Temperature-sensitive flavoring microcapsule for functional filter rod and preparation method thereof

Abstract

The application discloses a kind of functional filter stick temperature-sensitive perfuming microcapsules and preparation method thereof, including porous carrier, essence and flavour adsorbed in porous carrier and envelope coated on the surface of porous carrier;In the envelope, the mass ratio of palm oil and coconut oil is 1:0.5-2.When the mass ratio of palm oil and coconut oil is 1:0.5-2, the envelope is solid at room temperature (25-35 DEG C), can effectively encapsulate the essence and flavour adsorbed in porous carrier, prevent the volatilization of essence and flavour.While smoking, the temperature of filter tip is about 55 DEG C, at the temperature, the envelope melts, becomes liquid, loses the encapsulation effect of essence and flavour, so that essence and flavour volatilize rapidly, to improve the aroma of smoke.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flavoring carriers for cigarettes, and particularly relates to a temperature-sensitive flavoring microcapsule for functional filter rods and a preparation method thereof. BACKGROUND

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] In the cigarette flavoring technology, the tobacco or filter is generally flavored, and the adsorbent is generally used to adsorb flavoring to control the volatility of the flavoring, so that the flavoring can be smoothly volatilized in the smoking process.

[0004] However, the inventors have found in practice that different adsorbents have different adsorption capacities for flavoring, and different flavorings have different volatilities, and if only the adsorbent is used to adsorb the flavoring, the following problems are likely to occur: limited by the adsorption performance of the adsorbent or the volatilization performance of the flavoring, the adsorption capacity of the adsorbent for the flavoring is small, and the flavoring is likely to volatilize during the storage, transportation or sale of the cigarette, so that the concentration of the flavoring released in the smoking process is low, and the improvement of the smoke flavor is limited.

[0005] In addition, the adsorption of the adsorbent to the flavoring is relatively strong, and it is difficult to ensure the full release of the flavoring in a short smoking time of a cigarette, which not only is not conducive to the improvement of the smoke flavor, but also leads to the waste of the flavoring. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application aims to provide a temperature-sensitive flavoring microcapsule for functional filter rods and a preparation method thereof.

[0007] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0008] In the first aspect, the present application provides a temperature-sensitive flavoring microcapsule for functional filter rods, which comprises a porous carrier, flavoring adsorbed in the porous carrier, and a sealing film coated on the surface of the porous carrier; in the sealing film, the mass ratio of palm oil to coconut oil is 1:0.5-2.

[0009] When the mass ratio of palm oil to coconut oil is 1:0.5-2, the sealing film is solid at room temperature (25-35℃), which can effectively encapsulate the flavoring adsorbed in the porous carrier and prevent the volatilization of the flavoring. When smoking, the temperature of the filter is about 55℃, at which temperature the sealing film melts and becomes liquid, losing the encapsulation effect on the flavoring, so that the flavoring volatilizes quickly to improve the smoke flavor.

[0010] In order to ensure that the essence flavor can be volatilized in time when smoking, the film is required to melt quickly (e.g. in 5-7 seconds) at about 55℃. If the melting speed of the film is too slow, the aroma will be delayed. If the film melts easily at a lower temperature, it will be easy to fail during storage in a high-temperature environment such as summer. It is found through experiments that when the mass ratio of palm oil to coconut oil is 1:0.5-2, the film will not melt below 50℃, and can melt quickly at about 55℃, which can meet the packaging requirements in hot conditions such as summer and the requirement of quickly releasing aroma when smoking.

[0011] In addition, the cigarette filter rod is generally prepared from acetate tow, and the amount of the aroma substance added is determined by the amount of the aroma microcapsules attached to the surface of the acetate tow. When the amount of the aroma substance added is sufficient to meet the requirement, the expected purpose can be achieved. Therefore, the adhesion of the aroma microcapsules to the acetate tow is a key factor. It is found through experiments that when the mass ratio of palm oil to coconut oil in the film is 1:0.5-2, the adhesion of the aroma microcapsules to the surface of the acetate tow is improved.

[0012] In some embodiments, the mass ratio of palm oil to coconut oil in the film is 1:0.5-1.5, preferably 1:1.

[0013] In some embodiments, the porous carrier is porous starch, porous inorganic carrier, composite aroma microcapsule carrier or natural plant porous carrier.

[0014] Preferably, the porous starch is honeycomb-like porous starch obtained by treating starch by enzymatic method.

[0015] Preferably, the porous inorganic carrier is selected from silica, diatomite, attapulgite, kaolin or alumina.

[0016] Preferably, the composite aroma microcapsule carrier is obtained by uniformly mixing dextrin, microcrystalline cellulose and binder in a certain proportion, extruding and granulating, and drying.

