Lactobacillus plantarum DACN768 for reducing sour odor of sour bamboo shoots and application of lactobacillus plantarum DACN768

Abstract

The invention discloses a strain of Lactobacillus plantarum DACN768, and the preservation number of the Lactobacillus plantarum DACN768 is CCTCC (China Center for Type Culture Collection) NO: M 2024398. The invention further discloses application of the lactobacillus plantarum DACN768 or the microbial inoculum of the lactobacillus plantarum DACN768 as a high-activity leavening agent in preparation of fermented food and fermented feed. The lactobacillus plantarum DACN768 is an excellent lactobacillus leavening agent which has high activity such as acid resistance and salt resistance and has biological safety. The lactobacillus plantarum DACN768 is used for purebred fermentation of dendrocalamus latiflorus, the content of p-cresol and phenol in sour bamboo shoots can be remarkably reduced, and sensory evaluation shows that the purebred fermentation dendrocalamus latiflorus shows obvious advantages in color, taste and texture. The lactobacillus plantarum DACN768 can be used for reducing the sour odor of the sour bamboo shoots and improving and stabilizing the quality of the sour bamboo shoots, or can be widely applied to fermented food and fermented feed as a high-activity lactic acid bacteria starter.

Description

Technical Field

[0001] The invention relates to the field of microbial technology and food fermentation technology, and in particular to a plant lactobacillus DACN768 for reducing the sour smell of sour bamboo shoots and an application thereof. Background Art

[0002] Sour bamboo shoots are a traditional Chinese fermented vegetable made from bamboo shoots fermented by microorganisms. Currently, they are often used as ingredients for snail rice noodle and Guilin rice noodle. They are not only refreshing, crisp, sour and tender in taste, but also have a unique flavor, so they are deeply loved by consumers. The fermented sour bamboo shoots contain rich lactic acid bacteria resources, including Leuconostoc, Lactobacillus, Lactococcus and Weissella. Among them, the relevant functional strains such as Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus curvatum, Pediococcus pentosaceus and Leuconostoc mesenteroides have the effects of prebiotics, health care, and improving food safety. At the same time, 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, sour bamboo shoots are mainly fermented naturally, and their microbial communities are rich. The flavor substances in sour bamboo shoots mainly include organic acids, free amino acids, phenols, aldehydes, esters, ketones, etc. The unique odor is the unified flavor feature of naturally fermented sour bamboo shoots. Their unique smell mainly comes from phenols, including p-cresol, phenol, etc., showing cattle body odor, cellar mud odor, leather odor, and burnt skin odor. They are the key volatile flavor substances in naturally fermented sour bamboo shoots. They not only have low thresholds, but also high contents. They are mainly accumulated in the early stage of fermentation, first rising sharply and then slightly decreasing. They are significantly correlated with Lactobacillus, Lactococcus, Enterococcus, and Leuconostoc, and therefore have a significant impact on the flavor of sour bamboo shoots.

[0004] However, sour bamboo shoots have regional preferences. Some consumers like the crisp, refreshing and tender taste of sour bamboo shoots, but have a low acceptance of its sour smell. In addition, sour bamboo shoots mainly fermented naturally have obvious disadvantages in safety, flavor stability and cycle controllability. Therefore, fermenting sour bamboo shoots with pure strains of Lactobacillus plantarum lays the foundation for improving the quality and flavor of sour bamboo shoots.

[0005] Chinese patent application CN 106754472A isolated and screened a plant lactobacillus grx15 from Sichuan Laotan pickled cabbage. The optimum growth temperature of grx15 is 30°C, and the optimum initial growth pH is 6.4. It not only has good acid production performance, acid resistance and salt resistance, can quickly produce acid, inhibit pathogenic microorganisms, and has a strong nitrite degradation ability, but also the strain's ornithine, arginine, lysine, histidine, tyrosine, tryptophan and phenylalanine amino acid decarboxylase activities are negative, indicating that no biogenic amines are produced, which is conducive to improving the fermentation safety of subsequent pickles. However, the plant lactobacillus in this method is not specific in improving the quality of fermented vegetables and cannot significantly change the flavor of fermented vegetables.

