A method for panax ginseng fermentation

Abstract

The application discloses a method for American ginseng fermentation. Through comprehensive evaluation of multiple lactic acid bacteria, including acid production capacity, color regulation and flavor characteristic analysis, the application finally screens a most suitable strain for American ginseng fermentation, which exhibits significant flavor regulation advantages. On the one hand, it can completely degrade the characteristic earthy smell substances of American ginseng, effectively improving the bad flavor of the raw material; on the other hand, it can specifically produce compounds with fruity characteristics, giving the fermentation product a significant sweet flavor. In addition, the strain of the application maintains suitable acid production capacity and color stability, realizes significant improvement of flavor quality on the premise of ensuring fermentation efficiency. These characteristics make the strain an ideal fermentation strain for developing high-quality fermented American ginseng products.

Description

A method for fermenting American ginseng

[0001] Cross-references to related applications

[0002] This application is a divisional application of the same name filed on August 4, 2025, with application number CN202511081282.7 and entitled "A strain of Weissella esculenta for enhancing the fermented flavor of American ginseng and its uses thereof", which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to the field of fermentation, and more specifically to a method for fermenting American ginseng. Background Technology

[0004] American ginseng (Panax quinquefolius L.) is an important medicinal plant belonging to the genus Panax in the family Araliaceae, and is closely related to Asian ginseng (P. ginseng) and notoginseng (P. notoginseng). American ginseng is rich in various bioactive components, mainly including ginsenosides, polysaccharides, and polyacetylenes. It is commonly consumed by slicing or grinding into powder and taking it with water. However, the inherent strong earthy and musty off-flavor of American ginseng significantly affects consumer sensory acceptance, severely restricting its in-depth development and application in the food, health product, and pharmaceutical fields. Therefore, effectively improving or eliminating its unpleasant flavor is key to enhancing the overall quality of American ginseng products and expanding its market applications. Summary of the Invention

[0005] This invention provides a method for fermenting American ginseng. Specifically, the technical solution of this invention is as follows.

[0006] In a first aspect, the present invention provides a *Weissella cibaria* strain for enhancing the fermented flavor of American ginseng, namely *Weissella cibaria* GA2-3, which was deposited on May 8, 2025, at the China General Microbiological Culture Collection Center (CGMCC) in Beijing, China, with accession number CGMCC No. 34460, and classified as *Weissella cibaria*.

[0007] In a second aspect, the present invention provides a microbial inoculum for the fermentation of American ginseng, comprising the *Westernella esculenta* as described in the first aspect or a culture derived therefrom.

[0008] A third aspect of the present invention provides a fermentation method for enhancing the fermented flavor of American ginseng, comprising the step of fermenting American ginseng using the *Westernella edodes* strain described in the first aspect.

[0009] In some embodiments, the fermentation method for enhancing the fermented flavor of American ginseng according to the present invention includes:

[0010] (1) Sterilize the solution containing American ginseng powder or granules;

[0011] (2) The *Westernella esculenta* is inoculated into the solution and fermented under suitable conditions.

[0012] In some embodiments, the initial inoculum amount of *Westernella esculenta* in the fermentation method for enhancing the fermented flavor of American ginseng according to the present invention is 0.1-10 log CFU / ml.

[0013] In some embodiments, the initial pH of the solution in the fermentation method for enhancing the fermented flavor of American ginseng according to the present invention is weakly acidic.

[0014] In some embodiments, the method for enhancing the fermentation flavor of American ginseng according to the present invention includes at least one of the following:

[0015] (1) Degrade earthy-smelling substances or reduce the amount of earthy-smelling substances;

[0016] (2) To produce acidic compounds or increase the amount of acidic compounds;

[0017] (2) To produce fruit flavor compounds or increase the amount of fruit flavor compounds.

[0018] In some embodiments, the method for enhancing the fermentation flavor of American ginseng according to the present invention includes reducing the amount of aldehydes and alcohols, wherein the aldehydes and alcohols include at least one of hexanal, heptanal, octanal, and 2-ethylhexanol.

