Pediococcus acidilactici for degrading nitrite and application
By fermenting and pickling rapeseed with degraded nitrite Pac.G1, the problems of long fermentation cycle and unstable nitrite content during the traditional pickling process are solved, and the product quality and health are improved.
Patent Information
- Application Number
- CN202510600781.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-08-15
AI Technical Summary
The fermentation cycle of traditional rapeseed sprouts is too long and the nitrite content is unstable, which affects product quality and health and safety.
The degraded nitrite Pac.G1 was used for fermentation and pickling. After isolation, purification and identification, the strain was inoculated in rapeseed, the salt concentration was controlled and the fermentation was sealed for a certain period of time, which significantly reduced the nitrite content.
Significantly shorten the fermentation time, increase the vitamin C content, total acid content and umami amino acid content of rapeseed sprouts, improve chewability and flavor, and provide safer and healthier pickled vegetable products.
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Figure CN120485024A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of food processing, and particularly relates to a nitrite-degrading Pediococcus acidilactici bacterium and an application thereof. Background Art
[0002] Rapeseed is a major oil crop in the world, and the breeding and industrial development of dual-purpose oil and vegetable varieties are currently hot spots in the development of multifunctional rapeseed varieties. Dual-purpose oil and vegetable varieties are rapeseed varieties whose main stalks or side stalks are picked as vegetables (rapeseed stalks) during the bud stage, and the rapeseed is pressed for oil after it matures. Rapeseed stalks have a fragrant and delicious taste and are rich in nutrients such as vitamins, calcium, iron, and potassium. However, fresh rapeseed stalks are on the market for a short time and are not resistant to storage. Pickling and processing is an effective way to solve this problem. However, the traditional rapeseed stalk pickling process has problems such as a long fermentation cycle, nitrite in the product, and unstable quality, which poses a potential risk to human health. In order to reduce the content of nitrite in pickled vegetables, researchers have been exploring effective solutions.
[0003] In recent years, fermentation and pickling methods using Pediococcus acidilactici have garnered widespread attention due to its ability to impart a unique flavor to vegetables during the fermentation process. Therefore, to address the aforementioned technical issues, there is a need to provide Pediococcus acidilactici that degrades nitrites and methods for preparing rapeseed stalks using Pediococcus acidilactici. This approach would improve the flavor quality of the pickled rapeseed stalks while further reducing the nitrite content in the product.
[0004] Therefore, in order to solve the above technical problems, it is necessary to provide a nitrite-degrading Pediococcus acidilactici and its application.
[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention
[0006] The purpose of the present invention is to provide a nitrite-degrading Pediococcus acidilactici and its application, which can effectively shorten the fermentation time, significantly reduce the nitrite content, significantly improve the chewiness, and improve the taste while ensuring the quality of rapeseed stalks, thereby providing consumers with safer and healthier pickled vegetable products and having wide promotion value.
[0007] In order to achieve the above object, a technical solution provided by a specific embodiment of the present invention is as follows:
[0008] The invention discloses a nitrite-degrading Pediococcus acidilactici bacterium, which is deposited in the General Microbiology Center of China Culture Collection of Microorganisms with a deposit number of CGMCC No. 33428.
[0009] In one or more embodiments of the present invention, the nitrite-degrading Pediococcus acidilactici Pac.G1 is Gram-positive in a Gram stain, negative in a catalase contact test, and has a 16S rDNA sequence as shown in SEQ ID NO: 1.
[0010] In one or more embodiments of the present invention, the nitrite-degrading Pediococcus acidilactici Pac.G1 has a nitrite degradation rate greater than 95%, and grows well at a salt concentration of 4% or more.
[0011] An application of nitrite-degrading Pediococcus acidilactici refers to the application of nitrite-degrading Pediococcus acidilactici Pac.G1 in the preparation of low-nitrite rapeseed stalks. The preparation of low-nitrite rapeseed stalks includes the following steps:
[0012] S1. Preparation of nitrite-degrading Pediococcus acidilactici Pac.G1: Isolation, purification and identification of nitrite-degrading Pediococcus acidilactici;
[0013] S2. Preparation of rapeseed stalks: Pick the upper part of rapeseed stalks from the field and clean them:
[0014] S3, rapeseed stalk pretreatment: adding one portion of edible salt to one portion of rapeseed stalk, kneading the rapeseed stalk until water comes out of the surface of the rapeseed stalk, to obtain pretreated rapeseed stalk;
[0015] S4. Pickling rapeseed stalks: Place the pretreated rapeseed stalks in a pickle jar, flatten and compact them, add a portion of 8% brine that has been boiled and cooled to room temperature to the pickle jar until the rapeseed stalks are submerged, compact them with a vegetable press, and seal the container for 1 to 2 days;
[0016] S5. Inoculating nitrite-degrading Pediococcus acidilactici: adding the prepared Pediococcus acidilactici Pac.G1 suspension to the pickled rapeseed stalks in step S4, and sealing the container again;
[0017] S6. Manufacturing finished products: sealing the cauliflower in the pickle jar and pickling for 30-80 days to obtain a cauliflower product with low nitrite content.
