Weissella sinus strain for improving fermentation flavor of American ginseng and application of Weissella sinus strain

Abstract

The invention discloses a Weissella sinus strain for improving the fermentation flavor of American ginseng and application of the Weissella sinus strain. According to the present invention, through the comprehensive evaluation of a variety of lactic acid bacteria, including the acid production capacity, the chroma regulation and the flavor characteristic analysis, the optimal strain for the American ginseng fermentation is finally screened, and the strain shows the significant flavor regulation advantage. On one hand, characteristic earthy smell substances of American ginseng can be completely degraded, and the bad flavor of the raw materials is effectively improved; on the other hand, a compound with a fruity flavor characteristic can be specifically generated, and a fermentation product is endowed with a remarkable fragrant and sweet flavor. In addition, the strain disclosed by the invention maintains proper acid production capacity and chroma stability, and the flavor quality is remarkably improved on the premise of ensuring the fermentation efficiency. Due to the characteristics, the strain becomes an ideal fermentation strain for developing a high-quality fermented American ginseng product.

Description

Technical Field

[0001] The present invention relates to the field of fermentation, and in particular to a Weissella sinensis strain for improving the fermentation flavor of American ginseng and a use thereof. Background Art

[0002] American ginseng ( Panax quinquefolius L. ) is an important medicinal plant of the genus Panax in the Araliaceae family, and is related to Asian ginseng ( P. ginseng ) and Panax notoginseng ( P. notoginseng ) and other closely related species. American ginseng is rich in a variety of bioactive ingredients, mainly including ginsenosides, polysaccharides and polyacetylene compounds. It is commonly eaten 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 consumers' sensory acceptance, seriously restricting its in-depth development and application in the fields of food, health products and medicine. Therefore, effectively improving or removing its unpleasant flavor is the key to improving the overall quality of American ginseng products and broadening their market applications. Summary of the Invention

[0003] The present invention provides a Weissella sinusoidalis strain for improving the flavor of American ginseng fermentation and its use. Specifically, the technical solution of the present invention is as follows.

[0004] In a first aspect of the present invention, a Weissella edodes for enhancing the fermented flavor of American ginseng is provided, which is Weissella edodes GA2-3, deposited on May 8, 2025, at the General Microbiology Center of the China Culture Collection Administration Committee, Beijing, China, with a deposit number of CGMCC No. 34460, and is classified as Weissella edodes Weissella cibaria .

[0005] The second aspect of the present invention provides a microbial agent for American ginseng fermentation, which comprises the Weissella sinusoidalis described in the first aspect or a culture derived therefrom.

[0006] A third aspect of the present invention provides a fermentation method for improving the fermented flavor of American ginseng, comprising the step of fermenting American ginseng using the Weissella sinusoidalis described in the first aspect.

[0007] In certain embodiments, the fermentation method for improving the flavor of American ginseng fermentation according to the present invention comprises: (1) sterilizing a solution containing American ginseng powder or granules; (2) inoculating the Weissella sinusoidalis into the solution and fermenting under appropriate conditions.

[0008] In certain embodiments, the initial inoculation amount of Weissella sinusoidalis in the fermentation method for improving the fermented flavor of American ginseng of the present invention is 0.1-10 log CFU / ml.

[0009] In certain embodiments, the initial pH of the solution in the fermentation method for improving the fermented flavor of American ginseng of the present invention is weakly acidic.

[0010] In certain embodiments, the method for improving the fermentation flavor of American ginseng according to the present invention comprises at least one of the following: (1) Degrading earthy odor substances or reducing the amount of earthy odor substances; (2) producing sour compounds or increasing the amount of sour compounds; (2) Produce fruity flavor compounds or increase the amount of fruity flavor compounds.

[0011] In certain embodiments, the method for enhancing the fermentation flavor of American ginseng described in the present invention comprises reducing the amount of aldehydes and alcohol compounds, wherein the aldehydes and alcohol compounds include at least one of n-hexanal, heptanal, n-octanal and 2-ethylhexanol.

[0012] In certain embodiments, the method for improving the fermentation flavor of American ginseng of the present invention comprises degrading or reducing the amount of 1-octen-3-ol.

[0013] In certain embodiments, the method for improving the fermentation flavor of American ginseng of the present invention comprises promoting the production of hexanoic acid and n-heptanol.

[0014] The present invention screens a strain that can significantly improve the flavor quality of American ginseng solution by fermenting American ginseng solution, providing a new technical approach for developing high-value-added American ginseng products, and has important scientific research value and broad market application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The constructed phylogenetic tree is shown.

