Method for improving tobacco leaf quality of agricultural fermented cigar based on fermented grains or summer and autumn tea medium solution

Abstract

The invention relates to the technical field of cigars, in particular to a method for improving the quality of agricultural fermented cigar tobacco leaves based on a fermented grain or summer and autumn tea medium solution, which comprises the following steps: 1) uniformly mixing fermented grains or summer and autumn tea with distilled water to obtain a medium solution; (2) cigar tobacco leaves are prepared, the medium solution is evenly sprayed on the surfaces of the cigar tobacco leaves, then the cigar tobacco leaves are subjected to stacking fermentation, the fermentation humidity is set to be 65%-75%, the temperature is set to be 27-37 DEG C, and fermentation is conducted for 4-60 days. According to the cigar tobacco leaves treated through the method, the volatile aroma component substance content of the tobacco leaves can be obviously increased, the smoke characteristic and the combustion characteristic are improved, the sweet feeling is enhanced, and aroma enhancement and quality improvement of the cigar tobacco leaves are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of cigar tobacco, and specifically relates to a method for enhancing the flavor and quality of agricultural fermented cigar tobacco leaves by utilizing medium fermentation technology. Background Art

[0002] Due to the limitations of technical conditions, geographical environment and climatic factors, the style characteristics of domestic tobacco leaves are relatively weak, and there is still a certain gap in overall quality compared with imported tobacco leaves, which is mainly reflected in the low richness of aroma, heavy smell, obvious oral residue and weak sweetness, which makes the domestic and foreign cigar markets crowded by imported cigars all year round. After agricultural fermentation, the irritation and smell of cigar tobacco leaves are significantly reduced, and the internal substances are more coordinated, which effectively makes up for the quality defects of non-high-quality raw materials and improves the availability of domestic cigar tobacco raw materials. At the same time, it also lays a better raw material foundation for the subsequent industrial fermentation of cigar tobacco, effectively increasing the upper limit of cigar tobacco utilization.

[0003] During the fermentation process of cigar tobacco leaves, oxidation, microbial action and enzyme action jointly affect the quality of cigar tobacco. Fermentation media improves the quality of tobacco leaves by changing the chemical composition or bacterial environment in tobacco leaves. However, the current research on the fermentation process of cigar tobacco at home and abroad mainly focuses on the optimization of fermentation technology. There are few reports on the research on medium-cooperative fermentation of cigars, and the types of media available for actual production of cigar tobacco are scarce. In addition, given the large scale and high technical difficulty of agricultural fermentation operations, research on the optimization of tobacco leaf fermentation by adding fermentation media is still in its infancy, which indicates the great potential of tapping agricultural fermentation additives.

[0004] As the main body of liquor fermentation, fermented grains are rich in carbohydrates, proteins and flavor substances, and can increase aroma components through non-enzymatic browning reactions of sugars and amino acids. Tea is recognized as a healthy beverage in the world. Summer and autumn tea grows fast under strong light and high temperature conditions in summer and autumn, resulting in poor tenderness and easy aging of tea leaves. Its carbon metabolism is high and nitrogen metabolism is relatively low, which makes the polyphenols in tea higher, while the content of aromatic substances, vitamins, amino acids, etc. is low, and the quality is significantly lower than that of spring tea. However, fermentation can promote the transformation of summer and autumn tea components, produce many secondary metabolites, increase beneficial substances, form the unique flavor quality of summer and autumn tea and enhance the health benefits of summer and autumn tea. These two media have special fragrance and active substances, which can enrich the taste of tobacco leaves during the fermentation of cigar tobacco leaves. At the same time, fermented grains and summer and autumn tea are the main carriers of fermentation microorganisms. Through microbial metabolism, they can produce a variety of highly active enzymes such as protease, amylase and pectinase, promote the degradation of macromolecular substances such as starch and protein, increase the aroma components in cigar tobacco leaves, and optimize the fermentation quality. However, in the prior art, there has been no report on using fermented grains and summer and autumn tea as fermentation media to assist cigar tobacco leaves in agricultural fermentation to achieve the purpose of enhancing the flavor and quality of cigar tobacco. Summary of the invention

[0005] The purpose of the present invention is to provide a method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution, which can effectively enhance the flavor and quality of cigar tobacco leaves and promote the development of the Chinese cigar industry.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution, comprising the following steps: (1) Take fermented grains or summer and autumn tea and mix them with distilled water to obtain a medium solution; (2) preparing cigar tobacco leaves, spraying the medium solution obtained in step (1) evenly on the surface of the cigar tobacco leaves, and then stacking the cigar tobacco leaves for fermentation, setting the fermentation humidity to 65%-75%, the temperature to 27°C-37°C, and performing the fermentation cycle for 4-60 days.

