Purple grape skin-dried orange peel composite pigment for cigarette paper as well as preparation method and application of purple grape skin-dried orange peel composite pigment

Abstract

The invention discloses a purple grape skin-dried orange peel composite pigment for cigarette paper as well as a preparation method and application of the purple grape skin-dried orange peel composite pigment. The method comprises the following steps: respectively extracting purple grape skin and dried orange peel by adopting ethanol aqueous solutions with specific pH and concentration to obtain extracting solutions; adding the pericarpium citri reticulatae extracting solution into the purple grape skin extracting solution, adjusting the pH value of the mixed system to 4.0-5.0, stirring at 35-45 DEG C, and maintaining for 0.5-2 hours to carry out directional composite reaction; and finally, purifying the composite reaction liquid through a macroporous adsorption resin column, concentrating and drying to obtain the product. The composite pigment prepared by the method not only can endow cigarette paper with stable and elegant purplish red color, but also can synchronously release grape-pericarpium citri reticulatae composite fruity fragrance which is rich in layer and coordinated and unified during cigarette burning and smoking, so that the synergy of color stabilization and aroma enhancement is realized.

Description

Technical Field

[0001] This invention belongs to the field of cigarette paper additive technology, specifically relating to a purple grape skin-dried tangerine peel composite pigment for cigarette paper, its preparation method, and its application. Background Technology

[0002] In the differentiated and premium design of cigarette products, cigarette paper has transcended its traditional role as a wrapper, becoming a key carrier for shaping a unique visual identity and enhancing the sensory experience. Among these advancements, the development of dyed cigarette paper with elegant colors and the ability to impart a pleasant aroma to smoke using natural plant-derived pigments has become a clear technological trend.

[0003] Correspondingly, early technological development followed the core approach of "preserving color and reducing impurities." This approach focused on optimizing extraction and purification processes to obtain pigments with high color value and high purity, while also removing impurities such as sugars and pectin from the raw materials, aiming to reduce unpleasant odors that might be produced during combustion. However, this technological paradigm, guided by a single physicochemical indicator (color value and purity), has inherent functional limitations: in the process of vigorously purifying the pigment, various flavor substances that naturally coexist with the pigment in the raw materials and may contribute to the pleasant sensation of smoke are usually removed as impurities. The direct consequence is that the resulting product tends to have a single function, only usable as a colorant, and cannot simultaneously provide a harmonious aroma, thus failing to meet the market's demand for a composite function of "color and aroma in harmony" in cigarette paper.

[0004] To overcome the aforementioned limitations, a "color and aroma from the same source" technical approach has been developed in this field. This approach targets specific single plant raw materials (such as purple grape skins) and, through customized extraction and purification strategies, efficiently obtains pigments while consciously and selectively retaining the characteristic flavor substances of the raw material itself, thus achieving a significant advancement in synergistically obtaining color and aroma from a single raw material. However, when pursuing higher product quality, this single-raw-material-based technical approach faces a dual challenge. First, in terms of sensory dimensions, the aroma spectrum provided by a single raw material is relatively fixed. For example, purple grape skins mainly present a fresh fruity aroma, with a relatively thin aroma structure, lacking the complexity and harmony to enhance sensory levels and satisfaction. Second, in terms of physicochemical properties, when such extracts are further required to be applied to cigarette paper systems and meet high standards of long-term storage stability and sensory quality uniformity, the stability challenges faced by natural pigments, represented by anthocyanins, become more prominent. In the specific processing and usage scenarios of cigarette paper, how to further inhibit or delay pigment degradation and color change, ensuring long-term color stability, becomes a crucial technical challenge that must be overcome to improve product quality.

[0005] To enrich aroma, those skilled in the art readily consider combining extracts from different flavor sources. However, whether through simple physical mixing of separately prepared extracts or conventional co-extraction of different raw materials in the same system, the resulting products are mostly only physically mixed, failing to achieve deep fusion and stable binding at the molecular level. This leads to asynchronous thermal decomposition and release behaviors of the components during cigarette combustion, resulting in dispersed aroma, poor harmony, and the inability to provide additional stabilizing effects for pigments through inter-component interactions. Therefore, existing combination or co-extraction methods have not yet provided a systematic and effective solution to the challenges of thin aroma structure and insufficient long-term pigment stability in "color and aroma homology" technology.

