actual inhalation.

[0044] The third temperature range (115-125℃) simulates the boundary temperature of the core of the cigarette combustion cone and the high-temperature pyrolysis zone. At this high temperature, some base aroma components with higher boiling points or those tightly bound to the tobacco, as well as some fixatives themselves, may begin to volatilize or change. Examining the aroma retention efficiency (E3) of fixatives in this range allows us to explore their stability under extreme or continuous heating conditions, and their role in supporting the later stages of the overall aroma profile.

[0045] By dividing and evaluating the three characteristic temperature ranges mentioned above, this invention provides not just a single, general fragrance retention data point, but an efficacy spectrum (E1, E2, E3) of the fragrance retention behavior of fixatives under different thermodynamic conditions. This multi-temperature-dimensional evaluation method, which is related to actual application scenarios, can more accurately and realistically reflect the comprehensive performance of fixatives, thus providing in-depth information that traditional methods cannot provide for the precise design and optimization of fragrance formulations.

[0046] Preferably, the overall fragrance retention efficiency value Ecomprehensive of the fixative to be evaluated is calculated by weighted average or arithmetic average based on the signal inhibition rates E1, E2, and E3 obtained from the first interval, the second interval, and the third interval, respectively, and is used to evaluate its overall fragrance retention performance.

[0047] The present invention has the following beneficial effects:

[0048] 1. This invention abandons sensory evaluation that relies on subjective human judgment. It automates the entire process of sample processing, signal excitation, and acquisition through instrumentation (programmed temperature rise, plasma excitation, and optical detection), fundamentally eliminating the interference of subjective and uncontrolled factors such as personnel differences and environmental fluctuations. The obtained raw data are objective spectral signals, and data processing is based on a unified mathematical algorithm (Ei calculation formula), making the entire evaluation system highly standardized. Test results from different batches and different laboratories exhibit excellent comparability and reproducibility, providing a reliable benchmark tool for quality control and new product development.

[0049] 2. Compared to traditional instrumental analysis methods such as gas chromatography, this invention eliminates the need for complex sample pretreatment steps (such as adsorption, desorption, and concentration). Samples can be directly tested after preparation, enabling continuous online monitoring of fragrance volatility. The time from sample injection to obtaining the final evaluation index (Ei value) is significantly shortened, and analytical efficiency is significantly improved, making it more suitable for rapid screening of fragrance formulations and parallel detection of large numbers of samples.

[0050] 3. This invention pioneers a direct quantitative evaluation path for functional indicators, offering more refined and realistic evaluation dimensions. Existing instrumental methods largely focus on measuring the content of specific chemical components, failing to directly address the functional question of fragrance retention. This invention, through sample design (comparison of first, second, and third samples) and signal processing algorithms (Ei = 1 - [(Xi - Yi) / Zi]), transforms complex spectral signals into a quantitative parameter Ei that intuitively characterizes inhibition ability. This parameter has a clear physical meaning (signal inhibition rate) and directly corresponds to the fragrance retention function of the fixative, achieving a leap from component analysis to efficacy evaluation. Specifically, through programmed temperature rise and temperature-zone processing, this invention can obtain the fragrance retention efficacy E1, E2, E3 and the comprehensive value Ecomprehensive of the fixative in different characteristic temperature ranges (e.g., low, medium, and high temperatures), thereby revealing the fixative's characteristics across the entire temperature range. The evaluation dimensions are more refined and comprehensive, more accurately reflecting the fixative's performance in complex real-world environments.

[0051] 4. The device of this invention integrates sample reaction, discharge excitation, and optical detection into a single, compact structure. The metal cylinder serves as both the outer shell of the discharge chamber and the external electrode, a clever design that facilitates the generation of stable and uniform plasma. The axial arrangement of the optical observation window and the volatile inlet ensures that the volatiles carried by the carrier gas can fully penetrate the discharge core region and be effectively excited, while the optical signal is efficiently collected along the axial direction, improving detection sensitivity. The introduction of the control and data processing unit enables automated linkage of temperature, discharge, stirring, data acquisition, and processing, ensuring the consistency of experimental conditions and the reliability of results.

