A method for preparing a lactobacillus plantarum solid slurry primer

Abstract

The application discloses a preparation method and application of a Lactobacillus plantarum solid slurry starter. The steps of the preparation method of the Lactobacillus plantarum solid slurry starter include mixing, sterilization, strain activation, inoculation, fermentation and drying. The slurry starter can effectively improve the content of flavor substances in the prepared vegetable slurry, and also retains the sour and fragrant flavor of traditional slurry, so that the prepared slurry is excellent in taste and aroma.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology and relates to a method for preparing solid liquid starter from Lactobacillus plantarum. Background Technology

[0002] Fermented vegetable juice (jiangshui) is a traditional fermented vegetable food, beloved for its unique flavor and nutritional value. Fresh celery, radish, radish greens, alfalfa, chicory, cabbage, dandelion, and even some wild vegetables are selected as raw materials for making jiangshui. After blanching, these are added to noodle soup or rice water, along with old fermented vegetable juice as a starter. Fermentation is completed through the synergistic action of lactic acid bacteria and other microorganisms. With the booming economy and rising living standards, people have higher demands for the quality and flavor of jiangshui, thus facing challenges and improvements in its processing technology. Currently, the use of old fermented vegetable juice as a starter, with its complex fermentation microbial composition, leads to problems such as inconvenient access, contamination by other microorganisms, and unstable flavor and quality. Pure culture fermentation offers advantages such as a single strain, less contamination, and easier control over product quality.

[0003] Lactobacillus plantarum ( Lactobacillus plantarum *Lactobacillus plantarum* possesses strong acid and salt tolerance, enabling it to grow well in acidic fermentation environments and produce lactic acid and other metabolites. It is an important probiotic, found mostly in the human intestinal contents, mouth, feces, and vagina, and also frequently in dough, milk, cheese, fermented fruits and vegetables, and other foods. Recent studies have found that *Lactobacillus plantarum* exhibits various properties in the gut, including antibacterial activity, cholesterol reduction, improvement of the intestinal environment, blood sugar reduction, and blood pressure reduction. It can ferment a wide variety of sugars and survives in the gut, allowing for the production of functional probiotic products. In recent years, *Lactobacillus plantarum* has been used in the production of dairy products, soy products, flour products, and fermented fruit and vegetable products. Therefore, preparing a solid-state pure culture of *Lactobacillus plantarum* as a starter for fermented vegetable liquid production can overcome the shortcomings of traditional starters and is of great significance for developing high-quality fermented vegetable liquid. Summary of the Invention

[0004] To address the numerous problems in traditional fermentation and production of fermented vegetable juice, such as the lack of a good starter, contamination by other microorganisms, and unstable flavor and quality, this invention provides a method for preparing a solid-state fermented vegetable juice starter using *Lactobacillus plantarum* (CGMCC No. 26508) as the fermentation strain, comprising the following steps: 1. Mixing Mix 60-70 parts wheat flour, 5-10 parts celery flour, 5-10 parts cabbage flour, and 5-10 parts bran evenly to obtain a mixture; 2. Sterilization Place the mixture in a microwave oven and sterilize it at 80 degrees Celsius for 3-5 minutes, then let it stand to cool down. 3. Activation of bacterial strains Lactobacillus plantarum (CGMCC No. 26508) was inoculated into MRS liquid medium at a 3% inoculum and activated until the viable count of the activated culture reached 5 × 10⁻⁶. 7 CFU / mL; 4. Vaccination Add 40-50 parts of activated bacterial solution to the sterilized mixture, stir evenly, and knead into a block-shaped slurry starter; 5. Fermentation Ferment the lumpy starter in an incubator at 22-28℃ for 2-4 days, turning it over once during the process, to obtain the fermented starter. 6. Drying The fermented starter was dried in a drying oven at 35-45℃ for 42-48 hours to obtain the finished solid Lactobacillus plantarum starter.

[0005] The method for preparing solid Lactobacillus plantarum slurry primer of the present invention is simple, efficient and easy to operate; the raw materials are readily available and low in cost; the solid Lactobacillus plantarum slurry primer prepared by the present invention has high activity and is a pure culture slurry primer, which can be used for the production of high-quality slurry; the solid slurry primer is easy to store and transport at room temperature, filling a technological gap in the industry. Detailed Implementation

[0006] The following embodiments further illustrate the present invention, but do not limit the invention in any way. A method for preparing a solid slurry starter based on *Lactobacillus plantarum* NML21, wherein *Lactobacillus plantarum* NML21 is used as the fermentation bacteria, and the *Lactobacillus plantarum* NML21 (… Lactiplantibacillus plantarum The accession number for NML21 is CGMCCNo.26508.

[0007] Example 1: 60 parts wheat flour, 5 parts celery flour, 5 parts cabbage flour, and 5 parts wheat bran were mixed evenly to obtain a mixture. The mixture was placed in a microwave oven and sterilized at 80°C for 3 minutes, then allowed to cool. *Lactobacillus plantarum* was inoculated into MRS liquid culture medium at a 3% inoculum and activated until the viable count of the activated culture reached 5 × 10⁻⁶. 7 CFU / mL; Add 40 parts of activated bacterial solution to the sterilized mixture, stir evenly, and knead into a block-shaped slurry starter; Ferment the block-shaped slurry starter in an incubator at 22℃ for 2 days, turning it once in the middle, to obtain the fermented slurry starter; Dry the fermented slurry starter in a drying oven at 35℃ for 42 hours to obtain the finished solid slurry starter of Lactobacillus plantarum.