[0006] Chinese invention patent CN 113892609B provides a pickling method for improving the quality of Liuzhou sour bamboo shoots, wherein fresh large-headed bamboo shoots are pre-treated to obtain bamboo shoot meat, and the bamboo shoot meat is cut into a block size suitable for a pickling container, boiled with boiling water, cooled to room temperature after boiling, the bamboo shoot meat is taken out and compacted into a pickling container, sterilized water is added to cover the bamboo shoot meat, activated Lactobacillus paracasei MCC1849 bacterial liquid is introduced, the container mouth is sealed, and fermented at 20 to 26°C for 14 to 21 days to obtain salt-free acid bamboo shoots. The present invention does not use salt and other auxiliary materials in the pickling step, effectively reduces production costs, and fundamentally inhibits the generation of nitrite, and promotes the enrichment of characteristic flavor substances and the rapid dissolution of nutrients through fermentation of Lactobacillus paracasei MCC1849. However, at present, sour bamboo shoots are mainly fermented with salt, and most lactobacilli have low salt tolerance. This fermentation method is only applicable to salt-free fermentation, which has certain limitations. Summary of the invention

[0007] The invention aims to provide a strain of Lactobacillus plantarum DACN768 with the function of reducing the off-flavor of sour bamboo shoots and an application thereof, which can not only stabilize the flavor and improve the fermentation efficiency, but also inhibit the production of phenolic substances, especially p-cresol and phenol, and is used for reducing the off-flavor of sour bamboo shoots.

[0008] In order to achieve its purpose, the present invention adopts the following technical solution:

[0009] The first aspect of the present invention provides a strain of Lactobacillus plantarum DACN768, which is deposited in China Center for Type Culture Collection with a deposit number of CCTCCNO: M 2024398.

[0010] A second aspect of the present invention provides a bacterial agent, the active ingredient of which comprises the Lactobacillus plantarum DACN768 described in claim 1.

[0011] Preferably, the bacterial agent is a freeze-dried powder.

[0012] The third aspect of the present invention provides the use of the above-mentioned Lactobacillus plantarum DACN768 or the above-mentioned bacterial agent as a high-activity starter in the preparation of fermented food and fermented feed.

[0013] Preferably, the application is the application of Lactobacillus plantarum DACN768 in the fermentation process of sour bamboo shoots.

[0014] Preferably, the application is to inoculate Lactobacillus plantarum DACN768 into bamboo shoots for fermentation to reduce the sour smell of fermented bamboo shoots;

[0015] Preferably, reducing the sour smell of fermented sour bamboo shoots refers to reducing the content of p-cresol, phenol and total phenol in the fermented sour bamboo shoots.

[0016] The application comprises the following steps:

[0017] (1) peeling the fresh bamboo shoots, washing and cutting them into bamboo shoot pieces, cooking and cooling the bamboo shoot pieces, and placing the bamboo shoot pieces together with water into a fermentation tank;

[0018] (2) Activate the Lactobacillus plantarum DACN768 strain and inoculate the bacterial liquid into a fermentation tank for fermentation.

[0019] Wherein, in step (1), the salt concentration in the fermentation tank is ≤6%, and the solid-liquid ratio of the bamboo shoots to water is 1.5-2.5:2.5-3.5.

[0020] In step (2), the inoculation amount of Lactobacillus plantarum DACN768 is 1.5-2.5%, and the mixture is sealed and fermented at room temperature for 7-30 days after inoculation.

[0021] Preferably, the bamboo shoots are moso bamboo shoots, laminaria bamboo shoots or square bamboo shoots.

[0022] The beneficial effects of the present invention are:

[0023] The experimental study of the present invention confirms that Lactobacillus plantarum DACN768 is an excellent lactic acid bacteria fermentation agent with high activity such as acid resistance and salt resistance and biological safety. In the acid resistance and salt resistance experiments, the growth condition and OD600nm value of the strain on the plate were determined; the pure strain of Lactobacillus plantarum DACN768 fermented bamboo shoots, which can significantly reduce the content of p-cresol and phenol in the sour bamboo shoots. After sensory evaluation, the pure strain fermented bamboo shoots showed obvious advantages in color, taste and texture. Therefore, Lactobacillus plantarum DACN768 can be used to reduce the sour smell of sour bamboo shoots, improve and stabilize the quality of sour bamboo shoots, or be widely used in fermented foods and fermented feeds as a highly active lactic acid bacteria fermentation agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is the morphological identification of the strain: morphological staining and morphology in culture medium.

[0025] Figure 2 It is the result of constructing the phylogenetic tree of the strain.