[0052] 5. The evaluation method of this invention does not rely on the calibration of specific chemical components; its core is to monitor changes in the characteristic spectral signals of the entire flavoring. Therefore, this method is applicable to the evaluation of various tobacco flavorings combined with multiple types (plant-based and synthetic) fixatives, demonstrating strong universality. Furthermore, with slight adjustments to the apparatus and method (such as changing excitation parameters and expanding the spectral detection range), it can be applied to the evaluation of the fragrance retention ability of flavorings and fragrances in other fields (such as food and cosmetics), showing good technical extensibility.

[0053] 6. The metal cylinder of this invention directly serves as both the shell and outer electrode of the discharge cavity, forming a simplified coaxial discharge system with the inner metal electrode at the axial center. This design first achieves intrinsic uniformity and stability of the electric field: the inner surface of the metal cylinder, which acts as the outer electrode, is a continuous equipotential surface. This directly ensures a radially uniform distribution of the electric field within the discharge region (plasma region), allowing the volatiles carried by the carrier gas to be excited under a highly consistent electric field strength. This lays the physical foundation for obtaining characteristic optical signals with high reproducibility and low fluctuations.

[0054] Secondly, the excellent thermal conductivity of metallic materials allows the Joule heat generated by the discharge to be quickly dissipated, effectively preventing localized overheating in the plasma region. This ensures that the temperature background of the excitation environment remains stable throughout the entire programmed temperature rise test, avoiding discharge mode shifts or background spectral drift caused by thermal effects, thus resulting in a more stable baseline for the optical detection signal.

[0055] The high reproducibility and high baseline stability of the signal directly brought about by the integrated metal cavity design are the fundamental prerequisites for accurately dividing the temperature range, extracting effective feature signal intensity values ​​(Xi, Yi, Zi), and finally calculating reliable and comparable fragrance retention performance parameters (Ei, E-comprehensive). Attached Figure Description

[0056] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a schematic diagram of the overall structure of the device for evaluating the aroma retention ability of tobacco fixatives according to the present invention.

[0058] Figure reference numerals: 10, sample reaction bottle; 110, bottle body; 120, jacket; 121, medium inlet.

[0059] 122. Medium outlet; 130. Porous baffle; 11. Carrier gas inlet; 12. Volatile substance outlet; 20. Discharge detection device; 21. Metal cylinder; 22. Metal inner electrode; 23. High-voltage AC power supply; 24. Volatile substance inlet; 25. First optical observation window; 26. Insulating support; 30. First optical detector. Detailed Implementation

[0060] The present invention will be further described below through embodiments, but is not limited to these embodiments. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in manuals, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified.

[0061] Example 1

[0062] Combination Figure 1 As shown, the tobacco fixative retention ability evaluation device of the present invention includes a sample reaction bottle 10, a discharge detection device 20, a first optical detector 30, and a control and data processing unit (not shown in the figure) in its core structure.

[0063] The sample reaction bottle 10 is used to hold and heat the tobacco sample to be tested, and includes a bottle body 110. The bottle body 110 is preferably made of heat-resistant glass and has a sealable cap on top (not shown in the figure). A jacket 120 surrounds the outer periphery of the bottle body 110, forming an annular sealed cavity between the jacket 120 and the outer wall of the bottle body 110 for the flow of the heat exchange medium (such as silicone oil) required for programmed heating. The jacket 120 is provided with a medium inlet 121 and a medium outlet 122, which are respectively connected to an external constant-temperature circulating bath or a medium supply system to achieve precise control of the sample temperature inside the bottle body 110.

[0064] The optimized design of this embodiment lies in the internal structure of the bottle body 110. A porous baffle 130 is horizontally supported near the bottom of the cavity of the bottle body 110. This porous baffle 130 is preferably made of an inert metal (such as stainless steel) or high-temperature resistant ceramic, and has a large number of micropores evenly distributed on it. The porous baffle 130 divides the inner cavity of the bottle body 110 into an upper sample-containing area and a lower gas distribution area. The carrier gas inlet 11 is located at the bottom or lower side of the bottle body 110, directly leading to the gas distribution area. The volatile matter outlet 12 is located at the top of the bottle body 110.