[0008] Example 2: 65 parts wheat flour, 10 parts celery flour, 5 parts cabbage flour, and 10 parts wheat bran were mixed evenly to obtain a mixture. The mixture was placed in a microwave oven and sterilized at 80°C for 4 minutes, then allowed to cool. *Lactobacillus plantarum* was inoculated into MRS liquid medium at a 3% inoculum to activate the bacteria until the viable count in the activated solution reached 5 × 10⁻⁶. 7 CFU / mL; Add 45 parts of activated bacterial solution to the sterilized mixture, stir evenly, and knead into a block-shaped slurry starter; Ferment the block-shaped slurry starter in an incubator at 25℃ for 3 days, turning it once in the middle, to obtain the fermented slurry starter; Dry the fermented slurry starter in a drying oven at 40℃ for 46 hours to obtain the finished solid slurry starter of Lactobacillus plantarum.

[0009] Example 3: 70 parts wheat flour, 10 parts celery flour, 10 parts cabbage flour, and 10 parts wheat bran were mixed evenly to obtain a mixture. The mixture was placed in a microwave oven and sterilized at 80 degrees Celsius for 5 minutes, then allowed to cool. *Lactobacillus plantarum* was inoculated into MRS liquid culture medium at a 3% inoculum to activate the bacteria until the viable count in the activated culture reached 5 × 10⁻⁶. 7 CFU / mL; Add 50 parts of activated bacterial solution to the sterilized mixture, stir evenly, and knead into clumps of starter; ferment the clumps of starter in an incubator at 28℃ for 4 days, turning them once during the fermentation process, to obtain fermented starter; dry the fermented starter in a drying oven at 45℃ for 48 hours to obtain the finished solid Lactobacillus plantarum starter.

[0010] Example 4: Fresh celery and cabbage were picked, washed, and blanched. Wheat flour was mixed with cold water to form a thin paste, which was then poured into boiling water used to blanch the vegetables and cooked into a noodle soup. The blanched vegetables and noodle soup were placed in a clean container, and fermentation starter (solid fermentation starter and old fermentation starter) was added. The mixture was stirred evenly, the container was sealed, and fermented at room temperature for 3 days. The sensory quality of the prepared fermented vegetable liquid was evaluated and analyzed. The sensory quality scoring criteria and analysis results are shown in Tables 1 and 2. Table 2 shows that the fermented vegetable liquid made with solid fermentation starter has a harmonious flavor, rich layers, and high acceptability, and its score is higher than that made with old fermentation starter.

[0011] Table 1 Sensory Quality Scoring Criteria for Sliced ​​Slurry Color grayish / dark Slightly cloudy Clear and transparent, milky white odor Odor The aroma is bland. Fresh and tangy aroma, with a hint of fermented vegetables. taste Too acidic or bland acidity balance Refreshing taste Flavor monotonous Slightly astringent aftertaste Clearly defined Overall acceptance Poor overall flavor Acceptance is average The flavors are well-balanced and have high acceptance. Table 2. Comparison of sensory qualities of solid starter slurry and aged starter slurry. Color Milky white and translucent, without sediment. Milky white and translucent, without sediment. odor It has a refreshing lactic acid aroma with a slight celery scent and no unpleasant odors. It has a refreshing lactic acid aroma, mixed with a hint of celery, and a slightly jarring odor. taste Mild acidity, refreshing taste Mild acidity, refreshing taste Flavor Dominant lactic acid flavor, with a hint of celery umami. Dominant lactic acid flavor, with a hint of celery umami. Overall acceptance The flavors are harmonious, the layers are rich, and the overall appeal is high. The flavors are harmonious, the layers are rich, and the overall appeal is high. Total score (100) 97 points 90 points

Claims

1. This invention provides a method for preparing a solid liquid primer of *Lactobacillus plantarum*, comprising the following steps: (1) Mixing Mix 60-70 parts wheat flour, 5-10 parts celery flour, 5-10 parts cabbage flour, and 5-10 parts bran evenly to obtain a mixture; (2) Sterilization Place the mixture in a microwave oven and sterilize it at 80 degrees Celsius for 3-5 minutes, then let it stand to cool down. (3) Activation of strains Lactobacillus plantarum NML21 was inoculated into MRS liquid medium at a 3% inoculum and activated until the viable count of the activated bacterial solution reached 5 × 10⁻⁶. 7 CFU / mL; (5) Vaccination Add 40-50 parts of activated bacterial solution to the sterilized mixture, stir evenly, and knead into a block-shaped slurry starter; (6) Fermentation Ferment the lumpy starter in an incubator at 22-28℃ for 2-4 days, turning it over once during the process, to obtain the fermented starter. (7) Drying The fermented starter was dried in a drying oven at 35-45℃ for 42-48 hours to obtain the finished solid Lactobacillus plantarum starter.