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

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a purple grape skin-tangerine peel composite pigment for cigarette paper, its preparation method, and its application. Specifically, the present invention aims to overcome the dual technical bottlenecks of existing "color and aroma homology" technologies, which are limited to single raw materials resulting in a thin aroma structure, and the insufficient chemical stability of single plant pigments in cigarette paper application systems.

[0008] To achieve the above objectives, this invention provides an innovative synergistic stabilization preparation method. This method involves first selectively extracting the active ingredients from purple grape skins and dried tangerine peel, then subjecting the extracts to a controlled compounding reaction under specific pH and temperature conditions. This process promotes intermolecular interactions between anthocyanins in purple grape skins and key components such as flavonoids in dried tangerine peel, thereby obtaining a deeply integrated and stable composite pigment.

[0009] Ultimately, the composite pigment obtained by this invention was successfully applied to cigarette paper. While giving the paper a stable and elegant purplish-red color, it can simultaneously impart a rich, harmonious and unified complex fruity aroma to the cigarette smoke, completing a technological leap from "color and aroma sharing the same origin" to "color and aroma synergy" and "stabilizing color and enhancing aroma".

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] The first aspect of the present invention provides a purple grape skin-dried tangerine peel composite pigment, which is composed of purple grape skin extract and dried tangerine peel extract, wherein the mass ratio of anthocyanins in the purple grape skin extract to total flavonoids in the dried tangerine peel extract is 1:0.5 to 2; and the color difference value of its 10% ethanol solution after accelerated aging treatment at 85°C for 24 hours is less than 4.0.

[0012] A second aspect of the present invention provides a method for preparing the purple grape skin-dried tangerine peel composite pigment described in the first aspect, characterized by comprising the following steps:

[0013] Step (1): Extract the purple grape skin raw material and the dried tangerine peel raw material with ethanol aqueous solution respectively. After solid-liquid separation, the purple grape skin extract and the dried tangerine peel extract are obtained.

[0014] Step (2): Add the tangerine peel extract to the purple grape peel extract, stir evenly, adjust the pH of the mixture to 4.0 to 5.0, and stir at 35°C to 45°C for 0.5 to 2 hours to obtain the composite reaction solution;

[0015] Step (3): The composite reaction solution is purified by macroporous adsorption resin column, the target eluent is collected, and after concentration and drying, the purple grape skin-tangerine peel composite pigment is obtained.

[0016] Preferably, in step (1), the pH value of the ethanol aqueous solution used to extract the purple grape skin raw material is 2.5 to 3.5, and its volume fraction is 50% to 65%.

[0017] Preferably, in step (1), the volume fraction of the ethanol aqueous solution used to extract the tangerine peel raw material is 75% to 90%.

[0018] Preferably, in step (1), during the separate extraction:

[0019] The ratio of purple grape skin raw material to the ethanol aqueous solution used is 1g:8 mL to 1g:15 mL;

[0020] The ratio of raw tangerine peel to the aqueous ethanol solution used is 1g:8 mL to 1g:15 mL.

[0021] Preferably, in step (2), the volume ratio of the purple grape skin extract to the tangerine peel extract is 1:0.7 to 1:1.3.

[0022] Preferably, in step (3), an aqueous ethanol solution with a volume fraction of 50% to 70% is used for elution to collect the target eluent.

[0023] Preferably, in step (3), the macroporous adsorption resin is AB-8, HPD-300 or XDA-8.

[0024] A third aspect of the present invention provides a dyed cigarette paper, wherein the pulp contains the purple grape skin-dried tangerine peel composite pigment described in the first aspect; wherein the amount of the composite pigment added is 0.1% to 5.0% of the oven-dry weight of the pulp, the composite pigment is added and mixed evenly during the pulping or mixing stage, and the drying temperature of the dyed cigarette paper is 90°C to 120°C.

