Lactobacillus plantarum, leavening agent and application of lactobacillus plantarum to preparation of Dangshan pear can

Abstract

The invention provides lactobacillus plantarum, a leavening agent and application of the lactobacillus plantarum and the leavening agent to preparation of Dangshan pear cans, and belongs to the field of food. The invention provides Lactiplantibacillus plantarum L3 which is preserved in the China Center for Type Culture Collection on April 11, 2024, the preservation number is CCTCC NO: M 2024663, and the preservation address is the preservation center 202 of Wuhan University, Wuhan, Hubei Province. The lactobacillus plantarum leavening agent is prepared from the Lactiplantarum L3, and the leavening agent can be used for preparing a fermentation can. The invention also provides a Dangshan pear can and a preparation method thereof, the problems of single product and low utilization rate of the Dangshan pear at present are solved, the added value of the Dangshan pear is improved, and the Dangshan pear can prepared by the lactobacillus plantarum L3 solves the problems of sour and astringent taste and poor flavor caused by high yield of acetic acid in the fermentation process.

Description

Technical Field

[0001] The invention belongs to the field of food, and particularly relates to a Dangshan pear canned food with improved added value of the Dangshan pear. Background Art

[0002] Dangshan pear has a long history and is the first of the three traditional famous pears in China. It is famous both at home and abroad for its juicy, sweet taste and lung-moistening and cough-relieving effects. Dangshan pear is not only crisp and refreshing, but also melts in the mouth. It also has extremely high nutritional and health value. It is rich in soluble sugars, organic acids, vitamins, pectin and various minerals. Dangshan pears are mostly eaten fresh. At present, the processed products of Dangshan pears on the market mainly include pear preserves, pear juice, pear wine, pear paste and canned pears in syrup. The product chain is relatively single and the products are highly homogenized. In recent years, the competition in the fruit market has become increasingly fierce, and the market has a rich variety of pears. In order to develop and utilize Dangshan pear resources, increase the added value of Dangshan pear products, and meet consumers' demand for diversified processed products, functional foods and high value-added products, it is necessary to develop new Dangshan pear products with good flavor and high nutritional value.

[0003] Lactic acid bacteria fermentation is an important biotechnology in the food industry. It uses the metabolic activity of lactic acid bacteria to transform raw materials into products with specific flavors, nutrition and functionality. Compared with fruits with moderate sweetness and sourness such as apples and peaches, fresh pears and processed products such as canned pears are relatively sweet. The organic acids produced during the lactic acid bacteria fermentation process give fermented pear products a special fermentation flavor, while fermentation with high acetic acid-producing strains makes pears sour and astringent, which is not easily accepted by consumers. At the same time, browning during the fermentation process seriously affects the quality of fermented pear products. The strain is an important factor in determining the quality and function of fermented products. Different strains have great differences in tolerance, metabolic characteristics and ability to convert nutritional components. Selecting strains that are suitable for Dangshan pears is the key to developing new fermented Dangshan pear products. At present, fermented pear fruit products are mostly pear juice drinks and pear wine, and there has been no report on lactic acid bacteria fermented Dangshan pear products. Therefore, there is an urgent need to develop a fermentation strain suitable for Dangshan pear and develop a lactic acid bacteria fermented Dangshan pear canned food with excellent fermentation flavor and functionality, so as to improve the flavor quality and functional factor content of canned pear products, provide a new direction for the development of Dangshan pear products, provide a reference for the deep processing of Dangshan pear, and provide a theoretical basis and guidance for the research on lactic acid bacteria fermented fruits and vegetables. Summary of the invention

[0004] The invention provides a Lactiplantibacillus plantarum L3 and a fermented Dangshan pear can prepared by using the Lactiplantibacillus plantarum L3, which solve the problems of single Dangshan pear products and low utilization rate, improve the added value of the Dangshan pear, and the Dangshan pear can prepared by using the Lactiplantibacillus plantarum L3 solves the problems of sour taste and poor flavor caused by high acetic acid production during the fermentation process.

[0005] A plant lactobacillus, wherein the plant lactobacillus is Lactiplantibacillus plantarum L3, and the Lactiplantibacillus plantarum L3 is deposited in China Center for Type Culture Collection on April 11, 2024, with a deposit number of CCTCC NO:M 2024663, and a deposit address of 202, Collection Center of Wuhan University, Wuhan City, Hubei Province.

[0006] A plant lactobacillus fermentation agent is prepared by Lactiplantibacillus plantarum L3.

