Lactobacillus plantarum for enhancing aroma and improving quality of fermented sour bamboo shoots and application of lactobacillus plantarum

Abstract

The invention discloses lactobacillus plantarum for aroma enhancement and quality improvement of fermented sour bamboo shoots and application of the lactobacillus plantarum SS0831, and particularly relates to lactobacillus plantarum SS0831 which is separated from naturally fermented sour bamboo shoots and is preserved in China Center for Type Culture Collection on December 23, 2024, the preservation address is Wuhan University, Wuhan, China, and the preservation number is CCTCC NO: M20242877. The lactobacillus plantarum is used for preparing the fermented sour bamboo shoots, the content of volatile aroma components such as esters, alcohols and aldehydes in the fermented sour bamboo shoots is effectively increased, the flavor quality of the sour bamboo shoots is improved, and more pleasant sensory experience is provided for people.

Description

Technical Field

[0001] The invention belongs to the field of food science and technology, and provides a plant lactobacillus strain for enhancing the flavor and quality of fermented sour bamboo shoots and an application thereof. Background Art

[0002] Sour bamboo shoots are a traditional fermented bamboo shoot product, which is fermented by lactic acid bacteria and other microorganisms. Sour bamboo shoots are rich in 7 kinds of amino acids, dietary fiber, minerals and other active substances for the human body, and have low fat content and high nutritional value, which are beneficial to human health. At present, the fermentation production process of sour bamboo shoots in my country is mainly natural fermentation, that is, fermentation is carried out using the microorganisms carried by the sour bamboo shoots themselves. The microbial fermentation process determines the unique flavor quality of sour bamboo shoots. Microorganisms participate in material transformation by secreting a large number of enzymes, and finally form compounds related to the flavor of sour bamboo shoots. Representative bacterial genera include Pseudomonas, Lactobacillus, Weissella, Enterococcus, and Leuconostoc, among which Acetobacter and Lactobacillus are the dominant species in the entire fermentation stage. Microbial metabolism is the main source of sour bamboo shoot flavor and the core of sour bamboo shoot production. The two are closely related in the fermentation process.

[0003] At present, the fermentation of sour bamboo shoots is mainly carried out in a natural fermentation mode. The process forms an open and unique ecosystem with multiple bacterial species coexisting, providing a rich ecological niche for microorganisms. The process is complex and the cycle is long, and it usually takes several months to complete. However, due to the instability of the environment, raw materials, and fermentation conditions, there are also some harmful microorganisms in the fermentation process. These miscellaneous bacteria will interfere with the work of the main fermentation bacteria, and the flavor characteristics of the final product often show a singleness, especially the strong sour smell. For example, p-cresol, as one of the main volatile compounds, is too high in the sour bamboo shoots. The leather smell and cellar mud smell it brings make the sour bamboo shoots have a strong odor, and this odor cannot be accepted by most consumers, thereby limiting the consumption of sour bamboo shoots. The applicant's preliminary study found that inoculating plant lactobacillus to ferment sour bamboo shoots can effectively improve this problem. It mediates better microbial succession and functional balance by improving resource competition and metabolic interactions between members of the microbial ecology, thereby significantly improving the flavor quality of sour bamboo shoots, but there is currently a lack of lactic acid bacteria strains dedicated to sour bamboo shoot fermentation.

[0004] Therefore, the applicant proposed a strategy to improve the flavor quality of sour bamboo shoots based on the regulation of core microbial communities, established key technologies for improving the quality and flavor of sour bamboo shoots through biological fermentation, and broke through the bottlenecks of long production cycle, single flavor, lack of special fermentation strains and flavor regulation technology of sour bamboo shoots, thereby promoting the acceptance of sour bamboo shoots in a wider consumer market. Studies have shown that the biological fermentation of vegetables by inoculating special fermentation agents can effectively affect the interaction of microorganisms and their community structure, and by regulating the abundance of dominant species and the metabolism of microbial communities, the fermentation cycle can be shortened while achieving the purpose of regulating the nutrients and flavors in fermented vegetables. As the core microorganism in the fermentation process of sour bamboo shoots, Lactobacillus plantarum has become an important fermentation agent in fermented vegetables. Inoculation with Lactobacillus plantarum can significantly increase the levels of flavor compounds such as esters, alcohols and aldehydes in fermented vegetables. Therefore, Lactobacillus plantarum is expected to become the preferred choice for enhancing the flavor and quality of sour bamboo shoots.