[0017] Preferably, the natural plant porous carrier is obtained by crushing plant tissues, and the plant tissues are selected from dried tangerine or orange peel, red hemp, sugarcane residue or corn stalk.

[0018] Further preferably, the average particle size of the porous starch is 1.6 μm; the average particle size of the porous inorganic carrier is 207 μm; the average size of the composite aroma microcapsule is 2.05 x 0.897 mm; and the particle size of the natural plant porous carrier is 1.667 mm.

[0019] In some embodiments, the essence flavor is selected from D-limonene, 2-methylvaleric acid or 5-hydroxymethylfurfural.

[0020] In a second aspect, the present application provides a method for preparing the temperature-sensitive flavoring microcapsule for the functional filter rod, comprising the following steps:

[0021] Spraying the perfume solution on the porous carrier for multiple times to adsorb the perfume;

[0022] Melting the mixture of palm oil and coconut oil to a liquid state, adding the porous carrier adsorbed with the perfume into the liquid, then taking out the porous carrier and removing the excess liquid, and solidifying in an environment below 5°C to obtain the product.

[0023] In some embodiments, the oil absorption paper is used to adsorb the excess liquid.

[0024] Preferably, the porous carrier with the attached liquid is solidified in an environment of 0-5°C, preferably 4°C. Since the porous carrier has a small particle size and a large quantity, it is difficult to be effectively spaced, and solidification at room temperature can easily cause the particles to stick together, which makes it difficult to ensure the uniformity of the filter rod. If the microcapsules are separated by grinding or other methods, the membrane on the surface of the microcapsules can be damaged, which can cause the membrane to fail. Through experiments, it is found that by controlling the solidification temperature to about 4°C, the sticking between the particles can be effectively prevented, and loose temperature-sensitive microcapsules can be obtained, which can effectively ensure the quality of the filter rod.

[0025] The beneficial effects of one or more embodiments of the present application are as follows:

[0026] The membrane effectively encapsulates the perfume adsorbed in the porous carrier, preventing the perfume from volatilizing at room temperature. When smoking, the membrane melts rapidly and becomes liquid, losing its encapsulation effect on the perfume, allowing the perfume to volatilize rapidly to improve the aroma of the smoke.

[0027] The temperature-sensitive flavoring microcapsule is more conducive to improving the adhesion on the surface of the acetate fiber tows. The temperature-sensitive inorganic microcapsule has the best adsorption performance on the perfume, the best retention effect and release performance on the aroma substance, and the best adhesion on the surface of the acetate fiber tows, which has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings accompanying the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application.

[0029] Figure 1 The photos of four kinds of flavoring microcapsule porous carriers of the embodiments of the present application, wherein A is an organic microcapsule carrier, B is an inorganic microcapsule carrier, C is a composite flavoring microcapsule carrier, and D is a natural plant microcapsule carrier;

[0030] Figure 2 is a contrast chart of various ratio mixtures of palm oil and coconut oil in a molten state at 25℃ in the embodiments of the present application, wherein A is pure palm oil, B is palm oil: coconut oil 4:1, C is palm oil: coconut oil 1:1, D is palm oil: coconut oil 1:4, and E is pure coconut oil;

[0031] Figure 3 is a contrast chart of various ratio mixtures of palm oil and coconut oil in a molten state at 40℃ in the embodiments of the present application, wherein A is pure palm oil, B is palm oil: coconut oil 4:1, C is palm oil: coconut oil 1:1, D is palm oil: coconut oil 1:4, and E is pure coconut oil;

[0032] Figure 4 is a contrast chart of various ratio mixtures of palm oil and coconut oil in a molten state at 55℃ in the embodiments of the present application, wherein A is pure palm oil, B is palm oil: coconut oil 4:1, C is palm oil: coconut oil 1:1, D is palm oil: coconut oil 1:4, and E is pure coconut oil;

[0033] Figure 5 is a microstructure characterization chart of a temperature-sensitive organic microcapsule in the embodiments of the present application;

[0034] Figure 6 is a microstructure characterization chart of a temperature-sensitive inorganic microcapsule in the embodiments of the present application;

[0035] Figure 7 is a microstructure characterization chart of a temperature-sensitive composite flavoring microcapsule in the embodiments of the present application;

[0036] Figure 8 is a microstructure characterization chart of a temperature-sensitive natural plant microcapsule in the embodiments of the present application;

[0037] Figure 9 is a contrast chart of the hygroscopic properties of four microcapsule carriers in the embodiments of the present application, wherein A is an organic microcapsule carrier, B is an inorganic microcapsule carrier, C is a composite flavoring microcapsule carrier, and D is a natural plant microcapsule carrier;