[0018] In one or more embodiments of the present invention, the method for preparing the Pediococcus acidilactici suspension in step S5 is as follows: activating the Pediococcus acidilactici isolated and purified and stored at -80°C to the logarithmic growth phase, centrifuging the bacteria at 4°C, precipitating the bacteria, rinsing them 1-2 times with sterile saline, and resuspending them with an equal volume of sterile saline. After testing the density and activity of the bacteria, a Pediococcus acidilactici Pac.G1 suspension is obtained.
[0019] In one or more embodiments of the present invention, the length of the upper section of the cauliflower prepared in step S2 is 15 to 20 cm.
[0020] In one or more embodiments of the present invention, the weight ratio of one portion of the Chinese cabbage sprout to edible salt in step S3 is 500:32.
[0021] In one or more embodiments of the present invention, in step S5, the weight-to-volume ratio of the first Chinese cabbage to the activated Pediococcus acidilactici is (500:8) to (500:24).
[0022] In one or more embodiments of the present invention, step S5 further includes:
[0023] S51: Activate the isolated, purified, and stored at -80°C Pediococcus acidilactici to the logarithmic growth phase, precipitate the bacteria by centrifugation at 4°C, rinse 1 to 2 times with sterile saline, and resuspend in an equal volume of sterile saline. After testing the density and activity of the bacteria, a Pediococcus acidilactici Pac.G1 suspension is obtained.
[0024] In one or more embodiments of the present invention, the cabbage sprouts in the kimchi jar in step S6 are sealed and pickled for 60 days.
[0025] Compared with the existing technology, the nitrite-degrading Pediococcus acidilactici of the present invention and its application can significantly reduce the nitrite content of pickled rapeseed stalks, effectively shorten the fermentation time, and the rapeseed stalk products have higher vitamin C content, total acid content, and umami amino acid content, and their quality, taste and flavor are better, providing consumers with safer and healthier pickled vegetable products. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0027] Figure 1 The figure is a flow chart of a method for processing low-nitrite Chinese cabbage according to one embodiment of the present invention.
[0028] Figure 2 This is a screening diagram of the ability of Pediococcus acidilactici to degrade nitrite according to one embodiment of the present invention.
[0029] Figure 3 FIG1 is a colony diagram of Pediococcus acidilactici that degrades nitrite according to one embodiment of the present invention.
[0030] Figure 4 1 is a morphological diagram of Pediococcus acidilactici that degrades nitrite according to one embodiment of the present invention.
[0031] Figure 5This is a diagram showing changes in pH during fermentation of rapeseed stalks inoculated with nitrite-degrading Pediococcus acidilactici and naturally fermented rapeseed stalks according to one embodiment of the present invention.
[0032] Figure 6 1 is a graph showing changes in nitrite content during fermentation of rapeseed stalks inoculated with nitrite-degrading Pediococcus acidilactici and naturally fermented rapeseed stalks according to one embodiment of the present invention.
[0033] Figure 7 This is a comparison chart of the chewiness of rapeseed stalks fermented with Pediococcus acidilactici that degrades nitrite according to one embodiment of the present invention and naturally fermented;
[0034] Figure 8 is the serial number of the nitrite degrading device according to one embodiment of the present invention. DETAILED DESCRIPTION
[0035] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.
[0036] like Figure 1-Figure 3 As shown, the nitrite-degrading Pediococcus acidilactici was deposited in the General Microbiology Center of China Culture Collection Administration on January 15, 2025, with the deposit number CGMCC No. 33428, the deposit address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, and the name of the deposited organism is confirmed to be Pediococcus acidilactici Pac.G1.
[0037] Furthermore, the Gram stain of the nitrite-degrading Pediococcus acidilactici Pac.G1 was positive and the catalase contact test was negative, e.g. Figure 8 As shown, the nitrite-degrading Pediococcus acidilactici is 16S rDNA, and the 16S rDNA sequence number is SEQ ID NO: 1. Figure 8 shown.
[0038] The nitrite degradation rate of nitrite-degrading Pediococcus acidilactici was greater than 95%, and the bacteria grew well at a salt concentration of more than 4%.
