Re-drying feed liquid for improving sensory quality of burley tobacco and Maryland tobacco, preparation method and application

Abstract

The invention provides a redrying feed liquid for improving sensory quality of burley tobacco and Maryland tobacco, and a preparation method and application thereof, the redrying feed liquid comprises the following raw materials by weight: 10-40% of high fructose corn syrup, 1-10% of ammonium lactate, 2-20% of propylene glycol, and the balance of distilled water. The redrying feed liquid can be applied to threshing and redrying stages of burley tobacco or Maryland tobacco, and can effectively solve the problems that the sugar nitrogen ratio and the sugar alkali ratio of the burley tobacco and the Maryland tobacco are unbalanced, the acid-alkali substance content proportion is not coordinated, the reducing sugar content is relatively low and the like; the degradation of macromolecules such as starch, cellulose and protein in the alcoholization process of the burley tobacco and the Maryland tobacco is accelerated, the occurrence of series reactions such as Maillard reaction is promoted, the characteristic aroma of the burley tobacco and the Maryland tobacco is improved, the alcoholization time is effectively shortened, and the sensory quality of the burley tobacco and the Maryland tobacco is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco production, and particularly relates to a redrying liquid for improving the sensory quality of burley tobacco and Maryland tobacco, a preparation method and application thereof. BACKGROUND

[0002] Burley tobacco and Maryland tobacco are key raw materials for forming the core style and aroma characteristics of mixed cigarettes. The quality of burley tobacco and Maryland tobacco directly determines the sensory experience and market competitiveness of the final cigarette product. However, due to specific ecological and climatic conditions, cultivation and processing technology, and subsequent aging processing technology in China, domestic burley tobacco and Maryland tobacco generally have significant sensory quality defects, mainly including: the characteristic aroma (such as nutty aroma, roasting aroma) is not prominent, the aroma is rough, and the aroma is insufficient; at the same time, the smoke coordination is poor, and there are obvious irritability, green and miscellaneous aroma, woody aroma and other bad odors, and the aftertaste is not clean and the residual feeling is heavy. These defects seriously restrict the effective use and value improvement of domestic sun-cured tobacco in high-end mixed cigarette formulas.

[0003] In the tobacco industry, the addition of additives to tobacco leaves through the leaf redrying process is an important technical means to improve the internal quality of tobacco leaves and enhance their industrial usability. At present, research and application of redrying with additives mainly focus on flue-cured tobacco. However, there are essential differences between flue-cured tobacco and burley tobacco and Maryland tobacco in key chemical bases (such as sugar content, nitrogen content, alkaloid content and proportion) and sensory style characteristics. Flue-cured tobacco usually has high sugar content and low nitrogen content, while burley tobacco and Maryland tobacco have the opposite characteristics, showing typical low-sugar high-nitrogen and high-nicotine characteristics, resulting in a serious imbalance in the sugar-alkaloid ratio and the sugar-nitrogen ratio, and an acidic smoke. Therefore, directly applying the quality improvement technology developed based on the characteristics of flue-cured tobacco to burley tobacco and Maryland tobacco cannot effectively correct the imbalance of their internal chemical components, stimulate and enhance their characteristic aroma, but may exacerbate smoke incoordination due to mismatched components, even introduce new odors, or have negative effects on the physical processing performance of tobacco leaves (such as processing resistance and moisture retention), such as increased risk of mold and increased breakage rate.

[0004] So far, there is still a lack of redrying quality improvement technology specially designed for the unique chemical and sensory properties of burley tobacco and Maryland tobacco. The lack of existing technology makes it difficult to systematically and specifically improve the quality of domestic burley tobacco and Maryland tobacco at the key redrying processing link, and the improvement of their sensory quality relies heavily on long-term natural aging, which is time-consuming, costly and unstable.

[0005] Therefore, there is an urgent need in the art to develop a redrying liquid specifically for burley tobacco and Maryland tobacco and its supporting application method, which has important industrial practical significance for breaking through the bottleneck of domestic high-quality mixed cigarette raw materials and improving the self-supporting capability of raw materials. SUMMARY

[0006] This invention addresses the lack of effective re-drying and quality-enhancing technologies for Burley and Maryland tobacco in existing technologies, which leads to poor sensory quality, long aging cycles, and low industrial usability. It provides a re-drying solution specifically designed to improve the sensory quality of Burley and Maryland tobacco, along with its preparation method and application. This solution, through the synergistic effect of specific components, directionally improves the chemical composition of tobacco leaves during the re-drying stage. It precisely targets the low-sugar, high-nitrogen chemical characteristics of Burley and Maryland tobacco, effectively regulating the sugar-to-alkali ratio and acid-base balance, and directionally promoting key pathways such as the Maillard reaction to generate characteristic aroma substances. This effectively increases the content of characteristic aroma compounds and significantly improves sensory quality. Simultaneously, this solution ensures that the treated tobacco leaves have good industrial processing adaptability, preventing quality problems such as mold and clumping. It is a safe, efficient, and targeted re-drying solution and process.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a re-drying liquid for improving the sensory quality of Burley tobacco and Maryland tobacco, comprising the following components by weight percentage: 10%-40% fructose syrup, 1%-10% ammonium lactate, 2%-20% propylene glycol, and the balance being distilled water.

[0008] This invention has discovered that a specific combination of fructose syrup, ammonium lactate, and propylene glycol produces an unexpected synergistic effect: High-fructose corn syrup: provides highly reactive fructose and glucose, serving as a key carbon source for the Maillard reaction, directly supplementing the insufficient reducing sugars in tobacco leaves, and providing substrates for the generation of characteristic aroma compounds.

[0009] Ammonium lactate: As a weak acid-weak base salt, it possesses buffering properties and plays multiple roles: a) It helps regulate the acid-base balance of tobacco leaves, neutralizing some acidic components, maintaining a stable pH environment within the tobacco leaf tissue, avoiding the adverse effects of acid-base fluctuations on aroma compound formation, and reducing smoke irritation; b) It decomposes to provide amino groups, which, in synergy with the sugars provided by fructose syrup, promote the Maillard reaction; c) When used in conjunction with fructose syrup, it specifically addresses the core defects of imbalanced sugar-nitrogen and sugar-base ratios in Burley and Maryland tobacco. Propylene glycol: As a penetrant and humectant, it effectively reduces the osmotic resistance of tobacco cell walls, ensuring that fructose syrup and ammonium lactate can penetrate evenly and deeply into the tobacco leaf tissue, creating a uniform microenvironment for the full conduct of the Maillard reaction; at the same time, it maintains suitable water activity, preventing tobacco leaves from becoming brittle during processing.