[0065] The discharge detection device 20 is the core component used to excite and detect volatiles. It includes a metal cylinder 21 that serves as the external electrode and directly forms the shell of the discharge chamber. One end of the metal cylinder 21 has a volatile inlet 24 for connecting to the volatile outlet 12 from the sample reaction bottle 10; the other end has a first optical observation window 25, which is sealed with a light-transmitting material (such as quartz glass). Inside the metal cylinder 21, an internal metal electrode 22 is arranged along its axial center. This internal electrode 22 is fixed to both ends of the metal cylinder 21 by insulating supports 26 (such as ceramic or polytetrafluoroethylene), ensuring that its discharge portion maintains a uniform gap with the inner wall of the metal cylinder 21, thus forming a coaxial cylindrical discharge gap. The two output terminals of a high-voltage AC power supply 23 are electrically connected to the metal cylinder 21 (external electrode) and the internal metal electrode 22, respectively.

[0066] The detection end of the first optical detector 30 (e.g., a photomultiplier tube, a CCD spectrometer, or a combination of a monochromator) is aligned with the first optical observation window 25 to receive the light signal generated after the material in the discharge region is excited.

[0067] The control and data processing unit (e.g., computer and data acquisition card) is connected to the medium supply system (for temperature control), the high-voltage AC power supply 23 (for discharge parameters control), and the first optical detector 30 (for receiving and processing optical signals) of the jacket 120 via signal lines, thereby realizing automated control and data acquisition and analysis of the testing process.

[0068] 2. Working principle and process of the device

[0069] The working principle of this device is based on a combined mechanism of dynamic headspace evaporation-dielectric barrier discharge excitation-optical signal detection, and its working process is as follows:

[0070] (1) The weighed tobacco sample (such as the sample prepared in Example 2 or 3) is evenly spread on the porous baffle 130 inside the sample reaction bottle 10. After sealing the bottle mouth, a high-purity inert carrier gas (such as nitrogen) with a constant flow rate is introduced through the carrier gas inlet 11. The carrier gas first enters the gas distribution area at the bottom of the bottle 110, and then passes through the micropores of the entire porous baffle 130 to enter the sample layer above. This design effectively avoids the carrier gas forming a short circuit in the sample, ensuring that the carrier gas is in full contact with all the tobacco samples, thereby efficiently eluting out the aroma components and fixative components volatilized by heat to form a mixed gas flow. The mixed gas flow carrying the volatiles flows out from the volatiles outlet 12 at the top and is transported to the volatiles inlet 24 of the discharge detection device 20 via the connecting pipeline.

[0071] (2) The mixed gas flow enters the interior of the metal cylinder 21 through the volatile inlet 24 and flows axially through the annular discharge region formed by the inner metal electrode 22 and the metal cylinder 21. Simultaneously, the high-voltage AC power supply 23 applies high voltage between the working electrodes, forming a stable low-temperature plasma (such as dielectric barrier discharge). Volatile molecules flowing through this plasma region are collided with, ionized, and dissociated by high-energy electrons. The characteristic fragrance components are excited and transition to an excited state, emitting characteristic light of a specific wavelength during de-excitation. This light signal is emitted through the first optical observation window 25, captured in real time by the first optical detector 30, converted into an electrical signal, and transmitted to the control and data processing unit.

[0072] (3) Throughout the test, the control and data processing unit controls the temperature of the heat exchange medium flowing through the jacket 120 according to a preset program (e.g., increasing the temperature from 50°C to 120°C at a rate of 5°C / min), thereby performing programmed heating of the sample reaction bottle 10. The heating causes the flavorings and fixatives in the tobacco to volatilize successively at different temperature stages according to their boiling points and different binding forces with the matrix. The first optical detector 30 synchronously and continuously collects the light intensity signal throughout the entire heating process, and finally obtains a real-time curve of light intensity changing with time (or corresponding temperature).