[0038] Figure 10 is an apparent chart of the adsorption of three aroma substances by four different temperature-sensitive microcapsule carriers in the embodiments of the present application;

[0039] Figure 11 is a contrast chart of the adsorption properties of three aroma substances by four microcapsule carriers in the embodiments of the present application, wherein A is an organic microcapsule carrier, B is an inorganic microcapsule carrier, C is a composite flavoring microcapsule carrier, and D is a natural plant microcapsule carrier;

[0040] Figure 12A comparison chart of aroma retention performance of the organic microcapsule on aroma substances in the embodiment of the present application;

[0041] Figure 13 A comparison chart of aroma retention performance of the inorganic microcapsule on aroma substances in the embodiment of the present application, which has the same position correspondence relationship as that in Figure 12 ;

[0042] Figure 14 A comparison chart of aroma retention performance of the composite aroma-enhancing microcapsule on aroma substances in the embodiment of the present application, which has the same position correspondence relationship as that in Figure 12 ;

[0043] Figure 15 A comparison chart of aroma retention performance of the natural plant microcapsule on aroma substances in the embodiment of the present application, which has the same position correspondence relationship as that in Figure 12 ;

[0044] Figure 16 A photo of the gas chromatograph-mass spectrometer in the embodiment of the present application;

[0045] Figure 17 A comparison chart of release of D-limonene of the four kinds of microcapsules at different temperatures in the embodiment of the present application, wherein A is an unsealed organic microcapsule carrier, B is an unsealed inorganic microcapsule carrier, C is an unsealed composite aroma-enhancing microcapsule carrier, and D is an unsealed natural plant microcapsule carrier;

[0046] Figure 18 A comparison chart of release of 2-methylvaleric acid of the four kinds of microcapsules at different temperatures in the embodiment of the present application, wherein A is an unsealed organic microcapsule carrier, B is an unsealed inorganic microcapsule carrier, C is an unsealed composite aroma-enhancing microcapsule carrier, and D is an unsealed natural plant microcapsule carrier; which has the same position correspondence relationship as that in Figure 17 ;

[0047] Figure 19 A comparison chart of release of 5-hydroxymethylfurfural of the four kinds of microcapsules at different temperatures in the embodiment of the present application, wherein A is an unsealed organic microcapsule carrier, B is an unsealed inorganic microcapsule carrier, C is an unsealed composite aroma-enhancing microcapsule carrier, and D is an unsealed natural plant microcapsule carrier; which has the same position correspondence relationship as that in Figure 17 ;

[0048] Figure 20 A comparison chart of release of the unsealed and sealed microcapsules at 55℃ in the embodiment of the present application; the columnar chart and the marked part correspond to each other along the arrow direction;

[0049] Figure 21 A photo of the acetate fiber bundle in the embodiment of the present application;

[0050] Figure 22The following is a comparison chart of the adhesion of cellulose acetate filaments in the embodiments of the present application to four types of microcapsule carriers. A is an organic microcapsule carrier, B is an inorganic microcapsule carrier, C is a composite flavoring microcapsule carrier, and D is a natural plant microcapsule carrier. DETAILED DESCRIPTION

[0051] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0052] The present application will be further described below in conjunction with examples.

[0053] 1. Preparation of temperature-sensitive flavoring microcapsule carriers

[0054] The following is a comparison chart of the adhesion of cellulose acetate filaments in the embodiments of the present application to four types of microcapsule carriers. A is an organic microcapsule carrier, B is an inorganic microcapsule carrier, C is a composite flavoring microcapsule carrier, and D is a natural plant microcapsule carrier.

[0055] 1.1 Temperature-sensitive organic microcapsule

[0056] The temperature-sensitive organic microcapsule carrier is a porous honeycomb product formed by enzymatic treatment of starch and other materials. The specific preparation method is as follows. Corn starch and a citric acid-disodium hydrogen phosphate buffer solution with a pH of 4.6 are mixed at a ratio of 1:5 and preheated for 10 minutes. Accurately weighed 1:4 α-amylase and glucoamylase are mixed with the above suspension, and constant temperature oscillation reaction is carried out for 15 hours. The enzymatic reaction is stopped by adding 4% NaOH. The precipitate obtained by centrifugation is washed with distilled water several times, then dried in a 40°C oven, and then crushed and passed through a 100 mesh sieve to obtain the porous starch.