[0016] Figure 2 The growth ability of each strain in American ginseng solution is shown.

[0017] Figure 3 The acid production ability of each strain in American ginseng solution is shown.

[0018] Figure 4 Shown are the color changes of the solutions after fermentation of each strain in American ginseng solution.

[0019] Figure 5 Cluster heat map analysis results of volatile flavor compounds in American ginseng fermentation broth fermented by various strains.

[0020] Figure 6 Cluster heat map analysis results of key flavor compounds. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0022] It should be understood that the terms described in the present invention are only for describing particular embodiments and are not intended to limit the present invention. In addition, for the numerical ranges in the present invention, it should be understood that the upper and lower limits of the ranges and each intermediate value therebetween are specifically disclosed. Each smaller range between the intermediate value within any stated value or stated range and any other stated value or intermediate value within the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

[0024] Weissella sinusoidalis and microbial agents containing the same In the present invention, Weissella vegetative GA2-3 was deposited on May 8, 2025, at the General Microbiology Center of China Culture Collection Administration Committee, Beijing, China, with the deposit number CGMCC No. 34460, and was classified as Weissella vegetative Weissella cibaria .

[0025] The present invention further provides a microbial agent comprising Weissella sinusoidalis GA2-3 or a culture thereof, for use in fermenting American ginseng or enhancing the flavor of fermented American ginseng. The dosage form of the microbial agent product is not particularly limited and can be a powder, granules or liquid.

[0026] Fermentation method The present invention further provides a fermentation method for enhancing the fermented flavor of American ginseng, comprising fermenting American ginseng using the Weissella sinusoidalis described herein. The American ginseng used for fermentation can be roots or rhizomes. The fermentation substrate can be flaked, powdered, or granular American ginseng.

[0027] In a preferred embodiment, the fermentation method of the present invention comprises: (1) sterilizing a solution containing American ginseng powder or granules; (2) inoculating the Weissella sinusoidalis into the solution and fermenting under appropriate conditions.

[0028] In step (1), sterilization is performed by conventional sterilization procedures known in the art, and high-temperature sterilization is performed at 110-125° C. for 5-30 minutes. The solution can be distilled water, purified water, etc., and is not particularly limited thereto.

[0029] In step (2), the solution is cooled to room temperature before inoculating the strain. The initial inoculum size of the strain is 0.1-10 log CFU / ml, preferably 0.5-8 log CFU / ml, further preferably 1-8 log CFU / ml, further preferably 2-7.5 log CFU / ml, further 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.

[0030] In step (2), the fermentation conditions include: a fermentation temperature of 25-45°C, preferably 26-44°C, more preferably 28-42°C, further preferably 28-40°C, for example, 28, 30, 32, 34, 36, 38, 40°C; 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, 36 h. In one embodiment, fermentation is carried out at 30°C for 24 h.

[0031] In the present 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.

[0032] In a preferred embodiment, improving the flavor of American ginseng fermentation includes at least one of the following: (1) Degrading earthy odor substances or reducing the amount of earthy odor substances; (2) producing sour compounds or increasing the amount of sour compounds; (3) Produce fruity flavor compounds or increase the amount of fruity flavor compounds.

[0033] In a specific embodiment, improving the fermented flavor of American ginseng comprises reducing the amount of aldehydes and alcohol compounds, particularly reducing the amount of at least one of n-hexanal, heptanal, n-octanal and 2-ethylhexanol.

[0034] In one embodiment, improving the fermented flavor of American ginseng comprises degrading or reducing the amount of 1-octen-3-ol.

[0035] In a specific embodiment, improving the fermentation flavor of American ginseng comprises promoting the production of hexanoic acid and / or n-heptanol.

[0036] Example 1. Materials and Methods 1.1 Isolation and screening of lactic acid bacteria A 10-gram sample of radish kimchi was added to 10 times the volume of sterile water, homogenized, and serially diluted. The sample was then spread onto MRS solid medium containing 0.5% (w / v) CaCO₃ and incubated at 30°C for 48 hours. Single colonies with clearing zones were selected for purification and culture. The purified strains were subjected to catalase and Gram staining tests. Gram-positive, catalase-negative, and acid-producing strains were identified and preliminarily identified as lactic acid bacteria.