[0039] like Figure 1 As shown, an application of nitrite-degrading Pediococcus acidilactici refers to the application of nitrite-degrading Pediococcus acidilactici Pac.G1 in the preparation of low-nitrite rapeseed stalks, and the preparation of low-nitrite rapeseed stalks includes the following steps:
[0040] S1. Preparation of nitrite-degrading Pediococcus acidilactici: Isolation, purification and identification of nitrite-degrading Pediococcus acidilactici;
[0041] Among them, the nitrite-degrading Pediococcus acidilactici is Pediococcus acidilactici Pac.G1 which has strong nitrite-degrading ability, and its nitrite degradation rate is greater than 95%.
[0042] S2. Preparation of rapeseed stalks: Pick the upper part of rapeseed stalks from the field and clean them:
[0043] Preferably, the length of the upper section of the cauliflower is 15 to 20 cm.
[0044] S3, rapeseed stalk pretreatment: adding one portion of edible salt to one portion of rapeseed stalk, kneading the rapeseed stalk until water comes out of the surface of the rapeseed stalk, to obtain pretreated rapeseed stalk;
[0045] S4. Pickling rapeseed stalks: Place the pre-treated rapeseed stalks in a pickle jar, flatten and compact them, add a portion of brine that has been boiled and cooled to room temperature to the pickle jar until the rapeseed stalks are submerged, compact them with a vegetable press, and seal the container for 1-2 days;
[0046] Among them, the mass of salt in the brine accounts for 8% of the mass of the brine.
[0047] S5. Inoculating nitrite-degrading Pediococcus acidilactici: adding the prepared Pediococcus acidilactici Pac.G1 suspension to the pickled rapeseed stalks in step S4, and sealing the container again;
[0048] The weight-to-volume ratio of the first Chinese cabbage sprout to the activated Pediococcus acidilactici is (500:8) to (500:24).
[0049] Furthermore, step S5 further includes:
[0050] S51: Activate the isolated, purified, and stored at -80°C Pediococcus acidilactici to the logarithmic growth phase, precipitate the bacteria by centrifugation at 4°C, rinse 1 to 2 times with sterile saline, and resuspend in an equal volume of sterile saline. After testing the density and activity of the bacteria, a Pediococcus acidilactici Pac.G1 suspension is obtained.
[0051] S6. Manufacturing finished products: sealing the cauliflower in the pickle jar and pickling for 30-80 days to obtain a cauliflower product with a low nitrite content.
[0052] Preferably, the cauliflower in the kimchi jar is sealed and pickled for 60 days.
[0053] Example 1: Isolation, purification and identification of nitrite-degrading Pediococcus acidilactici
[0054] like Figure 1 As shown, a nitrite-degrading Pediococcus acidilactici bacterium and its application comprises the following steps:
[0055] S1. Take 1mL of laboratory pickled fermentation liquid and add it to 9mL of sterile saline for dilution. After fully mixing, dilute it with sterile saline in sequence. The dilution degrees are 10 -2 , 10 -3 , 10 -4 , 10 -5 , 10 -6 , and 10 -7 For each of the next four dilutions, 500 μL of each dilution was spread onto MRS-CaCO3 agar plates. The plates were inverted and incubated at 37°C for 48 hours. Colonies were separated based on the presence of calcium rings, size, color, shape, and edge characteristics.
[0056] S2. Purify the isolated strain by repeated streaking on MRS solid medium until a single, pure colony is observed on the medium.
[0057] S3. The single strain isolated by screening was subjected to Gram staining, catalase contact test, 16S-rDNA, and nitrite degradation ability identification.
[0058] like Figures 2 and 3 As shown in the figure, the method of using lactic acid bacteria to degrade nitrite and the method of preparing rapeseed stalks by using lactic acid bacteria to degrade nitrite is as follows. In the environment of 200 mg / L sodium nitrite, we successfully screened out the lactic acid bacteria strain Pac.G1 ( Figure 2 ), after Gram staining, the microscopic observation showed that the morphology was spherical ( Figure 3 ).
[0059] Example 2: Preparation of Low-Nitrite Rapeseed Stalks
[0060] like Figure 1 As shown, a nitrite-degrading Pediococcus acidilactici bacterium and its application comprises the following steps:
[0061] S1. Isolation, purification and identification of nitrite-degrading Pediococcus acidilactici;
[0062] S2. Preparation of rapeseed stalks: Pick the upper part of the rapeseed stalks and wash them clean;
[0063] S3, rapeseed stalk pretreatment: adding one portion of edible salt to one portion of rapeseed stalk, kneading the rapeseed stalk until water comes out of the surface of the rapeseed stalk, to obtain pretreated rapeseed stalk;
[0064] S4. Pickling rapeseed stalks: placing the pre-treated rapeseed stalks in a pickle jar, flattening and compacting them, and adding a portion of brine that has been boiled and cooled to room temperature into the pickle jar until the rapeseed stalks are submerged;
[0065] S5. Inoculating Pediococcus acidilactici with strong nitrite degradation: adding the prepared Pediococcus acidilactici Pac.G1 suspension to the pickled rapeseed stalks in S4, and sealing the container again;
[0066] S6. Sealing the cauliflower in the pickle jar and pickling for about 60 days to obtain a cauliflower product with a low nitrite content.