[0010] The formation of characteristic aroma compounds: Pyrazine compounds such as 2-ethyl-6-methylpyrazine, 2-ethyl-3-methylpyrazine, and 2,3,5-trimethylpyrazine are characteristic aroma compounds of Burley tobacco for their nutty and roasted notes, and their content directly determines the richness and complexity of the nutty aroma. Fructose in high-fructose corn syrup (with significantly higher reactivity than glucose) provides C2-C6 carbon chains. Ammonium lactate decomposition products (amino groups) enhance nucleophilicity and synergistically provide a nitrogen source with amino acids in tobacco leaves. Propylene glycol reduces the osmotic resistance of tobacco cell walls, allowing fructose and ammonium lactate to penetrate more easily into the tobacco tissue and react fully with the amino acids in the tobacco leaves. This helps promote the formation of characteristic aroma compounds of Burley tobacco, such as 2-ethyl-6-methylpyrazine, and Maillard reaction aroma precursors. It increases the content of characteristic aroma compounds and Maillard reaction aroma precursors in Burley tobacco, effectively enhancing the nutty and roasted aromas of Burley and Maryland tobacco, improving the aroma quality, increasing the aroma quantity, improving the fineness of the smoke, reducing irritation, and improving the aftertaste.

[0011] Meanwhile, the re-drying liquid of this application will not cause abnormalities such as mold, pests, clumping and sticking in Burley tobacco and Maryland tobacco, will not affect the industrial processing resistance of sun-dried tobacco, will not increase the breakage of tobacco leaves and shreds, and can improve the quality of tobacco sheets and increase the usability of tobacco leaves, providing technical support for the production and processing of high-quality Burley tobacco and Maryland tobacco.

[0012] Of particular importance, the inventors discovered through extensive experimentation that replacing any of the three key components—fructose corn syrup, ammonium lactate, and propylene glycol—with other substances of the same class (e.g., replacing the corn syrup with other sugars, or ammonium lactate with other ammonium compounds), or altering their proportions, failed to achieve the same sensory improvement, especially in significantly enhancing the characteristic nutty and roasted aromas of Burley tobacco, and drastically reducing its effectiveness in reducing irritation and harmonizing the smoke. This demonstrates the non-obviousness and technical inventiveness of this specific component combination.

[0013] Preferably, the re-baking liquid comprises the following ingredients by weight percentage: 12%-35% fructose syrup, 2%-8% ammonium lactate, 5%-15% propylene glycol, and the balance being distilled water.

[0014] More preferably, the re-baking liquid comprises the following ingredients by weight percentage: 18%-30% fructose syrup, 3%-6% ammonium lactate, 8%-12% propylene glycol, and the balance being distilled water.

[0015] More preferably, by weight percentage, the re-baking liquid comprises the following ingredients: 20%-30% fructose syrup, 3%-6% ammonium lactate, 8%-12% propylene glycol, and the balance being distilled water.

[0016] Preferably, the fructose syrup is F55 type fructose syrup, wherein the fructose content is 50%-55% and the glucose content is 40%-45%.

[0017] Furthermore, in preparing the re-baking liquid, the fructose syrup is added in the form of an aqueous solution with a concentration of 40%-60%.

[0018] Secondly, the present invention also provides a method for preparing the re-baking liquid as described above, comprising: Step 1): Add distilled water to the high-fructose corn syrup to obtain a high-fructose corn syrup solution with a concentration of 30%-70%. High-fructose corn syrup is relatively viscous. Diluting it with distilled water to a high-fructose corn syrup solution within the above concentration range can help dissolve the subsequent ammonium lactate, allowing both to better enhance the sensory quality of Burley tobacco and Maryland tobacco. Step 2): Add ammonium lactate, propylene glycol, and the remaining distilled water to the fructose syrup solution and stir to dissolve.

[0019] Furthermore, the temperature of the distilled water used in step 1) is 55–70°C, preferably 60–70°C.

[0020] Preferably, in step 1), the mass ratio of fructose syrup to distilled water is 0.5 to 2:1; Preferably, the temperature during stirring in step 2) is 50–70°C, and more preferably 60–65°C.

[0021] More preferably, the temperature during stirring is 60°C.

[0022] The above preparation method is simple to operate, can ensure that all components are fully dissolved and maintain their activity, and is suitable for industrial production.

[0023] Thirdly, the present invention also provides the application of the re-drying liquid described above in improving the sensory quality of Burley tobacco and Maryland tobacco, including the following steps: after vacuum rehydration of Burley tobacco or Maryland tobacco, the tobacco is threshed; then the re-drying liquid is added to the tobacco leaves obtained after threshing; the tobacco leaves after adding the liquid are further separated by an air classifier to remove dust, fragments, and light inorganic impurities, thereby improving the purity of the tobacco leaves; subsequently, the tobacco leaves are conveyed to a reciprocating spreading device for reciprocating spreading, further improving the uniformity of the tobacco leaves. After storage for 0.5-2 hours, a six-stage drying process is performed; the dried tobacco leaves are rehydrated until the moisture content is 11.5%-12.8%, and then subjected to aging treatment.

[0024] Furthermore, the vacuum rehumidification is used to adjust the moisture content of tobacco leaves to 11%-13%, improve the flexibility of tobacco leaves, and provide a process adaptation basis for subsequent leaf threshing and feeding processes.

[0025] Furthermore, the amount of re-drying liquid added is 4%-10% of the dry basis weight of the tobacco leaves, and the addition temperature of the re-drying liquid to the tobacco leaves is 25℃-45℃. Controlling the amount of re-drying liquid added within the above range can achieve a better effect in improving the sensory quality of Burley tobacco and Maryland tobacco.

[0026] Preferably, the amount of the re-drying liquid added is 5%-8% of the dry basis weight of the tobacco leaves, the feeding temperature is 35°C, and the storage time is 1 hour.

[0027] Furthermore, the temperature during vacuum rehydration is 58℃-70℃, and the temperature during alcoholization is 10℃-32℃.

[0028] Preferably, the temperature during vacuum rehydration is 66°C.

[0029] Furthermore, the six-stage baking process is as follows: the first stage baking temperature is 68℃-82℃, and the baking time is 1.0min-2.0min; the second stage baking temperature is 74℃-89℃, and the baking time is 1.5min-3min; the third stage baking temperature is 78℃-94℃, and the baking time is 1.5min-3min; the fourth stage baking temperature is 87℃-98℃, and the baking time is 1.5min-3min; the fifth stage baking temperature is 76℃-90℃, and the baking time is 1.0min-2.0min; and the sixth stage baking temperature is 70℃-85℃, and the baking time is 1.0min-2.0min.

[0030] Preferably, the baking temperature for the first stage is 76-79℃ and the baking time is 1.2-1.7 min; the baking temperature for the second stage is 84-89℃ and the baking time is 1.8-2.5 min; the baking temperature for the third stage is 88-94℃ and the baking time is 1.8-2.5 min; the baking temperature for the fourth stage is 92-98℃ and the baking time is 1.8-2.5 min; the baking temperature for the fifth stage is 86-90℃ and the baking time is 1.2-1.7 min; and the baking temperature for the sixth stage is 78-85℃ and the baking time is 1.2-1.7 min.