[0037] 1.2 Molecular biological identification Total DNA of the lactic acid bacteria to be tested was extracted using a bacterial genomic DNA extraction kit. Universal primers were used for 16S rRNA gene amplification. Primers were 27F (5'-AGAGTTTGATCMTGGCTCAG-3') and 1492R (5'-TACGGYTACCTTGTTACGACTT-3'). The PCR system (20 μL total) consisted of 14.9 μL double-distilled water (ddH2O), 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 as follows: 95°C initial denaturation for 5 min; 95°C denaturation for 1 min; 54°C annealing for 1 min; 30 cycles of extension at 72°C for 90 s; and 72°C extension for 10 min; then storage at 4°C.

[0038] The PCR products were sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing. The sequencing results were compared with the GenBank database in NCBI by BLAST, and the phylogenetic tree was constructed using MEGA 7.0.

[0039] The sequence information obtained from the sequencing results of the 16S rRNA gene is shown in SEQ ID No. 1:

[0040] According to the BLAST homology analysis of gene sequencing results, a phylogenetic tree was constructed. The results are shown in Figure 1 , strain GA2-3 and Weissella sinusoidal type strain JCM12495 T The homology was the highest (100%), and the strain GA2-3 was finally identified and named Weissella sinusoidalis GA2-3.

[0041] 1.3 Strain culture A large number of lactic acid bacteria have been screened from traditional fermented foods, and the six preferred strains described above were initially selected through experiments with American ginseng fermentation. Each of these lactic acid bacteria was inoculated into MRS medium and cultured at 30°C for 24 hours. The cells were harvested by centrifugation at 8000 rpm for 5 minutes at 4°C and washed twice with 0.85% (w / v) saline. The harvested cells were resuspended in 0.85% saline and adjusted to an absorbance of 1 at 600 nm for the initial inoculation of the American ginseng solution.

[0042] 1.4 Preparation and sampling of fermented American ginseng Dissolve 10 g of American ginseng powder in 1000 mL of distilled water and sterilize by autoclaving at 121°C for 15 minutes. The American ginseng solution is then cooled to room temperature for inoculation. The aforementioned lactic acid bacteria are inoculated into the American ginseng solution at a 3% (v / v) concentration and fermented at 30°C for 24 hours. Samples are collected and analyzed at 0 and 24 hours of fermentation. Each sample is assayed in triplicate.

[0043] 1.5 Lactic acid bacteria count The American ginseng solutions fermented for 0 h and 24 h were diluted and spread on MRS solid culture medium, and cultured at 30°C for 48 h to calculate the number of lactic acid bacteria.

[0044] 1.6 pH of fermentation broth The pH value of the fermented American ginseng solution was measured using a pH meter.

[0045] 1.7 Chroma 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.

[0046] 1.8 Flavor Analysis (GC-MS) Volatile flavor compounds were analyzed using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). A 2.0 g sample was accurately weighed, and 20 μL of 0.1 mg / mL 3-octanol was added as an internal standard. After incubation at 70°C for 10 min, the sample was adsorbed in the headspace using a 50 / 30 μm DVB / CAR / PDMS tip at 70°C for 30 min. Subsequently, the tip was desorbed from the GC inlet at 250°C in splitless mode for 5 min. Chromatographic conditions included an SH stabilwax column (60 m × 0.25 mm × 0.25 μm) and helium as the carrier gas (1.0 mL / min). The temperature program was as follows: initial temperature at 40°C for 3 min, then increased at 5°C / min to 115°C, then to 150°C at 2°C / min, and finally to 230°C at 7°C / min, where it was 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 spectral library and retention index (RI). Semi-quantification was performed using the internal standard method, and relative odor activity values ​​(OAVs) were calculated to screen for key flavor compounds.

[0047] 1.9 Data Processing Each data set was measured three times and expressed as "mean ± standard deviation." Data were processed using Origin 2021. One-way analysis of variance was performed using SPSS 26.0 to verify significant differences between data.

[0048] 2. Results 2.1 Lactic acid bacteria growth and changes in fermentation broth pH The number of viable lactic acid bacteria is a key indicator to measure their growth ability in American ginseng solution. Figure 2 As shown, after fermentation, the viable counts of each strain increased significantly to 8.24-8.71 log CFU / mL, indicating that the selected lactic acid bacteria were able to grow in the American ginseng matrix. Specifically, there were significant differences in the growth abilities of the strains: Lactobacillus breve had the strongest growth ability; Lactobacillus plantarum, Weissella sinusoids, and Lactococcus lactis were second; and Leuconostoc mesenteroides had the weakest growth ability. This result suggests that different lactic acid bacteria have different adaptability to the American ginseng matrix. Among them, Lactobacillus breve, Lactobacillus plantarum, Weissella sinusoids, and Lactococcus lactis showed high substrate utilization efficiency, while the proliferation ability of Leuconostoc mesenteroides was relatively limited.

