A method for making a Maduro wrapper

Abstract

The present invention relates to the technical field of cigar processing, and discloses a method for making a Maduro wrapper. Existing Maduro wrappers made by kneading have the defects of mottled surface color and poor oil content. In order to solve the above problems, the present invention provides a method for making a Maduro wrapper. The present invention sequentially obtains a Maduro wrapper with uniform color and sufficient oil content through vacuum rehumidification, primary moisturizing, removal of the main veins of tobacco leaves, secondary moisturizing, kneading, freezing, and aging. In particular, a freezing step is added to slow down the reaction of melanin precursors under low temperature conditions, so that the melanin precursors are at a slower reaction rate. Then, an aging treatment is performed to promote oxidation of the precursors at a similar rate in the tobacco leaves, thereby forming a Maduro wrapper with uniform color.

Description

Technical Field

[0001] The present invention relates to the technical field of cigar processing, and in particular to a method for making a Maduro wrapper. Background Art

[0002] A complete cigar consists of three parts: the filler, the binder, and the wrapper. The wrapper, the outermost layer of the cigar, determines the cigar's appearance and is therefore the most expensive part of the tobacco. Wrapper tobacco can be divided into seven categories based on color. Maduro wrapper, which ranges from brown to nearly black, offers a unique sensory experience for smokers, characterized by its dark color, high sugar content, and high oil content. It is highly favored by consumers and cigar manufacturers alike. Therefore, research into the production of Maduro wrappers has become a hot topic among domestic cigar manufacturers.

[0003] At present, domestic cigar manufacturers are in the exploratory stage for the production process of Maduro wrappers. Traditional Maduro production methods include natural fermentation, pressure fermentation and artificial dyeing, but all of them have certain defects. There is still no relevant report on the practical Maduro wrapper production process. For example, the Chinese patent application publication number CN113331456A discloses a method for rolling and making Maduro wrappers, which includes the following steps: (1) selecting tobacco leaves; (2) moistening the tobacco leaves with deionized water until the moisture content of the tobacco leaves is 25-35%; (3) the moistened tobacco leaves are placed in an environment with a temperature of 30-50°C and a relative humidity of 70-85% for moisture balance; (4) all the main veins of the tobacco leaves after moisture balance are removed; (5) the stemmed tobacco leaves are soaked in a container with a water temperature of 35-50°C for 10-25 minutes; (6) the soaked wrapper tobacco leaves are grasped into a ball by hand and rubbed in the palm of the hand; (7) the rolled tobacco leaves are spread out and aired in an environment with a temperature of 18-30°C and a relative humidity of 50-65% until the rolled moisture content is 26-32% and then stored for use. The method provided by this patent has the following defects: first, the tobacco leaves have a high moisture content after soaking, and the overflow of moisture during the kneading process will take away some oil substances, resulting in the deterioration of the oil content of the tobacco leaves after kneading; second, directly drying the eggplant wrapper after kneading will cause the oil content to deteriorate, the color to become lighter, and the surface to become mottled.

[0004] The domestic cigar market is developing rapidly, the speed of innovation of cigar products is accelerating, and the demand for cigar raw materials and quality requirements of cigar industry enterprises are increasing. There is an urgent need for new high-quality methods for preparing Maduro wrappers to meet the needs of this field. Summary of the Invention

[0005] Existing rolling methods for making Maduro wrappers suffer from a mottled surface color and poor oil content. To address these issues, the present invention provides a method for making a Maduro wrapper. The method sequentially undergoes vacuum rehumidification, primary humidification, removal of the tobacco leaf's main veins, secondary humidification, rolling and pressing, freezing, and aging to produce a Maduro wrapper with uniform color and sufficient oil content. Specifically, the freezing step is added to slow the reaction of melanin precursors at low temperatures, resulting in a slower reaction rate. The aging step then promotes oxidation of the precursors at a similar rate within the tobacco leaf, resulting in a uniformly colored Maduro wrapper.