[0031] The six-stage gradient baking process described in this invention is a key technology that matches the re-baking liquid. This process is not a simple drying process, but rather involves precisely controlling the temperature gradient and time: Early to mid-stages (stages one to four): The temperature gradually increases, removing the additional moisture introduced by the feed while providing the optimal temperature window for the Maillard reaction between sugars, ammonium salts, and amino acids in the tobacco leaves, thus directionally promoting the formation of characteristic pyrazine compounds such as 2-ethyl-6-methylpyrazine. Late stage (stages five to six): The temperature gradually decreases, achieving slow drying and effectively reducing the damage and volatilization of already formed aroma compounds by high temperatures, maximizing aroma retention. This baking curve is highly synergistic with the characteristics of the feed liquid, achieving a targeted improvement in sensory quality while meeting the process moisture requirements.

[0032] This invention optimizes the six-stage baking and drying curve. Compared with the prior art, the above-mentioned six-stage baking conditions have the following significant advantages: Targeted generation of characteristic aroma substances: By precisely controlling the temperature gradient formed by the baking temperature and time of each stage, the reducing sugars and lactic acid in the re-baking liquid can be effectively promoted to undergo Maillard reaction with the amino acids contained in the tobacco leaves, thereby generating characteristic aroma substances that meet the quality requirements of Burley tobacco and Maryland tobacco, and significantly improving the richness and harmony of the tobacco aroma. Precise control of tobacco leaf moisture: This technology specifically addresses the technical challenge of introducing additional moisture into tobacco leaves after re-drying with the molten material. By employing a six-stage stepped drying process, it achieves gradient evaporation of moisture, ensuring that the moisture content of the re-dried tobacco leaves strictly meets the standards and requirements of the tobacco industry and subsequent processing. This prevents problems such as mold and quality deterioration from occurring during the subsequent aging, storage, and processing of the tobacco leaves. Significantly reduces the loss of aroma compounds: The combination of temperature and time parameters in this roasting process can effectively reduce the thermal volatility loss of the main aroma compounds in tobacco leaves, retain the tobacco leaves and the aroma active ingredients generated by the reaction to the greatest extent, and ensure the stability and superiority of the sensory quality of Burley and Maryland tobacco.

[0033] Fourthly, the present invention also provides a preferred formulation module for different grades of tobacco leaves to further maximize the quality improvement effect of the re-drying liquid of the present invention: Furthermore, the Burley tobacco and Maryland tobacco are tobacco leaves of various quality grades, specifically: The burley tobacco is composed of burley tobacco of quality grades B2F and X2F in a mass ratio of (1-3):(1-7). Preferably, the low-grade tobacco leaf module of the burley tobacco is composed of burley tobacco of quality grades B2F and X2F in a mass ratio of 3:2.

[0034] Preferably, the burley tobacco is composed of burley tobacco of quality grades C1F, C2F and C3F in a mass ratio of 1:(1-3):(2-4).

[0035] More preferably, the medium-to-high grade burley tobacco leaf module is composed of burley tobacco of quality grades C1F, C2F and C3F in a mass ratio of 2:3:5; Preferably, the Maryland tobacco is composed of Maryland tobacco of quality grades C1, C2, C3, B1, B2 and X2 in a mass ratio of 1:(1-2):(2-4):(1-2):(1-3):(1-3).

[0036] More preferably, the Maryland tobacco leaf module is composed of Maryland tobacco of quality grades C1, C2, C3, B1, B2 and X2 in a mass ratio of 1:1:3:1:2:2.

[0037] The lower-grade tobacco leaf modules of Burley tobacco: While the upper leaves of Burley tobacco (such as B2F) have a rich aroma, they are extremely low in sugar and have excessively high levels of nicotine and nitrogenous compounds, resulting in strong irritation, a rough smoke, and off-flavors. The lower leaves (such as X2F), due to insufficient accumulation, are less irritating and burn well, but suffer from a weak aroma and a bland taste. This invention optimizes the tobacco leaf formula, preferably using a 3:2 mass ratio of B2F and X2F to achieve complementary advantages: the upper leaves provide a full aroma base, while the lower leaves effectively dilute the excessive strength and irritation, and harmonize the sugar-to-alkali ratio and nitrogen-to-alkali ratio of the mixed leaves. This lays the foundation for the enhanced effect of the subsequent re-drying liquor—the fructose syrup in the liquor precisely replenishes the overall sugar content, and ammonium lactate further regulates the acid-base balance, thus significantly improving overall harmony. Ultimately, this synergistically enhances the smoothness, sweetness, and sensory comfort of the smoke, achieving a significant quality improvement effect.

[0038] The medium-to-high grade tobacco leaf module of Burley tobacco: The middle leaves of Burley tobacco (such as C1F, C2F, and C3F) are generally considered to be the part with a more balanced quality and style. Their characteristics are between the rich but pungent upper leaves and the mild lower leaves: the aroma is sufficient, with the typical mellow aroma of Burley tobacco; the nicotine and total nitrogen content is moderate; the pungentness, strength, and off-flavors are generally better than the upper leaves, and it is the core raw material that constitutes the main body of the formula. In this invention, C1F, C2F, and C3F are blended in a mass ratio of 2:3:5. Its core advantage is that it is not a simple mixture, but a deliberate enhancement of the quality gradient and defect targets within the middle leaves. Among them, the dominant lower grade C3F (50%), although belonging to the middle, has a relatively high nicotine content, low sugar content, coarser aroma, and a certain degree of pungentness and off-flavors; while C1F and C2F (total 50%) represent the middle leaves with a more mellow aroma and better texture. This formulation creates a mixed system that is "primarily composed of low to medium-grade tobacco, with slight quality defects but a solid aroma foundation." Its chemical composition (such as the sugar-to-alkali ratio) and sensory quality are in a sensitive range requiring optimization and improvement, thus providing a clear target for efficient intervention with the liquor. For this mixed system, the re-drying liquor of this invention plays a targeted quality-enhancing role: Fructose syrup (10%-40%): directly replenishes the overall insufficient sugar content in the middle leaves, improving sweetness and mellowness, and providing a key substrate for the Maillard reaction. Ammonium lactate (1%-10%): plays a key regulatory role. On the one hand, it adjusts the pH of the tobacco leaves, reducing irritation and softening the smoke; on the other hand, it provides a nitrogen source to promote the Maillard reaction process, effectively improving aroma richness and transforming undesirable off-flavors, especially strengthening and modifying the aroma quality of low to medium-grade tobacco leaves. Propylene glycol (2%-20%): ensures uniform penetration and distribution of the liquor in the middle leaves, improving physical moisture retention. This formula maximizes the sweetening, spiciness-reducing, aroma-enhancing, and moisturizing functions of the liquor by combining specific proportions of the internal grades of the middle tobacco leaves. This transforms the originally uneven quality of the middle leaf mixture into a high-quality raw material with a mellow aroma, harmonious taste, and significantly reduced irritation, achieving a targeted leap in sensory quality.