[0073] It should be noted that the driving force for the continuous flow of gas from the sample reaction bottle 10 to the discharge detection device 20 comes from the carrier gas flow throughout the system. At the start of the test, an inert carrier gas (such as nitrogen) at a constant flow rate is introduced into the sealed sample reaction bottle 10 through the carrier gas inlet 11. This continuously flowing carrier gas establishes and maintains a positive pressure within the bottle that is higher than the ambient pressure at the outlet, thus generating a driving force. Driven by this pressure, the carrier gas, after eluting the components volatilized from the sample, forms a mixed gas flow, which is then "pushed" from the volatiles outlet 12 to the volatiles inlet 24 of the discharge detection device 20 via the connecting pipe, and finally discharged from the system after passing through the discharge area. The entire path constitutes a continuous carrier gas flow system, the core driving force of which is the pressure difference generated by the constant flow rate of the input carrier gas.

[0074] Example 2

[0075] This embodiment uses linalool, a key aroma component commonly found in fragrances, as an example to demonstrate the basic principles, operating procedures, and data processing methods of the present invention, and to verify its feasibility in evaluating the volatilization inhibition efficacy of a single substance, as detailed below:

[0076] 1. Determination of characteristic spectral signals

[0077] Chromatographically pure linalool standard was selected and prepared into a stock solution of 10 mg / mL using anhydrous ethanol.

[0078] Weigh 0.5g of blank tobacco (already equilibrated) and place it in an open weighing dish. Using a micro-spray device, evenly spray 10μL of the above linalool stock solution onto the surface of the tobacco. Then, equilibrate the tobacco in a constant temperature and humidity chamber (22±2℃, 60±5%RH) for 24 hours to ensure complete solvent evaporation, uniform distribution of linalool in the tobacco matrix, and the attainment of adsorption equilibrium, thus obtaining the calibration sample.

[0079] Next, we will conduct a spectral signal calibration test:

[0080] (1) Place all the prepared calibration samples into the sample reaction bottle 10 and seal the bottle mouth.

[0081] (2) Introduce high-purity nitrogen into the system as a carrier gas and set the flow rate to 100 mL / min.

[0082] (3) The temperature control device of the medium supply system is controlled by the control and data processing unit to raise the temperature of the heat exchange medium (such as silicone oil) flowing through the jacket (120), thereby stabilizing the temperature of the sample reaction bottle at 60°C. This temperature is maintained for 2-5 minutes to allow linalool to evaporate fully and stably. This isothermal step aims to allow linalool to evaporate fully and stably in order to obtain its characteristic emission spectrum.

[0083] (4) Start the high-voltage AC power supply (23) and adjust its output to an AC voltage peak of 8kV and a frequency of 30kHz to form a stable plasma region between the electrodes of the discharge detection device (20) for exciting the volatiles. At the same time, start the photomultiplier tube system equipped with a 430nm narrowband filter, which serves as the first optical detector 30, to collect the optical signal of the plasma region.

[0084] (5) Analyzing the collected signals confirmed that linalool volatiles produce a stable characteristic emission peak near a wavelength of 430 nm after excitation. This peak was determined by this calibration experiment and serves as an exemplary characteristic emission wavelength of linalool. This characteristic peak is identified as the characteristic spectral signal of the target fragrance for subsequent quantitative monitoring.

[0085] 2. Preparation of the sample to be tested

[0086] (1) Use blank flue-cured tobacco as the substrate, which is exactly the same as the previous steps (i.e., equilibrate for 48 hours at 22±2℃ and 60±5%RH).

[0087] (2) Weigh three portions of the above-balanced blank tobacco, 1g each, and place them in three clean sample dishes.

[0088] (3) Using a micro-spray device, the prepared test solution is evenly sprayed onto the surface of the tobacco:

[0089] First sample (test sample): Spray an ethanol solution containing 1.0% (w / w) linalool and 0.2% (w / w) synthetic musk.

[0090] Second sample (blank control): Only sprayed with an ethanol solution containing 0.2% (w / w) synthetic musk.

[0091] Third sample (reference sample): Only spray an ethanol solution containing 1.0% (w / w) linalool.

[0092] (4) Transfer the above three samples to a constant temperature and humidity chamber (22±2℃, 60±5%RH) for 24 hours to ensure that the solvent is completely evaporated, the components are evenly distributed in the tobacco matrix and reach adsorption equilibrium, and the test samples are obtained.

[0093] 3. Testing and Data Acquisition

[0094] (1) Weigh 1g of each of the first, second and third test samples prepared above and place them in sample reaction bottle 10 respectively for three independent tests.