[0007] Furthermore, in step (1), the mass of the fermented grains accounts for 10-20% of the mass of the distilled water, and the mass of the summer and autumn tea accounts for 10-20% of the mass of the distilled water.

[0008] Furthermore, in step (1), the mass of the fermented grains accounts for 10-15% of the mass of the distilled water, and the mass of the summer and autumn tea accounts for 10-15% of the mass of the distilled water.

[0009] Furthermore, in step (2), the mass of the medium solution accounts for 10-30% of the mass of the cigar tobacco leaves.

[0010] Furthermore, in step (2), the mass of the medium solution accounts for 10-20% of the mass of the cigar tobacco leaves.

[0011] Furthermore, in step (2), the fermentation conditions are: fermentation humidity 70%, temperature 32° C., and fermentation cycle 32 days.

[0012] It also includes a chemical composition detection step, specifically: taking tobacco leaf samples during the fermentation process and after the fermentation for testing, using an electronic nose, a fully automatic amino acid analyzer and HS-SPME GC / MS to quickly detect the free amino acids and volatile aroma components of the core tobacco leaves, and conducting sensory evaluation.

[0013] Among them, according to the actual stacking time, samples were collected on the 4th, 32nd and 60th days of agricultural fermentation of the cigar core tobacco leaves. All samples belonged to the middle part of the cigar core tobacco leaves of the same origin, the same variety and the same original tobacco grade.

[0014] The chemical composition detection comprises the following steps: (1) The E-Nose detector was used to detect tobacco leaf samples at different stages of agricultural fermentation under different media treatments. The difference information of the samples was obtained based on the response values ​​of the 10 sensors of the electronic nose. (2) An automatic amino acid analyzer was used to test tobacco leaf samples from different fermentation media at different stages to obtain the characteristic information of free amino acid changes in the samples; (3) HS-SPME GC / MS detection and analysis technology was used to detect tobacco leaf samples at different stages of agricultural fermentation under different media treatments to obtain the volatile flavor substances of the samples; (4) Use sensory evaluation method to evaluate the quality of fermented tobacco leaves.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The cigar tobacco leaves treated by the method of the present invention can significantly increase the content of volatile aroma components in the tobacco leaves, improve smoke characteristics and combustion characteristics, enhance sweetness, and achieve alkali reduction, aroma enhancement and quality improvement of the cigar tobacco leaves. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the radar diagram of the electronic nose of filler tobacco leaves treated with different media.

[0017] Figure 2 The composition and content of free amino acids in filler tobacco leaves treated with different media.

[0018] Figure 3 The composition and content of volatile flavor substances in filler tobacco leaves treated with different media. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] A method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution, the specific steps are: (1) 0.25 kg of fermented grains and 0.25 kg of summer and autumn tea were mixed with 2 kg of distilled water respectively, and soaked for 3 h. The mixture was stirred continuously during soaking, and then allowed to stand, precipitate, and filter to finally obtain 1.5 kg of fermented grains medium solution and 1.5 kg of summer and autumn tea medium solution.

[0021] (2) Prepare 10.0 kg of cigar tobacco leaves, spray the fermented grains medium solution and summer and autumn tea medium solution evenly on the surface of the cigar tobacco leaves, and then pile up the tobacco leaves for fermentation. The fermentation conditions are: fermentation humidity of 70%, temperature of 32°C, and fermentation period of 60 days. Samples were taken from the tobacco leaves on the 4th day (early fermentation), 32nd day (middle fermentation), and 60th day (late fermentation). The free amino acids and volatile aroma components of the cigar core tobacco leaves were quickly detected using sensory evaluation, electronic nose (E-Nose), fully automatic amino acid analyzer, and headspace solid phase microextraction-gas chromatography / mass spectrometry (HS-SPME GC / MS).

[0022] In addition, the fermented grains and summer and autumn tea medium solutions were replaced with pure water, and a blank control group experiment was carried out following the same steps.

[0023] The following is a detailed description of the test results of filler tobacco leaves at different stages of agricultural fermentation under different media treatments, combined with specific operating steps.