[0039] Maryland Tobacco Leaf Modules: The sensory quality of the upper, middle, and lower leaves of Maryland tobacco all exhibit significant shortcomings, directly impacting their suitability and usage ratio in cigarette blends. The upper leaves' sensory deficiencies are concentrated in their strong, irritating smoke with noticeable off-flavors. They are not only too harsh but also have a slight spiciness. After drying, they tend to retain woody and burnt notes, resulting in an unpleasant aftertaste. They also tend to mask the main aroma of the cigarette, disrupting the smoke's harmony. While the middle leaves represent a higher overall quality portion, their sensory shortcomings are still significant. The initial smoke intensity is weak, resulting in insufficient smoke burst and low smoking satisfaction. The flavor profile is also shallow, making it unsuitable for formulations requiring a rich aroma. Furthermore, the leaves are not very resilient, making them prone to breakage during processing, leading to fluctuating smoke stability. The lower leaves exhibit the most prominent sensory shortcomings: a bland and uncharacteristic aroma, thin and lacking body, a short aftertaste with little salivation, and often a slight grassy or unpleasant aftertaste. Smoking satisfaction is extremely low, and uneven smoke formation during combustion is common, completely failing to meet the sensory requirements of high-end cigarettes. The advantages of the blended module: C1, C2, C3, B1, B2, X2 (1:1:3:1:2:2) covers the upper, middle, and lower parts. The multi-part blending allows for a wider distribution of chemical components (such as sugars and nitrogen), and the diversity of physical structures facilitates layered penetration and action of the liquid. The liquid can simultaneously compensate for the deficiencies of each part, such as the low sugar and high spiciness of the upper part, the dryness of the middle part, and the blandness of the lower part, thereby improving the overall quality.

[0040] The re-drying liquid of this invention can be used to treat specific Burley tobacco and Maryland tobacco composed of the above three different quality grades, and can achieve better quality improvement.

[0041] The present invention also provides burley tobacco and / or Maryland tobacco prepared by a processing method that uses the re-drying liquid described above to improve the sensory quality of burley tobacco or Maryland tobacco.

[0042] The present invention also provides the application of Burley tobacco or Maryland tobacco prepared by the processing method described above in the preparation of blended cigarettes.

[0043] This invention provides a re-drying liquid, preparation method, and application for improving the sensory quality of Burley tobacco and Maryland tobacco. The re-drying liquid can be applied to the leaf-cutting and re-drying stage of Burley tobacco or Maryland tobacco. Under the synergistic effect of fructose syrup, ammonium lactate, and propylene glycol, it can not only solve the problems of imbalanced sugar-nitrogen ratio and sugar-alkali ratio, uncoordinated acid-base content, and relatively low reducing sugar content in Burley tobacco and Maryland tobacco, but also improve the characteristic aroma of Burley tobacco and Maryland tobacco, effectively shorten the aging time, and improve the sensory quality of Burley tobacco and Maryland tobacco. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a comparison chart of the Maillard reaction aroma precursor content between the control group and the re-baking treatment group in Test Example 1; Figure 2 This is a comparison diagram of characteristic aroma compounds between the control group and the re-roasting group with added ingredients in Test Example 1. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] The following is combined Figure 1 and Figure 2 The present invention describes the re-baking liquid, its preparation method, and its application.

[0048] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0049] The F55 high-fructose corn syrup used in the examples was purchased from Shanghai Peony Fragrance & Flavor Co., Ltd. The F55 high-fructose corn syrup contains 55% fructose and 45% glucose.

[0050] Example 1 A re-drying liquid for enhancing the sensory quality of Burley and Maryland tobacco is composed of the following components by weight percentage: 20% F55 fructose syrup, 3.5% ammonium lactate, 6% propylene glycol, and the balance being distilled water.

[0051] This embodiment also provides a method for preparing the above-mentioned re-baking liquid, including: Step 1) Weigh out F55 type fructose syrup according to the above ratio, add distilled water at 65℃ to F55 type fructose syrup at a mass ratio of 1:1, stir for 5 minutes to obtain fructose syrup solution (concentration of 50%). Step 2) Add ammonium lactate, propylene glycol and the remaining distilled water to the fructose syrup solution obtained in Step 1), stir and dissolve at 60°C to obtain the re-baking solution.

[0052] This embodiment also provides the application of the above-mentioned re-drying liquid in improving the sensory quality of Burley tobacco, used for processing Burley tobacco, and the processing steps are as follows: a) Application of reheating liquid Appropriate amounts of Burley tobacco leaves of grades C1F, C2F, and C3F were vacuum rehydrated for 10 minutes sequentially, with the core temperature of the tobacco bale controlled at 50-60℃. The different quality grades of Burley tobacco (C1F, C2F, and C3F) were mixed at a mass ratio of 2:3:5, and 6000 kg was precisely fed into the bale using a leaf-laying and feeding device. After threshing, the separated tobacco flakes were conveyed to a drum-type feeding device for precise feeding, adding the aforementioned re-drying liquid. The amount of re-drying liquid added was 6.5% of the dry weight of the tobacco flakes. The feeding temperature was strictly controlled at 35℃ to ensure full adsorption and fusion of the re-drying liquid with the tobacco flakes. After feeding, the tobacco flakes were further separated by an air-classifying device to remove dust, fragments, and light inorganic impurities, improving the purity of the tobacco flakes. Subsequently, the tobacco flakes underwent repeated spreading to further improve their uniformity.

[0053] b) Tobacco leaf curing After being fed and stored for 1 hour, the tobacco undergoes a six-stage baking process. The first stage baking temperature is 79℃, and the baking time is 1.2 minutes; the second stage baking temperature is 84℃, and the baking time is 1.8 minutes; the third stage baking temperature is 88℃, and the baking time is 1.8 minutes; the fourth stage baking temperature is 92℃, and the baking time is 1.8 minutes; the fifth stage baking temperature is 86℃, and the baking time is 1.2 minutes; and the sixth stage baking temperature is 78℃, and the baking time is 1.2 minutes. After baking, the tobacco is rehydrated at 66℃ until the moisture content reaches 12.1%-12.5%. After packaging, it is aged for 2 years at 10℃-32℃ to obtain the upgraded Burley tobacco (CA).

[0054] Example 2 A re-drying liquid for enhancing the sensory quality of Burley and Maryland tobacco is composed of the following components by weight percentage: 26% F55 fructose syrup, 5% ammonium lactate, 8% propylene glycol, and the balance being distilled water.

[0055] This embodiment also provides a method for preparing the above-mentioned re-baking liquid, including: Step 1): Weigh out F55 type fructose syrup according to the above ratio, add 60℃ distilled water at a mass ratio of F55 type fructose syrup to distilled water of 4:6, stir for 5 minutes to obtain fructose syrup solution (concentration of 40%). Step 2): Add ammonium lactate, propylene glycol and the remaining distilled water to the fructose syrup solution obtained in step (1), and stir to dissolve at 60°C to obtain the re-baking solution.