[0019] In some embodiments, the improvement of the fermentation flavor of American ginseng in the fermentation method of the present invention includes degrading or reducing the amount of 1-octen-3-ol.

[0020] In some embodiments, the method for enhancing the fermentation flavor of American ginseng according to the present invention includes promoting the production of hexanoic acid and n-heptanol.

[0021] This invention screened a strain that can significantly improve the flavor and quality of American ginseng solution by fermenting it, providing a new technical approach for developing high-value-added American ginseng products. It has important scientific research value and broad market application potential. Attached Figure Description

[0022] Figure 1 shows the constructed phylogenetic tree.

[0023] Figure 2 shows the growth capacity of each strain in American ginseng solution.

[0024] Figure 3 shows the acid-producing capacity of each strain in American ginseng solution.

[0025] Figure 4 shows the color changes of the solution after fermentation of various strains in American ginseng solution.

[0026] Figure 5 shows the clustering heatmap analysis results of volatile flavor compounds in the fermentation broth of American ginseng from various strains.

[0027] Figure 6 shows the clustering heatmap analysis results of key flavor compounds. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, the numerical ranges in this invention should be understood to specifically disclose the upper and lower limits of the range and every intermediate value between them. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention.

[0031] Weissella esculenta and microbial agents containing it

[0032] In this invention, *Weissella cibaria* GA2-3 was deposited on May 8, 2025, at the China General Microbiological Culture Collection Center (CGMCC), Beijing, China, with accession number CGMCC No. 34460, and classified as *Weissella cibaria*.

[0033] The present invention further provides a microbial inoculant containing *Westernella tamariscina* GA2-3 or a culture of this bacterium for use in American ginseng fermentation or to enhance the flavor of fermented American ginseng. The dosage form of the microbial inoculant product is not particularly limited and may be a powder, granules, or liquid.

[0034] Fermentation methods

[0035] This invention further provides a fermentation method for enhancing the flavor of fermented American ginseng, comprising the step of fermenting American ginseng using the *Westernella stolonifera* strain described in this invention. The American ginseng used for fermentation can be the root or rhizome. The fermentation substrate can be American ginseng in flake, powder, or granule form.

[0036] In a preferred embodiment, the fermentation method of the present invention includes:

[0037] (1) Sterilize the solution containing American ginseng powder or granules;

[0038] (2) The *Westernella esculenta* is inoculated into the solution and fermented under suitable conditions.

[0039] In step (1), sterilization is performed using conventional sterilization procedures known in the art, at a high temperature of 110-125°C for 5-30 minutes. The solution can be distilled water, purified water, etc., and there are no particular limitations.

[0040] In step (2), the solution is cooled to room temperature before inoculation with the strain. The initial inoculation amount of the strain is 0.1-10 log CFU / ml, preferably 0.5-8 log CFU / ml, more preferably 1-8 log CFU / ml, more preferably 2-7.5 log CFU / ml, more preferably 3-7.5 log CFU / ml, for example 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 log CFU / ml.

[0041] In step (2), the fermentation conditions include: a fermentation temperature of 25-45℃, preferably 26-44℃, more preferably 28-42℃, and even more preferably 28-40℃, for example, 28, 30, 32, 34, 36, 38, or 40℃; and a fermentation time of 10-72 h, preferably 12-36 h, for example, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, or 36 h. In one specific embodiment, fermentation is carried out at 30℃ for 24 h.

[0042] In this invention, the initial pH of the solution is weakly acidic, preferably 3.5-5.5, more preferably 4-5.5, for example 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5.

[0043] In a preferred embodiment, enhancing the fermented flavor of American ginseng includes at least one of the following:

[0044] (1) Degrade earthy-smelling substances or reduce the amount of earthy-smelling substances;

[0045] (2) To produce acidic compounds or increase the amount of acidic compounds;

[0046] (3) To produce fruit flavor compounds or increase the amount of fruit flavor compounds.