[0057] The porous starch particle surface has small pores and extends to the inside of the particle, and is a hollow particle similar to a wasp, which can hold various substances therein and has good adsorption properties. The temperature-sensitive organic microcapsule is prepared by enzymatic method because it is derived from microorganisms, and enzyme preparations can be produced in large quantities by fermentation. Moreover, the process for preparing the temperature-sensitive organic microcapsule by enzymatic method is simple and easy to operate, and the obtained temperature-sensitive organic microcapsule is a hollow particle, as shown in Figure 1 which has a large adsorption capacity.

[0058] 1.2 Temperature-sensitive inorganic microcapsule

[0059] The temperature-sensitive inorganic microcapsule carrier is a silicon dioxide powder, which is a white highly dispersed amorphous powder with an average particle size of 207 μm, as shown in Figure 1The middle B is shown, the specific gravity of 2.319-2.653, melting point of 1750 ℃, insoluble in water and most of the acid, stable to other chemical drugs, high temperature resistance, not decomposition, not burning, with very high electrical insulation, porosity, internal surface area, non-toxic, so the temperature-sensitive inorganic microcapsules can absorb aroma substances and used for functional filter stick.

[0060] 1.3 temperature-sensitive composite flavoring microcapsules

[0061] The dextrin, microcrystalline cellulose, hydroxypropyl cellulose binder is mixed uniformly in a mass ratio of 40:10:15, extruded and granulated, and dried to obtain the finished product, such as Figure 1 The middle C is shown, and the temperature-sensitive composite flavoring microcapsules can be used to directly absorb aroma substances.

[0062] 1.4 temperature-sensitive natural plant microcapsules

[0063] The pericarpium citri reticulatae is crushed to 1-3 mm using the porous structure of the plant itself to prepare the temperature-sensitive natural plant microcapsules, such as Figure 1 The middle D is shown, and this carrier preparation method is simple and natural, and can be used to absorb aroma substances.

[0064] 2. Selection of aroma substances

[0065] The aroma experiment substances are selected from D-limonene, 2-methylvaleric acid, and 5-hydroxymethylfurfural. The next experiment is carried out according to the analysis of volatility difference and dissolution characteristics. The greater the saturated vapor pressure, the more volatile the substance. D-limonene has a large saturated vapor pressure and belongs to a strong volatile substance; 5-hydroxymethylfurfural has a moderate saturated vapor pressure and belongs to a moderately volatile substance; 2-methylvaleric acid has the smallest saturated vapor pressure and belongs to a difficult volatile substance.

[0066] The antioxidant and anti-quality change determination method of the aroma substance is as follows: after the aroma substance is placed in the air for one week, the component change is determined by gas chromatography-mass spectrometry. After three weeks, none of the three substances decomposes to produce other substances.

[0067] Table 1 Physical and chemical properties of three aroma substances

[0068]

[0069]

[0070] 3. Selection and preparation of film-forming substances

[0071] Considering that aroma substances are only adsorbed on the surface of microcapsules, the volatility to some extent depends on the nature of the substance itself. Therefore, a temperature-sensitive coating is selected to be applied to the outer surface of the microcapsules adsorbed with aroma substances, which plays a certain protective role during storage.

[0072] In the experiment, oil gel is selected as the coating material. Oil gel has temperature sensitivity, and presents a solid state during storage to provide protection, and presents a liquid state during smoking to promote the release of aroma substances. In addition, oil gel must meet the requirement of no odor, which to some extent meets the needs of aroma microcapsules.

[0073] Oil gel is selected to be compounded with palm oil and coconut oil, and the most suitable ratio is obtained through testing. The compounding ratio is set as: pure palm oil, palm oil: coconut oil (4:1, 1:1, 1:4), and pure coconut oil. The compounded samples are heated in a water bath at different temperatures, with the temperature set at 25℃, 40℃, and 55℃. The state of the samples is observed, and the oil gel meeting the requirements is selected for the following experiments.

[0074] As Figure 2 , Figure 3 and Figure 4 can be seen, according to the state at three temperatures, it can be observed that at 25℃, the five kinds of oil gels are in a solid state; at 40℃, except for pure coconut oil and 1:4 ratio, the other oil gels are in a solid state; after 55℃ water bath, the oil gels of the five ratios are in a liquid state. The melting conditions at 48℃ and 55℃ water bath are shown in Table 2. Considering that the storage effect is best at room temperature, and the aroma is released fastest during smoking (the filter temperature is mostly 50-60℃), the oil gel should meet the requirements of solid state at room temperature and quickly become liquid within a certain temperature range. Finally, the oil gel compounded with palm oil and coconut oil at a ratio of 1:1 is selected as the coating material. In addition, the use cost of palm oil is lower than that of other oils, which has certain advantages in use.

[0075] Table 2

[0076]

[0077] The melting time in Table 2 refers to the time consumed from solid state to liquid state.