[0005] Patent application CN117243350A proposes a method for preparing acid bamboo shoots rich in gastrodin aglycones by fermenting bamboo shoots of Longzhu with Lactobacillus plantarum DGM21. The method can significantly increase the content of gastrodin aglycones in acid bamboo shoots and shorten the fermentation cycle by adding the activated bacterial liquid to fresh Longzhu bamboo shoots at an inoculation amount of 0.5-3% and fermenting at 32-37°C for 8-12 days. After testing, the pH value of the acid bamboo shoots prepared by this method can reach about 3.12, and the gastrodin aglycone content can reach up to 0.26mg / mL. In addition, Lactobacillus plantarum, as a probiotic, helps maintain intestinal health and promote nutrient absorption. However, this method focuses on increasing the content of gastrodin aglycones, a specific secondary metabolite, which may limit the production of other flavor substances, and its fermentation conditions are strict, and there may be limitations on the applicability of bamboo shoots of different types or sources.

[0006] Patent CN114736836B discloses the application of two lactic acid bacteria, Lactobacillus plantarum HZAU-R1 and Pediacoccus acidilactici HZAU-R9, screened from sour bamboo shoot fermentation broth. These two strains have efficient acid production and nitrite degradation capabilities, respectively. This patented technology can ferment at 35-40°C for 5-10 days by using these two strains in synergy, thereby improving the quality of sour bamboo shoots and shortening the fermentation cycle. But overall, the impact on the flavor of sour bamboo shoots is relatively limited, and its basic flavor characteristics are not significantly improved or changed. In addition, since this method is highly dependent on specific lactic acid strains, it may not be possible to replicate the same effect in a fermentation environment without the same microbial community or when using different raw materials. This means that under different production conditions, the effect of this method may vary, thereby limiting the possibility of its widespread application. In addition, for products that seek diversified flavors or special flavor performances, this standardized fermentation process may not meet the needs. Summary of the invention

[0007] In view of this, the object of the present invention is to provide a plant lactobacillus for fermenting sour bamboo shoots to enhance the flavor and quality and application thereof, so as to improve the flavor quality of sour bamboo shoots.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] 1. A strain of Lactobacillus plantarum for fermenting sour bamboo shoots to enhance the flavor and improve the quality, classified and named Lactobacillus plantarum SS0831, was deposited in the China Center for Type Culture Collection on December 23, 2024, with the deposit address being Wuhan University, Wuhan, China, and the deposit number being CCTCC NO:M 20242877.

[0010] 2. Use of the aforementioned plant lactobacillus strain for enhancing the flavor and quality of fermented sour bamboo shoots in the preparation of a high-activity starter.

[0011] As one of the preferred technical solutions, high activity includes: acid resistance and salt resistance.

[0012] As one of the further preferred technical solutions, the acid resistance condition is pH ≥ 3, and the salt resistance condition is sodium chloride mass content ≤ 6%.

[0013] 3. A highly active fermentation agent comprising the aforementioned Lactobacillus plantarum.

[0014] 4. Application of the aforementioned plant lactobacillus or highly active fermentation agent in sour bamboo shoot fermentation.

[0015] As one of the preferred technical solutions, the raw material for sour bamboo shoot fermentation includes any one of moso bamboo shoots, hemp bamboo shoots or square bamboo shoots.

[0016] As one of the preferred technical solutions, the aforementioned plant lactobacillus or highly active fermentation agent is used to enhance the flavor and quality of fermented sour bamboo shoots.

[0017] As one of the further preferred technical solutions, the method of enhancing flavor and improving quality is to increase the types and contents of volatile aroma components in the sour bamboo shoots to improve the flavor quality of the sour bamboo shoots.

[0018] As one of the further preferred technical solutions, the volatile aroma components include: esters, alcohols, aldehydes and the like.

[0019] 5. A method for preparing sour bamboo shoots, which uses fresh bamboo shoots as raw materials, inoculates the aforementioned Lactobacillus plantarum after pretreatment, and ferments.

[0020] As one of the preferred technical solutions, the bamboo shoots are selected from any one of moso bamboo shoots, magnolia bamboo shoots or square bamboo shoots.

[0021] As one of the preferred technical solutions, the fermentation conditions are: sealed fermentation at room temperature (25°C) for 28 days.

[0022] As one of the preferred technical solutions, the specific method is: first peel off the shell of fresh bamboo shoots, wash and cut into 30g to 50g bamboo shoot pieces, then add the bamboo shoot pieces into boiling water, boil the water for 25 minutes, and naturally cool to room temperature to obtain pretreated bamboo shoot pieces; then add the pretreated bamboo shoot pieces into salt water as a fermentation substrate, inoculate the aforementioned plant lactobacillus, and ferment them in a sealed manner at room temperature (25°C) for 28 days.