[0047] In one specific implementation, enhancing the fermented flavor of American ginseng includes reducing the amount of aldehydes and alcohols, particularly reducing the amount of at least one of hexanal, heptanal, octanal, and 2-ethylhexanol.

[0048] In one specific implementation, enhancing the fermented flavor of American ginseng includes degrading or reducing the amount of 1-octen-3-ol.

[0049] In one specific implementation, enhancing the fermented flavor of American ginseng includes promoting the production of hexanoic acid and / or n-heptanol.

[0050] Example

[0051] 1. Materials and Methods

[0052] 1.1 Isolation and screening of lactic acid bacteria

[0053] Take 10 grams of radish kimchi sample, add 10 times its volume of sterile water, homogenize, and serially dilute. Spread the mixture on MRS solid medium containing 0.5% (w / v) CaCO3 and incubate at 30°C for 48 hours. Select single colonies with a clear zone for purification culture. Perform catalase and Gram staining tests on the purified strains. Screen for Gram-positive, catalase-negative, and acid-producing strains, which are preliminarily identified as lactic acid bacteria.

[0054] 1.2 Molecular biological identification

[0055] Total DNA was extracted from the lactic acid bacteria to be tested using a bacterial genomic DNA extraction kit. Universal primers were used for 16S rRNA gene amplification. The primers were 27F (5'-AGAGTTTGATCMTGGCTCAG-3') and 1492R (5'-TACGGYTACCTTGTTACGACTT-3'). The PCR system (total 20 μL) consisted of: 14.9 μL double-distilled water (dd H2O), 2 μL 10×Taq buffer, 0.3 μL dNTPs, 0.3 μL Taq DNA polymerase, 1 μL upstream primer 27F, 1 μL downstream primer 1492R, and 0.5 μL DNA template. PCR reaction conditions were: 95℃ pre-denaturation for 5 min; 95℃ denaturation for 1 min; 54℃ annealing for 1 min; 72℃ extension for 90 s; 30 cycles; 72℃ extension for 10 min; and storage at 4℃.

[0056] The PCR products were sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing results were compared with the GenBank database in NCBI using BLAST, and a phylogenetic tree was constructed using MEGA 7.0.

[0057] The sequence information obtained from the sequencing of the 16S rRNA gene is shown in SEQ ID No. 1:

[0058]

[0059] Based on the BLAST homology analysis and gene sequencing results, a phylogenetic tree was constructed, as shown in Figure 1. Strain GA2-3 is related to the type strain of *Westernella spp.*, *Westernella sinensis*, JCM12495. T With the highest homology (100%), strain GA2-3 was finally identified and named as Weissella tamariscina GA2-3.

[0060] 1.3 Strain Culture

[0061]

[0062] A large number of lactic acid bacteria were screened from traditional fermented foods, and through American ginseng fermentation experiments, the above-mentioned six superior strains were preliminarily selected. These lactic acid bacteria were inoculated into MRS medium and cultured at 30℃ for 24 h. Cells were collected by centrifugation at 8000 rpm for 5 min at 4℃ and washed twice with 0.85% (w / v) physiological saline. The collected cells were resuspended in 0.85% physiological saline, and the absorbance of the bacterial solution was adjusted to 1 at 600 nm for initial inoculation with the American ginseng solution.

[0063] 1.4 Preparation and Sampling of Fermented American Ginseng

[0064] 10 g of American ginseng powder was dissolved in 1000 mL of distilled water and autoclaved at 121 °C for 15 min. The ginseng solution was then cooled to room temperature for inoculation. The above-mentioned lactic acid bacteria were inoculated into the American ginseng solution at 3% (v / v) and fermented at 30 °C for 24 h. Samples were taken at 0 h and 24 h of fermentation for analysis. Each sample was measured three times.

[0065] 1.5 Lactic acid bacteria count

[0066] Dilute the American ginseng solutions from 0 h and 24 h of fermentation and spread them on MRS solid medium. Incubate at 30℃ for 48 h and calculate the number of lactic acid bacteria.

[0067] 1.6 pH value of fermentation broth

[0068] The pH value of the fermented American ginseng solution was measured using a pH meter.