[0095] (2) The following uniform instrument parameters and procedures were set for each test to ensure the comparability of the results:

[0096] Carrier gas and flow rate: High-purity nitrogen gas, with a constant flow rate of (100±5) mL / min.

[0097] Programmed heating: The temperature of the silicone oil medium inside jacket 120 is controlled and adjusted by the control and data processing unit, and uniformly heated from 50℃ to 120℃ at a constant rate of (5.0±0.2)℃ / min, and held at 120℃ for 2 minutes. This dynamic heating program aims to simulate the temperature changes of fragrance during actual use in order to examine the fragrance retention performance of fixatives in different temperature ranges.

[0098] Discharge excitation parameters: The high-voltage AC power supply 23 is set to: high-voltage AC, peak value (8.5±0.5)kV, frequency (30±2)kHz, to ensure the formation of stable low-temperature plasma within the discharge detection device 20.

[0099] Optical detection: The first optical detector 30 (a photomultiplier tube equipped with a 430nm narrowband filter) continuously monitors the determined characteristic wavelength, and the detector acquires light intensity and temperature signals every 100ms.

[0100] Stirring: The stirring blade (140) operates at a constant speed of (60±5) rpm to ensure that the sample is heated evenly and that volatiles are fully released.

[0101] (3) Following this process, the tests of the three samples are completed in sequence, and the data acquisition system automatically records and stores the corresponding curves of light intensity-time-temperature.

[0102] 4. Data Processing and Result Analysis

[0103] (1) Based on the time-temperature correspondence in the programmed heating curve, the three light intensity-temperature curves obtained in step (3) are divided into three preset characteristic temperature ranges for independent analysis: I (50-70℃), II (90-110℃), and III (115-125℃). This segmentation aims to examine the efficacy of fixatives at different stages, such as initial dispersion at low temperatures, main release, and high-temperature action.

[0104] (2) For each temperature range, calculate the signal integral value of the light intensity-time curve of the first sample (test sample), the second sample (blank control sample), and the third sample (reference sample) at the characteristic wavelength of 430 nm. The integral value represents the total luminous intensity in the range and is denoted as Xi, Yi, and Zi (where i = I, II, III).

[0105] (3) Calculate the signal inhibition rate of synthetic musk on linalool volatilization in each temperature range according to the formula Ei=1-[(Xi-Yi) / Zi], which is the fragrance retention performance evaluation parameter Ei.

[0106] (4) Based on the above method, the collected data are processed to obtain a set of exemplary calculation results as follows:

[0107] For temperature range I (50-70℃): EI = 0.28

[0108] For temperature range II (90-110℃): EII = 0.65

[0109] For temperature range III (115-125℃): EIII = 0.82

[0110] (5) In order to obtain an overall evaluation index, the arithmetic mean method is used to calculate the overall fragrance retention efficiency value of the fixative: Ecomprehensive = (EI + EII + EIII) / 3 = (0.28 + 0.65 + 0.82) / 3 = 0.58.

[0111] This embodiment directly obtained the quantitative evaluation results of the fixative (synthetic musk) on the volatilization of linalool through experiments and calculations. Its signal inhibition rates in the three characteristic temperature ranges were EI = 0.28, EII = 0.65, and EIII = 0.82, respectively, and the calculated comprehensive fragrance retention efficiency value was Ecomprehensive = 0.58. The signal inhibition rate Ei directly characterizes the degree to which the fixative inhibits the volatilization of aroma components; a higher value indicates a stronger fragrance retention ability. For example, EIII (0.82) is much greater than EI (0.28), intuitively indicating that the fixative has significantly stronger fragrance retention efficiency in the high-temperature range.

[0112] Therefore, this embodiment demonstrates that the device and method described in this invention can objectively measure and calculate the quantitative index (Ei and E combined) that directly characterizes the fragrance retention ability of fixatives, thereby verifying the feasibility of this technical solution for quantitative and refined evaluation of fixative efficacy.

[0113] Example 3

[0114] This embodiment uses commercially available compound floral tobacco flavorings (mixtures) as the direct evaluation object to demonstrate how the method of the present invention can directly quantify the overall aroma retention function of fixatives in complex systems without analyzing specific chemical components, further verifying the universality and practicality of the method, as detailed below:

[0115] 1. Determination of characteristic spectral signals of mixtures

[0116] Since the target substance is a complex fragrance mixture, its characteristic spectral signal is determined by the excitation spectrum of its overall volatiles.