[0006] The specific technical solutions of the present invention are:

[0007] In a first aspect, the present invention provides a method for producing a Maduro wrapper. The method uses the Maduro wrapper variety as tobacco leaf raw material and performs the following steps:

[0008] Step S1: vacuum conditioning to make the oil content in the tobacco leaves uniform;

[0009] Step S2, performing a moistening process to make the tobacco leaves reach a low moisture content state of 15-20%;

[0010] Step S3, removing the main vein of the tobacco leaf;

[0011] Step S4: performing secondary humidification to make the tobacco leaves reach a high moisture content state of 43-47%;

[0012] Step S5: performing a kneading process to promote the release of melanin precursor substances from tobacco leaf cells;

[0013] Step S6: performing a freezing treatment to slow down the reaction of the melanin precursor;

[0014] Step S7: performing alcoholization treatment to uniformly generate melanin from the precursor material.

[0015] The principle behind rolling a Maduro wrapper is to disrupt the tobacco leaf's cellular structure, promoting the release of melanin precursors and enzymes. These precursors react with enzymes or oxygen to produce melanin, darkening the tobacco leaf's color and resulting in the tan-to-black wrapper known as the Maduro wrapper. The inventors discovered that as moisture escapes during the rolling process, these precursors are also carried to the tobacco leaf's surface. Due to the varying duration of these precursors' exposure to oxygen, this can lead to a mottled surface when the tobacco leaves dry.

[0016] To address the problem of surface mottle in rolling-made Maduro wrappers, the inventors added a freezing step after the rolling process. This low temperature slows the reaction of melanin precursors, causing them to react at a slower rate. This is then followed by an aging process, which encourages the precursors to oxidize at a similar rate within the tobacco leaves, resulting in a uniformly colored Maduro wrapper. This method sequentially undergoes vacuum rehumidification, primary humidification, removal of the tobacco leaf's main veins, secondary humidification, rolling, freezing, and aging, resulting in a Maduro wrapper with uniform color and sufficient oil content.

[0017] To further improve the color uniformity of the wrapper's surface, the moisture content of the tobacco leaves during the rolling process needs to be controlled within a range of 43-47%. Rolling is intended to disrupt the tobacco leaf's cellular structure and encourage the cells to produce melanin precursors. If the tobacco leaves have insufficient moisture, rolling and breaking the cellular structure is difficult, and the production of precursors requires the presence of water. Therefore, rolling the tobacco leaves at a higher moisture content is necessary to disrupt the cells and encourage the production of melanin precursors. However, the moisture content of the tobacco leaves during rolling cannot be too high. This is because the moisture that overflows during rolling will carry away these precursors. Excessive moisture content in the tobacco leaves results in more moisture overflow, which in turn carries away more precursors. This leads to oxidation during the rolling process, producing more melanin. This can cause noticeable mottled spots on the tobacco leaf surface, even if the oxidation rate is controlled by freezing in the subsequent steps. Therefore, based on the above considerations, the present invention requires that the moisture content of the tobacco leaves during rolling be within a range of 43-47%.

[0018] The purpose of primary humidification is to remove the main veins after the tobacco leaves reach an appropriate moisture content. Maduro wrapper varieties have thicker leaves with coarse veins, so removing the main veins improves the moistening and aging process in the later stages. The main veins must maintain a moisture content within a certain range, preferably between 15% and 20%. If the moisture content is too low, the leaves will break during the extraction process. If the moisture content is too high, the main veins will adhere to the connection between the leaves, making them difficult to remove in one go. Therefore, the moisture content must be kept within an appropriate range.

[0019] Preferably, in step S1, the vacuum degree of vacuum rehumidification is not less than -85 kPa.