[0024] Among them, the electronic nose was used to quickly smell the changes in volatile aroma components of fermented cigar core tobacco leaf samples. Cigar core tobacco leaf samples at different stages under different agricultural fermentation media treatments were accurately weighed and placed in 20 mL injection bottles, which were tightly sealed with injection bottle caps and placed in a 60°C water bath for heating for 10 min. During the detection, the zero gas needle and the electronic nose injection needle were simultaneously inserted into the headspace injection bottle for sampling, and the volatile gas was inhaled into the electronic nose sensor system for detection. The sensor chamber flow rate of the electronic nose was 400 mL / min, the initial injection flow rate was 400 mL / min, the sampling interval was 1.0 s, the cleaning time was 90 s, the zeroing time was 5 s, the pre-injection time was 5 s, and the measurement time was 150 s. Among them, the 10 sensors of the electronic nose include: W1C, which is sensitive to aromatic compounds; W5S, which is sensitive to nitrogen oxides; W3C, which is sensitive to ammonia and aromatic compounds; W6S, which is sensitive to hydrogen substances; W5C, which is sensitive to alkanes and aromatic compounds; W1S, which is sensitive to methyls; W1W, which is sensitive to inorganic sulfides and terpenes; W2S, which is sensitive to alcohols and some aromatic compounds; W2W, which is sensitive to aromatic compounds and organic sulfides; and W3S, which is sensitive to alkanes. The electronic nose response values ​​of the tobacco leaves in the early, middle and late fermentation stages under different media treatments of agricultural fermentation are shown in Table 1 and Table 2. Figure 1 shown.

[0025] Table 1 Electronic nose response values ​​of filler tobacco leaves under different media treatments

[0026] Note: Lowercase letters after different groups of data at the same fermentation period indicate significant differences at the P<0.05 level.

[0027] The response value of the electronic nose sensor can reflect the relative content of sensitive substances corresponding to different samples. At the same fermentation time, the response values ​​of tobacco leaves with different fermentation media were compared, and it was found that the composition of flavor substances was similar, but there were obvious differences in the content, and the nitrogen oxides corresponding to W5S were a more prominent type of substance in tobacco leaves. In the early stage of fermentation, the proportion of nitrogen oxides in fermented mash and summer and autumn tea was relatively high. In the middle stage of fermentation, the nitrogen oxide content of the three treatment groups increased significantly, and the nitrogen oxides in fermented mash were lower than those in the other two groups. In the late stage of fermentation, the response values ​​of tobacco leaves in the fermented mash and summer and autumn tea groups to W5S were lower than those in the distilled water group, indicating that fermented mash and summer and autumn tea play an important role in degrading the content of nitrogen oxides represented by nicotine, and the decrease in nicotine content can reduce the physiological strength and irritation of tobacco leaves and improve the aroma quality of tobacco leaves.

[0028] An amino acid automatic analyzer was used to detect the samples of cigar core tobacco leaves at different stages under different agricultural fermentation media treatments to accurately quantify the composition and content of free amino acids in cigar core tobacco leaves. A total of 17 free amino acids were detected, including two umami amino acids: aspartic acid (Asp) and glutamic acid (Glu); five sweet amino acids: serine (Ser), glycine (Gly), threonine (Thr), alanine (Ala), and proline (Pro); nine bitter amino acids: tyrosine (Tyr), valine (Val), methionine (Met), isoleucine (Ile), histidine (His), arginine (Arg), leucine (Leu), phenylalanine (Phe), lysine (Lys), and a tasteless amino acid cysteine ​​(Cys). The composition and content of free amino acids in cigar core tobacco leaves at the early, middle, and late stages of fermentation under different agricultural fermentation media treatments are shown in Tables 2 and 3. Figure 2 shown.

[0029] Table 2 Composition and content of free amino acids in tobacco leaves of filler under different media treatments (mg / g)

[0030] Note: Lowercase letters after different groups of data at the same fermentation period indicate significant differences at the P<0.05 level.

[0031] In the fermented cigar core tobacco leaves, sweet amino acids dominated, followed by bitter and umami amino acids, and the content of tasteless amino acids was the lowest. The total amount of umami amino acids in the tobacco leaves fermented with fermented mash and summer and autumn tea was lower than that in the distilled water group, but sweet amino acids became more prominent, which shows that when fermented mash and summer and autumn tea media are introduced into cigar tobacco leaves for synergistic fermentation, the dominant position of sweet amino acids in tobacco leaves is more prominent, shaping the flavor characteristics of tobacco leaves under agricultural fermentation that are sweeter than those fermented with traditional distilled water.