[0056] This embodiment also provides the application of the above-mentioned re-drying liquid in improving the sensory quality of Burley tobacco, used for processing Burley tobacco, and the processing steps are as follows: a) Application of reheating liquid Take appropriate amounts of Burley B2F and X2F grade tobacco leaves and vacuum rehydrate them for 10 minutes, controlling the core temperature of the tobacco bale at 50-60℃. Mix the above-mentioned Burley B2F and X2F tobacco leaves of different quality grades at a mass ratio of 3:2, and accurately feed 5000kg of the mixture through a leaf-laying and feeding device. After the tobacco leaves are threshed, the separated tobacco flakes are conveyed to a drum-type feeding device for precise feeding, in which the above-mentioned re-drying liquid is added to the tobacco flakes. The amount of re-drying liquid added is 7.0% relative to the dry basis mass of the tobacco flakes. During the feeding process, the feeding temperature is strictly controlled at 35℃ to ensure that the re-drying liquid and the tobacco flakes are fully adsorbed and integrated. After feeding, the tobacco flakes are further separated by an air classifier to remove dust, fragments and light inorganic impurities, improving the purity of the tobacco flakes. Then, the tobacco flakes are conveyed to a reciprocating spreading device for reciprocating spreading, further improving the uniformity of the tobacco flakes.

[0057] b) Tobacco leaf curing After being fed and stored for 0.5 hours, the tobacco undergoes a six-stage baking process. The first stage baking temperature is 76℃, and the baking time is 1.4 minutes; the second stage baking temperature is 87℃, and the baking time is 2.2 minutes; the third stage baking temperature is 90℃, and the baking time is 2.2 minutes; the fourth stage baking temperature is 96℃, and the baking time is 2.2 minutes; the fifth stage baking temperature is 88℃, and the baking time is 1.4 minutes; and the sixth stage baking temperature is 83℃, and the baking time is 1.4 minutes. After baking, the tobacco is rehydrated at 68℃ until the moisture content reaches 11.8%-12.6%. After packaging, it is aged for 2 years at 10℃-32℃ to obtain upgraded Burley tobacco.

[0058] Example 3 A re-drying liquid for enhancing the sensory quality of Burley and Maryland tobacco is composed of the following components by weight percentage: 30% F55 fructose syrup, 4% ammonium lactate, 10% propylene glycol, and the balance being distilled water.

[0059] This embodiment also provides a method for preparing the above-mentioned re-baking liquid, including: Step 1) Weigh out F55 type fructose syrup according to the above ratio, add 70℃ distilled water at a mass ratio of F55 type fructose syrup to distilled water of 6:4, stir for 5 minutes to obtain fructose syrup solution (concentration of 60%). Step 2) Add ammonium lactate, propylene glycol and the remaining distilled water to the fructose syrup solution obtained in step (1), and stir to dissolve at 60°C to obtain the re-baking solution.

[0060] This embodiment also provides the application of the above-mentioned re-drying liquid in improving the sensory quality of Maryland tobacco, used for processing Burley tobacco, and the processing steps are as follows: a) Application of reheating liquid Appropriate amounts of Maryland tobacco leaves of grades C1, C2, C3, B1, B2, and X2 were sequentially vacuum-rehydrated for 10 minutes, with the core temperature of the tobacco bale controlled at 50–60°C. The different quality grades of Maryland tobacco (C1, C2, C3, B1, B2, and X2) were then mixed in a mass ratio of 1:1:3:1:2:2, and 8000 kg was precisely fed into the mixture using a leaf-laying and feeding device. After leaf threshing, the separated tobacco flakes were conveyed to a drum-type feeding device for further processing. A precise feeding operation is performed to add the aforementioned re-drying liquid to the tobacco flakes. The amount of re-drying liquid added is 8.5% of the dry basis weight of the tobacco flakes. During the feeding process, the feeding temperature is strictly controlled at 35℃ to ensure that the re-drying liquid and tobacco flakes are fully adsorbed and integrated. After feeding, the tobacco flakes are further separated by an air classifier to remove dust, fragments and light inorganic impurities, thereby improving the purity of the tobacco flakes. Subsequently, the tobacco flakes are conveyed to a reciprocating spreading device for reciprocating spreading treatment to further improve the uniformity of the tobacco flakes.

[0061] b) Tobacco leaf curing After being fed and stored for 1 hour, the tobacco undergoes a six-stage baking process. The first stage baking temperature is 79℃, and the baking time is 1.7 minutes; the second stage baking temperature is 89℃, and the baking time is 2.5 minutes; the third stage baking temperature is 94℃, and the baking time is 2.5 minutes; the fourth stage baking temperature is 98℃, and the baking time is 2.5 minutes; the fifth stage baking temperature is 90℃, and the baking time is 1.7 minutes; and the sixth stage baking temperature is 85℃, and the baking time is 1.7 minutes. After baking, the tobacco is rehydrated at 65℃ until the moisture content reaches 12.3%-12.8%. After packaging, it is aged at 10℃-32℃ for 1 year to obtain upgraded Maryland tobacco.

[0062] Example 4 A re-drying liquid for enhancing the sensory quality of Burley and Maryland tobacco is composed of the following components by weight percentage: 10% F55 fructose syrup, 1% ammonium lactate, 2% propylene glycol, and the balance being distilled water.

[0063] This embodiment also provides a method for preparing the above-mentioned re-baking liquid, including: Step 1) Weigh out F55 type fructose syrup according to the above ratio, add distilled water at 65℃ to F55 type fructose syrup at a mass ratio of 1:1, stir for 5 minutes to obtain fructose syrup solution (concentration of 50%). Step 2) Add ammonium lactate, propylene glycol and the remaining distilled water to the fructose syrup solution obtained in Step 1), stir and dissolve at 60°C to obtain the re-baking solution.

[0064] This embodiment also provides the application of the above-mentioned re-drying liquid in improving the sensory quality of Burley tobacco, used for processing Burley tobacco, and the processing steps are as follows: a) Application of reheating liquid Take an appropriate amount of Burley B2F grade tobacco leaves and vacuum rehydrate for 10 minutes. Control the core temperature of the tobacco bale at 50-60℃. Precisely feed 5000kg of leaves using a leaf-laying and feeding device. After the tobacco leaves are threshed, the separated tobacco flakes are conveyed to a drum-type feeding device for precise feeding. The above-mentioned re-drying liquid is added to the tobacco flakes at a rate of 6.5% of the dry weight of the tobacco flakes. During the feeding process, the feeding temperature is strictly controlled at 35℃ to ensure that the re-drying liquid and tobacco flakes are fully adsorbed and integrated. After feeding, the tobacco flakes are further separated by an air classifier to remove dust, fragments, and light inorganic impurities, improving the purity of the tobacco flakes. Then, the tobacco flakes are conveyed to a reciprocating spreading device for reciprocating spreading to further improve the uniformity of the tobacco flakes.

[0065] b) Tobacco leaf curing After feeding and storing for 1 hour, the tobacco undergoes a six-stage baking process. The first stage baking temperature is 79℃, and the baking time is 1.2 minutes; the second stage baking temperature is 84℃, and the baking time is 1.8 minutes; the third stage baking temperature is 88℃, and the baking time is 1.8 minutes; the fourth stage baking temperature is 92℃, and the baking time is 1.8 minutes; the fifth stage baking temperature is 86℃, and the baking time is 1.2 minutes; and the sixth stage baking temperature is 78℃, and the baking time is 1.2 minutes. After baking, the tobacco is rehydrated at 66℃ until the moisture content is 12.1%-12.5%. After packaging, it is aged for 2 years at 10℃-32℃ to obtain the upgraded Burley tobacco C3F.