[0020] During the kneading process, the tobacco leaves are in a high moisture content state of 43-47%. This moisture content state can cause the tobacco leaf cells to be damaged by kneading and produce melanin precursor substances. However, it is difficult to avoid some water overflow during the kneading process. For the precursor substances, the precursor substances brought out with the overflowing water can avoid the formation of color difference on the tobacco leaf surface, but for the tobacco leaf oil content, the oil content will be brought out with the overflowing water, causing the tobacco leaf oil content to deviate. In order to solve the problem of poor oil content in tobacco leaves, the present invention optimizes the tobacco leaf rehumidification method, rehumidifies in multiple times and promotes the uniformity of oil content through vacuum rehumidification, enhances the wettability of tobacco leaves, and makes the oil content sufficient. Among them, in order to improve the oil content uniformity of tobacco leaves and enhance the oily feel, the present invention finds that it can be achieved through vacuum treatment. Under vacuum conditions, it is conducive to improving the uniformity of oil and water in tobacco leaves.

[0021] More preferably, the vacuum rehumidification temperature is 60-70° C. and the time is 10-15 minutes, and the vacuum rehumidification increases the moisture content of the tobacco leaves by 2-4%.

[0022] Vacuum conditioning involves placing tobacco leaves in a conditioning chamber, adjusting the temperature to 60-70°C, and applying a vacuum to a minimum of -85kPa. Once the chamber reaches a preset vacuum level, a fine mist of water is sprayed into the chamber, increasing the moisture content of the leaves by 2-4%. The leaves are then treated for 10-15 minutes in a vacuum of at least -85kPa to achieve a uniform oil content.

[0023] Preferably, in step S2 and step S4, the temperature of the water used for rehumidification is 40-45°C.

[0024] Preferably, in step S2 and step S4, the water used for rehumidification is tobacco stem water, and the method for preparing the tobacco stem water is: taking tobacco stems of the Maduro wrapper variety, adding 90-100°C water at a mass ratio of 1:10-15, soaking for 10-16 hours, and filtering to obtain the water.

[0025] The water used for rehumidification is preferably at a temperature of 40 to 45°C, which can make the rehumidification more complete. It is preferably tobacco stem water at a temperature of 40 to 45°C, which can increase the oiliness of the tobacco leaves.

[0026] Preferably, in step S5, the kneading treatment method is: knead the tobacco leaves into a ball, place it in the palm of your hand, and squeeze the palms of both hands against each other for 40 to 60 seconds, and repeat this 2 to 3 times.

[0027] Preferably, in step S6, the freezing treatment method is: placing the tobacco leaves in an environment of 0 to 4°C and letting them stand for 0.5 to 10 days.

[0028] Freezing is a key step in producing the uniformly colored, oily Maduro wrapper of this invention. After rolling, the leaves are conditioned at 0-4°C for 0.5-10 days to reduce the oxidation rate of melanin precursors and prevent surface mottle.

[0029] More preferably, in step S6, the freezing treatment method is: placing the tobacco leaves in an environment of 0 to 4°C and letting them stand for 1 to 7 days.

[0030] For freezing treatment, the leaves are preferably placed at 0-4°C for 1-7 days. The purpose of freezing treatment is to reduce the oxidation rate of precursors. Keeping the leaves at 0-4°C for more than 1 day is more effective; keeping the leaves at 0-4°C for less than 7 days allows the precursors to oxidize more effectively during the later aging stage to produce melanin.

[0031] Preferably, in step S7, the method of aging treatment is: transferring the frozen tobacco leaves to a high humidity environment for aging.

[0032] Tobacco leaf aging is the chemical process that converts nicotine in tobacco into nicotine alcohol. Frozen tobacco leaves are then placed in a high-humidity environment for aging, which promotes the uniform oxidation of precursor substances throughout the leaves to produce melanin, resulting in a more uniform dark-brown color.

[0033] Preferably, the relative humidity of the alcoholization environment is 70-80%, and the temperature of the alcoholization environment is 20-25°C.

[0034] During aging in a high humidity environment of 70-80% relative humidity, tobacco leaves are prone to mildew, forming mold spots on the surface. To prevent the appearance of mold spots and further improve the color uniformity of the tobacco leaf surface, the present invention requires controlling the aging environment temperature to a relatively low 20-25°C. However, the temperature cannot be too low. Too low a temperature can cause two problems: first, poor aging effect, resulting in a strong smoking irritation of the tobacco leaves; second, poor oxidation of precursor substances, resulting in a lighter color of the tobacco leaves.