[0007] The invention discloses an application of a Lactobacillus plantarum fermentation agent in the preparation of fermented canned food.

[0008] The specific steps of a preparation method of Dangshan pear can are:

[0009] Step 1: placing Dangshan pear pieces and sugar solution into a fermentation tank; the Dangshan pear pieces are pear pieces with a size of 2 to 3 cm;

[0010] Step 2: adding the fermentation agent of claim 2 into a fermentation tank for fermentation;

[0011] Step 3: After fermentation is completed, the fermented liquid and pear pieces are canned in a weight ratio of 1.5:1, and then auxiliary materials are added;

[0012] Step 4: sealing the cans and sterilizing at high temperature, wherein the high temperature is 100-105° C. and maintained for 15-20 minutes to obtain canned Dangshan pears fermented by lactic acid bacteria.

[0013] The sugar solution is obtained by dissolving 15 to 16 parts by weight of white sugar in 100 to 110 parts by weight of pure water.

[0014] In the step 1, the mass ratio of the Dangshan pear pieces to the sugar solution is 1:1.2.

[0015] The amount of the leavening agent added in step 2 is 2% by weight.

[0016] The fermentation conditions in step 2 are as follows: a temperature of 35-37° C., an ambient humidity of 50%-60%, and static fermentation for 22-24 hours.

[0017] The auxiliary materials in step 3 include kumquat, tremella and lily, and the weight ratios of the added amounts are 0.3%, 0.3% and 0.05% respectively.

[0018] A Dangshan pear canned food, characterized in that the canned food is prepared by the above method.

[0019] Beneficial Effects

[0020] The invention obtains a strain of Lactiplantibacillus plantarum L3 by isolating it from pickled cabbage mother water in Chongqing, and prepares Dangshan pear canned food by using Lactobacillus plantarum L3. After fermentation, the flavor, antioxidant capacity, nutritional components and taste of the Dangshan pear canned food are significantly improved. In addition, by preparing the Dangshan pear canned food, the problems of single product and homogeneity of the existing Dangshan pear are solved, and the added value of the Dangshan crisp pear is improved. A new approach is also provided for other canned products. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the bacterial characteristics of Lactobacillus plantarum L3;

[0022] Figure 2 is the total phenol content of the Dangshan pear can of the present invention;

[0023] Figure 3 is the total flavonoids content of the Dangshan pear canned food of the present invention;

[0024] Figure 4 is the DPPH free radical scavenging rate of the Dangshan pear can of the present invention;

[0025] Figure 5 is the ABTS free radical scavenging rate of the Dangshan pear can of the present invention;

[0026] Figure 6 is the α-glucosidase inhibition rate of the Dangshan pear canned food of the present invention;

[0027] Figure 7 is the organic acid content of the Dangshan pear can of the present invention;

[0028] Figure 8 The volatile flavor substance content test result of the Dangshan pear can of the present invention is shown in FIG.

[0029] Fig. 9 The sensory evaluation results of the Dangshan pear canned food of the present invention are as follows. DETAILED DESCRIPTION

[0030] 1. The culture medium involved in the embodiment is as follows

[0031] MRS solid medium: peptone 10g / L, beef extract 10g / L, glucose 20g / L, sodium acetate 2g / L, yeast powder 5g / L, diammonium hydrogen citrate 2g / L, K 2 HPO 4 ·3H 2 O 2.6g / L, MgSO 4 7H 2 O0.1g / L, MnSO 4 ·H 2 O 0.05g / L, Tween 80 1mL / L, agar powder 15g / L, cysteine ​​salt 0.5g / L.

[0032] MRS liquid culture medium: peptone 10g / L, beef extract 10g / L, glucose 20g / L, sodium acetate 2g / L, yeast powder 5g / L, diammonium hydrogen citrate 2g / L, K 2 HPO 4 ·3H 2 O 2.6g / L, MgSO 4 7H 2 O0.1g / L, MnSO 4 ·H 2 O 0.05g / L, Tween 80 1mL / L, cysteine ​​salt 0.5g / L.

[0033] Example 1. Preparation method of Dangshan pear can.

[0034] 1. Screening, identification and preservation of Lactiplantibacillus plantarum L3.