[0023] As one of the further preferred technical solutions, the mass ratio of the bamboo shoots, boiling water and salt water is 2:4:3, and the mass concentration of sodium chloride contained in the salt water is 6%.

[0024] As one of the further preferred technical solutions, the inoculation amount of Lactobacillus plantarum is 1% of the volume of the fermentation substrate.

[0025] 6. Sour bamboo shoots obtained by the aforementioned preparation method.

[0026] The beneficial effects of the present invention are:

[0027] The plant lactobacillus (Lactobacillus plantarum) SS0831 of the present invention is isolated from naturally fermented sour bamboo shoots and has been preserved in the China Center for Type Culture Collection on December 23, 2024, with the preservation address being Wuhan University, Wuhan, China, and the preservation number being CCTCC NO:M 20242877.

[0028] The invention adopts the plant lactobacillus to prepare fermented sour bamboo shoots, effectively increases the content of volatile aroma components such as esters, alcohols and aldehydes in the fermented sour bamboo shoots, improves the flavor quality of the sour bamboo shoots, and provides people with a more pleasant sensory experience.

[0029] The present invention uses bamboo shoots as raw materials and obtains sour bamboo shoots with a pleasant aroma through biological fermentation with Lactobacillus plantarum SS0831. The present invention has the following advantages:

[0030] 1. The plant lactobacillus SS0831 of the present invention has a salt tolerance of up to 6%, and thus can be widely used in medium-salt or high-salt fermentation of sour bamboo shoots.

[0031] 2. The plant lactobacillus SS0831 of the present invention can not only shorten the fermentation period, but also significantly increase the content of volatile aroma components such as esters, alcohols and aldehydes, thereby increasing the sour bamboo shoot aroma.

[0032] 3. The plant lactobacillus SS0831 biologically fermented sour bamboo shoots of the present invention have obvious advantages over naturally fermented sour bamboo shoots in terms of color, taste, smell and texture.

[0033] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 For strain identification, A is the microscopic structure of Lactobacillus plantarum SS0831 after Gram staining; B is the round, smooth white colonies of Lactobacillus plantarum SS0831 after culture in MRS broth at 37°C for 48 hours;

[0036] Figure 2 This is the result of constructing the strain phylogenetic tree;

[0037] Figure 3 The acid resistance of Lactobacillus plantarum SS0831;

[0038] Figure 4 is the salt tolerance of Lactobacillus plantarum SS0831;

[0039] Figure 5 The composition of volatile flavor substances in naturally fermented sour bamboo shoots;

[0040] Figure 6The composition of volatile flavor substances in LP1105 bio-fermented sour bamboo shoots;

[0041] Figure 7 The composition of volatile flavor substances in SS0831 bio-fermented sour bamboo shoots.

[0042] Collection Information

[0043] Classification name: Lactobacillus plantarum SS0831

[0044] Latin name: Lactobacillus plantarum SS0831

[0045] Deposit number: CCTCC NO: M 20242877

[0046] Name of depository: China Center for Type Culture Collection (CCTCC)

[0047] Address of depository: Wuhan University, Wuhan, China

[0048] Deposit date: December 23, 2024 DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with specific implementation modes.

[0050] Example 1: Culture of bacteria and analysis of their tolerance

[0051] 1 Experimental Materials

[0052] The Lactobacillus plantarum SS0831 strain was deposited in the China Center for Type Culture Collection on December 23, 2024, with the deposit address being Wuhan University, Wuhan, China, and the deposit number being CCTCC NO:M 20242877.

[0053] 2 Experimental methods

[0054] 2.1 Morphological identification of lactic acid bacteria

[0055] The lactic acid bacteria were stained according to the instructions of the Gram staining kit, and then the morphology was observed under a binocular microscope at 100 times the oil lens.

[0056] 2.2 PCR amplification of 16S rDNA sequences

[0057] The DNA of the strain was extracted using a bacterial genomic DNA extraction kit. A 25 μL reaction system was used for PCR amplification, and agarose gel electrophoresis was used for detection after the reaction. Qualified samples were sent to the Chengdu Branch of Beijing Qingke Biotechnology Co., Ltd. for sequencing, and the sequencing results were analyzed for homology comparison using the BLAST program in NCBI.

[0058] 2.3 Construction of phylogenetic tree

[0059] Lactic acid bacteria with homology greater than 98% with the obtained lactic acid bacteria 16S rDNA gene sequence and standard strains in Genome were selected from GeneBank as reference sequences, and then the Neighbor-Joining method in MEGA5.05 program was used to construct a phylogenetic tree of the obtained strains.