[0078] II. Property determination and application evaluation of temperature-sensitive aroma microcapsule carrier

[0079] 1. Structure characterization

[0080] Modern analytical instruments are used to characterize the structures of the prepared temperature-sensitive organic microcapsules, inorganic microcapsules, composite aroma microcapsules, and natural plant microcapsules, including scanning electron microscopy, microcapsule size, pore size distribution, specific surface area, and texture characteristics.

[0081] 1.1 Scanning electron microscope analysis

[0082] The temperature-sensitive organic microcapsules, inorganic microcapsules, composite flavoring microcapsules, and natural plant microcapsules were cooled with liquid nitrogen and then sliced into thin sections using a cryo-sectioning machine. These sections were placed on the surface of a square single crystal silicon wafer (6 mm * 6 mm). Finally, a layer of conductive gold or platinum was coated on the sections using a sputter coater, and then the microstructure was observed using a SEM instrument (zeiss, Germany), as shown in Figures 5-8

[0083] 1.2 Microcapsule size

[0084] From the results of section 1.1, the sizes of the four types of carriers, temperature-sensitive organic microcapsules, inorganic microcapsules, composite flavoring microcapsules, and natural plant microcapsules, are shown in Table 3. Among them, the size of the temperature-sensitive natural plant microcapsules is the largest, and the size of the organic microcapsules is the smallest.

[0085] Table 3 Particle size of various microcapsule carriers

[0086]

[0087] 1.3 Pore size distribution

[0088] The pore size distribution of the temperature-sensitive flavoring microcapsules was analyzed by scanning electron microscopy. The pore size distribution is often related to the adsorption capacity of the microcapsule carrier. According to the SEM results, it can be seen that the temperature-sensitive organic microcapsules and the temperature-sensitive natural plant microcapsules have a relatively uniform pore size, as shown in Figure 5 and Figure 8 However, compared with each other, the pore size of the temperature-sensitive natural plant microcapsules is too large, and the contact area of the adsorbed aroma substances with the outside air is relatively large. In the SEM images of the temperature-sensitive inorganic microcapsules and the temperature-sensitive composite flavoring microcapsules, no regular pores can be observed, as shown in Figure 6 and Figure 7 However, there are many voids, which are beneficial to adsorb aroma substances and better retain them.

[0089] 1.4 Specific surface area

[0090] The multilayer adsorption capacity of the measured samples (temperature-sensitive organic microcapsule carrier, temperature-sensitive inorganic microcapsule carrier, temperature-sensitive composite flavoring microcapsule carrier, and temperature-sensitive natural plant microcapsule carrier) under different nitrogen partial pressures was measured, and the P / P0 was taken as the X axis and the P / V (P0-P) was taken as the Y axis. The linear fitting was performed by plotting the BET equation to obtain the slope and intercept of the straight line, and thus the Vm value was calculated to obtain the specific surface area of the measured sample.

[0091] The specific surface area of the temperature-sensitive inorganic microcapsule carrier is the largest, with a BET of 117 m 2 ​ / g, followed by the temperature-sensitive composite flavoring microcapsule carrier, the specific surface area of the temperature-sensitive organic microcapsule carrier is the smallest, only 5.297 m 2 / g.

[0092] The BET equation is as follows:

[0093]

[0094] In the formula: P: nitrogen partial pressure

[0095] P0: the saturated vapor pressure of nitrogen at liquid nitrogen temperature

[0096] V: the actual adsorption amount of nitrogen on the surface of the sample

[0097] V m : the saturated adsorption amount of a nitrogen monolayer

[0098] C: a constant related to the adsorption capacity of the sample.

[0099] Table 4

[0100]

[0101] 1.5 Texture measurement

[0102] The texture analysis of the four temperature-sensitive microcapsule carrier materials was carried out to characterize their hardness, and the results are shown in Table 5. The texture test used a TA / 36 cylindrical probe, and the full texture test mode was selected, the test type was down pressure, the target mode was deformation, the target value was 20%, the time was 2s, the probe speed before test was 2.00mm / s, the test speed and the test speed after test was 1.00mm / s, the trigger point type was force, and the trigger force was 5gf.

[0103] Table 5 Hardness of four carriers

[0104]

[0105] It can be found from the texture tester test results that the hardness of the temperature-sensitive natural plant microcapsule carrier is much greater than that of the other three temperature-sensitive microcapsule carriers. The hardness of the four temperature-sensitive flavoring microcapsule carriers is in the order of: natural plant microcapsule > composite flavoring microcapsule > inorganic microcapsule > organic microcapsule.