[0035] The specific steps are as follows:

[0036] (1) Screening:

[0037] The kimchi mother water from Chongqing was used as a sample and diluted 10 times with sterile saline to 10 -5 Then take 200 μL of the dilution factor of 10 -3 , 10 -4 , 10 -5The dilution was plated on MRS solid culture medium, inverted and cultured at 37°C for 48 hours, and the colony morphology was observed and recorded. Colonies of different morphologies on the MRS solid culture medium were picked for streaking separation. After static culture at 37°C for 24 hours, single colonies of different morphologies on the MRS solid culture medium were picked again for streaking separation until single colonies with consistent morphology were obtained; the colony morphology of single colonies was observed, and the obtained colonies were examined by microscopy, Gram staining, and physiological and biochemical characteristics. The colonies with small, round, milky white, raised, and smooth morphologies, rod-shaped Gram staining, and positive Gram staining results were selected, and a strain that may be Lactobacillus plantarum was obtained and named Lactiplantibacillus plantarum L3 (hereinafter referred to as L3). The bacterial characteristics of L3 are shown in Figure 1 . The Gram staining method refers to the textbook "Industrial Microbiological Breeding" (author: Zhuge Jian).

[0038] (2) Identification:

[0039] The genome of L3 was extracted, and the 16S rDNA of strain L3 was amplified and sequenced (sequencing was performed by Sangon Biotech (Shanghai) Co., Ltd., and the sequence obtained was compared with the nucleic acid sequence in NCBI. The results showed that strain L3 was Lactobacillus plantarum, and was named Lactiplantibacillus plantarum L3.

[0040] (3)Save:

[0041] A single colony of Lactobacillus plantarum L3 was picked and inoculated into MRS liquid culture medium, and cultured at 37°C for 24 hours to obtain a bacterial solution; 1 mL of the bacterial solution was taken into a bacterial preservation tube, centrifuged at 8000 rpm for 5 minutes, and the supernatant was discarded. The bacterial mud was resuspended in a 30% (v / v) glycerol solution and stored at -80°C. Lactiplantibacillus plantarum L3 was deposited in the China Center for Type Culture Collection on April 11, 2024, with a deposit number of CCTCCNO: M 2024663, and the deposit address is 202, Wuhan University Collection Center, Wuhan, Hubei Province.

[0042] 2. Leavening agent.

[0043] The above-mentioned Lactobacillus plantarum L3 was inoculated into MRS medium for cultivation, and cultured at 37°C for 24 hours to obtain a culture solution; the culture solution was centrifuged (8000g, 20min) to obtain bacteria; the bacteria were washed and centrifuged with PBS buffer; the cryoprotectant and bacteria were resuspended in a ratio of 1:1 (w:w) to obtain a resuspension; the resuspension was vacuum freeze-dried. Vacuum freeze-drying process: pre-freezing: the plate layer was pre-cooled to below zero, a vial containing 1mL of bacterial suspension was placed, the temperature was lowered to -50°C, and maintained for 4 hours; the vacuum degree was reduced to 200μbar; primary drying: the temperature of the layer was controlled to -30°C, and maintained for 24 hours; secondary drying: the vacuum degree was reduced to 20μbar, and the temperature of the layer was controlled to rise by 5°C in stages, and each stage was maintained for 0.5h until it reached 25°C, and then maintained for 18h, and finally the fermentation agent was obtained.

[0044] Ingredients of the protective agent: 120g / L skim milk powder, 60g / L trehalose, and 30g / L sodium L-glutamate.

[0045] 3. Prepare canned Dangshan pears.

[0046] Raw materials in parts by weight: 100-110 parts of purified water, 15-16 parts of white sugar, and 100-105 parts of Dangshan pear.

[0047] The auxiliary materials are: a combination of kumquat, white fungus and lily.

[0048] The preparation steps are as follows:

[0049] (1) preparing sugar solution: dissolving 15 to 16 parts by weight of white granulated sugar in 100 to 110 parts by weight of purified water, and mixing well to obtain sugar solution;

[0050] (2) Wash the Dangshan pears, remove the impurities on the skin, peel them, remove the beard, and cut them into small pieces of 2 to 3 cm;

[0051] (3) placing Dangshan pear pieces and sugar solution in a mass ratio of 1:1.2 into a fermentation tank;

[0052] (4) introducing 2% by weight of the above-mentioned fermentation agent into a fermentation tank, and allowing the fermentation to proceed at a temperature of 35-37° C., a humidity of 50%-60%, and a fermentation time of 22-24 h;

[0053] (5) After the fermentation is completed, the fermentation liquid and the pear pieces are quantitatively canned in a weight ratio of 1.5:1, and then auxiliary materials of 0.3% by weight of kumquat, 0.3% by weight of white fungus, and 0.05% by weight of lily are added;

[0054] (6) After canning, high temperature sterilization is performed, the sterilization temperature is set to 100-105° C., and the sterilization operation is maintained for 15-20 minutes to obtain lactic acid bacteria fermented Dangshan pear canned food.