[0060] 2.4 Biochemical identification of lactic acid bacteria API 50CH kit

[0061] The isolated strains were cultured at 37°C for 18 hours, centrifuged at 3000 r / min for 15 minutes to collect the cells, washed with sterile saline and resuspended into a bacterial suspension. The operation was performed according to the instructions of the API 50CH kit of BioMérieux (France).

[0062] 2.5 Acid resistance determination

[0063] The bacterial suspension of the strain to be tested was added to MRS broth medium with pH 4, pH 3.5, pH 3, and pH 2.5 (purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd.) at a volume inoculation rate of 2%, and cultured at 37°C for 20 h. Samples were taken at 0 h, 2 h, 4 h, 6 h, and 8 h to determine the OD600nm value. Samples were taken at 20 h, spread on MRS agar medium, and cultured at 37°C for 48 h to observe the growth of the strain.

[0064] 2.6 Salt tolerance determination

[0065] After activation, resuspend the strain to be tested and adjust the concentration of the bacterial solution to 1×10 9 The bacterial suspension was added to MRS broth containing 0%, 2%, 4%, 6%, 8%, and 10% NaCl at a volume inoculation rate of 2%, cultured at 37°C for 24h, and samples were taken at 0h and 24h to measure the OD600nm value.

[0066] 3 Results and analysis

[0067] 3.1 Strain identification Morphological identification

[0068] The colony diameter is between 0.5-2 mm, the front is round, the side is protruding, the edges are neat, creamy white, opaque, and the surface is moist and smooth ( Figure 1 ).

[0069] 3.2 Analysis of strain 16S rDNA sequences

[0070] The 16S rDNA sequence is shown in SEQ ID NO. 1, and the result shows that the strain is Lactobacillus plantarum.

[0071] 3.3 Construction results of strain phylogenetic tree ( Figure 2 )

[0072] 3.4 Acid resistance test results

[0073] During the fermentation process, sour bamboo shoots will produce organic acids such as lactic acid and acetic acid, which will reduce the pH of the fermentation environment. Too low pH will inhibit the growth of lactic acid bacteria. In this experiment, Lactobacillus plantarum SS0831 has a good tolerance to pH ≥ 3. At pH = 2.5, its OD600nm is only 0.01. Therefore, Lactobacillus plantarum SS0831 can maintain a high activity ( Figure 3 ).

[0074] 3.6 Salt tolerance test results

[0075] In the fermentation of sour bamboo shoots, a salt concentration of 6% is usually preferred, which can effectively inhibit miscellaneous bacteria and promote lactic acid bacteria to become the dominant flora, while avoiding the negative impact of excessive salinity (>6%) on the survival of lactic acid bacteria and the quality of sour bamboo shoots. In this experiment, when the concentration of NaCl was ≥6%, the OD value was below 0.3, and the strain showed low activity. Therefore, Lactobacillus plantarum SS0831 has a good tolerance to salt concentrations of ≤6%, and can maintain a high activity during the fermentation of sour bamboo shoots ( Figure 4 ).

[0076] Example 2: Application of Lactobacillus plantarum SS0831 in enhancing flavor and improving the quality of sour bamboo shoots

[0077] 1 Experimental Materials

[0078] Fresh bamboo shoots: sourced from Beibei Farmers’ Market in Beibei District, Chongqing.

[0079] Experimental strain: the aforementioned Lactobacillus plantarum SS0831, deposit number CCTCC NO: M 20242877.

[0080] In order to compare the aroma enhancement effect of SS0831, the applicant used Lactobacillus plantarum LP1105 with good fermentation performance commercially available from Shandong Zhongke Jiayi Bioengineering Co., Ltd. as a control group. In this way, the unique advantage of SS0831 in enhancing the aroma of sour bamboo shoots can be more accurately evaluated.

[0081] 2 Experimental methods

[0082] 2.1 Activation of strains

[0083] Before use, LP1105 and SS0831 were inoculated into MRS broth and cultured at 37°C for 24 h, after which the strains were inoculated into new MRS broth and cultured at 30°C for 12 h. The seed solution was then centrifuged at 8000 rpm for 2 min at 4°C, washed twice with sterile 0.85% (w / v) saline, and suspended in sterile 0.85% saline to adjust to 10 7 Colony forming units (CFU).

[0084] 2.2 Preparation of Sour Bamboo Shoots

[0085] The fresh bamboo shoots were peeled, washed and cut into 30-50g bamboo shoots, boiled in 100℃ boiling water for 25min, cooled and divided into 5L fermentation tanks according to the solid-liquid ratio of 2:3, the salt concentration of the water was 6%, and LP1105 and SS0831 were added at a volume inoculation of 1% respectively for sealed fermentation at room temperature for 28 days. At the same time, a part of the bamboo shoots were directly put into the fermentation barrel at the same proportion for natural fermentation at room temperature as the natural fermentation group.