[0032] The volatile flavor substances in the samples were detected by headspace solid phase microextraction-gas chromatography-mass spectrometry. Sample pretreatment: Weigh 0.5 g of undried tobacco leaf sample into a 20 mL headspace bottle, add 1 μL (1.03 μg / μL) phenylethyl acetate internal standard solution and 8 mL saturated sodium chloride solution, put into the rotor, balance at 65 °C for 20 min (speed of 300 r / min), extract for 35 min, then quickly pull out the extraction head and insert it into the injection port, analyze at 250 °C for 5 min before detection. Gas chromatography and mass spectrometry conditions: chromatographic column, DB-5MS (30m×0.25mm×0.25μm); carrier gas, He; splitless injection, flow rate, 0.8mL / min; injection port temperature 250℃, transfer line temperature 280℃, ion source temperature 230℃, heating program: initial temperature 60℃, hold for 1min, increase to 180℃ at a rate of 3℃ / min, hold for 2min, increase to 260℃ at a rate of 6℃ / min, hold for 2min; ionization energy 70 eV; mass number range 35~450 amu. The volatile flavor substances were qualitatively identified by combining the mass spectral information with the NIST 20 standard mass spectral database, and the internal standard method was used to quantitatively analyze the substances. The content results of the substances in the early, middle and late fermentation stages are shown in Tables 3, 4, 5 and Figure 3 shown.

[0033] Table 3 Composition and content of volatile flavor substances in filler tobacco leaves treated with different media in the early stage of fermentation (μg / g)

[0034] Note: Lowercase letters after the same data indicate significant differences at the P<0.05 level, and “ / ” indicates no difference was detected.

[0035] Obviously, the cigar tobacco leaves in the early stage of distilled water fermentation contain fewer aroma components and weaker style characteristics. After adding fermented grains and summer and autumn tea for synergistic fermentation, the types and contents of aroma substances increased significantly, especially the total amount of new phytadiene, ketones, esters and aldehydes. These substances have been reported to play a certain role in reducing the irritation of tobacco leaves and increasing the aroma quality of tobacco leaves.

[0036] Table 4 Composition and content of volatile flavor substances in filler tobacco leaves treated with different media in the middle stage of fermentation (μg / g)

[0037] Note: Lowercase letters after the same data indicate significant differences at the P<0.05 level, and “ / ” indicates no difference was detected.

[0038] Compared with the early stage of fermentation, the aroma substance content of tobacco leaves in the middle stage of fermentation increased significantly. In particular, the new phytodienes, alcohols, aldehydes, and acids in cigar tobacco leaves fermented with fermented grains increased significantly, and the common aroma components in cigar tobacco leaves, such as 4,7,9-megatriene-3-one, dihydroactinol, and isophorone, increased significantly. These substances are reported to have certain effects in reducing irritation, reducing green impurities, alcohols, and smoke, thereby improving the sensory quality of tobacco leaves.

[0039] Table 5 Composition and content of volatile flavor substances in filler tobacco leaves treated with different media in the late fermentation period (μg / g)

[0040] Note: Lowercase letters after the same data indicate significant differences at the P<0.05 level, and “ / ” indicates no difference was detected.

[0041] When fermentation reached the later stage, the total amount of aroma in each group decreased, but the nicotine content decreased significantly in general. At the same time, the content of neophytadiene in the fermented mash and summer and autumn tea groups was significantly higher than that in the distilled water group. In addition, the aroma components such as β-damascenone, acetophenone, tea ketone, solanone, and isophorone increased in the tobacco leaves fermented with fermented mash medium. This shows that fermentation will increase the content of aroma substances in the tobacco leaves of the cigar core. Although the fermentation stage at this time will cause the loss of aroma substances, it has a significant promoting effect on the degradation of nicotine and the continuous accumulation of neophytadiene.