[0025] The fourth aspect of this invention provides the application of a purple grape skin-dried tangerine peel composite pigment in the preparation of cigarettes, wherein the application is used to simultaneously impart a stable purple-red color and a harmonious grape-dried tangerine peel composite fruit aroma to the cigarettes; wherein the purple grape skin-dried tangerine peel composite pigment is the composite pigment described in the first aspect.

[0026] The present invention has the following beneficial effects:

[0027] 1. Existing technologies often rely on regulating the external environment (such as antioxidants) to delay anthocyanin degradation, but the effects are limited and unstable. This invention, through a unique process, promotes intermolecular interactions between anthocyanins from purple grape skins and flavonoids from tangerine peel under controlled conditions, forming a stable chemical complex in situ. This combination at the molecular structure level is equivalent to constructing an internal protective layer for the sensitive chromophores, thereby fundamentally and significantly improving the chemical stability of the pigment.

[0028] 2. This invention is not a physical mixture of color and aroma. During the molecular compounding process, the flavor substances of the two types of raw materials also achieve fusion and recombination, forming a completely new system with coordinated thermal decomposition and release behavior. Therefore, when this composite pigment is applied to cigarette paper, multiple effects can be achieved simultaneously: visually, it gives the paper an elegant, uniform, and non-browning purplish-red color; olfactorily and gustatorily, it releases a rich, distinct, and integrated grape-tangerine peel complex fruit aroma when the cigarette is burned, rather than a simple superposition of discrete aromas; at the same time, due to the simultaneous release of key components, it effectively reduces off-flavors and improves the purity and sensory satisfaction of the mainstream smoke.

[0029] 3. The effectiveness of the preparation method of this invention stems from its interconnected systematic design. First, considering the different solubility characteristics of anthocyanins in purple grape skins and flavonoids in dried tangerine peel, differentiated extraction conditions (such as specific pH and ethanol concentration) are optimized to achieve efficient and targeted dissolution of the two target active ingredients, laying a pure material foundation for subsequent compounding. Next, in the core compounding step, a specific reaction environment is created by precisely controlling the pH (4.0-5.0) and temperature (35-45℃) of the reaction system, promoting intermolecular interactions between anthocyanins in purple grape skins and flavonoids in dried tangerine peel, thereby guiding and achieving their directional compounding. Subsequently, macroporous adsorption resin is used to selectively enrich and purify the target complex formed in the reaction solution, effectively separating the core product of deep component fusion. Through the above-described process design of partitioned extraction-directional compounding-selective purification, the highly stable purple grape skin-dried tangerine peel composite pigment described in this invention is finally prepared efficiently and stably. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a process flow diagram of the method for preparing purple grape skin-dried tangerine peel composite pigment provided in an embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the accompanying drawings and embodiments are not intended to limit the technical solutions of the present invention.

[0033] Example 1

[0034] This embodiment provides a method for preparing a purple grape skin-dried tangerine peel composite pigment. The specific steps are as follows: (1) Prepare commercially available dried purple grape skins for later use. At the same time, pulverize commercially available tangerine peels using a traditional Chinese medicine pulverizer, pass them through a 20-mesh sieve, and collect the powder that passes through the sieve for later use.

[0035] (2) Accurately weigh 100.0 g of purple grape skin slices. Prepare a 60% (v / v) ethanol aqueous solution and adjust the pH to 3.0 with citric acid. Take 1000 mL of this acidic ethanol aqueous solution and add it together with the purple grape skin raw material into a sealable extraction container. Extract for 1.5 hours by shaking (120 rpm) in a constant temperature water bath at 55℃. After extraction, filter and collect the filtrate.

[0036] (3) Accurately weigh 100.0 g of dried tangerine peel powder. Prepare 800 mL of 80% ethanol aqueous solution (solid-liquid ratio 1:8). Mix the dried tangerine peel powder with the ethanol aqueous solution and extract for 2 hours by shaking (120 rpm) in a constant temperature water bath at 70℃. After extraction, filter and collect the filtrate to obtain dried tangerine peel extract.