[0106] 2 Hygroscopicity

[0107] Five grams of each of the temperature-sensitive organic microcapsule, temperature-sensitive inorganic microcapsule, temperature-sensitive composite flavoring microcapsule, and temperature-sensitive natural plant microcapsule carrier materials were weighed, laid flat in a glassware, and placed in a temperature of 25℃ and humidity of 60% condition, and the mass was measured at intervals to determine the hygroscopicity of the microcapsule carrier.

[0108] AsFigure 9 As shown in the hygroscopicity results of the four kinds of temperature-sensitive microcapsule carriers, the hygroscopicity of all the temperature-sensitive microcapsule carriers showed a trend of first increasing and then flattening. Among them, the hygroscopicity of the temperature-sensitive natural plant microcapsule carrier was the highest, reaching 10.78%, while the hygroscopicity of the temperature-sensitive inorganic microcapsule carrier was the lowest. The reason may be that the natural plant microcapsule carrier has larger holes, and water can easily enter it, while the inorganic microcapsule carrier has small and dense holes, and it is difficult for water to enter it. The results also show that the temperature-sensitive inorganic microcapsule carrier is the most suitable for the properties of tobacco microcapsules.

[0109] 3.3 Determination of the adsorption rate of aroma

[0110] 3.1 Aroma-adding process

[0111] A certain amount of temperature-sensitive organic microcapsule carrier, inorganic microcapsule carrier, composite flavoring microcapsule carrier, and natural plant microcapsule carrier dry samples were weighed in a glass container. D-limonene, 2-methylpentene, and 5-hydroxymethyl furfural, three kinds of aroma substances, were sprayed on the above four kinds of microcapsule carriers, and each sample reached the maximum adsorption capacity for each aroma substance (a small amount of multiple spraying to prevent excessive aroma substances). Finally, 12 samples were obtained, as shown in Figure 10 .

[0112] As shown in Figure 10 , the apparent pictures of the four different temperature-sensitive microcapsule carriers after adsorbing three kinds of aroma substances. Compared with the blank control group, the appearance of the aroma-adding carrier did not change significantly, and the color of some of the aroma-adding carriers deepened due to the adsorption of the aroma substances (with color), indicating that the microcapsule carrier had stable properties and good adsorption performance.

[0113] 3.2 Determination of the adsorption rate of aroma

[0114] The initial microcapsule carrier mass was measured and recorded (m1); then it was subjected to aroma-adding treatment, and after removing the surface residual aroma substances, it was weighed and recorded (m2). Thus, the formula gives: aroma-adding rate (%) = (m2-m1) / m1. According to the aroma-adding rate results, the adsorption performance of organic microcapsule, inorganic microcapsule, composite flavoring microcapsule, and natural plant microcapsule samples to aroma substances was evaluated.

[0115] As shown in Figure 11 , the adsorption capacity of organic microcapsule carrier, composite flavoring microcapsule carrier, and natural plant microcapsule carrier to aroma substances was weak, among which the adsorption rate of natural plant microcapsule carrier to D-limonene was only 24%. In contrast, the inorganic microcapsule carrier had the best adsorption performance to aroma substances, among which the adsorption capacity to 2-methylpentene was the strongest, reaching 225.25%.

[0116] 3.3 Preparation of thermosensitive microcapsules

[0117] The selected oleogels are heated until they become liquid. Microcapsule carriers containing various aroma substances are then added to the oleogel. After ensuring complete adhesion of the microcapsule particles, the oleogel is immediately removed from the liquid state. Excess oleogel is absorbed with absorbent paper, and the mixture is allowed to solidify at 4°C to prevent the particles from sticking together.

[0118] 4. Determination of storage stability (aroma retention rate) and temperature response (release rate at different temperatures) 4.1 Determination of storage stability (aroma retention rate)

[0119] Weigh 5g each of the 12 samples with attached aroma substances and the above samples sealed with oleogel (the amount of aroma attached to each sample is known), and measure their mass after being placed at room temperature for 1d, 3d, 7d, 15d and 30d, so as to determine the aroma retention rate of the aroma-carrying substances.

[0120] The fragrance retention rates of four microcapsule carriers for D-limonene, 2-methylvaleric acid, and 5-hydroxymethylfurfural were compared. Figures 12-15 As shown, the four microcapsule carriers exhibited the best aroma retention rate for 5-hydroxymethylfurfural and the worst for D-limonene, indicating that 5-hydroxymethylfurfural-like aroma compounds are suitable for fragrance application, while surface adsorption of D-limonene-like aroma compounds is unsuitable for fragrance application. Among the four thermosensitive microcapsule carriers, the inorganic microcapsule carrier showed the best aroma retention rate for 5-hydroxymethylfurfural, retaining 90.4% of the aroma compounds after 30 days of storage, followed by the thermosensitive organic microcapsule carrier (82.1%).