[0069] 1.7 Chromaticity

[0070] The L*, a*, and b* values ​​of the fermented American ginseng solution were measured using a colorimeter. L* represents brightness, a* represents red-green, and b* represents yellow-blue.

[0071] 1.8 Flavor Compound Analysis (GC-MS)

[0072] Volatile flavor compounds were analyzed using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). 2.0 g of sample was accurately weighed, and 20 μL of 0.1 mg / mL 3-octanol was added as an internal standard. After equilibration at 70°C for 10 min, headspace adsorption was performed at 70°C for 30 min using a 50 / 30 μm DVB / CAR / PDMS extraction head. Subsequently, the extraction head was desorbed at 250°C in splitless mode for 5 min at the GC inlet. The chromatographic conditions were as follows: an SH stabilwax column (60 m × 0.25 mm × 0.25 μm) was used, with helium as the carrier gas (1.0 mL / min). The temperature program was: initial temperature 40°C, held for 3 min; ramped to 115°C at 5°C / min; ramped to 150°C at 2°C / min; and finally ramped to 230°C at 7°C / min and held for 10 min. Mass spectrometry conditions: EI ion source (70 eV), mass scan range m / z 50-550. Substances were qualitatively identified by comparison with the NIST17 library and retention index (RI), semi-quantitatively determined using the internal standard method, and relative odor activity (OAV) values ​​were calculated to screen key flavor compounds.

[0073] 1.9 Data Processing

[0074] Each data set was measured three times and expressed as mean ± standard deviation. Data processing was performed using Origin 2021. One-way ANOVA was conducted using SPSS 26.0 to verify the significance of differences between the data sets.

[0075] 2. Results

[0076] 2.1 Growth of lactic acid bacteria and changes in pH of fermentation broth

[0077] The viable count of lactic acid bacteria is a key indicator for assessing their growth ability in American ginseng solution. As shown in Figure 2, after fermentation, the viable counts of each strain significantly increased to 8.24-8.71 log CFU / mL, indicating that the selected lactic acid bacteria could grow in the American ginseng substrate. Specifically, there were significant differences in the growth ability of each strain: *Lactobacillus brevis* had the strongest growth ability; followed by *Lactobacillus plantarum*, *Westernella esculenta*, and *Lactococcus lactis*; while *Leuconostoc mesenteroides* had the weakest growth ability. This result indicates that different lactic acid bacteria have different adaptability to the American ginseng substrate. Among them, *Lactobacillus brevis*, *Lactobacillus plantarum*, *Westernella esculenta*, and *Lactococcus lactis* showed high substrate utilization efficiency, while the proliferation ability of *Leuconostoc mesenteroides* was relatively limited.

[0078] As shown in Figure 3, the initial pH of the American ginseng solution was 5.38. After fermentation with lactic acid bacteria, the pH value decreased significantly, indicating that the lactic acid bacteria had a strong acid-producing capacity during fermentation. The acid-producing capacity of different strains varied significantly. After fermentation, the pH values ​​of each group, from highest to lowest, were: *Lactobacillus plantarum* PJ4-2 (4.76), *Lactobacillus brevis* PL6-1 (4.45), *Westernella tamariscina* GI2-1 (4.41), *Leuconostoc mesenteriae* RO1-3 (4.18), *Lactococcus lactis* GA2-2 (4.11), and *Westernella tamariscina* GA2-3 (4.08), which exhibited the strongest acid-producing capacity. The results indicate that *Westernella tamariscina* GA2-3 demonstrated superior acid-producing capacity.

[0079] 2.2 Chromaticity

[0080] The L*, a*, and b* values ​​in a colorimeter are three key parameters used to quantify color characteristics. L* represents the sample's brightness, a* reflects the difference between red and green, b* reflects the difference between yellow and blue, and ΔE characterizes the overall color difference of the sample. In this embodiment, the color change of the fermented American ginseng solution was mainly characterized by L*, a*, b*, and ΔE. As shown in Figure 4, the L* value of the unfermented American ginseng solution (NF group) was 24.78. After fermentation with Leuconostoc mesenteroides RO1-3, the L* value decreased to 24.15, showing the most significant change among all strains. However, the overall color difference remained insignificant, indicating that these strains had a relatively small impact on the brightness of the American ginseng solution.