[0066] Example 5 A re-drying liquid for enhancing the sensory quality of Burley and Maryland tobacco is composed of the following components by weight percentage: 40% F55 fructose syrup, 10% ammonium lactate, 20% propylene glycol, and the balance being distilled water.

[0067] This embodiment also provides a method for preparing the above-mentioned re-baking liquid, including: Step 1) Weigh out F55 type fructose syrup according to the above ratio, add distilled water at 65℃ to F55 type fructose syrup at a mass ratio of 1:1, stir for 5 minutes to obtain fructose syrup solution (concentration of 50%). Step 2) Add ammonium lactate, propylene glycol and the remaining distilled water to the fructose syrup solution obtained in Step 1), stir and dissolve at 60°C to obtain the re-baking solution.

[0068] This embodiment also provides the application of the above-mentioned re-drying liquid in improving the sensory quality of Burley tobacco, used for processing Burley tobacco, and the processing steps are as follows: a) Application of reheating liquid Take an appropriate amount of Burley B2F grade tobacco leaves and vacuum rehydrate for 10 minutes. Control the core temperature of the tobacco bale at 50-60℃. Precisely feed 5000kg of leaves using a leaf-laying and feeding device. After the tobacco leaves are threshed, the separated tobacco flakes are conveyed to a drum-type feeding device for precise feeding. The above-mentioned re-drying liquid is added to the tobacco flakes at a rate of 6.5% of the dry weight of the tobacco flakes. During the feeding process, the feeding temperature is strictly controlled at 35℃ to ensure that the re-drying liquid and tobacco flakes are fully adsorbed and integrated. After feeding, the tobacco flakes are further separated by an air classifier to remove dust, fragments, and light inorganic impurities, improving the purity of the tobacco flakes. Then, the tobacco flakes are conveyed to a reciprocating spreading device for reciprocating spreading to further improve the uniformity of the tobacco flakes.

[0069] b) Tobacco leaf curing After being fed and stored for 0.5 hours, the tobacco undergoes a six-stage baking process. The first stage baking temperature is 76℃, and the baking time is 1.4 minutes; the second stage baking temperature is 87℃, and the baking time is 2.2 minutes; the third stage baking temperature is 90℃, and the baking time is 2.2 minutes; the fourth stage baking temperature is 96℃, and the baking time is 2.2 minutes; the fifth stage baking temperature is 88℃, and the baking time is 1.4 minutes; and the sixth stage baking temperature is 83℃, and the baking time is 1.4 minutes. After baking, the tobacco is rehydrated at 68℃ until the moisture content reaches 11.8%-12.6%. After packaging, it is aged for 2 years at 10℃-32℃ to obtain the upgraded Burley tobacco B2F.

[0070] Comparative Example 1 The difference between this comparison and Example 1 is that step a) in the method for processing Burley tobacco is different. Specifically, step a) does not include the step of adding the re-drying liquid of Example 1 to the tobacco leaves. Instead, the tobacco leaves obtained after leaf threshing are directly subjected to the same subsequent steps as in Example 1, such as wind separation.

[0071] Comparative Example 2 The difference between this comparison and Example 1 is that step a) in the method for processing Burley tobacco is different. Specifically, step a) does not include the step of adding the re-drying liquid of Example 2 to the tobacco leaves. Instead, the tobacco leaves obtained after leaf threshing are directly subjected to subsequent steps such as wind separation, which are the same as in Example 2.

[0072] Comparative Example 3 The difference between this comparison and Example 1 is that step a) in the method for processing Maryland tobacco is different. Specifically, step a) does not include the step of adding the re-drying liquid of Example 3 to the tobacco leaves. Instead, the tobacco leaves obtained after leaf threshing are directly subjected to the same subsequent steps as in Example 3, such as wind separation.

[0073] Comparative Example 4 The difference between this comparison and Example 1 is that step a) in the method for processing Burley tobacco is different. Specifically, step a) does not include the step of adding the re-drying liquid of Example 4 to the tobacco leaves. Instead, the tobacco leaves obtained after leaf threshing are directly subjected to the same subsequent steps as in Example 4, such as wind separation.

[0074] Comparative Example 5 The difference between this comparison and Example 1 is that step a) in the method for processing Burley tobacco is different. Specifically, step a) does not include the step of adding the re-drying liquid of Example 5 to the tobacco leaves. Instead, the tobacco leaves obtained after leaf threshing are directly subjected to subsequent steps such as wind separation, which are the same as in Example 5.

[0075] Comparative Example 6 This comparative example is basically the same as Example 1, except that the composition of the re-baking liquid is different. Specifically, the F55 type fructose syrup in Example 1 is replaced with glucose.

[0076] Comparative Example 7 This comparative example is basically the same as Example 1, except that the composition of the re-baking liquid is different. Specifically, the F55 type fructose syrup in Example 1 is replaced with fructose.

[0077] Comparative Example 8 This comparative example is basically the same as Example 1, except that the composition of the re-baking liquid is different. Specifically, the ammonium lactate slurry in Example 1 is replaced with ammonium bicarbonate.

[0078] Comparative Example 9 This comparative example is basically the same as Example 1, except that the composition of the re-baking liquid is different. Specifically, the ammonium lactate slurry in Example 1 is replaced with diammonium hydrogen phosphate.

[0079] Comparative Example 10 The difference between this comparative example and Example 1 lies in the processing method and the preparation method of the re-baking liquid. Specifically, the six-stage baking process in Example 1 is replaced with a three-stage baking process.

[0080] The three-stage baking process is as follows: the first stage baking temperature is 79℃, and the baking time is 3.0 minutes; the second stage baking temperature is 92℃, and the baking time is 3.0 minutes; the third stage baking temperature is 78℃, and the baking time is 3.0 minutes. After baking, the tobacco leaves are rehydrated at 66℃ until the moisture content is 12.1%-12.5%. After packaging, they are aged for 2 years at 10℃-32℃ to obtain the upgraded Burley tobacco (CA).

[0081] Test Example 1: Online Production Application Verification The test case used Burley tobacco or Maryland tobacco with improved sensory quality through the processing methods of Examples 1-5 to produce blended cigarettes, and conducted online production application tests and verifications of blended cigarettes in a certain brand of product in Zhongnanhai.