[0121] By comparing the storage stability (aroma retention rate) of microcapsules before and after sealing, it was found that the aroma retention performance of various microcapsules was greatly improved after sealing with oleogel, especially for D-limonene, which had the worst storage stability. For D-limonene, the aroma retention rate of the sealed microcapsules after 30 days of storage was approximately 4-20 times that of the directly adsorbed microcapsules. Furthermore, it was observed that after 30 days of storage, the aroma retention rates of the three aroma substances in the oleogel-sealed microcapsules were all above 80%, with the organic and inorganic microcapsules exceeding 90%. This indicates that the oleogel sealing played an effective protective role during storage.

[0122] 4.2 Temperature Response (Release Rate at Different Temperatures) Determination

[0123] A. Static headspace-GC / MS detection conditions and standard curve plotting

[0124] Weigh 3g of aromatic microcapsules and place them in a 20mL headspace vial. After heating and equilibration for 30min, inject 1mL of headspace gas into the gas chromatography-mass spectrometry (GC-MS) inlet for analysis. Figure 16 As shown.

[0125] Headspace condition: Headspace bottle volume 20 mL; Equilibrium time 30 min; Headspace bottle pressure 103 kPa; Quantification ring volume 1 mL; Quantification ring temperature 180℃; Transfer line temperature 200℃.

[0126] Chromatographic condition: 7890A / 7697A GC / MS (Agilent, USA); HP-Innowax column (30 m x 0.25 mm, 0.25 μm); Carrier gas: high purity helium; Carrier gas flow rate: 1.0 mL / min; Injection port temperature: 230℃; Split ratio: 10:1; Temperature program: initial temperature 70℃ (hold for 5 min), increase to 230℃ at 5℃ / min (hold for 8 min).

[0127] Mass spectrometric condition: Electron impact (EI) ion source; Electron energy 70 eV; Ion source temperature: 230℃; Mass range: m / z 33-300 amu.

[0128] Working curve: 100 μL of different concentrations of mixed flavor component standard samples containing D-limonene, 2-methylvaleric acid, and 5-hydroxymethylfurfural were respectively taken to 20 mL headspace bottles, the heating temperature was set to 140℃, 1 mL of headspace gas was taken after 30 min of heating and equilibration, and was injected into the GC / MS for analysis, and the peak area of each type of flavor component was plotted against the corresponding concentration to obtain the working curve. The working curve was used to quantify the release amount of the four types of flavor microcapsule carriers at different heating temperatures, and thus the corresponding release rates were measured.

[0129] B. Temperature response characterization (determination of the release amount of flavor substances at different temperatures)

[0130] The smoking effect of a cigarette is generally determined by the final release amount of flavor substances, and the release amount of flavor substances is determined by the loading amount of microcapsules and the release rate of flavor substances. Therefore, the release amount of directly adsorbed flavor substances and the release amount of flavor substances after sealing were determined by static headspace-GC / MS.

[0131] (1) Release amount of flavor substances of unsealed microcapsules

[0132] According to research, the temperature of a cigarette filter under the condition of ignition is about 50-60℃. In addition, the microcapsules are stored at room temperature for a long time. Therefore, based on the existing conclusion, the equilibrium time was fixed at 30 min, and the headspace equilibrium heating temperatures were set to 25℃, 40℃, and 55℃, respectively.

[0133] The temperature responsiveness of the aroma substances was characterized by measuring the release performance of each microcapsule carrier for the three aroma substances (D-limonene, 2-methylpentene, 5-hydroxymethylfurfural) at different temperatures (25°C, 40°C, 55°C). Figures 17-19 As can be seen from Table 6, the release amount of each temperature-sensitive microcapsule carrier for the aroma substances gradually increased with increasing temperature, regardless of the type of aroma substance.

[0134] It was also observed that the inorganic microcapsule had the largest release amount for the three aroma substances, with a release amount of 525.17 mg / g, 468.09 mg / g, and 360.30 mg / g at 55°C, indicating that the inorganic microcapsule had the best release performance. The release amount of the microcapsule depends on the loading amount of the microcapsule and the release rate of the aroma substance, and thus, the high release amount of the inorganic microcapsule can be due to the large loading amount of the aroma substance. However, according to the attachment rate above, the loading amount of D-limonene was smaller than that of 5-hydroxymethylfurfural, but the release amount was opposite, which can be due to the high volatility of D-limonene. In summary, the main factor determining the smoking effect is the final release amount, and the inorganic microcapsule has the best release performance.