[0035] More preferably, the alcoholization treatment time is 60 to 80 days.

[0036] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0037] (1) The present invention sequentially processes vacuum conditioning, primary moisturizing, removal of the tobacco leaf's main veins, secondary moisturizing, kneading, freezing, and aging to produce a Maduro wrapper with uniform color and sufficient oil content. Specifically, the freezing step is added to slow the reaction of melanin precursors at low temperatures, subjecting them to a slower reaction rate. The aging step then promotes oxidation of the precursors at a similar rate within the tobacco leaf, resulting in a uniformly colored Maduro wrapper.

[0038] (2) The purpose of the kneading treatment is to destroy the cell structure of the tobacco leaves and encourage the cells to produce precursor substances that produce melanin. If the moisture content of the tobacco leaves is insufficient, it is difficult to knead and destroy the cell structure, and the production of precursor substances requires the participation of water. Therefore, the tobacco leaf cells need to be kneaded and pressed at a higher moisture content to destroy the cells and produce melanin precursor substances. However, the moisture content of the tobacco leaves during the kneading treatment cannot be too high. The reason is that the water overflowed by kneading will immediately carry out these precursor substances. If the moisture content of the tobacco leaves is too high, more water will overflow, and thus more precursor substances will be carried out. During the kneading stage, they will be oxidized to produce more melanin, so that even if the oxidation rate is controlled by freezing treatment in the later process, obvious spots will form on the surface of the tobacco leaves. Therefore, based on the above considerations, the present invention sets the moisture content of the tobacco leaves during the kneading treatment to be in the range of 43-47%, further improving the uniformity of the color of the wrapper surface.

[0039] (3) The purpose of freezing treatment is to reduce the oxidation rate of precursor substances. Leaving the tobacco leaves at 0-4°C for more than one day has a good effect in reducing the oxidation rate. Leaving the leaves at 0-4°C for less than seven days can better oxidize the precursor substances to produce melanin during the later aging stage. Therefore, the present invention further optimizes the freezing treatment by placing the tobacco leaves at 0-4°C for one to seven days. Freezing the tobacco leaves under these conditions can further improve the uniformity of the color on the wrapper surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 1 is a comparison chart of the cigar wrappers prepared in Comparative Examples 1 to 7 and Example 1.

[0041] In the figure: from left to right, the wrappers are those obtained in Example 1 and Comparative Examples 1 to 7. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the following embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a portion of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0043] In the embodiment of the present invention, the Maduro wrapper variety is selected as the tobacco leaf raw material.

[0044] Example 1

[0045] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0046] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0047] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0048] Step S3: removing the main veins of the tobacco leaves.

[0049] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0050] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0051] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0052] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0053] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0054] Example 2

[0055] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0056] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0057] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0058] Step S3: removing the main veins of the tobacco leaves.

[0059] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0060] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0061] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 1 day to slow down the reaction of melanin precursor substances.

[0062] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0063] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0064] Example 3

[0065] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0066] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0067] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0068] Step S3: removing the main veins of the tobacco leaves.

[0069] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0070] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0071] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 7 days to slow down the reaction of melanin precursor substances.

[0072] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0073] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0074] Example 4

[0075] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0076] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0077] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0078] Step S3: removing the main veins of the tobacco leaves.

[0079] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0080] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0081] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 0.5 days to slow down the reaction of melanin precursor substances.

[0082] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0083] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0084] Example 5

[0085] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0086] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0087] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0088] Step S3: removing the main veins of the tobacco leaves.

[0089] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0090] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0091] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 10 days to slow down the reaction of melanin precursor substances.

[0092] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0093] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0094] Example 6

[0095] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0096] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0097] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0098] Step S3: removing the main veins of the tobacco leaves.

[0099] Step S4: Moisten the tobacco leaves by rehumidifying the leaves in small amounts and multiple times. After sealing the leaves in plastic bags, carry out moisture balance in an environment of 36° C., so that the tobacco leaves reach a high moisture content of 43%.