[0037] (4) Slowly add all the tangerine peel extract obtained in step (3) to the purple grape peel extract obtained in step (2) while stirring, and stir until homogeneous. Finely adjust the pH of the mixture to 4.5 with 1 mol / L sodium hydroxide aqueous solution. Transfer the mixture to a 40℃ constant temperature water bath and maintain gentle stirring (80 rpm) for 1 hour for compound reaction. After the reaction is completed, the compound reaction solution is obtained.

[0038] (5) Load the composite reaction solution into a pre-treated and equilibrated AB-8 macroporous adsorption resin column (column bed volume approximately 200 mL) at a flow rate of 2 column volumes per hour (2 BV / h). After loading, rinse with 5 BV of deionized water to remove highly polar impurities such as sugars and organic acids. Then, perform isocratic elution with a 60% (v / v) ethanol aqueous solution at a flow rate of 1.5 BV / h.

[0039] The elution process was monitored online using an ultraviolet detector at 520 nm (characteristic absorption of anthocyanins) and 330 nm (characteristic absorption of flavonoids). Elution fractions with strong signals and consistent trends at both wavelengths were collected and combined to obtain the target eluent.

[0040] The target eluent was subjected to reduced pressure rotary evaporation at 45°C and -0.09 MPa to recover ethanol and concentrate to a viscous paste (solid content approximately 30%). This paste was transferred to a vacuum freeze dryer and freeze-dried at -50°C and <10 Pa for 48 hours to obtain a loose, porous solid. After removal, it was gently ground in a mortar and pestle and passed through an 80-mesh sieve to obtain a deep purplish-red purple grape skin-tangerine peel complex pigment powder with a rich grape fruit aroma and a sweet, tangerine peel fragrance. This powder was sealed and stored away from light. High-performance liquid chromatography (HPLC) analysis showed that the mass ratio of anthocyanins (calculated as cyanidin-3-O-glucoside) to total flavonoids (calculated as rutin) in the product of this example was approximately 1:1.2.

[0041] Example 2

[0042] This embodiment provides a method for preparing a purple grape skin-dried tangerine peel composite pigment, the specific steps of which are as follows:

[0043] (1) Prepare the dried purple grape skins available in the market. At the same time, crush the dried tangerine peel available in the market using a Chinese medicine pulverizer, pass it through a 20-mesh sieve, and collect the powder that passes through the sieve for later use.

[0044] (2) Accurately weigh 100.0 g of purple grape skin slices. Prepare a 55% (v / v) ethanol aqueous solution and adjust the pH to 2.5 with hydrochloric acid. Take 1200 mL of this acidic ethanol aqueous solution and add it together with the purple grape skin raw material into a sealable extraction container. Extract for 2 hours by shaking (120 rpm) in a constant temperature water bath at 50℃. After extraction, filter and collect the filtrate.

[0045] (3) Accurately weigh 100.0 g of dried tangerine peel powder. Prepare 1000 mL of 75% ethanol aqueous solution (solid-liquid ratio 1:10). Mix the dried tangerine peel powder with the ethanol aqueous solution and extract for 1.5 hours by shaking in a constant temperature water bath at 65℃ (120 rpm). After extraction, filter and collect the filtrate to obtain dried tangerine peel extract.

[0046] (4) Slowly add all the tangerine peel extract obtained in step (3) to the purple grape peel extract obtained in step (2) while stirring, and stir until homogeneous. Finely adjust the pH of the mixture to 4.0 with 1 mol / L sodium hydroxide aqueous solution. Transfer the mixture to a 35℃ constant temperature water bath and maintain gentle stirring (80 rpm) for 2 hours for compound reaction. After the reaction is completed, the compound reaction solution is obtained.

[0047] (5) Load the composite reaction solution into a pre-treated and equilibrated HPD-300 macroporous adsorption resin column (column bed volume approximately 200 mL) at a flow rate of 2 column volumes per hour (2 BV / h). After loading, rinse with 5 BV of deionized water to remove highly polar impurities such as sugars and organic acids. Then, perform isocratic elution with a 55% (v / v) ethanol aqueous solution at a flow rate of 1.5 BV / h.