[0082] Specifically, the following experiment was conducted: domestic Burley tobacco and Maryland tobacco in the leaf blend formula of a certain brand of Zhongnanhai product were replaced with Burley tobacco and Maryland tobacco processed using the methods described in Examples 1-3 to improve their sensory quality (the ratio of the three types of tobacco leaves in Examples 1, 2, and 3 in the product leaf blend formula was 1:1:1). An online feeding experiment was carried out and named the feeding and re-drying treatment group. Burley tobacco and Maryland tobacco from the same year that were not fed with re-drying liquid and were normally processed and re-dried were used as the control group (i.e., comparative example 1 replaced the Burley tobacco in Example 1 of the feeding and re-drying treatment group, comparative example 2 replaced the Burley tobacco in Example 2 of the feeding and re-drying treatment group, and comparative example 3 replaced the Maryland tobacco in Example 3 of the feeding and re-drying treatment group).

[0083] Sensory evaluation (Table 1), Maillard aroma precursor analysis, and aroma component analysis were performed on cigarette samples prepared from the control group and the re-drying group. Figure 1 and Figure 2 The determination of the content of aroma precursors and aroma compounds by Maillard reaction is based on CN113219111A.

[0084] Table 1 Sensory evaluation results

[0085] Table 1 shows that the re-drying treatment group with added ingredients significantly outperformed the control group in key indicators such as aroma quantity, aroma quality, harmony, and aftertaste. This was manifested in enhanced blended characteristic aroma, improved aroma quality, increased aroma richness, reduced off-flavors, decreased irritation, and significantly improved oral comfort and sweetness. This indicates that the re-drying liquid of this invention can effectively improve the sensory quality of blended cigarettes, enhance blended characteristic aroma, and improve oral comfort and sweetness. Figure 1 and 2It is evident that by employing the re-drying liquid treatment of Examples 1-3, the content of key aroma products (such as pyrazines and furans) and Maillard aroma precursors in blended tobacco raw materials and finished blended cigarettes can be significantly increased, laying a material foundation for improving sensory quality.

[0086] Test Example 2 (Alcoholization Process Tracking Analysis) This test example sampled the aging process of Burley tobacco processed with the re-drying liquid of Example 1 and the aging process of Burley tobacco processed in Comparative Example 1. During aging, samples were taken every 6 months for sensory quality evaluation, Maillard aroma precursor analysis, and aroma component analysis. The sensory evaluation was conducted by 7 qualified smoke testers in accordance with the YC / T 138—1998 Sensory Quality Evaluation Method for Single-Film Tobacco. The average value of each item was calculated and the sensory quality was described. The sensory quality results are shown in Table 2, and the Maillard aroma precursor content and characteristic aroma substance content are shown in Tables 3 and 4.

[0087] Table 2 Sensory evaluation results

[0088] As shown in Table 2, the Burley tobacco treated with the re-drying liquid of Example 1 exhibits enhanced characteristic aromas such as nutty and roasted notes, significantly improved aroma quality, richer aroma, increased aroma quantity, reduced off-flavors, and improved aftertaste. Compared to Comparative Example 1, at each aging time point, the sensory quality of the Burley tobacco corresponding to Example 1 is superior, and this advantage increases with prolonged aging time. Particularly noteworthy is that the tobacco leaves aged for 6 months in Example 1 are already of higher quality than those aged for 24 months in Comparative Example 1. This demonstrates that the present invention not only improves quality but also significantly shortens the aging cycle and reduces storage costs.

[0089] Table 3. Content of Maillard reaction aroma precursors (μg / g) during Burley tobacco aging.

[0090] As shown in Table 3, the content and total content of Maillard reaction aroma precursors in the burley tobacco processed with the re-drying liquid of Example 1 were significantly higher than those in Comparative Example 1 during the aging process (p<0.001). Furthermore, the total content of Maillard reaction aroma precursors continued to increase with the aging time during the aging process, indicating that the re-drying liquid prepared in this invention can significantly increase the content of Maillard reaction aroma precursors in burley tobacco, laying a sufficient substrate foundation for the formation of subsequent aroma substances.

[0091] Table 4. Content of characteristic aroma compounds during the aging process of Burley tobacco (μg / g)

[0092] As shown in Table 4, Example 1 showed a significant increase in the content of 37 characteristic aroma compounds of Burley tobacco compared to Comparative Example 1 (p<0.05). In particular, pyrazine compounds, the main contributors to the characteristic nutty and roasted aromas of Burley tobacco, saw the largest increase, ranging from 75.3% to 477.32% after two years of aging. The content of 5-methylfurfural, a characteristic aroma compound of Burley tobacco, increased by 147.13%. Maltol and furanone, the main contributors to sweet and caramel aromas, increased by 113.80% and 96.66%, respectively. Furthermore, the proportions of key neutral aroma compounds of Burley tobacco, such as β-damascone and megastigmatrienone, also increased by more than 10%. This significant increase and synergistic growth in the content of these key characteristic aroma compounds is the direct material reason for the comprehensive improvement in the sensory quality of Burley tobacco, directly confirming the inseparable synergistic effect among F55 type fructose syrup, ammonium lactate, and propylene glycol in the re-drying liquid of this invention. This synergistic effect is multi-layered and multi-pathway, jointly leading to a leap in sensory quality. Its mechanism is mainly reflected in the following aspects: 1. Synergistic Driving of Targeted Pyrazine Formation: Pyrazines, as the core source of the nutty and roasted aromas of Burley tobacco, are formed through the condensation and cyclization reactions of carbonyl and amino compounds. The specific ratio of fructose to glucose in F55 high-fructose corn syrup provides ample and stable carbonyl donors for the reaction. Its monosaccharide molecular structure readily undergoes enolization, generating unsaturated aldehyde and ketone intermediates. Ammonium lactate not only acts as a highly efficient amino donor, but its dissociated free ammonia can also rapidly combine with carbonyl compounds produced by sugar degradation to form Schiff base intermediates. Simultaneously, ammonium lactate maintains pH stability, eliminating the inhibitory effect of pH fluctuations on the reaction. The synergistic effect of these two factors drives the intermediates through cyclization and dehydrogenation, ultimately generating a series of pyrazines such as 2-ethyl-6-methylpyrazine and 2,5-dimethylpyrazine. This is the core reason for the high pyrazine formation increases of 75.3%-477.32% shown in the table, far exceeding the effects of using sugars or ammonium salts alone.

[0093] 2. Synergistic Synthesis of Furans and Sweet Aroma Compounds: The significant increase in sweet and caramel aroma compounds such as 5-methylfurfural, furfuryl alcohol, maltol, and furanones, as shown in the table, is also attributed to the synergistic effect of these two compounds. Monosaccharides in F55 fructose syrup are prone to dehydration reactions during thermal processing and alcoholization, forming furan ring structures. Ammonium lactate, through proton transfer, accelerates the dehydration condensation of hydroxyl groups within sugar molecules, reducing side reactions such as monosaccharide carbonization and promoting the formation of primary furan compounds such as furfural and 5-methylfurfural. Simultaneously, the amino groups provided by ammonium lactate can further undergo Amadori rearrangement with sugar degradation products, directionally transforming them into higher aroma compounds with sweet characteristics, such as maltol and furanones. Data shows that the 113.80% increase in maltol and the 96.66% increase in furanones directly reflect this synergistic mechanism of "carbon source supply - reaction regulation." This pathway cannot be replicated using other sugars and ammonium salts (Comparative Examples 6-9), resulting in lower total amounts and product types of pyrazine compounds compared to this invention.