[0086] 2.3 Determination of volatile flavor substances

[0087] Sour bamboo shoots were mixed with distilled water at a ratio of 1:2 (g:g) and stirred evenly with a homogenizer. Then 5 g of the homogenate was accurately weighed and placed in a 20 mL headspace bottle, 2 g of NaCl was added, and the mixture was sealed and stirred at 60 °C for 20 min. At the same time, a 50 / 30 μm DVB / CAR / PDMS optical fiber was inserted into an aged 50 / 30 μm DVB / CAR / PDMS optical fiber, adsorbed in a 60 °C water bath for 30 min, inserted into the GC-MS inlet, and dissolved again at 250 °C for 3 min. The inlet temperature was 250 °C; the carrier gas was high-purity helium; the flow rate was 1 mL / min. The heating program was as follows: initial column temperature 40 °C, 4 min; then 6 °C / min to 140 °C, 5 min; 3 °C / min to 150 °C for 1 min; 5 °C / min to 197 °C for 2 min; then 1 °C / min to 205 °C for 0 min; then 7 °C / min to 240 °C for 15 min. MS conditions: ionization EI, electron energy 70 eV, filament emission current 0.25 mA, detector temperature 230 ° C, ion source temperature 230 ° C, quadrupole temperature 150 ° C, mass scan range 40 ~ 400u, scan mode: full scan. Volatile peaks were identified by matching them with the volatile peaks in the National Institute of Standards and Technology (NIST) 17.0 mass spectral database. The semi-quantitative degree of each compound was calculated by comparing its area with the internal standard. Samples were analyzed in triplicate.

[0088] 2.4 Sensory evaluation

[0089] The sour bamboo shoots were subjected to sensory evaluation. An 8-member sensory evaluation panel (4 men and 4 women, including 2 sensory evaluation experts) scored the sour bamboo shoots based on their color, taste, flavor and flavor. The scoring criteria are shown in Table 6.

[0090] 3 Results and analysis

[0091] 3.1 Results of determination of volatile flavor substances

[0092] At 1d, 3d, 7d, 14d, and 28d of fermentation, we determined the diversity of volatile flavor compounds in fresh bamboo shoots, naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots, and SS0831 bio-fermented sour bamboo shoots. Figure 5 , Figure 6 , Figure 7 The composition of volatile flavor substances in naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots and SS0831 bio-fermented sour bamboo shoots is shown in Table 1. The types and relative contents of volatile flavor substances in fresh bamboo shoots, naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots and SS0831 bio-fermented sour bamboo shoots at the middle stage of fermentation (14 days) are shown in Table 1.

[0093] Table 1 Volatile flavor types and contents of fresh bamboo shoots, naturally fermented sour bamboo shoots, SS1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0094]

[0095] The results showed that the types of volatile flavor substances in fresh bamboo shoots, naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots, and SS0831 bio-fermented sour bamboo shoots were 33, 41, 47, and 63, respectively. In particular, the diversity of volatile flavor substances in SS0831 bio-fermented sour bamboo shoots significantly surpassed other similar products. Compared with the LP1105 fermented samples, SS0831 bio-fermented sour bamboo shoots not only showed a richer variety of flavor substances, but also significantly reduced the odor-producing substances in sour bamboo shoots, especially the content of phenolic substances was reduced by 32.87%. This significant improvement effectively reduced the unpleasant odor of sour bamboo shoots, giving them a more refreshing and pleasant flavor, thereby greatly improving the sensory quality and consumer acceptance of the product. In addition, compared with the 56 flavor substances obtained by inoculating and fermenting with other plant lactobacilli in a recent report, SS0831 bio-fermented sour bamboo shoots not only had 7 more in number, but also showed unique advantages in flavor complexity and richness (Xue et al., 2025).

[0096] Table 2 Comparison of the contents of the main volatile components in GXLZTY sour bamboo shoots

[0097]

[0098] Table 3 Comparison of the contents of the main volatile components in GXLZTY sour bamboo shoots

[0099]

[0100] As shown in Table 2 and Table 3, Liao An et al. analyzed the volatile components in GDYBNX acid bamboo shoots and GXLZTY acid bamboo shoots by GC-MS technology and found that the relative content of p-cresol in the GXLZTY acid bamboo shoot sample was 95.19%, and a small amount of hexanoic acid (1.14%), octanoic acid (0.47%), 2-ethylhexanol (0.14%) and sulfur dioxide (0.08%) were also detected, while the proportion of p-cresol in GDYBNX acid bamboo shoots was as high as 99.5% (Liao An et al., 2024). Compared with the results of literature research, it was found that the content of phenols in SS0831 fermented acid bamboo shoots was significantly reduced to 30.15%, and the relative content of acids and aldehydes increased to 6.42% and 23.11%. This shows that a specific biological fermentation process can effectively reduce the content of p-cresol, thereby reducing its odor. At the same time, this fermentation process promotes the production of other aroma substances, including esters, ketones, alkenes, acids and aldehydes. These substances work together to not only mediate a more excellent and balanced fermentation process, but also significantly improve the flavor complexity and overall quality of the product.