[0026] Figure 3 This is the result of the acid resistance test of Lactobacillus plantarum DACN768.

[0027] Figure 4 This is the result of the salt tolerance test of Lactobacillus plantarum DACN768. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with embodiments, but the present invention is not limited thereto.

[0029] The experimental methods in the following examples are conventional methods unless otherwise specified; the materials and reagents used are obtained from commercial sources unless otherwise specified.

[0030] Example 1: Culture of bacteria and analysis of their tolerance

[0031] 1 Experimental Materials

[0032] Lactobacillus plantarum DACN768 strain: originated from the strain bank of Suo Huayi Laboratory, School of Food Science, Southwest University, and isolated from kimchi in Chongqing residents' homes.

[0033] 2 Experimental methods

[0034] 2.1 Morphological identification of lactic acid bacteria

[0035] 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.

[0036] 2.2 PCR amplification of 16S rDNA sequences

[0037] 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 Sangon Biotech (Shanghai) Co., Ltd. for sequencing, and the sequencing results were analyzed for homology comparison using the BLAST program in NCBI.

[0038] 2.3 Construction of phylogenetic tree

[0039] 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.

[0040] 2.4 Acid resistance determination

[0041] The bacterial suspension of the strain to be tested was added to MRS broth culture medium of pH 4, pH 3.5, pH 3, and pH 2.5 at an inoculum 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.

[0042] 2.5 Salt tolerance determination

[0043] 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 into MRS broth containing 0%, 1%, 3%, 5%, 7%, 9%, and 11% NaCl at a 2% inoculum, cultured at 37°C for 24 h, and samples were taken at 0 h and 24 h to measure the OD600nm value.

[0044] 3 Results and analysis

[0045] 3.1 Strain identification Morphological identification

[0046] 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 ).

[0047] 3.2 Analysis of strain 16S rDNA sequences

[0048] The 16S rDNA sequencing result of strain DACN768 is shown in SEQ ID No: 1:

[0049] TGGGGGGTGCTATACMTGCAGTCGAACGAACTCTGGTATTGATTGGTGCTTGCATCATGATTTACA

[0050] TTTGAGTGAGTGGCGAACTGGTGAGTAACACGTGGGAAACCTGCCCAGAAGCGGGGGATAACA

[0051] CCTGGAAACAGATGCTAATACCGCATAACAACTTGGACCGCATGGTCCGAGTTTGAAAGATGGCT

[0052] TCGGCTATCACTTTTGGATGGTCCCGCGGGCTATTAGCTAGATGGTGGGGTAACGGCTCACCATGG

[0053] CAATGATACGTAGCCGACCTGAGAGGGTAATCGGCCACATTGGGACTGAGACACGGCCCAAACT

[0054] CCTACGGGAGGCAGCAGTAGGGAATCTTCCACAATGGACGAAAGTCTGATGGAGCAACGCCGCG

[0055] TGAGTGAAGAAGGGTTTCGGCTCGTAAAACTCTGTTGTTAAAGAAGAACATATCTGAGAGTAACT

[0056] GTTCAGGTATTGACGGTATTTAACCAGAAAGCCACGGCTAACTACGTGCCAGCAGCCGCGGTAAT

[0057] ACGTAGGTGGCAAGCGTTGTCCGGATTTATTGGGCGTAAAGCGAGCGCAGGCGGTTTTTTAAGTC

[0058] TGATGTGAAAGCCTTCGGCTCAACCGAAGAAGTGCATCGGAAACTGGGAAACTTGAGTGCAGAA

[0059] GAGGACAGTGGAACTCCATGTGTAGCGGTGAAATGCGTAGATATATGGAAGAACACCAGTGGCG

[0060] AAGGCGGCTGTCTGGTCTGTAACTGACGCTGAGGCTCGAAAGTATGGGTAGCAAACAGGATTAG

[0061] ATACCCTGGTAGTCCATACCGTAAACGATGAATGCTAAGTGTTGGAGGGTTTCCGCCCTTCAGTGC

[0062] TGCAGCTAACGCATTAAGCATTCCGCCTGGGGAGTACGGCCGCAAGGCTGAAACTCAAAGGAAT

[0063] TGACGGGGGCCCGCACAAGCGGTGGAGCATGTGGTTTAATTCGAAGCTACGCGAAGAACCTTAC

[0064] CAGGTCTTGACATACTATGCAAATCTAAGAGATTAGACGTTCCCTTCGGGGACATGGATACAGGTG

[0065] GTGCATGGTTGTCGTCAGCTCGTGTCGTGAGATGTTGGGTTAAGTCCCGCAACGAGCGCAACCCT

[0066] TATTATCAGTTGCCAGCATTAAGTTGGGCACTCTGGTGAGACTGCCGGTGACAAACCGGAGGAAG

[0067] GTGGGGATGACGTCAAATCATCATGCCCCTTATGACCTGGGCTACACACGTGCTACAATGGATGGT

[0068] ACAACGAGTTGCGAACTCGCGAGAGTAAGCTAATCTCTTAAAGCCATTCTCAGTTCGGATTGTAG

[0069] GCTGCAACTCGCCTACATGAAGTCGGAATCGCTAGTAATCGCGGATCAGCATGCCGCGGTGAATA

[0070] CGTTCCCGGGCCTTGTACACACCGCCCGTCACACCATGAGAGTTTGTAACACCCAAAGTCGGTGGGGTAACCTTTAGGAACCAGCCGCCTAAGGTGRACCGGAA.

[0071] 3.3 Construction results of strain phylogenetic tree

[0072] Strains with 16S rDNA gene sequence homology greater than 99% with the test strain in Gene Bank and standard strains in Genome were used as reference sequences, and the phylogenetic tree was constructed using the neighbor-joining method in MEGA 5.0 software. Figure 2 Based on the bacterial morphology, physiological and biochemical characteristics and genetic characteristics, it was named Lactobacillus plantarum DACN768.

[0073] The deposit information of Lactobacillus plantarum DACN768 is as follows:

[0074] The Lactobacillus plantarum DACN768 strain was sent to the China Center for Type Culture Collection (CCTCC) for preservation in March 2024. The address is Wuhan University, No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province. The preservation date is March 6, 2024, the preservation number is CCTCC NO: M 2024398, and the classification name is Lactobacillus plantarum DACN768.

[0075] 3.4 Acid resistance test results

[0076] 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 DACN768 has a good tolerance to pH ≥ 3. At pH = 2.5, its OD600nm is only 0.02. At pH ≥ 3, Lactobacillus plantarum DACN768 can maintain a high activity ( Figure 3 ).

[0077] 3.5 Salt tolerance test results

[0078] The salt concentration in the fermented water of sour bamboo shoots is generally 6% to 8%, which has a certain inhibitory effect on the growth of lactic acid bacteria. Figure 4 According to the results of the salt tolerance experiment, in this experiment, when the concentration of NaCl was ≥7%, the OD value was below 0.5, and the strain showed low activity. Lactobacillus plantarum DACN768 had good tolerance to salt concentrations ≤6% and could maintain high activity during the fermentation of sour bamboo shoots.

[0079] Example 2: Application of Lactobacillus plantarum DACN768 in reducing the sour smell of sour bamboo shoots and improving the quality of sour bamboo shoots

[0080] 1 Experimental Materials

[0081] Fresh bamboo shoots: sourced from Beibei Farmers’ Market in Beibei District, Chongqing.

[0082] The experimental strain was Lactobacillus plantarum DACN768.

[0083] 2 Experimental methods

[0084] 2.1 Activation of strains

[0085] Before use, DACN768 was inoculated into MRS broth and cultured at 37°C for 24 h, after which the strain was 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).

[0086] 2.2 Preparation of Sour Bamboo Shoots

[0087] The fresh bamboo shoots were peeled, washed and cut into 20-30g bamboo shoots, boiled in 100℃ boiling water for 15min, cooled and packed in 5L fermentation tanks according to the solid-liquid ratio of 2:3, the salt concentration of the water was 6%, and DACN876 was added at a 1% inoculum for sealed fermentation at room temperature for 21 days. At the same time, the blanched and cooled bamboo shoots were directly put into the fermentation tanks at the same proportion for natural fermentation at room temperature as the natural fermentation group.

[0088] 2.3 Determination of volatile flavor substances

[0089] The determination method of volatile flavor substances mainly refers to the following literature:

[0090] [1] Tian Yufeng, Sun Minghao, Xu Jiamin, et al. Study on characteristic flavor compounds of sour bamboo shoots in Guangxi[J]. Food and Fermentation Industries, 2023, 49(23): 299-306. DOI: 10.13995 / j.cnki.11-1802 / ts.033768.