[0117] (1) Following the subsequent “2. Preparation steps of the sample to be tested (3)”, prepare a third sample (reference sample, i.e., a sample containing only 1.0% (w / w) of compound floral fragrance).

[0118] (2) Weigh 1.00 g of the reference sample and place it in the sample reaction bottle 10 and seal it. Introduce high-purity nitrogen as the carrier gas at a flow rate of 100 mL / min.

[0119] (3) The temperature is increased from 50℃ to 120℃ at a rate of 5℃ / min by the control and data processing unit. At the same time, the high-voltage AC power supply 23 (parameters: peak value 8.5kV, frequency 30kHz) is started to form a plasma region, and a photomultiplier tube system (as the first optical detector 30) connected with the scanning monochromator is used to scan in the wavelength range of 200-800nm ​​and collect the full-band emission spectrum.

[0120] (4) Analysis of the collected full spectrum revealed a stable, broad characteristic emission band in the 300-450 nm range of the compound fragrance. A significant and stable peak at approximately 450 nm was selected as a characteristic fingerprint signal representing the overall volatility behavior of the compound fragrance for subsequent quantitative monitoring.

[0121] 2. Preparation of the sample to be tested

[0122] (1) Use the same blank flue-cured tobacco as in Example 1 as the matrix (equilibrate for 48 hours at 22±2℃ and 60±5%RH).

[0123] (2) Weigh three portions of the blank tobacco after the above equilibrium, each portion weighing 1.00g, and place them in three clean sample dishes respectively.

[0124] (3) Using a micro-spray device, the prepared test solution is evenly sprayed onto the surface of the tobacco:

[0125] First sample (test sample): Spray an ethanol solution containing 1.0% (w / w) of complex floral fragrance and 0.2% (w / w) of synthetic sandalwood (such as acetylated cedarene).

[0126] Second sample (blank control): Only sprayed with an ethanol solution containing 0.2% (w / w) synthetic sandalwood (fixative).

[0127] Third sample (reference sample): Only sprayed with an ethanol solution containing 1.0% (w / w) of complex floral fragrance.

[0128] (4) Place the above three samples in a constant temperature and humidity chamber (22±2℃, 60±5%RH) for 24 hours to ensure that the solvent is completely evaporated, the components are evenly distributed and adsorption equilibrium is reached, and the sample to be tested is obtained.

[0129] 3. Testing and Data Acquisition

[0130] The testing procedure and conditions are the same as step 3 in Example 1, except that the optical detection is adjusted to use a photomultiplier tube system equipped with a 450nm narrowband filter to monitor the light intensity signal at this characteristic wavelength. The first, second, and third samples are tested sequentially, and each light intensity-time-temperature curve is automatically recorded.

[0131] 4. Data Processing and Result Analysis

[0132] The data processing method is the same as step 4 in Example 1, using the same temperature range division and calculation formula Ei=1-[(Xi-Yi) / Zi].

[0133] (1) Based on the experimental data, the signal inhibition rate of synthetic sandalwood on compound floral fragrances in each temperature range was calculated:

[0134] For temperature range I (50-70℃): EI = 0.15

[0135] For temperature range II (90-110℃): EII = 0.40

[0136] For temperature range III (115-125℃): EIII = 0.60

[0137] (2) Calculate the overall fragrance retention value: E_overall = (0.15 + 0.40 + 0.60) / 3 = 0.38.

[0138] This embodiment directly obtained a quantitative evaluation result of the fixative (synthetic sandalwood) on the overall volatilization of the complex floral fragrance through experiments and calculations. Its signal inhibition rates in the three characteristic temperature ranges were EI = 0.15, EII = 0.40, and EIII = 0.60, respectively, and the calculated comprehensive fragrance retention efficiency value was Ecomprehensive = 0.38. The signal inhibition rate Ei directly characterizes the degree to which the fixative inhibits the volatilization of aroma components; a higher value indicates a stronger fragrance retention ability. The data also show a temperature-dependent inhibition effect, with EIII (0.60) being greater than EI (0.15), indicating that the fixative has a stronger fragrance retention efficiency in the high-temperature range.