[0101] Table 4 Relative contents of various compounds in sour bamboo shoots in different regions of Liuzhou

[0102]

[0103] As shown in Table 4, compared with the research results of Tian Yufeng et al., SS0831 bio-fermented sour bamboo shoots demonstrated its excellent performance in improving the flavor of sour bamboo shoots (Tian Yufeng et al., 2023). Specifically, the content of phenolic substances, the main source of odor in sour bamboo shoots, in SS0831 bio-fermented sour bamboo shoots was reduced by more than half. This significant reduction not only effectively weakened the presence of unpleasant odors, but also laid a solid foundation for improving the overall aroma quality of sour bamboo shoots. In addition, as important flavor contributors, the content of alcohol and aldehyde compounds in SS0831 bio-fermented sour bamboo shoots increased by 29.67%. These compounds play a key role in enhancing the layering and complexity of the aroma of sour bamboo shoots, and the increase in their content directly leads to a significant enhancement of the aroma quality of sour bamboo shoots. As shown in Tables 5-1 to 5-5, the key aroma content of naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots and SS0831 bio-fermented sour bamboo shoots is compared.

[0104] Table 5-1 Comparison of the contents of key aroma components in naturally fermented sour bamboo shoots, LP1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0105]

[0106] Table 5-2 Comparison of the contents of key aroma components in naturally fermented sour bamboo shoots, LP1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0107]

[0108]

[0109] Table 5-3 Comparison of the contents of key aroma components in naturally fermented sour bamboo shoots, LP1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0110]

[0111] Table 5-4 Comparison of the contents of key aroma components in naturally fermented sour bamboo shoots, LP1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0112]

[0113] Table 5-5 Comparison of the contents of key aroma components in naturally fermented sour bamboo shoots, LP1105 sour bamboo shoots and SS0831 sour bamboo shoots

[0114]

[0115] As the main contributors to the flavor of sour bamboo shoots, alcohol and aldehyde compounds were found in SS0831 fermented sour bamboo shoots, with 7 and 19 contents respectively, accounting for 23.11% and 15.78% of the total content, which were significantly higher than the corresponding values ​​in naturally fermented sour bamboo shoots and LP1105 fermented sour bamboo shoots. Hexanal added a fresh smell to the sour bamboo shoots with its unique raw oil and grassy aroma, while benzaldehyde gave the sour bamboo shoots a richer layered texture with its unique bitter almond aroma. The contents of these two substances were higher in SS0831 fermented sour bamboo shoots. Compounds such as trans-2-octenal, trans-2-nonenal and nonanal played an indispensable role in shaping the unique and slightly irritating "stink" of sour bamboo shoots. The contents of these substances were highest in naturally fermented sour bamboo shoots, followed by LP1105 fermented sour bamboo shoots, which showed the excellent ability of SS0831 plant lactobacillus in metabolic regulation and proved that it could mediate a more coordinated and comprehensive metabolic process. This optimized metabolic activity makes the SS0831 bio-fermented sour bamboo shoots emit a softer and richer aroma, greatly improving its sensory quality. Through the action of SS0831 plant lactobacillus, the sour bamboo shoots not only retain the unique flavor brought by traditional fermentation, but also further enhance the layering and complexity of the aroma, achieving a true aroma enhancement effect. In addition, specific alcohols such as nerolidol, linalool, benzyl alcohol, geraniol, 2-heptanol, carveol and cyclobutanol give the sour bamboo shoots unique aroma characteristics and contribute significantly to the complexity and appeal of the overall flavor. Nerolidol is a compound with a strong floral, woody and sweet aroma; linalool has a fresh clove and citrus aroma; geraniol has a rose-like aroma and is often found in various essential oils; carveol has a distinct mint or pepper-like aroma. These compounds account for 9.82% in naturally fermented sour bamboo shoots, 10.49% in LP1105 bio-fermented sour bamboo shoots, and 15.91% in SS0831 bio-fermented sour bamboo shoots. These substances are essential for enhancing the aroma of sour bamboo shoots, together producing a more harmonious and diversified flavor system and helping to build its unique flavor profile.