[0081] The a* value is used to represent the difference between red and green in a sample, with a positive value indicating a higher perception of red. The a* value of the unfermented American ginseng solution (NF group) was 0.48. The a* values ​​of the four fermentation broths, including *Lactobacillus brevis* PL6-1, *Leuconostoc mesenteriae* RO1-3, and two strains of *Westernella esculenta* (GA2-3 and GI2-1), all decreased (0.27-0.41), indicating that the fermentation of these lactic acid bacteria led to a decrease in the red color of the American ginseng solution. In contrast, the a* values ​​of the *Lactococcus lactis* GA2-2 and *Lactobacillus plantarum* PJ4-2 fermentation groups increased to 0.49 and 0.58, respectively, indicating that the red color of the fermented American ginseng solution deepened.

[0082] The b* value is used to characterize the yellow-blue difference of a sample, with a positive value indicating a higher perceived yellow hue. The b* value of the NF group was 1.27, indicating that the unfermented ginseng solution exhibited a slight yellow tint. As fermentation progressed, the b* values ​​of all fermentation groups showed a decreasing trend, indicating a reduction in the perceived yellow hue of the ginseng solution after fermentation. Notably, the b* values ​​of the RO1-3 fermentation group remained at a relatively high level.

[0083] The ΔE value is used to quantify the total color difference between samples. When ΔE is less than 1, the color difference is difficult to perceive with the naked eye. Although the American ginseng fermentation liquid before and after fermentation with different lactic acid bacteria showed varying degrees of difference in the three color parameters L*, a*, and b*, in this example, the ΔE value of the American ginseng solution after fermentation remained between 0.62 and 0.93, indicating that the color difference caused by lactic acid bacteria fermentation could not be observed with the naked eye, and the overall hue of the American ginseng fermentation liquid did not change significantly before and after fermentation.

[0084] 2.3 Analysis of the flavor characteristics of fermented American ginseng

[0085] GC-MS analysis showed that the fermentation samples contained a variety of volatile flavor compounds, including 10 aldehydes, 7 alcohols, 4 acids, 5 ketones, and 9 other compounds.

[0086] As shown in Figure 5, cluster heatmap analysis of volatile flavor compounds in the fermented ginseng broth revealed that six aldehydes and alcohols—hexanal, heptanal, octanal, nonanal, 1-octen-3-ol, and 2-ethylhexanol—were present in high concentrations in the unfermented ginseng solution (NF), contributing significantly to its earthy, oily, and grassy aromas. As fermentation progressed, the concentrations of these six compounds decreased significantly, with the decrease being particularly pronounced in the *Westernobacterium stoloniferum* GA2-3, GI2-1, and *Lactococcus lactis* GA2-2 fermentation groups. Further analysis showed that lactic acid bacteria inoculation significantly enhanced the diversity of volatile flavors in the ginseng solution. Specifically, the *Lactococcus lactis* GA2-2 and *Westernobacterium stoloniferum* GI2-1 and GA2-3 fermentation groups exhibited a more complex and abundant volatile flavor composition. This difference is related to the metabolic characteristics and enzyme activities of different lactic acid bacteria. *Lactococcus lactis* GA2-2 and *Westernella tamariscina* GI2-1 and GA2-3 exhibit stronger metabolic capabilities in the synthesis of esters, alcohols, and acids, significantly promoting the production of alcohols and acids. These changes add richer floral and sour flavors to the fermented ginseng solution, thus giving the fermentation liquid a more complex flavor profile. The research results not only reveal the metabolic mechanism of lactic acid bacteria in the fermentation process of American ginseng but also provide a theoretical basis for optimizing the fermentation process and improving the flavor quality of fermented American ginseng products.