[0067] According to the present invention, the low-nitrite rapeseed stem processing method enhances the flavor of the rapeseed stems with prolonged fermentation. When pickling the rapeseed stems, ensure that all utensils used are completely oil-free to ensure the quality of the pickling. Before consumption, the rapeseed stems should be washed and soaked in clean water. Depending on personal preference, the rapeseed stems can be chopped or not, and can be used in a variety of dishes, including stir-fries, stews, and soups.
[0068] like Figures 4 to 6 As shown, a is a Brassica rapa stalk, and b is a Brassica rapa stalk.
[0069] Using this specific strain to pickle rapeseed stems shortens the fermentation cycle and simplifies the production process while maintaining product quality. Fermenting rapeseed stems with Pediococcus acidilactici significantly reduces nitrite content and improves chewiness. The rapeseed stem product also has higher levels of vitamin C, total acid, and umami amino acids, resulting in improved quality, taste, and flavor. This provides consumers with a safer and healthier pickled vegetable product with broad promotional value.
[0070] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.
[0071] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.
Claims
1. A nitrite-degrading Pediococcus acidilactici bacterium, characterized in that: The nitrite-degrading Pediococcus acidilactici is deposited in the General Microbiology Center of China Culture Collection Administration, with the deposit number being CGMCC No. 33428.
2. The nitrite-degrading Pediococcus acidilactici bacterium according to claim 1, characterized in that: The Gram staining of the nitrite-degrading Pediococcus acidilactici Pac.G1 is positive, and the catalase contact test is negative. The nitrite-degrading Pediococcus acidilactici Pac.G1 is 16S rDNA, and the sequence number of the 16S rDNA is SEQ ID NO:
1.
3. The nitrite-degrading Pediococcus acidilactici bacterium according to claim 1 or 2, characterized in that: The nitrite degradation rate of the nitrite-degrading Pediococcus acidilactici is greater than 95%, and the bacteria grows well at a salt concentration of more than 4%.
4. An application of Pediococcus acidilactici for degrading nitrite, characterized in that: For preparing low-nitrite rapeseed stalks, the preparation of low-nitrite rapeseed stalks comprises the following steps: S1. Preparation of nitrite-degrading Pediococcus acidilactici: Isolation, purification and identification of nitrite-degrading Pediococcus acidilactici; S2. Preparation of rapeseed stalks: Pick the upper part of rapeseed stalks from the field and clean them: S3, rapeseed stalk pretreatment: adding one portion of edible salt to one portion of rapeseed stalk, kneading the rapeseed stalk until water comes out of the surface of the rapeseed stalk, to obtain pretreated rapeseed stalk; S4. Pickling rapeseed stalks: Place the pretreated rapeseed stalks in a pickle jar, flatten and compact them, add a portion of 8% brine that has been boiled and cooled to room temperature to the pickle jar until the rapeseed stalks are submerged, compact them with a vegetable press, and seal the container for 1 to 2 days; S5. Inoculating nitrite-degrading Pediococcus acidilactici: adding the prepared Pediococcus acidilactici Pac.G1 suspension to the pickled rapeseed stalks in step S4, and sealing the container again; S6. Manufacturing finished products: sealing the rapeseed stalks in the pickle jar and pickling them for 30-80 days to obtain a rapeseed stalk product with low nitrite.
5. The use of Pediococcus acidilactici for degrading nitrite according to claim 4, characterized in that: The preparation method of the Pediococcus acidilactici suspension in step S5 is as follows: the Pediococcus acidilactici isolated and purified and stored at -80°C is activated to the logarithmic growth phase, the bacteria are centrifuged at 4°C, the bacteria are precipitated, washed 1 to 2 times with sterile saline, and then resuspended with an equal volume of sterile saline. After testing the density and activity of the bacteria, a Pediococcus acidilactici Pac.G1 suspension is obtained.
6. The use of Pediococcus acidilactici for degrading nitrite according to claim 5, characterized in that: In step S5, the weight-to-volume ratio of the first Chinese cabbage sprout to the activated Pediococcus acidilactici is (500:8) to (500:24).