[0116] In contrast, ester compounds are directly involved in the generation of sour bamboo shoot aroma. Two, three and seven esters were detected in naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots and SS0831 bio-fermented sour bamboo shoots, respectively. Their relative contents are shown in Table 2. The ester content in SS0831 bio-fermented sour bamboo shoots far exceeds that in naturally fermented sour bamboo shoots and LP1105 bio-fermented sour bamboo shoots. Methyl hexanoate, as a common ester component of the three, brings a fresh and attractive fruity aroma to all three products. In particular, methyl acetate and methyl octanoate are the key factors in the dominant flavor. These two esters not only contribute their own unique fragrance, but also their synergistic effect significantly enhances the overall flavor characteristics of sour bamboo shoots. In SS0831 bio-fermented sour bamboo shoots, the content of these two esters is 0.55% higher than that of LP1105. This difference fully demonstrates the outstanding performance of SS0831 in improving flavor complexity and quality. In addition, the presence of methyl salicylate adds a unique cool or herbal flavor to SS0831 bio-fermented sour bamboo shoots, further enriching its flavor level. Through the combined action of these esters, SS0831 bio-fermented sour bamboo shoots not only retain the core flavor of traditional sour bamboo shoots, but also develop a more complex and refined taste experience on this basis, thereby further enriching its aroma level and improving the sensory quality of the product. Phenolic compounds, especially phenol and p-benzoylphenol, are the main factors that cause sour bamboo shoots to produce odor. In SS0831 bio-fermented sour bamboo shoots, the content of phenolic substances is reduced by 30.91% and 32.87% compared with naturally fermented sour bamboo shoots and LP1105 bio-fermented sour bamboo shoots, respectively. This change shows that the generation of phenol and p-benzoylphenol is effectively inhibited during the SS0831 bio-fermentation process, thus creating a more delicate and harmonious flavor profile.

[0117] Olefins, with their unique aroma properties, also add a fresh and charming flavor to sour bamboo shoots. α-Pinene has the aroma of turpentine, dry wood and resin, bringing a fresh woody flavor to sour bamboo shoots. β-Myrcene is an important raw material for synthesizing terpenes such as geraniol and linalool, proving that β-Myrcene interacts with other flavor substances to further enrich the aroma level of sour bamboo shoots. In addition to enhancing the overall flavor complexity of sour bamboo shoots, d-limonene also has certain antibacterial activity, which may help inhibit the growth of certain corrupt microorganisms and indirectly maintain the quality of sour bamboo shoots. And longifolene has a woody and herbal flavor, which can add a mild and lasting background aroma to sour bamboo shoots. It is worth noting that the relative content of these olefins in SS0831 bio-fermented sour bamboo shoots is 0.52% and 2.01% higher than that in naturally fermented sour bamboo shoots and LP1105 bio-fermented sour bamboo shoots, respectively. This difference shows that the use of SS0831 pure lactic acid bacteria for fermentation can not only control the quality and safety of the fermentation process, but also effectively improve the aroma characteristics of sour bamboo shoots. Although other flavor substances such as ketones and alkanes contribute to the overall flavor of sour bamboo shoots, their impact is relatively small, and their performance in the three types of sour bamboo shoots is roughly the same.

[0118] 3.2 Analysis of sensory evaluation results

[0119] According to the sensory scoring criteria in Table 6, the sensory evaluation of naturally fermented sour bamboo shoots, LP1105 bio-fermented sour bamboo shoots and SS0831 bio-fermented sour bamboo shoots was carried out (see Table 7). The evaluation results showed that the naturally fermented sour bamboo shoots had the lowest score of only 54 points, while the score of LP1105 bio-fermented sour bamboo shoots was slightly higher, but only 67 points. This shows that LP1105 has limited effect on improving the flavor of sour bamboo shoots and has failed to significantly improve the overall sensory quality of the product. In contrast, SS0831 bio-fermented sour bamboo shoots have obvious advantages in color, taste, smell and texture (up to 96 points), especially smell. SS0831 bio-fermented sour bamboo shoots are mainly characterized by mild sour fragrance, accompanied by a slight ester aroma, a slight aftertaste of plant fermentation, and no unpleasant overly heavy odor (see Table 7). Compared with the sour bamboo shoots fermented with lactic acid bacteria composite culture solution (Kang Linzhi et al., 2023), the sour bamboo shoots fermented with SS0831 biological fermentation showed a stronger smell and taste, with crisp and tender meat, tight and elastic internal structure of bamboo shoots, and pure product without impurities. Furthermore, compared with other sour bamboo shoots fermented with plant lactobacillus on the market (Li Shiwen et al., 2024) (Table 7), under the same fermentation conditions of 1% inoculation, the sour bamboo shoots fermented with SS0831 biological fermentation not only have a stronger smell and richer taste, but also have a unique plant fermentation aftertaste after eating. This good sensory quality gives SS0831 a significant advantage in improving the flavor quality of sour bamboo shoots.