[0055] Example 2. Detection of Dangshan pear cans.

[0056] 1. pH value detection method:

[0057] After homogenizing the Dangshan pear canned food with a tissue grinder, 10 mL of the sample was taken and the pH was measured with a pH meter. The pH of the Dangshan pear canned food was 5.00-5.10 before fermentation, and the pH of the Dangshan pear canned food was significantly reduced to 3.90-3.92 after fermentation. The reduction in pH can inhibit the growth of pathogens in the Dangshan pear canned food.

[0058] 2. Detection method of total acid content:

[0059] After homogenizing the canned Dangshan pear, take 5 mL of sample and determine the total acid content according to the national standard GB / T 12456-2008 "Determination of total acid in food". Lactic acid bacteria produce organic acids during the fermentation process, which leads to a significant increase in the total acid content of the fermentation system. The total acid content of the canned Dangshan pear is 0.15-0.18 g / L, and the total acid content after lactic acid bacteria fermentation is 2.13-2.17 g / L.

[0060] 3. Detection method of total phenol content:

[0061] The total phenol content was determined by the Folin-phenol method. 1.0 mL of the diluted Dangshan pear can homogenate was mixed with 2.0 mL of 10% Folin-Ciocalteu reagent at a ratio of 1:79, and allowed to stand at room temperature for 3 min. 2 ml of Na 2 CO 3 (15% w / v) was mixed. Then, the solution was placed in the dark for 0.5 h and the absorbance was measured at 765 nm. The results were expressed as gallic acid equivalent (mg / L). Figure 2 As shown in the figure, after fermentation with L3 fermentation agent, the total phenol content in Dangshan pear canned food increased significantly. Total phenol content is one of the important indicators to measure the quality of natural products such as food. Phenolic compounds are a class of compounds with multiple biological activities such as antioxidant and anti-inflammatory. The total phenol content reflects the nutritional value and functionality of the product. That is to say, after fermentation with L3 fermentation agent, the nutritional value and functionality of Dangshan pear canned food are significantly improved.

[0062] 4. Detection method of total flavonoids content:

[0063] The total flavonoid content was determined by aluminum chloride colorimetry. 1 mL of the diluted Dangshan pear canned slurry was mixed with 5 mL of NaNO 2 (50g / L) in a ratio of 1:19 and placed at room temperature for 5 min to obtain the sample. 3(100g / L) was mixed, shaken, and placed at room temperature for 5 minutes to obtain a solution. The solution was then mixed with 2.0mL NaOH (2mol / L), and the absorbance was measured at 510nm after 10 minutes. The results were expressed as rutin equivalent (mg / L). Figure 3 As shown in the figure, after fermentation with L3 fermentation agent, the total flavonoid content in Dangshan pear canned food increased significantly. Total flavonoids represent flavonoid compounds, which are widely found in vegetables and fruits. The effects of total flavonoids include anti-inflammatory and antioxidant effects. In other words, the anti-inflammatory ability and antioxidant properties of Dangshan pear canned food fermented with L3 fermentation agent are significantly improved.

[0064] 5. Detection method of DPPH free radical scavenging rate:

[0065] DPPH free radical scavenging rate is widely used to evaluate the antioxidant capacity of food. An increase in DPPH free radical scavenging rate indicates that the antioxidant capacity of the product has improved. The detection method is as follows: accurately aspirate 100μL of Dangshan pear canned homogenate, add 100μL of DPPH anhydrous ethanol solution with a mass concentration of 0.304mmol / L, mix and react in the dark for 30 minutes, and measure the absorbance value at 517nm. The DPPH free radical scavenging rate is calculated as follows:

[0066] DPPH free radical scavenging ability = [1-(A1-A2) / A3] × 100%

[0067] Where A1: 100uL sample solution + 100uL DPPH reagent;

[0068] Where A2: 100uL sample solution + 100uL anhydrous ethanol;

[0069] Where A3: 100uL anhydrous ethanol + 100uL DPPH reagent.