[0048] The elution process was monitored online using an ultraviolet detector at 520 nm (characteristic absorption of anthocyanins) and 330 nm (characteristic absorption of flavonoids). Elution fractions with strong signals and consistent trends at both wavelengths were collected and combined to obtain the target eluent.

[0049] The target eluent was subjected to reduced pressure rotary evaporation at 50°C and -0.09 MPa to recover ethanol and concentrate to a viscous paste (solid content approximately 30%). This paste was transferred to a vacuum drying oven and dried under vacuum at 50°C and <100 Pa until constant weight. After removal, it was gently ground in a mortar and pestle and passed through an 80-mesh sieve to obtain a deep purplish-red purple grape skin-tangerine peel complex pigment powder with a rich aroma of grape fruit and tangerine peel sweetness. This powder was sealed and stored away from light. High-performance liquid chromatography (HPLC) analysis showed that the mass ratio of anthocyanins (calculated as cyanidin-3-O-glucoside) to total flavonoids (calculated as rutin) in the product of this example was approximately 1:0.8.

[0050] Example 3

[0051] This embodiment provides a method for preparing a purple grape skin-dried tangerine peel composite pigment, the specific steps of which are as follows:

[0052] (1) Prepare the dried purple grape skins available in the market. At the same time, crush the dried tangerine peel available in the market using a Chinese medicine pulverizer, pass it through a 20-mesh sieve, and collect the powder that passes through the sieve for later use.

[0053] (2) Accurately weigh 100.0 g of purple grape skin slices. Prepare a 65% (v / v) ethanol aqueous solution and adjust the pH to 3.5 with tartaric acid. Take 800 mL of this acidic ethanol aqueous solution and add it together with the purple grape skin raw material into a sealable extraction container. Extract for 1 hour by shaking (120 rpm) in a constant temperature water bath at 60℃. After extraction, filter and collect the filtrate.

[0054] (3) Accurately weigh 100.0 g of dried tangerine peel powder. Prepare 1500 mL of 90% ethanol aqueous solution (solid-liquid ratio 1:15). Mix the dried tangerine peel powder with the ethanol aqueous solution and extract for 2.5 hours by shaking (120 rpm) in a constant temperature water bath at 75℃. After extraction, filter and collect the filtrate to obtain dried tangerine peel extract.

[0055] (4) Slowly add all the tangerine peel extract obtained in step (3) to the purple grape peel extract obtained in step (2) while stirring, and stir until homogeneous. Finely adjust the pH of the mixture to 5.0 with 1 mol / L sodium hydroxide aqueous solution. Transfer the mixture to a 45℃ constant temperature water bath and maintain gentle stirring (80 rpm) for 0.5 hours for the composite reaction. After the reaction is completed, the composite reaction solution is obtained.

[0056] (5) Load the composite reaction solution into a pre-treated and equilibrated XDA-8 macroporous adsorption resin column (column bed volume approximately 200 mL) at a flow rate of 2 column volumes per hour (2 BV / h). After loading, rinse with 5 BV of deionized water to remove highly polar impurities such as sugars and organic acids. Then, elute isocratically with a 70% (v / v) ethanol aqueous solution at a flow rate of 1.5 BV / h.

[0057] The elution process was monitored online using an ultraviolet detector at 520 nm (characteristic absorption of anthocyanins) and 330 nm (characteristic absorption of flavonoids). Elution fractions with strong signals and consistent trends at both wavelengths were collected and combined to obtain the target eluent.

[0058] The target eluent was subjected to reduced pressure rotary evaporation at 45°C and -0.09 MPa to recover ethanol and concentrate to a viscous paste (solid content approximately 30%). This paste was transferred to a vacuum freeze dryer and freeze-dried at -50°C and <10 Pa for 48 hours to obtain a loose and porous solid. After removal, it was gently ground in a mortar and pestle and passed through an 80-mesh sieve to obtain a deep purplish-red purple grape skin-tangerine peel complex pigment powder with a rich grape fruit aroma and a sweet tangerine peel fragrance. It was then sealed and stored away from light. High-performance liquid chromatography (HPLC) analysis showed that the mass ratio of anthocyanins (calculated as cyanidin-3-O-glucoside) to total flavonoids (calculated as rutin) in the product of this example was approximately 1:1.6.