[0100] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0101] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0102] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0103] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0104] Example 7

[0105] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0106] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0107] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0108] Step S3: removing the main veins of the tobacco leaves.

[0109] Step S4: Moisten the tobacco leaves by rehumidifying the leaves in small amounts and multiple times. After sealing the leaves in plastic bags, perform moisture balance in an environment of 36° C. to make the tobacco leaves reach a high moisture content of 47%.

[0110] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0111] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0112] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor material. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0113] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0114] Example 8

[0115] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0116] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0117] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0118] Step S3: removing the main veins of the tobacco leaves.

[0119] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0120] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0121] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0122] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 70%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0123] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0124] Example 9

[0125] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0126] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 65°C, and evacuate to -85kPa. Maintain the vacuum in the chamber at -85kPa for 12 minutes. When the vacuum reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 3%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -85kPa.

[0127] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content of 18%.

[0128] Step S3: removing the main veins of the tobacco leaves.

[0129] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0130] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0131] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0132] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 80%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 60 days.

[0133] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 95° C. water at a mass ratio of 1:12, soaking for 15 hours, and filtering.

[0134] Example 10

[0135] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0136] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 60°C, and evacuate to -100 kPa. Maintain the vacuum in the chamber at -100 kPa for 10 minutes. When the vacuum in the chamber reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 2%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -100 kPa.

[0137] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags and performing moisture balance in an environment of 36° C., so that the tobacco leaves reach a low moisture content of 15%.

[0138] Step S3: removing the main veins of the tobacco leaves.

[0139] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0140] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0141] Step S6: Place the tobacco leaves in a 5°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0142] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 20° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 70 days.

[0143] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 40° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 100° C. water at a mass ratio of 1:10, soaking for 10 hours, and filtering.

[0144] Example 11

[0145] This embodiment provides a Maduro wrapper with uniform color and sufficient oil content. The preparation method includes the following steps:

[0146] Step S1: Place tobacco leaves in a dehumidification chamber, adjust the chamber temperature to 70°C, and evacuate to -105 kPa. Maintain the vacuum level at -105 kPa for 15 minutes. When the vacuum level reaches a preset value, spray a fine mist of water into the chamber to increase the moisture content of the tobacco leaves by 4%. This achieves a uniform oil content in the tobacco leaves under a vacuum of -105 kPa.

[0147] Step S2: Moisturizing the tobacco leaves by spraying, sealing the leaves in plastic bags, and performing moisture balance in an environment of 36° C. to make the tobacco leaves reach a low moisture content state of 20%.

[0148] Step S3: removing the main veins of the tobacco leaves.

[0149] Step S4: moisturize the tobacco leaves by rehumidifying them in small amounts and multiple times. After sealing them in plastic bags, they are placed in an environment of 36° C. for moisture balance, so that the tobacco leaves reach a high moisture content of 45%.

[0150] Step S5: Kneading to promote the release of melanin precursors from tobacco leaf cells. The kneading method is as follows: knead the tobacco leaf into a ball, place it in the palm of your hand, and squeeze it firmly with your palms facing each other for 40 to 60 seconds. Repeat this 2 to 3 times. The kneading strength, time, and number of times are adjusted appropriately according to the thickness of the tobacco leaf.

[0151] Step S6: Place the tobacco leaves in a 0°C environment and let them stand for 5 days to slow down the reaction of melanin precursor substances.

[0152] Step S7: performing an alcoholization treatment to uniformly generate melanin from the precursor. The alcoholization treatment method is as follows: adjusting the temperature of the alcoholization chamber to 25° C. and the relative humidity to 75%, and placing the tobacco leaves in the alcoholization chamber for alcoholization for 80 days.

[0153] In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the temperature of the rehumidification water is 45° C. The tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 90° C. water at a mass ratio of 1:15, soaking for 16 hours, and filtering.