[0139] This embodiment demonstrates that the method of the present invention does not require the identification and separation of specific components of complex fragrances. By monitoring changes in the overall optical fingerprint signal, it can successfully quantify the overall fragrance retention efficiency of the fixative on the fragrance mixture. This corroborates Example 1, jointly demonstrating that the technical solution described in this invention is feasible, objective, and universally applicable for the functional evaluation of both single substances and complex mixture systems.

[0140] Comparative Example 1

[0141] This comparative example uses a discharge detection unit with an alternative structure to replace the discharge detection device 20 in Embodiment 1 of the present invention. Except for this discharge unit, the rest (including the sample vial, control computer, optical detector, and all test samples) are exactly the same as in Embodiment 1.

[0142] The alternative discharge unit has the following structure: a quartz glass cylinder serves as an insulating cavity, and a layer of stainless steel foil is tightly wrapped around the outer wall of the cylinder as an external electrode. Inside the cylinder, a metal internal electrode 22 with the same specifications as in Embodiment 1 of this invention is placed. The stainless steel foil external electrode and this internal electrode are respectively connected to the same high-voltage AC power supply 23, thus forming a comparative structure of an insulating cavity + external electrode.

[0143] Next, the same test conditions, operating procedures, and data analysis methods as in Embodiment 1 of the present invention were strictly adopted. Using the above-described comparative apparatus, three independent repeated tests were performed on the same batch of first, second, and third test samples.

[0144] The test results are shown in Table 1 below:

[0145] Table 1 Comparison of test results between Comparative Example 1 and Example 1

[0146] Test number Peak temperature (°C) Peak light intensity (au) Fragrance retention (Ei) Comparative Example 1-1 97.2 850 0.41 Comparative Examples 1-2 104.5 1430 0.69 Comparative Examples 1-3 99.8 1050 0.53 Example 1-1 101.5 1220 0.55 Examples 1-2 101.3 1190 0.54 Examples 1-3 101.6 1230 0.56

[0147] As can be seen, the three measurement results of Comparative Example 1 fluctuated greatly, with its key evaluation parameter, the fragrance retention efficiency Ei value, diverging between 0.41 and 0.69 and failing to converge. This indicates that reliable and consistent quantitative evaluation results cannot be obtained based on this unstable device. In contrast, the measurement data (Ei value: 0.54-0.56) of Example 1 of the present invention exhibited high accuracy and repeatability, verifying the effectiveness of the evaluation method provided by the present invention.

[0148] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A device for evaluating the aroma retention ability of tobacco fixatives, characterized in that, include: The sample reaction bottle (10) is provided with a carrier gas inlet (11) and a volatile matter outlet (12); The discharge detection device (20) includes a metal cylinder (21) that serves as an outer electrode and forms the shell of the discharge cavity, a metal inner electrode (22) disposed inside the metal cylinder (21), and a high-voltage AC power supply (23). The two output terminals of the high-voltage AC power supply (23) are electrically connected to the metal cylinder (21) and the metal inner electrode (22), respectively. First optical detector (30); The volatile outlet (12) is connected to the metal cylinder (21), and the detection end of the first optical detector (30) is configured to receive light signals from inside the metal cylinder (21).

2. The apparatus according to claim 1, characterized in that, The inner metal electrode (22) is fixed inside the metal cylinder (21) by an insulating support (26), and the discharge portion of the inner metal electrode (22) is kept at a distance from the inner wall of the metal cylinder (21).

3. The apparatus according to claim 1 or 2, characterized in that, One end of the metal cylinder (21) is provided with a first optical observation window (25), and the other end of the metal cylinder (21) or the cylinder wall is provided with a volatile inlet (24); the volatile outlet (12) is connected to the internal cavity of the metal cylinder (21) through the volatile inlet (24); the detection end of the first optical detector (30) is aligned with the first optical observation window (25) to receive the light signal from the discharge area of ​​the metal inner electrode (22).