[0059] Comparative Example 1

[0060] The comparative example follows the same process steps as Example 1, except that the pH adjustment and constant temperature stirring reaction in step (4) are completely omitted. The remaining steps are the same, and the specific steps are as follows:

[0061] (1) Prepare the dried purple grape skins available in the market. At the same time, crush the dried tangerine peel available in the market using a Chinese medicine pulverizer, pass it through a 20-mesh sieve, and collect the powder that passes through the sieve for later use.

[0062] (2) Prepare purple grape skin extract according to step (2) of Example 1.

[0063] (3) Prepare tangerine peel extract according to step (3) of Example 1.

[0064] (4) Add all of the tangerine peel extract obtained in step (3) to the purple grape skin extract obtained in step (2) and stir well. The subsequent pH adjustment and constant temperature stirring steps are omitted, and the mixture is used directly as the solution to be purified.

[0065] (5) The subsequent purification and drying operations are exactly the same as step (5) in Example 1.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that a conventional co-extraction process is used instead of stepwise extraction and compound reaction. The specific steps are as follows: (1) Commercially available dried purple grape skins and commercially available dried tangerine peel (crushed through a 20-mesh sieve) are mixed at a dry weight ratio of 1:1. (2) 200.0 g of the mixed raw materials are placed in a sealable extraction container, and 1800 mL of 70% ethanol aqueous solution with pH adjusted to 3.5 by citric acid is added. The mixture is extracted at 60°C with shaking for 3.5 hours, and the co-extract is obtained by filtration. (3) The subsequent purification and drying operations are exactly the same as step (5) of Example 1.

[0068] Comparative Example 3-A

[0069] The only difference between this comparative example and Example 1 is that the pH value of the mixed system is adjusted to 3.5 (below the scope of the claims) in step (4), while the other steps and parameters are exactly the same as in Example 1.

[0070] Comparative Example 3-B

[0071] The only difference between this comparative example and Example 1 is that the pH value of the mixed system is adjusted to 5.5 in step (4) (higher than the scope of the claims), while the other steps and parameters are exactly the same as in Example 1.

[0072] Application Example 1

[0073] To objectively evaluate the application performance of the samples obtained in the examples and comparative examples, they were uniformly applied to the preparation of cigarette paper and rolled into standard cigarettes.

[0074] 1. Preparation of dyed cigarette paper:

[0075] Take 0.50 g (dry weight) each of the composite pigment / extract powder samples prepared in Examples 1-3, Comparative Examples 1, 2, 3-A, and 3-B, and dissolve them in 100 mL of deionized water, stirring until completely dissolved to prepare a homogeneous dyeing solution with a mass concentration of 0.5%. Weigh a quantity of bleached wood pulp board, defragment it, and prepare a pulp suspension with a concentration of 2.0%. Slowly add each dyeing solution to an equal volume of pulp suspension under stirring (ensuring that the final additive loading in each portion of pulp is consistent), and continue stirring thoroughly for 30 minutes to ensure uniform mixing. The mixed pulp was formed into wet paper sheets with a basis weight of 30 g / m² using a paper forming machine. After pressing and dewatering, the sheets were dried to constant weight in a forced-air drying oven at 105℃ to obtain the corresponding dyed cigarette paper samples, which were labeled as: Sample-E1, Sample-E2, Sample-E3, Sample-C1, Sample-C2, Sample-C3A, and Sample-C3B, respectively. A separate sample of the same pulp without any added pigments was prepared using the same process and served as a blank control sample (Sample-B).

[0076] 2. Standard cigarette rolling:

[0077] To eliminate interference from differences in tobacco shreds, flue-cured tobacco shreds from the same batch and with the same formula were used and equilibrated for 48 hours under standard constant temperature and humidity conditions (22℃, 60%RH). Using a laboratory cigarette rolling machine, each of the above-prepared dyed cigarette paper samples was rolled with an equal amount of tobacco shreds of the same filling density into cigarettes of standard circumference and standard length. The corresponding cigarette samples were labeled as: Cigarette-E1, Cigarette-E2, Cigarette-E3, Cigarette-C1, Cigarette-C2, Cigarette-C3A, Cigarette-C3B, and Cigarette-B (blank). At least 50 cigarettes of each sample were rolled. All rolled cigarettes were placed under standard constant temperature and humidity conditions (22℃, 60%RH) for at least 72 hours for equilibration before testing.