[0087] Table 1 Key flavor compounds of fermented American ginseng

[0088]

[0089] OAV values ​​reflect the contribution of volatile flavor compounds to the flavor of fermented American ginseng. As shown in Table 1, five key aroma compounds with OAV > 1 were detected in all samples: hexanal, heptanal, 1-octen-3-ol, heptanol, and hexanoic acid. Cluster heatmap analysis of volatile flavor compounds with OAV > 1 in the fermented American ginseng broth was performed, as shown in Figure 6. In the unfermented American ginseng solution (NF), the concentrations of hexanal, heptanal, and 1-octen-3-ol were relatively high, while the concentrations of heptanol and hexanoic acid were relatively low, indicating that the unfermented American ginseng solution mainly exhibits a fatty, grassy, ​​and earthy aroma. After lactic acid bacteria fermentation, the concentrations of hexanal, heptanal, and 1-octen-3-ol were significantly reduced in the American ginseng solutions fermented with *Westernella spp.* GA2-3, GI2-1, *Lactococcus lactis* GA2-2, and *Lactobacillus plantarum* PJ4-2. These concentrations were also reduced to varying degrees in the fermentation groups with *Lactobacillus brevis* PL6-1 and *Leuconostoc mesenteriae* RO1-3, resulting in a significant reduction in fatty, grassy, ​​and earthy flavors. The concentrations of heptanol and hexanoic acid increased in all fermentation groups, with the highest concentration in *Westernella spp.* GA2-3, which imparted a significant fruity and acidic flavor to the fermented American ginseng broth. This study indicates that inoculation with different lactic acid bacteria species or strains has a significant impact on the flavor of the fermented American ginseng solution.

[0090] Hexanal, a key aroma compound in the NF group, reached a concentration of 13.99 μg / kg, contributing a rich oily and grassy flavor to the NF group. With the inoculation and fermentation of lactic acid bacteria, most strains significantly reduced the concentration of hexanal to 5.15-9.86 μg / kg, effectively reducing the grassy taste. However, the content actually increased after fermentation with *Lactobacillus brevis* PL6-1, indicating significant differences in the metabolic capacity of different strains for aldehydes. Lactic acid bacteria contain aldehyde reductase (AKR), which reduces hexanal in the ginseng solution to hexanol under the action of aldehyde reductase. Due to differences in bacterial species, the activity of aldehyde reductase also varies significantly. The hexanal content in ginseng fermented with *Westernella esculenta* GA2-3 decreased to 5.15 μg / kg, showing the most significant decrease, reducing the grassy taste of the ginseng. Simultaneously, the generated hexanol imparted rich fruity and floral flavors to the ginseng. 1-Octen-3-ol reached 4.28 μg / kg in the NF group, and was the main earthy-tasting compound in American ginseng solution. After fermentation with lactic acid bacteria, it significantly decreased to 0-1.60 μg / kg, being converted into esters and other compounds. 1-Octen-3-ol was not detected in American ginseng solution fermented with *Wesleyanus gluteni* GA2-3, indicating that this bacterium is more suitable for removing the earthy taste from American ginseng solution.

[0091] n-Heptanol mainly exhibits a fruity flavor in American ginseng solutions. Its concentration was 0.66 μg / kg in the NF group, which significantly increased to 2.41-8.34 μg / kg after fermentation. n-Heptanol originates from the oxidation and degradation of polyunsaturated fatty acids. In particular, after fermentation with *Westernella tamariscina* GA2-3, n-Heptanol significantly increased to 8.34 μg / kg, giving the American ginseng solution a richer fruity flavor.

[0092] Hexanoic acid, a key acidic compound, primarily contributes to the aroma of cheese. It was not detected in the NF group, but its concentration significantly increased to 2.75-5.32 μg / kg after fermentation. Enzymes in the fatty acid biosynthesis (FAB) pathway directly influence hexanoic acid synthesis; higher enzyme activity leads to higher hexanoic acid production. Among them, *Westernella tamariscina* GA2-3 and GI2-1 produced more hexanoic acid after fermenting American ginseng, imparting a richer cheese aroma and acidity to the ginseng solution.