[0091] [2] Zhang Yawen, Zhong Yuan, Guo Ailing, et al. Dynamic analysis of volatile substances and bacterial diversity in bamboo shoot fermentation[J]. Chinese Condiment, 2023, 48(01): 1-7+13.

[0092] Mix the sour bamboo shoots with distilled water at a ratio of 1:2 (g:g) and stir them evenly with a homogenizer. Then accurately weigh 6g of the homogenate, put it into a 20mL headspace bottle, add 1.2g of NaCl, and seal and stir at 50℃ for 30min. At the same time, insert the aged 50 / 30μm DVB / CAR / PDMS extraction head in a 50℃ water bath for adsorption for 30min, then insert it into the GC-MS inlet and dissolve it at 250℃ for 3min. The inlet temperature is 250℃; the carrier gas is high-purity helium; the flow rate is 1mL / min. The heating program is: initial column temperature 40℃, 4 minutes; then 6℃ / min to 140℃, 5 minutes; 3℃ / min to 150℃ for 1 minute; 5℃ / min to 197℃ for 2 minutes; then 1℃ / min to 205℃ for 0 minutes; then 7℃ / min to 240℃ for 15 minutes. 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. Based on the analysis of the mass spectral library (WILEY 10N), it was used to identify the compounds separated by total ionization chromatography (TIC).

[0093] 2.4 Sensory evaluation

[0094] The sensory evaluation of the sour bamboo shoots fermented for 21 days was carried out by a sensory evaluation panel composed of 8 professionally trained personnel (4 men and 4 women, including 2 sensory evaluation experts). They scored the sour bamboo shoots in terms of color, taste, taste and flavor. The scoring criteria are shown in Table 1.

[0095] Table 1 Sensory scoring standards for sour bamboo shoots

[0096]

[0097]

[0098] 3 Results and analysis

[0099] 3.1 Results of determination of volatile flavor substances

[0100] The sour smell of sour bamboo shoots is mainly caused by the total phenols, p-cresol and phenol content in Table 3. These substances dominate the sour smell of sour bamboo shoots. When their content is lower, the sour smell of sour bamboo shoots is weaker. Phenols, aldehydes, alcohols and esters in Table 2 are the main volatile flavor substances in sour bamboo shoots. Among them, phenols, aldehydes and alcohols have low thresholds and high contents, becoming the key flavor substances in sour bamboo shoots. Phenols provide sour smell of sour bamboo shoots, aldehydes and alcohols provide sour bamboo shoots with fruity aroma and aromatic taste, and esters present flower and fruity smell. Among them, the content of phenols in sour bamboo shoots occupies a clear advantage, usually accounting for more than 50% of the total volatile flavor substances of naturally fermented sour bamboo shoots. The p-cresol content in phenols accounts for more than 70% of the total phenols, becoming the core flavor active substance in sour bamboo shoots. Therefore, if the sour smell of sour bamboo shoots is to be reduced, the generation of p-cresol must be fundamentally reduced.

[0101] At 21 days of fermentation, the total types of volatile flavor substances in fresh bamboo shoots, naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots by DACN768 were 33, 48 and 52 respectively (Table 2). The types of esters and alcohols in the two were comparable, but the content was significantly higher than that in naturally fermented sour bamboo shoots. Aldehydes are important contributors to the flavor of sour bamboo shoots. The content and types of aldehydes in pure fermented sour bamboo shoots by DACN768 were significantly higher than those in naturally fermented sour bamboo shoots. Other flavor substances such as acids, ketones and ethers contributed less to the flavor of sour bamboo shoots, and showed comparable levels in naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots by DACN768.

[0102] Among them, the main analysis was on the changes in the content of total phenols, p-cresol and phenol in naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots of DACN768. The results (see Table 3) showed that compared with fresh bamboo shoots, the total phenol content of naturally fermented sour bamboo shoots with Ma bamboo shoots as raw materials increased by 47.58±0.05mg / kg, of which p-cresol increased by 45.42±0.09mg / kg and phenol increased by 1.95±0.02mg / kg, while the total phenol content of pure fermented sour bamboo shoots of DACN768 increased by 7.98±0.05mg / kg, p-cresol content increased by 9.01±0.03mg / kg, and phenol content increased by 0.51±0.01mg / kg.