[0049] like Figure 3As shown in the results, the initial pH value of the American ginseng solution was 5.38. After lactic acid bacteria fermentation, the pH value decreased significantly, indicating that lactic acid bacteria have a strong ability to produce acid during the fermentation process. There were significant differences in the acid production capacity of different strains. After the fermentation, the pH values ​​of the groups were ranked from high to low as follows: Lactobacillus plantarum PJ4-2 (4.76), Lactobacillus breve PL6-1 (4.45), Weissella sinusoidalis GI2-1 (4.41), Leuconostoc mesenteroides RO1-3 (4.18), Lactococcus lactis GA2-2 (4.11), and Weissella sinusoidalis GA2-3 (4.08), which had the strongest acid production capacity. The results showed that Weissella sinusoidalis GA2-3 exhibited excellent acid production capacity.

[0050] 2.2 Chroma The L*, a*, and b* values ​​in a colorimeter are three key parameters used to quantify color characteristics. The L* value represents the brightness of the sample, the a* value reflects the difference between red and green, the b* value reflects the difference between yellow and blue, and ΔE is used to characterize the overall color difference of the sample. In this example, the color change of the fermented American ginseng solution was mainly characterized by the L* value, a* value, b* value, and ΔE. Figure 4 As shown in the figure, the L* value of the unfermented American ginseng solution (NF group) was 24.78. After fermentation with Leuconostoc mesenteroides RO1-3, the L* value dropped to 24.15, which was the most obvious change among all strains. However, the overall color difference was still not significant, indicating that these strains had little effect on the brightness of the American ginseng solution.

[0051] The a* value is used to represent the difference between the red and green colors of a sample, with positive values ​​indicating red perception. The a* value for the unfermented American ginseng solution (NF group) was 0.48. The a* values ​​for the four fermentation groups, including Lactobacillus breve PL6-1, Leuconostoc mesenteroides RO1-3, and two strains of Weissella sinusoidalis (GA2-3 and GI2-1), decreased (ranging from 0.27 to 0.41), indicating that fermentation with these lactic acid bacteria led to a decrease in the red color of the American ginseng solution. The a* values ​​for the fermentation groups with Lactococcus lactis GA2-2 and Lactobacillus plantarum PJ4-2 increased to 0.49 and 0.58, respectively, indicating that the red color of the fermented American ginseng solution deepened.

[0052] The b* value characterizes the difference between the yellow and blue hues of a sample, with positive values ​​indicating a stronger yellow perception. The b* value of the NF group was 1.27, indicating a slight yellow tint to the unfermented American ginseng solution. As fermentation progressed, the b* values ​​of all fermentation groups showed a downward trend, indicating a decrease in the perceived yellowness of the fermented American ginseng solution. Notably, the b* values ​​of the RO1-3 fermentation groups remained relatively high.

[0053] The ΔE value quantifies the overall color difference between samples. When ΔE is less than 1, the color difference is difficult to discern with the naked eye. Although the three colorimetric parameters, L*, a*, and b*, differed to varying degrees between the American ginseng fermentation broths before and after fermentation with different lactic acid bacteria, 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 cannot be observed with the naked eye, and the overall color tone of the American ginseng fermentation broth did not change significantly before and after fermentation.

[0054] 2.3 Analysis of the flavor characteristics of fermented American ginseng GC-MS analysis showed that the fermentation samples contained a variety of volatile flavor compounds, including 10 aldehyde compounds, 7 alcohol compounds, 4 acid compounds, 5 ketone compounds and 9 other compounds.