[0094] Test Example 3 In this test, samples were taken from Burley tobacco and Maryland tobacco processed with the re-drying liquids of Examples 2, 3, 4, and 5, and Comparative Examples 2, 3, 4, and 5, and samples aged for 24 months were evaluated for sensory quality. The results are shown in Table 5.

[0095] Table 5 Sensory Evaluation Results

[0096] As shown in Table 5, the total sensory quality scores of the tobacco leaves treated in Examples 2-5, after 24 months of aging, were significantly higher than those of the corresponding untreated tobacco leaves (Comparative Examples 2-5). This indicates that the re-drying liquid and processing method provided by this invention have a universal quality-improving effect on Burley tobacco and Maryland tobacco of different grades and origins, and can stably enhance characteristic aromas, improve aroma quality, and reduce irritation.

[0097] Test Example 4 In this test case, the re-drying liquid of Example 1 and Comparative Examples 6-10 were used to process Burley tobacco. After aging for 24 months, samples were taken for sensory quality evaluation. The results are shown in Table 6.

[0098] Table 6 Sensory Evaluation Results

[0099] As shown in the table above, replacing high-fructose corn syrup with other sugars (such as glucose and fructose) reduces the sensory quality of Burley tobacco, failing to effectively enhance its characteristic aroma and thus failing to achieve the goal of improving its sensory quality. This indicates that F55 high-fructose corn syrup has an irreplaceable advantage in promoting the Maillard reaction and forming a specific aroma profile, demonstrating that the specific ratio of glucose to fructose in F55 high-fructose corn syrup (suitable for the Maillard reaction requirements of tobacco) cannot be replaced by a single sugar. Replacing ammonium bicarbonate or diammonium hydrogen phosphate with ammonium lactate reduces the sensory quality of Burley tobacco, significantly worsening the aroma synergy and aftertaste indicators, indicating that ammonium lactate plays a unique role in regulating reaction pH, influencing aroma formation pathways, and improving aftertaste. Replacing the six-stage roasting process with a three-stage roasting process fails to achieve the precise temperature control and graded reactions of the six-stage process, resulting in insufficient formation of aroma compounds and a decline in the sensory quality of Burley tobacco. This indicates that the six-stage temperature-controlled roasting process can precisely match the reaction process of the liquor and tobacco leaves, which is a key step in ensuring quality improvement.

[0100] In summary, the core raw materials selected in this invention, such as F55 fructose syrup, ammonium lactate, and propylene glycol, as well as the step-by-step preparation and six-stage baking processes, form a synergistic and compatible technical system. None of them can be omitted; otherwise, the sensory quality will be significantly reduced.

[0101] Based on the above test analysis, the Burley and Maryland tobacco treated with the re-drying liquid of this invention not only retain the characteristic nutty and roasted aromas of Burley tobacco, but also significantly enhance the content of aroma components with sweet and caramel aromas, Maillard reaction aroma precursors, and other characteristic aromas of sun-dried tobacco, resulting in a marked improvement in aroma quality, richness, quantity, reduction of off-flavors, and aftertaste. Replacing the fructose syrup and ammonium lactate in the re-drying liquid of this invention with other raw materials will significantly reduce the quality improvement and efficiency enhancement effect on Burley and Maryland tobacco, failing to achieve the goal of effectively improving the sensory quality of Burley and Maryland tobacco.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A re-drying liquid for improving the sensory quality of Burley tobacco and Maryland tobacco, characterized in that, The re-baking liquid comprises the following ingredients by weight percentage: 10%-40% fructose syrup, 1%-10% ammonium lactate, 2%-20% propylene glycol, and the balance being distilled water.

2. The re-drying liquid according to claim 1, characterized in that, The re-baking liquid comprises the following ingredients by weight percentage: 12%-35% fructose syrup, 2%-8% ammonium lactate, 5%-15% propylene glycol, and the balance being distilled water; The re-baking liquid preferably comprises the following ingredients by weight percentage: 20%-30% fructose syrup, 3%-6% ammonium lactate, 8%-12% propylene glycol, and the balance being distilled water.

3. The re-drying liquid according to claim 1 or 2, characterized in that, The fructose syrup is F55 type fructose syrup; Preferably, when preparing the re-baking liquid, the fructose syrup is added in the form of an aqueous solution with a concentration of 30%-70%.

4. The method for preparing the re-baking liquid according to any one of claims 1-3, characterized in that, include: Step 1): Add distilled water to the high-fructose corn syrup to obtain a high-fructose corn syrup solution; Step 2): Add ammonium lactate, propylene glycol, and the remaining distilled water to the fructose syrup solution and stir to dissolve.

5. The method for preparing the re-baking liquid according to claim 4, characterized in that, The temperature of the distilled water used in step 1) is 55-70°C, and preferably the temperature during stirring in step 2) is 50-70°C.

6. The use of the re-drying liquid according to any one of claims 1-3 or the re-drying liquid according to claim 4 or 5 in improving the sensory quality of Burley tobacco and Maryland tobacco.

7. The application of the re-drying liquid according to claim 6, characterized in that, include: Burley tobacco or Maryland tobacco is threshed, and then the re-drying liquid is added to the tobacco leaves obtained after threshing. After removing light impurities, the tobacco leaves are evenly spread and stored for 0.5-2 hours. Then, a six-stage drying process is carried out. The dried tobacco leaves are re-moistened until the moisture content is 11.5%-12.8%, and then aging is carried out.

8. The application of the re-drying liquid according to claim 7, characterized in that, The amount of the re-drying liquid added is 4%-10% of the dry basis weight of the tobacco leaves, and the feeding temperature when adding the re-drying liquid to the tobacco leaves is 25℃-45℃.

9. The application of the re-drying liquid according to claim 7 or 8, characterized in that, The six-stage baking process is as follows: the first stage baking temperature is 68℃-82℃, and the baking time is 1.0min-2.0min; the second stage baking temperature is 74℃-89℃, and the baking time is 1.5min-3min; the third stage baking temperature is 78℃-94℃, and the baking time is 1.5min-3min; the fourth stage baking temperature is 87℃-98℃, and the baking time is 1.5min-3min; the fifth stage baking temperature is 76℃-90℃, and the baking time is 1.0min-2.0min; and the sixth stage baking temperature is 70℃-85℃, and the baking time is 1.0min-2.0min.

10. The application of the re-drying liquid according to any one of claims 6-9, characterized in that, The burley tobacco is composed of burley tobacco of quality grades B2F and X2F in a mass ratio of (1-3):(1-7) or the burley tobacco is composed of burley tobacco of quality grades C1F, C2F and C3F in a mass ratio of (1-2):(1-3):(2-5); And / or, the Maryland tobacco is composed of Maryland tobacco of quality grades C1, C2, C3, B1, B2 and X2 in a mass ratio of 1:(1-2):(2-4):(1-2):(1-3):(1-3).

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