[0078] Test Example 1

[0079] The cigarette paper samples and rolled cigarettes prepared in Example 1 were subjected to system testing to verify and quantify the synergistic effect of the composite pigments of the present invention.

[0080] 1. Color performance and accelerated aging stability test

[0081] The initial CIE L*a*b* colorimetric values ​​of each cigarette paper sample were measured using a colorimeter. The samples were then subjected to accelerated aging treatment at 85℃ in a constant-temperature forced-air drying oven for 24 hours to simulate long-term storage. The colorimetric values ​​were measured again, and the color difference (ΔE) was calculated. The results are shown in Table 1 below. Table 1: Comparison of Cigarette Paper Color and Accelerated Aging Stability

[0082]

[0083] Conclusion: Samples (E1-E3) prepared via directional compounding reaction within the pH range (4.0-5.0) specified in the claims of this invention exhibited the brightest and purest color in their dyed cigarette paper, with minimal color change after accelerated aging (ΔE 3.2-3.8), meeting the technical requirement of ΔE < 4.0. Their color stability was significantly superior to the control groups that omitted the compounding reaction (C1), used conventional co-extraction (C2), and had pH values ​​outside the range (C3A / B). This demonstrates that the directional compounding reaction step and the specific pH range play a decisive role in forming a stable complex and enhancing the long-term stability of the pigment in the application system.

[0084] 2. Ultraviolet-Visible Spectroscopy Analysis

[0085] To investigate the structural characteristics of the composite product, the final product powders from Example 1, Comparative Example 1, and Comparative Example 2 were precisely prepared into solutions of the same mass concentration (0.1 mg / mL) using a 60% ethanol aqueous solution at pH 4.5. The absorption spectra were scanned in the wavelength range of 400-700 nm using a UV-Vis spectrophotometer, and the results were recorded and compared.

[0086] Specifically as follows:

[0087] The maximum absorption wavelength (λmax) of the solution in Example 1 (the composite pigment of the present invention) is 526 nm.

[0088] The λmax of the Comparative Example 1 (physically mixed) solution is 520 nm.

[0089] The λmax of the solution in Comparative Example 2 (conventional co-extraction) was 521 nm.

[0090] Compared to the two comparative examples, the sample of Example 1 showed a clear red shift of approximately 5-7 nm in the maximum absorption wavelength of anthocyanins (λmax shifted from ~520 nm to 526 nm). Simultaneously, data showed that the absorption intensity and spectral shape of the sample of Example 1 in the 400-450 nm range (the characteristic absorption band of components such as flavonoids) also differed significantly from those of Comparative Examples 1 and 2.

[0091] The aforementioned spectral changes (red shift and altered absorption profile) are typical indicators of changes in the electronic transition energy levels or microenvironment of the chromophores in anthocyanin molecules. This phenomenon usually originates from intermolecular interactions such as π-π stacking, hydrogen bonding, or hydrophobic interactions between anthocyanins and flavonoids in dried tangerine peel. This result directly confirms that the present invention successfully guided the specific binding between anthocyanins from purple grape skins and flavonoids in dried tangerine peel, forming a composite system with a structure different from simple physical mixtures, thus providing a structural explanation for the significantly improved color stability (ΔE < 4.0) of the composite pigment.

[0092] 3. Sensory evaluation:

[0093] An evaluation panel of seven experienced professional smoke testers conducted single-blind tastings of cigarette samples in a standard tasting room. Scores were given based on dimensions such as aroma characteristics, harmony, off-flavors, irritation, sweetness, and aftertaste (0-10 points, higher scores are better), while the attractiveness of the cigarette's appearance and color was also evaluated. The average scores for the main dimensions are shown in Table 2 below. One-way ANOVA and Duncan's multiple comparison test (significance level α=0.05) were performed on the data using SPSS 26.0 software.