[0055] like Figure 5 As shown in Figure 2, a cluster heat map analysis of the volatile flavor compounds in American ginseng fermentation broth revealed that six aldehydes and alcohols—n-hexanal, heptanal, octanal, nonanal, 1-octen-3-ol, and 2-ethylhexanol—were present at high concentrations in the unfermented American ginseng solution. These six aldehydes and alcohols are the primary flavor contributors to the unfermented American ginseng solution (NF), imparting distinct earthy, greasy, and grassy notes. As fermentation progressed, the concentrations of these six compounds decreased significantly, with a particularly pronounced downward trend in the fermentation groups with Weissella sinusoids GA2-3, GI2-1, and Lactococcus lactis GA2-2. Further analysis revealed that lactic acid bacteria inoculation significantly enhanced the volatile flavor diversity of the American ginseng solution. Specifically, the fermentation groups with Lactococcus lactis GA2-2, and those with Weissella sinusoids GI2-1 and GA2-3 exhibited a more complex and richer volatile flavor profile. This difference is related to the metabolic characteristics and enzyme activities of different lactic acid bacteria. Lactococcus lactis GA2-2 and Weissella sinusoidalis GI2-1 and GA2-3 exhibited stronger metabolic capacity in the synthesis of esters, alcohols, and acids, significantly promoting the production of alcohols and acids. These changes add a richer floral aroma and sourness to the fermented American ginseng solution, thus giving the fermented liquid a richer flavor. The results not only reveal the metabolic mechanism of lactic acid bacteria in the American ginseng fermentation process, but also provide a theoretical basis for optimizing the fermentation process and improving the flavor quality of American ginseng fermented products.

[0056] Table 1 Key flavor compounds in fermented American ginseng The OAV value reflects 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, namely n-hexanal, heptanal, 1-octen-3-ol, n-heptanol and hexanoic acid. Cluster heat map analysis of volatile flavor compounds with OAV>1 in American ginseng fermentation broth was performed, as shown in Table 1. Figure 6 As shown, in the unfermented American ginseng solution (NF), the concentrations of n-hexanal, heptanal, and 1-octen-3-ol were high, while the concentrations of n-heptanol and hexanoic acid were low, indicating that the unfermented American ginseng solution mainly exhibited fat, grassy, ​​and earthy aromas. After lactic acid bacteria fermentation, the concentrations of n-hexanal, heptanal, and 1-octen-3-ol were significantly reduced in the American ginseng solutions fermented by Weissella sinusoids GA2-3, GI2-1, Lactococcus lactis GA2-2, and Lactobacillus plantarum PJ4-2. The concentrations also decreased to varying degrees in the fermentation groups of Lactobacillus breve PL6-1 and Leuconostoc mesenteroides RO1-3, significantly reducing the fat, grassy, ​​and earthy aromas. The concentrations of n-heptanol and hexanoic acid increased in all fermentation groups, with Weissella sinusoids GA2-3 having the highest concentration, imparting a distinct fruity and sour flavor to the American ginseng fermentation liquid. Studies have shown that there are significant differences in the flavor of American ginseng fermented solution when inoculated with different lactic acid bacteria species or strains.

[0057] n-Hexanal, a key aroma compound in the NF group, reached a concentration of 13.99 μg / kg, imparting a rich, oily, and grassy flavor. Following inoculation and fermentation with lactic acid bacteria, most strains significantly reduced the n-hexanal concentration to 5.15-9.86 μg / kg, effectively reducing the grassy flavor. However, the n-hexanal concentration increased after fermentation with Lactobacillus breve PL6-1, indicating significant differences in the metabolic capacity of aldehydes among different strains. Lactic acid bacteria contain aldehyde reductase (AKR), which reduces n-hexanal in the American ginseng solution to n-hexanol. The activity of AKR varied significantly depending on the lactic acid bacteria strain. The n-hexanal content in American ginseng fermented with Weissella sinusoidea GA2-3 decreased most significantly, to 5.15 μg / kg, reducing the grassy flavor. The generated n-hexanol, meanwhile, imparted a rich, fruity, and floral flavor to the ginseng. 1-Octen-3-ol, the primary earthy odor compound in the American ginseng solution, reached 4.28 μg / kg in the NF group. This level significantly decreased to 0-1.60 μg / kg after inoculation with lactic acid bacteria, transforming into esters and other compounds. No 1-Octen-3-ol was detected in the American ginseng solution fermented with Weissella sinusoidalis GA2-3, suggesting this strain is more suitable for removing the earthy odor from American ginseng solutions.

[0058] n-Heptanol mainly presents a fruity flavor in the American ginseng solution. The concentration in the NF group was 0.66 μg / kg, which increased significantly to 2.41-8.34 μg / kg after fermentation. n-Heptanol originates from the oxidation and degradation of polyunsaturated fatty acids. Among them, the concentration of n-heptanol increased significantly to 8.34 μg / kg after fermentation by Weissella sinusoidalis GA2-3, giving the American ginseng solution a richer fruity flavor.