[0135] (2) Release amount of microcapsule aroma substance after encapsulation

[0136] The outer surface of the microcapsule loaded with the aroma substance was encapsulated with the oil gel, which played a protective role during storage, but it was not clear whether it had an effect on the release of the aroma substance during the release process. Therefore, the release performance of the unencapsulated and encapsulated microcapsules was compared at 55°C under the same conditions.

[0137] According to Table 7, Figure 20 As can be seen from Table 7, the release amount of the encapsulated microcapsule for each aroma substance was lower than that of the unencapsulated microcapsule at 55°C, but the decrease was small. For D-limonene, which had the largest decrease, the release amount of the four encapsulated microcapsules decreased by only 9.67%, 13.88%, 12.21%, and 12.60%. Therefore, it can be concluded that the encapsulation of the oil gel has a small effect on the release of the aroma substance.

[0138] 4. Filament attachment performance

[0139] A cigarette filter refers to the upper part of a cigarette and is a tool designed specifically for smokers, which can reduce the inhalation of smoke, tar, and suspended particles generated during combustion, and is generally made of acetate fiber filaments under the action of an adhesive.

[0140] Thermosensitive organic microcapsule, thermosensitive inorganic microcapsule, thermosensitive composite flavoring microcapsule and thermosensitive natural plant microcapsule are added in cigarette filter as flavor-attached carrier to improve the aroma of cigarette. The amount of carrier attached determines the amount of aroma added. Therefore, it is crucial to investigate the adhesion of flavor-attached materials in the filter.

[0141] In the experiment, acetate fiber tows were selected. As shown in the figure, four kinds of microcapsules were contacted with the tows to maximize the attachment of the carrier. The mass of the tow before and after the attachment was weighed to obtain the adhesion of the filter material to each kind of microcapsule. Figure 21

[0142] Table 5

[0143]

[0144] The results of the attachment amount of the tow to the thermosensitive flavor-attached microcapsule show that the adhesion of the tow to the thermosensitive inorganic microcapsule is the best. The amount of thermosensitive flavor-attached microcapsule determines the amount of aroma added, so it is most suitable for adding to the cigarette filter to improve the aroma of cigarette.

[0145] In summary, the thermosensitive inorganic microcapsule has stable properties, the best adsorption performance, the best retention effect and release performance of aroma, and has a wide application prospect.

[0146] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.​

Claims

1. A temperature-sensitive aroma-providing microcapsule for functional filter rods, characterized by: The porous carrier, the essence flavor adsorbed in the porous carrier and the sealing film coated on the surface of the porous carrier; the mass ratio of palm oil to coconut oil in the sealing film is 1:0.5-2; The porous carrier is porous starch with an average particle size of 1.6 μm, porous inorganic carrier with an average particle size of 207 μm, composite flavoring microcapsule carrier with an average size of 2.05*0.897 mm or natural plant porous carrier with a particle size of 1.667 mm.

2. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by: The mass ratio of palm oil to coconut oil in the sealing film is 1:0.5-1.

5.

3. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 2, characterized by: The mass ratio of palm oil to coconut oil in the sealing film is 1:

1.

4. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by: The porous starch is honeycomb-shaped porous starch obtained by treating starch by enzymatic method.

5. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by: The porous inorganic carrier is selected from silica, diatomite, attapulgite, kaolin or alumina.

6. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by: The composite flavoring microcapsule is obtained by uniformly mixing dextrin, microcrystalline cellulose and binder in a certain proportion, extruding and granulating and drying.

7. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by The natural plant porous carrier is obtained by crushing plant tissues, and the plant tissues are selected from dried tangerine or orange peel, red pith, sugar cane residue or corn stalk.

8. The temperature-sensitive flavor-releasing microcapsule for functional filter rods according to claim 1, characterized by: The essence flavor is selected from D-limonene, 2-methylvaleric acid or 5-hydroxymethylfurfural.

9. A process for the preparation of temperature-sensitive aroma-providing microcapsules for functional filter rods according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: Spraying essence flavor solution on the porous carrier for multiple times to adsorb the essence flavor; Heating the mixture of palm oil and coconut oil to melt it into liquid state, adding the porous carrier adsorbed with the essence flavor into the liquid, taking out the porous carrier, removing the excess liquid and solidifying it in an environment below 5 ℃.

10. The method of claim 9, wherein: Absorbing the excess liquid by using oil absorption paper.

11. The method of claim 9, wherein: Solidifying the porous carrier with liquid attached in an environment of 0-5 ℃.

12. The method of claim 11, wherein: Solidifying the porous carrier with liquid attached in an environment of 4 ℃.

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