[0154] Comparative Example 1

[0155] The main difference from Example 1 is that the 0° C. environment treatment in step S6 is not performed. The other steps are the same as those in Example 1.

[0156] Comparative Example 2

[0157] The main difference from Example 1 is that in step S6, the mixture is left for 12 days. The other steps are the same as those in Example 1.

[0158] Comparative Example 3

[0159] The main difference from Example 1 is that in step S4, the moisture content of the tobacco leaves is adjusted to 40%. The other steps are the same as those in Example 1.

[0160] Comparative Example 4

[0161] The main difference from Example 1 is that in step S4, the moisture content of the tobacco leaves is adjusted to 50%. The other steps are the same as those in Example 1.

[0162] Comparative Example 5

[0163] The main difference from Example 1 is that the vacuum rehumidification treatment in step S1 is not performed. The other steps are the same as those in Example 1.

[0164] Comparative Example 6

[0165] The main difference from Example 1 is that in step S1, the vacuum treatment is maintained for 5 minutes. The other steps are the same as in Example 1.

[0166] Comparative Example 7

[0167] The main difference from Example 1 is that in step S1, the vacuum treatment is maintained for 20 minutes. The other steps are the same as in Example 1.

[0168] Performance Characterization

[0169] The wrappers obtained in Examples 1 to 11 and Comparative Examples 1 to 7 were rolled into cigarettes, and the color of the cigarettes was recorded as shown in Table 1. Figure 1 , wherein the cigarettes from left to right are Example 1 and Comparative Examples 1-7.

[0170] Table 1

[0171] Cigarette color Example 1 Nearly black, uniform color, good oil content, strong oily feeling Example 2 Nearly black, uniform color, good oil content, strong oily feeling Example 3 Nearly black, uniform color, good oil content, strong oily feeling Example 4 Dark brown, uniform color, good oil content, strong oily feeling Example 5 Dark brown, uniform color, good oil content, strong oily feeling Example 6 Nearly black, uniform color, good oil content, strong oily feeling Example 7 Nearly black, uniform color, good oil content, strong oily feeling Example 8 Nearly black, uniform color, good oil content, strong oily feeling Example 9 Nearly black, uniform color, good oil content, strong oily feeling Example 10 Nearly black, uniform color, good oil content, strong oily feeling Example 11 Nearly black, uniform color, good oil content, strong oily feeling Comparative Example 1 Mottled and uneven color, average oil content, poor oiliness Comparative Example 2 The color is mottled and lighter, the color is uneven, and the oiliness is poor Comparative Example 3 The color is mottled and lighter, the color is uneven, and the oiliness is poor Comparative Example 4 Mottled color, uniform color, poor oiliness Comparative Example 5 Light color, uniform color, poor oiliness Comparative Example 6 Light color, uniform color, poor oiliness Comparative Example 7 Lighter color, uniform color, poor oil content, poor oiliness

[0172] From this we can see that:

[0173] ① As shown in the resulting wrapper produced in this embodiment of the present invention, the present invention achieves a Maduro wrapper with uniform color and sufficient oil content through a sequential process of vacuum conditioning, primary humidification, removal of the tobacco leaf's main veins, secondary humidification, kneading, freezing, and aging. Specifically, the addition of the freezing step slows the reaction of melanin precursors at low temperatures, subjecting them to a slower reaction rate. The aging step then promotes oxidation of the precursors at a similar rate within the tobacco leaf, resulting in a uniformly colored Maduro wrapper.

[0174] ② Comparison of Comparative Examples 1 and 2 with Example 1 reveals that Comparative Example 1, which was not frozen, produced a mottled and uneven wrapper, demonstrating that low temperatures can promote the formation of a uniform dark brown color. Comparative Example 2, which was stored at 0°C for 12 days, produced a lighter wrapper. This may be due to the fact that low temperatures hinder the oxidation of melanin precursors. However, prolonged freezing reduces the catalytic efficiency of the enzymes that convert precursors to melanin, making it difficult to restore high catalytic efficiency during the later aging stage.