[0120] Table 6 Sensory scoring standards for sour bamboo shoots

[0121]

[0122]

[0123] Table 7 Sensory evaluation of fresh bamboo shoots, naturally fermented sour bamboo shoots, fermented sour bamboo shoots of LP1105 and SS0831, and other sour bamboo shoots

[0124]

[0125] Therefore, the SS0831 biological fermentation has obvious advantages in improving the color, taste, smell and texture of sour bamboo shoots, especially can significantly improve the aroma of sour bamboo shoots, so as to achieve the purpose of enhancing the aroma of sour bamboo shoots. In summary, the present invention can be applied to the enhancement of the aroma of fermented sour bamboo shoots such as moso bamboo shoots, ma bamboo shoots, square bamboo shoots, etc., and has very good application prospects.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

[0127]

References

[0128] 1. Kang Linzhi, Nie Danxia, ​​Chen Lin, et al. Effects of different processing technologies on the quality of sour bamboo shoots[J]. Food Industry Science and Technology,

[0129] 2024,45(08):182-189.DOI:10.13386 / j.issn1002-0306.2023050284.

[0130] 2. Li Shiwen, Yi Kuixin, Tang Yun, Kang Jiajia. Effect of salt concentration on the quality of fermented bamboo shoots with Lactobacillus plantarum[J]. World Bamboo and Rattan Newsletter, 2024,

[0131] 22(5):91-95.DOI:10.12168 / sjzttx.2024.09.11.001

[0132] 3. Liao An, Du Haiping, Cheng Hao, et al. Comparison of main components, volatile components and antioxidant activities of two kinds of sour bamboo shoots [J]. Food and Machinery,

[0133] 2024,40(01):145-151.DOI:10.13652 / j.spjx.1003.5788.2023.80653.

[0134] 4. Tian Yufeng, Sun Minghao, Xu Jiamin, et al. Study on characteristic flavor compounds of sour bamboo shoots in Guangxi [J]. Food and Fermentation Industries,

[0135] 2023,49(23):299-306.DOI:10.13995 / j.cnki.11-1802 / ts.033768.

[0136] 5. Xue, B., You, Y., Du, M., Ibrahim, A., Suo, H., Zhang, F., & Zheng, J. (2025). Metagenomic analysis of lactobacillus plantarum DACN768 inoculation effects on volatile flavor compounds, microbial succession, and flavor metabolic network in suansun. Food Research International,199,115382.https: / / doi.org / 10.1016 / j.foodres.2024.115382

Claims

1. A plant lactobacillus strain for fermenting sour bamboo shoots to enhance flavor and improve quality, characterized in that: The strain was classified and named Lactobacillus plantarum SS0831, and was deposited in the China Center for Type Culture Collection on December 23, 2024. The deposit address is Wuhan University, Wuhan, China, and the deposit number is CCTCC NO: M 20242877.

2. Use of the plant lactobacillus strain for enhancing the flavor and quality of fermented sour bamboo shoots according to claim 1 in the preparation of a high-activity starter.

3. A highly active starter comprising the plant lactobacillus of claim 1.

4. Use of the plant lactobacillus described in claim 1 or the high-activity starter described in claim 3 in sour bamboo shoot fermentation.

5. The use according to claim 4, characterized in that: Application of Lactobacillus plantarum or highly active starter cultures in enhancing the flavor and quality of fermented sour bamboo shoots.

6. A method for preparing sour bamboo shoots, characterized in that: Fresh bamboo shoots are used as raw materials, and the aforementioned plant lactobacillus is inoculated after pretreatment, and fermentation is performed.

7. The preparation method according to claim 6, characterized in that: Fermentation conditions: sealed fermentation at room temperature for 28 days.

8. The preparation method according to claim 6, characterized in that: The specific method is as follows: first peel off the shell of fresh bamboo shoots, wash and cut into 30g to 50g bamboo shoot pieces, then add the bamboo shoot pieces into boiling water, boil for 25 minutes, and naturally cool to room temperature to obtain pretreated bamboo shoot pieces; then add the pretreated bamboo shoot pieces into salt water as a fermentation substrate, inoculate the aforementioned plant lactobacillus, and ferment in a sealed container at room temperature for 28 days.

9. Sour bamboo shoots obtained by the preparation method according to any one of claims 6 to 8.

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