[0093] In summary, through comprehensive evaluation of various lactic acid bacteria (including acid production capacity, color regulation, and flavor characteristic analysis), *Westernella tamariscina* GA2-3 was confirmed as the most suitable strain for American ginseng fermentation. Firstly, GA2-3 exhibits the strongest metabolic activity and acid production capacity in the American ginseng substrate, enabling efficient fermentation. Simultaneously, its lower pH value helps enhance the flavor of American ginseng and inhibits the growth of unwanted microorganisms, ensuring product safety. Secondly, it demonstrates superior flavor regulation advantages: on the one hand, it effectively removes unpleasant flavors. Unfermented American ginseng has a significant earthy taste, primarily derived from 1-octen-3-ol. GA2-3 can completely degrade this substance, and it was undetectable after fermentation (OAV value decreased from 4.28 to 0), making it the most effective strain among all strains. Another unpleasant flavor of unfermented American ginseng is a grassy and oily taste, mainly from hexanal. GA2-3 can reduce its concentration to 5.15 μg / kg, showing the most significant reduction among all strains. In addition, GA2-3 can significantly enhance the ideal flavor of American ginseng fermentation broth: (1) Increase fruity aroma: GA2-3 can increase the concentration of n-heptanol, which brings fruity aroma, to 8.34 μg / kg, the highest among all strains, bringing a pleasant fruity aroma to the fermentation broth; (2) Increase rich cheese aroma and sourness: GA2-3 can efficiently produce hexanoic acid, which brings cheese aroma and sourness, with an OAV value as high as 5.38 (second only to GI2-1's 5.98), making it one of the strains with the strongest hexanoic acid production capacity. It gives the fermentation product a more pleasant and richer flavor profile. While effectively improving the flavor, this strain has little impact on the original color of the American ginseng solution, and its overall performance is better than other strains. These characteristics make Weissella tamariscina GA2-3 an ideal fermentation strain for developing high-quality fermented American ginseng products.

Claims

1. A method for fermenting American ginseng, characterized in that, The method includes the step of fermenting American ginseng with Weissellacibaria GA2-3, which was deposited on May 8, 2025, at the China General Microbiological Culture Collection Center (CGMCC) in Beijing, China, with accession number CGMCC No. 34460.

2. The method for fermenting American ginseng according to claim 1, characterized in that, The method includes: (1) reacting a solution containing American ginseng powder or granules at 110 °C. (1) Sterilize at 125℃; (2) Inoculate the Weissella esculenta into the solution and ferment it.

3. The method for fermenting American ginseng according to claim 2, characterized in that, Fermentation temperature is 25-45℃.

4. The method for fermenting American ginseng according to claim 2, characterized in that, The initial inoculum size of the *Westernophora oryzae* was 0.1-10 log CFU / ml.

5. The method for fermenting American ginseng according to claim 2, characterized in that, The initial pH of the solution is 3.5-5.

5.

6. The method for fermenting American ginseng according to claim 2, characterized in that, The method can enhance the fermented flavor of American ginseng, and the enhancement of the fermented flavor of American ginseng includes at least one of the following: (1) degrading earthy substances or reducing the amount of earthy substances; (2) Produces acidic compounds or increases the amount of acidic compounds; (3) Produces fruity flavor compounds or increases the amount of fruity flavor compounds.

7. The method for fermenting American ginseng according to claim 6, characterized in that, The enhancement of the fermented flavor of American ginseng includes reducing the amount of aldehyde compounds, which include at least one of hexanal, heptanal, and octanal.

8. The method for fermenting American ginseng according to claim 6, characterized in that, The enhancement of the fermented flavor of American ginseng includes degrading 1-octen-3-ol or reducing the amount of 1-octen-3-ol.

9. The method for fermenting American ginseng according to claim 6, characterized in that, The enhancement of the fermented flavor of American ginseng includes promoting the production of hexanoic acid and / or n-heptanol.

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