[0175] ③ From the comparative analysis of Comparative Examples 3 and 4 and Example 1, it can be seen that the main difference between Comparative Examples 3 and 4 and Example 1 is the moisture content of the tobacco leaves during the kneading process. The color of the tobacco leaves is mottled and uneven. The reason for this is: the kneading process is to destroy the cell structure of the tobacco leaves and encourage the cells to produce precursor substances that produce melanin. If the moisture content of the tobacco leaves is not enough, it is difficult to rub and destroy the cell structure. The generated melanin precursor substances are prone to uneven distribution, so the color mottled phenomenon on the surface of the tobacco leaves is prone to occur. When the moisture content of the tobacco leaves is too high during the kneading process, the moisture overflowed by kneading will immediately bring out these precursor substances. The excessive moisture content of the tobacco leaves will lead to an increase in the overflow of moisture. Therefore, during the kneading stage, more melanin will be oxidized on the surface of the tobacco leaves, so that even if the oxidation rate is controlled by freezing treatment in the later stage, it will cause obvious mottled formation on the surface of the tobacco leaves. Therefore, the color mottled phenomenon of Comparative Examples 3 and 4 is obvious.

[0176] ④ Comparison of Comparative Examples 5-7 with Example 1 demonstrates the enhanced vacuum rehydration effect of the present invention. Comparative Example 5, which did not undergo vacuum treatment, and Comparative Example 6, which underwent a shorter vacuum treatment time, resulted in a less oily wrapper. This demonstrates that vacuum conditions improve the uniformity of oil and moisture content within the tobacco leaves, enhancing the oiliness. However, Comparative Example 7, underwent vacuum treatment for an extended period, resulting in a decrease in oil content.

[0177] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0178] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for producing a Maduro wrapper, characterized by: Using the Maduro wrapper variety as tobacco leaf, the following steps were performed: Step S1: vacuum conditioning at a temperature of 60-70°C for 10-15 minutes to make the oil content in the tobacco leaves uniform; Step S2: adding moisture once to make the tobacco leaves reach a low moisture content state of 15-20%; Step S3, removing the main vein of the tobacco leaf; Step S4: performing secondary humidification to make the tobacco leaves reach a high moisture content state of 43-47%; Step S5: performing a kneading process to promote the release of melanin precursor substances from tobacco leaf cells; Step S6: placing the tobacco leaves in a 0-4°C environment for 0.5-10 days for freezing treatment to slow down the reaction of melanin precursor substances; Step S7: performing alcoholization treatment to uniformly generate melanin from the precursor material.

2. The method for making a Maduro wrapper according to claim 1, wherein: In step S1, the vacuum degree of vacuum rehumidification is not less than -85 kPa.

3. The method for making a Maduro wrapper according to claim 1, wherein: In step S2 and step S4, the temperature of the water used for rehumidification is 40-45°C.

4. The method for making a Maduro wrapper according to claim 1 or 3, wherein: In step S2 and step S4, the water used for rehumidification is tobacco stem water, and the tobacco stem water is prepared by taking tobacco stems of the Maduro wrapper variety, adding 90-100°C water at a mass ratio of 1:10-15, soaking for 10-16 hours, and filtering to obtain the obtained water.

5. The method for making a Maduro wrapper according to claim 1, wherein: In step S5, the kneading treatment method is: knead the tobacco leaves into a ball, place it in the palm of your hand, and squeeze the palms of both hands against each other for 40 to 60 seconds, and repeat this 2 to 3 times.

6. The method for making a Maduro wrapper according to claim 1, wherein: In step S6, the freezing treatment method is: placing the tobacco leaves in an environment of 0-4°C and letting them stand for 1-7 days.

7. The method for making a Maduro wrapper according to claim 1, wherein: In step S7, the method of aging treatment is: transferring the frozen tobacco leaves to a high humidity environment for aging.

8. The method for making a Maduro wrapper according to claim 7, wherein: The relative humidity of the aging environment is 70~80%.

9. The method for making a Maduro wrapper according to claim 1, wherein: The temperature of the aging environment is 20~25℃.

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