[0042] Comparison of different fermentation media to improve the sensory quality evaluation of agricultural fermented cigar tobacco leaves, cigar tobacco leaves in the process of distilled water, fermented grains and summer and autumn tea fermentation were rolled into single-material cigarettes according to the specifications of 110mm in length and 47mm in circumference. The evaluation team was composed of 5 smoking evaluation experts with certificates issued by the National Tobacco Quality Supervision and Inspection Center, and the sensory quality was scored using a 9-point system. Among them, aroma quality, aroma volume, aftertaste, miscellaneous smell, sweetness, irritation, and gray accounted for 18%, 16%, 16%, 10%, 10%, 12%, 10%, and 8% respectively.

[0043] Table 6 Sensory evaluation of filler tobacco leaves treated with different media

[0044] From the sensory results in Table 6, the tobacco leaves in the middle and late fermentation stages of the fermented mash performed best overall, especially in terms of aroma, aftertaste and combustibility. Especially in the middle fermentation stage, the sensory qualities of the fermented mash and summer and autumn tea were relatively balanced, with good performance in terms of aroma, aftertaste and gray, less impurities, moderate sweetness, good combustibility, and relatively stable overall performance.

[0045] From the analysis results of the electronic nose, free amino acids and aroma components of the above cigar samples, it can be seen that when the fermented mash medium and summer and autumn tea medium are added during the fermentation of cigar tobacco leaves, it can be clearly found that during the entire fermentation process, the content of volatile aroma components in the fermented mash medium group and the summer and autumn tea medium group is significantly higher than that in the distilled water group. Through medium fermentation, the nicotine content in cigar tobacco leaves is reduced, the aroma components are accumulated, and the sweet amino acids are more prominent, further achieving the effect of reducing alkali and increasing aroma. In addition, according to the results of sensory evaluation, the introduction of fermented mash medium and summer and autumn tea medium can significantly increase the aroma, aftertaste and sweetness of tobacco leaves, and improve the impurities and combustion characteristics.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution, characterized in that: The following steps are involved: (1) Take fermented grains or summer and autumn tea and mix them with distilled water to obtain a medium solution; (2) preparing cigar tobacco leaves, spraying the medium solution obtained in step (1) evenly on the surface of the cigar tobacco leaves, and then stacking the cigar tobacco leaves for fermentation, setting the fermentation humidity to 65%-75%, the temperature to 27°C-37°C, and performing the fermentation cycle for 4-60 days.

2. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 1, characterized in that: In the step (1), the weight of the fermented grains accounts for 10-20% of the weight of the distilled water, and the weight of the summer and autumn tea accounts for 10-20% of the weight of the distilled water.

3. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 2, characterized in that: In the step (1), the mass of the fermented grains accounts for 10-15% of the mass of the distilled water, and the mass of the summer and autumn tea accounts for 10-15% of the mass of the distilled water.

4. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 1, characterized in that: In the step (2), the mass of the medium solution accounts for 10-30% of the mass of the cigar tobacco leaves.

5. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 4, characterized in that: In the step (2), the mass of the medium solution accounts for 10-20% of the mass of the cigar tobacco leaves.

6. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 1, characterized in that: In step (2), the fermentation conditions are: fermentation humidity 70%, temperature 32°C, and fermentation cycle of 32 days.

7. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 1, characterized in that: It also includes a chemical composition detection step, specifically: taking tobacco leaf samples during the fermentation process and after the fermentation for testing, using an electronic nose, a fully automatic amino acid analyzer and HS-SPME GC / MS to quickly detect the free amino acids and volatile aroma components of the core tobacco leaves, and conducting sensory evaluation.

8. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 7, characterized in that: According to the actual stacking time, samples were collected on the 4th, 32nd and 60th days of agricultural fermentation of the core tobacco leaves. All samples were from the middle core tobacco leaves of the same origin, variety and original tobacco grade.

9. The method for improving the quality of agricultural fermented cigar tobacco leaves based on fermented grains or summer and autumn tea medium solution according to claim 8, characterized in that: Chemical composition testing includes the following steps: (1) The E-Nose detector was used to detect tobacco leaf samples at different stages of agricultural fermentation under different media treatments. The difference information of the samples was obtained based on the response values ​​of the 10 sensors of the electronic nose. (2) An automatic amino acid analyzer was used to test tobacco leaf samples from different fermentation media at different stages to obtain the characteristic information of free amino acid changes in the samples; (3) HS-SPME GC / MS detection and analysis technology was used to detect tobacco leaf samples at different stages of agricultural fermentation under different media treatments to obtain the volatile flavor substances of the samples; (4) Use sensory evaluation method to evaluate the quality of fermented tobacco leaves.

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