[0103] Table 2 Types of volatile flavor substances in fresh bamboo shoots, naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots of DACN768

[0104]

[0105] Table 3 Phenolic contents of fresh bamboo shoots, naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots of DACN768

[0106]

[0107]

[0108] 3.2 Analysis of sensory evaluation results

[0109] The sensory evaluation of naturally fermented sour bamboo shoots and DACN768 pure fermented sour bamboo shoots was carried out (see Table 4). The results showed that compared with naturally fermented sour bamboo shoots, DACN768 pure fermented sour bamboo shoots had obvious advantages in color, taste, smell and texture, especially smell. DACN768 pure fermented sour bamboo shoots had a slightly lighter odor, but with a slight aftertaste of plant fermentation.

[0110] Table 4 Sensory evaluation of fresh bamboo shoots, naturally fermented sour bamboo shoots and pure fermented sour bamboo shoots of DACN768

[0111] type Color odor taste texture Total score Fresh bamboo shoots 9 29 10 9 57 Naturally fermented sour bamboo shoots (21d) 15 8 15 16 54 DACN768 pure fermented sour bamboo shoots (21d) 16 25 23 20 84

[0112] Therefore, the fermented sour bamboo shoots based on the pure strain of DACN768 have obvious advantages in improving the color, taste, smell and texture of the sour bamboo shoots, especially in significantly reducing the sour smell of the sour bamboo shoots, thereby achieving the purpose of reducing the odor of the sour bamboo shoots. In summary, this technology can be applied to the reduction of odor of fermented sour bamboo shoots such as moso bamboo shoots, ma bamboo shoots, and square bamboo shoots, and has obvious innovation and application prospects.

[0113] This embodiment uses bamboo shoots as raw materials, and ferments pure strains of Lactobacillus plantarum DACN768 to obtain sour bamboo shoots with a lower sour smell. Compared with the existing methods for improving the flavor of sour bamboo shoots, it has the following advantages:

[0114] (1) The plant lactobacillus DACN768 of the present invention has a salt tolerance of 6%-7%, and thus can be widely used in salt-added fermentation and salt-free fermentation of sour bamboo shoots.

[0115] (2) The plant lactobacillus DACN768 of the present invention can not only increase the fermentation rate and stabilize the flavor, but also inhibit the production of phenols in sour bamboo shoots and reduce the peculiar smell of sour bamboo shoots.

[0116] (3) The pure strain of plant lactobacillus DACN768 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.

Claims

1. A strain of Lactobacillus plantarum DACN768, which is deposited in China Center for Type Culture Collection with a deposit number of CCTCC NO: M 2024398.

2. A bacterial agent, the active ingredient of which comprises the Lactobacillus plantarum DACN768 according to claim 1.

3. The bacterial agent according to claim 2, characterized in that: The bacterial agent is freeze-dried powder.

4. Application of plant lactobacillus DACN768 as claimed in claim 1 or the bacterial agent as claimed in claim 2 or 3 as a high-activity starter in the preparation of fermented food and fermented feed.

5. The use according to claim 4, characterized in that: Application of Lactobacillus plantarum DACN768 in sour bamboo shoot fermentation processing.

6. The use according to claim 5, characterized in that: The application is to inoculate Lactobacillus plantarum DACN768 into bamboo shoots for fermentation, thereby reducing the sour smell of the fermented bamboo shoots; Preferably, reducing the sour smell of fermented sour bamboo shoots refers to reducing the content of p-cresol, phenol and total phenol in the fermented sour bamboo shoots.

7. The use according to claim 6, characterized in that: The application comprises the following steps: (1) peeling the fresh bamboo shoots, washing and cutting them into bamboo shoot pieces, cooking and cooling the bamboo shoot pieces, and placing the bamboo shoot pieces together with water into a fermentation tank; (2) Activate the Lactobacillus plantarum DACN768 strain and inoculate the bacterial liquid into a fermentation tank for fermentation.

8. The use according to claim 7, characterized in that: In step (1), the salt concentration in the fermentation tank is ≤6%, and the solid-liquid ratio of the bamboo shoots to water is 1.5-2.5:2.5-3.

5.

9. The use according to claim 7, characterized in that: In step (2), the inoculation amount of Lactobacillus plantarum DACN768 is 1.5-2.5%, and the mixture is sealed and fermented at room temperature for 7-30 days after inoculation.

10. The use according to claim 7, characterized in that: The bamboo shoots are moso bamboo shoots, hemp bamboo shoots or square bamboo shoots.

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