[0059] Caproic acid, a key sour compound responsible for the cheese aroma, was not detected in the NF group but significantly increased to 2.75-5.32 μg / kg after fermentation. Enzymes in the fatty acid biosynthesis (FAB) pathway directly influence caproic acid synthesis; higher activity leads to higher caproic acid production. Specifically, the fermentation of American ginseng by Weissella sinusoidalis GA2-3 and GI2-1 produced higher amounts of caproic acid, giving the American ginseng solution a richer cheese aroma and sour taste.

[0060] In summary, through a comprehensive evaluation of various lactic acid bacteria (including analysis of acid production, colorimetric control, and flavor characteristics), Weissella sinusoidalis GA2-3 was confirmed to be the optimal strain for American ginseng fermentation. First, GA2-3 exhibits the strongest metabolic activity and acid production in the American ginseng matrix, enabling efficient fermentation. Its low pH helps enhance the flavor of the ginseng and inhibits the growth of contaminants, ensuring product safety. Second, it exhibits excellent flavor control advantages: First, it effectively removes unpleasant flavors. Unfermented American ginseng has a pronounced earthy odor, primarily derived from 1-octen-3-ol. GA2-3 completely degrades this odor, rendering it undetectable after fermentation (OAV value reduced from 4.28 to 0). This performance is the best among all strains. Another unpleasant flavor characteristic of unfermented American ginseng is grassy and oily, primarily derived from n-hexanal. GA2-3 reduced its concentration to 5.15 μg / kg, the most significant reduction among all strains. In addition, GA2-3 can significantly enhance the ideal flavor of American ginseng fermentation liquid: (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 liquid; (2) Increase rich cheese aroma and sourness: GA2-3 can efficiently produce caproic acid, which brings cheese aroma and sourness, with an OAV value of up to 5.38 (second only to GI2-1's 5.98), making it one of the strains with the strongest caproic acid production ability. This gives the fermentation product a more pleasant and richer flavor layer. While effectively improving the flavor, this strain has little effect on the original color of the American ginseng solution, and its overall performance is better than other strains. These characteristics make Weissella sinusoidalis GA2-3 an ideal fermentation strain for the development of high-quality fermented American ginseng products.

Claims

1. A Weissella quinquefolia for improving the flavor of American ginseng fermentation, characterized in that: It is Weissella sinusoids GA2-3, which was deposited in the General Microbiology Center of China Culture Collection Administration on May 8, 2025, with the deposit address being CGMCC No. 34460 in Beijing, China, and is classified as Weissella sinusoids Weissella cibaria .

2. A microbial agent or composition for American ginseng fermentation, characterized in that: The method comprises the Weissella sinensis according to claim 1 or a culture derived therefrom.

3. A fermentation method for improving the fermentation flavor of American ginseng, characterized in that: The method comprises the step of fermenting American ginseng using the Weissella sinusoids according to claim 1, the method comprising: (1) Sterilize the solution containing American ginseng powder or granules; (2) inoculating the Weissella sinensis into the solution and performing fermentation.

4. The fermentation method for improving the fermented flavor of American ginseng according to claim 3, characterized in that: The fermentation temperature is 25-45℃.

5. The fermentation method for improving the fermented flavor of American ginseng according to claim 3, characterized in that: The initial inoculum size of the Weissella sinusitis is 0.1-10 log CFU / ml.

6. The fermentation method for improving the fermented flavor of American ginseng according to claim 4, characterized in that: The initial pH of the solution was 3.5-5.

5.

7. The fermentation method for improving the fermented flavor of American ginseng according to claim 4, characterized in that: The method of improving the fermented flavor of American ginseng includes at least one of the following: (1) Degrading earthy odor substances or reducing the amount of earthy odor substances; (2) producing sour compounds or increasing the amount of sour compounds; (3) Produce fruity flavor compounds or increase the amount of fruity flavor compounds.

8. The fermentation method for improving the fermented flavor of American ginseng according to claim 4, characterized in that: The method of improving the fermented flavor of American ginseng includes reducing the amount of aldehydes and alcohol compounds, wherein the aldehydes include at least one of n-hexanal, heptanal, and n-octanal, and the alcohol compounds include 2-ethylhexanol.

9. The fermentation method for improving the fermented flavor of American ginseng according to claim 4, characterized in that: The method of improving the fermented flavor of American ginseng includes degrading 1-octen-3-ol or reducing the amount of 1-octen-3-ol.

10. The fermentation method for improving the fermented flavor of American ginseng according to claim 4, characterized in that: The method of improving the fermentation flavor of American ginseng includes promoting the production of hexanoic acid and / or n-heptanol.

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