[0094] Table 2: Comparison of Average Sensory Evaluation Scores for Cigarette Samples

[0095]

[0096] Conclusion: The composite pigment (cigarette-E1) prepared using the process of this invention scored significantly higher than all control samples in terms of aroma harmony, characteristic fruity aroma prominence, and sweetness (p<0.05). The tasters unanimously agreed that its aroma integration was high, its layers were distinct, and it had no off-putting notes, and its appearance was more attractive. This directly confirms that this invention, through deep component integration, achieves a significant "color-aroma synergy" effect in application, effectively improving the overall sensory quality of cigarettes.

[0097] In summary, the system data from Test Example 1 demonstrate that the preparation method provided by this invention can obtain a novel composite pigment that differs from simple mixtures in both structure and function. This product not only exhibits excellent color thermal stability (ΔE < 4.0) and spectral characteristics indicating molecular interactions in its physicochemical properties, but also simultaneously imparts a stable and elegant purplish-red color and a rich, harmonious, and unified complex fruity aroma to cigarette paper. Its overall performance is significantly superior to traditional physical mixing or conventional co-extraction processes.

[0098] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A purple grape skin-dried tangerine peel composite pigment, characterized in that, It is composed of purple grape skin extract and tangerine peel extract, wherein the mass ratio of anthocyanins in the purple grape skin extract to total flavonoids in the tangerine peel extract is 1:0.5 to 2; and the color difference value of its 10% ethanol solution after accelerated aging treatment at 85°C for 24 hours is less than 4.

0.

2. A method for preparing the purple grape skin-dried tangerine peel composite pigment as described in claim 1, characterized in that, Includes the following steps: Step (1): Extract the purple grape skin raw material and the dried tangerine peel raw material with ethanol aqueous solution respectively. After solid-liquid separation, the purple grape skin extract and the dried tangerine peel extract are obtained. Step (2): Add the tangerine peel extract to the purple grape peel extract, stir evenly, adjust the pH of the mixture to 4.0 to 5.0, and stir at 35°C to 45°C for 0.5 to 2 hours to obtain the composite reaction solution; Step (3): The composite reaction solution is purified by macroporous adsorption resin column, the target eluent is collected, and after concentration and drying, the purple grape skin-tangerine peel composite pigment is obtained.

3. The method according to claim 2, characterized in that, In step (1), the pH value of the ethanol aqueous solution used to extract the purple grape skin raw material is 2.5 to 3.5, and its volume fraction is 50% to 65%.

4. The method according to claim 2, characterized in that, In step (1), the volume fraction of the ethanol aqueous solution used to extract the tangerine peel raw material is 75% to 90%.

5. The method according to claim 2, characterized in that, In step (1), during the separate extraction: The ratio of purple grape skin raw material to the ethanol aqueous solution used is 1g:8 mL to 1g:15 mL; The ratio of raw tangerine peel to the aqueous ethanol solution used is 1g:8 mL to 1g:15 mL.

6. The method according to claim 2, characterized in that, In step (2), the volume ratio of the purple grape skin extract to the tangerine peel extract is 1:0.7 to 1:1.

3.

7. The method according to claim 2, characterized in that, In step (3), an aqueous ethanol solution with a volume fraction of 50% to 70% is used for elution to collect the target eluent.

8. The method according to claim 2, characterized in that, In step (3), the macroporous adsorption resin is AB-8, HPD-300 or XDA-8.

9. A dyed cigarette paper, wherein the pulp contains the purple grape skin-dried tangerine peel composite pigment as described in claim 1; wherein, The amount of the composite pigment added is 0.1% to 5.0% of the oven-dry weight of the pulp. The composite pigment is added and mixed evenly during the pulping or mixing stage, and the drying temperature of the dyed cigarette paper is 90°C to 120°C.

10. The application of purple grape skin-dried tangerine peel complex pigment in the preparation of cigarettes, characterized in that, The application is used to simultaneously impart a stable purplish-red color and a harmonious grape-tangerine peel complex fruity aroma to the cigarette; wherein, the purple grape skin-tangerine peel complex pigment is the complex pigment described in claim 1.

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