4. The apparatus according to claim 1, characterized in that, The sample reaction flask (10) includes: Bottle body (110); A jacket (120) is wrapped around the outer peripheral wall of the bottle body (110). The jacket (120) and the bottle body (110) form an annular sealed cavity for the flow of heat exchange medium. The jacket (120) is provided with a medium inlet (121) and a medium outlet (122). A porous baffle (130) is supported within the cavity of the bottle body (110); The carrier gas inlet (11) and the volatile matter outlet (12) are disposed on the bottle body (110).

5. The apparatus according to claim 1, characterized in that, The volatile inlet (24) and the first optical observation window (25) are respectively located at both ends of the axial direction of the metal cylinder (21) so that the carrier gas flow path passes through the discharge area of ​​the metal inner electrode (22) and the first optical detector (30) can observe the discharge area along the axial direction.

6. The apparatus according to claim 4, characterized in that, It also includes a control and data processing unit; The control and data processing unit is connected to the media supply system of the jacket (120), the high-voltage AC power supply (23), and the first optical detector (30).

7. A method for evaluating the aroma retention ability of tobacco fixatives, using the apparatus as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Step (1): Prepare the first sample, the second sample, and the third sample; The first sample is a tobacco sample with the target flavoring and the fixative to be evaluated added; the second sample is a blank control sample of tobacco with the same matrix as the first sample, but with an equal amount of the fixative to be evaluated added and no target flavoring added; the third sample is a reference sample of tobacco with the same matrix as the first sample, but with an equal amount of the target flavoring added and no fixative added. Step (2): Under the same test conditions, the first sample, the second sample, and the third sample are subjected to the following operations in sequence: the sample is placed in the sample reaction bottle (10), heated by programmed temperature rise, and carrier gas is introduced through the carrier gas inlet (11) so that the volatilized substances enter the discharge detection device (20) through the volatile substance outlet (12); the high-voltage AC power supply (23) is turned on so that a discharge is generated between the metal inner electrode (22) and the metal cylinder (21) to ionize and dissociate the volatilized substances; at the same time, the first optical detector (30) is used to collect the continuous optical signal generated by ionization and dissociation during the entire programmed temperature rise process; Step (3): Based on the time-temperature relationship of the programmed heating process, the acquired optical signal is divided into multiple data segments corresponding to different temperature ranges; For the characteristic spectral signals representing key aroma components in the target fragrance, the signal intensity values ​​of the first sample, the second sample, and the third sample in each temperature range are extracted respectively; the signal intensity value of the first sample in the i-th temperature range is denoted as Xi, the signal intensity value of the second sample in the i-th temperature range is denoted as Yi, and the signal intensity value of the third sample in the i-th temperature range is denoted as Zi. Step (4): For each temperature range i, calculate the evaluation parameter Ei of the fragrance retention effect of the fixative to be evaluated on the target fragrance. The calculation formula is as follows: Ei = 1 - [(Xi - Yi) / Zi] In the formula: (Xi-Yi) characterizes the actual net volatile signal intensity of the target fragrance in the presence of the fixative in the first sample after subtracting the background of the matrix and fixative; Zi characterizes the intensity of the original volatile signal of the target fragrance in the third sample without a fixative; The ratio (Xi-Yi) / Zi represents the relative volatility of the fragrance in the presence of a fixative. Ei represents the signal inhibition rate of the fixative on the volatilization of the fragrance; The value of Ei serves as the basis for evaluating the fragrance retention ability of the fixative under evaluation within the corresponding temperature range. The larger the value of Ei, the stronger the ability to inhibit fragrance volatilization and the better the fragrance retention ability.

8. The method according to claim 7, characterized in that, The specific conditions for the programmed temperature rise are: heating from 50°C to 120°C at a temperature rise rate of 3°C / minute to 8°C / minute.

9. The method according to claim 7 or 8, characterized in that, The temperature range in step (3) includes a first range of 50-70℃, a second range of 90-110℃, and a third range of 115℃ to 125℃.

10. The method according to claim 9, characterized in that, Based on the signal suppression rates E1, E2, and E3 calculated from the first, second, and third intervals respectively, the comprehensive fragrance retention efficiency value Ecomprehensive of the fixative to be evaluated is calculated by weighted average or arithmetic average, and used to evaluate its overall fragrance retention performance.

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