[0070] The results are as follows Figure 4 As shown in the figure, after fermentation with L3 starter, the DPPH radical scavenging rate in Dangshan pear canned food was significantly improved, that is to say, the antioxidant capacity of Dangshan pear canned food after fermentation with L3 starter was significantly improved, which further confirmed the results of the total flavonoids content test.

[0071] 6. ABTS free radical scavenging rate detection method:

[0072] ABTS free radical scavenging rate is widely used to evaluate the antioxidant capacity of food. An increase in ABTS free radical scavenging rate indicates that the antioxidant capacity of the product is improved. The detection method is as follows: ABTS diammonium salt stock solution with a concentration of 7.27mmol / L is mixed with K 2 S 2 O 8Mix the two in equal volumes, react in the dark for 12 hours, and dilute to A with anhydrous ethanol. 734 =0.70±0.02. Mix the ABTS working solution with the Dangshan pear canned slurry and shake well, then react in the dark for 6 minutes. The ABTS free radical scavenging rate is calculated as follows:

[0073] ABTS free radical scavenging ability = [1-(A1-A2) / A3] × 100%

[0074] Where A1: 2mL ABTS + 200uL sample solution;

[0075] Where A2: 2mL anhydrous ethanol + 200uL sample solution;

[0076] Where A3: 2mL ABTS + 200uL anhydrous ethanol.

[0077] The results are as follows Figure 5 As shown in the figure, the ABTS free radical scavenging rate in Dangshan pear canned food was significantly improved after fermentation with L3 starter.

[0078] 7. Detection method of α-glucosidase inhibition rate:

[0079] α-glucosidase is involved in the digestion and absorption of carbohydrates. By inhibiting the activity of α-glucosidase, the decomposition and absorption of carbohydrates can be slowed down, and the blood sugar level after a meal can be reduced. The α-glucosidase inhibition rate refers to the degree of inhibition of α-glucosidase activity. The increase in the α-glucosidase inhibition rate indicates that the product has improved its ability to lower blood sugar and lipid metabolism.

[0080] The detection method is as follows: prepare 0.1 mol / L pH 6.8 PBS reagent, 5 mmol / L p-nitrophenyl-α-D-pyranoglucoside (pNPG) solution and 0.2 mol / L Na 2 CO 3 Stop solution, and then prepare 20U / mL α-glucosidase solution with PBS reagent. First add PBS buffer reagent to the 96-well plate, then add sample solution, then add 20μL α-glucosidase solution, react at 37℃ for 10min, then add 20μL pNPG color developer, react at 37℃ for 30min, and finally add 50μL Na 2 CO 3 The solution was used to terminate the reaction and the absorbance was measured at 405 nm. The α-glucosidase inhibition rate was calculated as follows:

[0081] α-glucosidase inhibition rate = 1-(A3-A1) / (A4-A2)×100%

[0082] Wherein: A1 is the absorbance value of the sample blank group; A2 is the absorbance value of the blank group; A3 is the absorbance value of the sample group; A4 is the absorbance value of the control group.

[0083] The results are as follows Figure 6 After fermentation with L3 fermentation agent, the α-glucosidase inhibition rate in canned Dangshan pear was greatly improved, that is, the ability of canned Dangshan pear to lower blood sugar and lipid metabolism was greatly improved after fermentation with L3 fermentation agent.

[0084] 8. Detection method of organic acid content:

[0085] Organic acids are not only important flavor components in fermented foods, but also can bring special effects, such as anti-oxidation, hypoglycemic, and hypolipidemic effects. The production of organic acids in the fermentation process is closely related to microorganisms, and lactic acid fermentation has an important influence on the content of organic acids. After the Dangshan pear can was homogenized at 12000r / min for 10 minutes, the supernatant was filtered twice with a 0.45um microporous membrane. The contents of tartaric acid, oxalic acid, citric acid, malic acid, lactic acid, and acetic acid in Dangshan pear before and after fermentation were detected by high performance liquid chromatography.

[0086] HPLC conditions: XBridge C18 analytical column (250×4.6 mm, 5 um) was used, the detection wavelength was 210 nm, the mobile phase was 0.01 mol / L potassium dihydrogen phosphate and methanol (97:3) at pH 2.7, the mobile phase flow rate was 0.6 mL / min, the column temperature was maintained at 25°C, and the injection volume was 10 uL.

[0087] The results are as follows Figure 7 After fermentation with L3 fermentation agent, two organic acids, lactic acid and acetic acid, are added to the canned Dangshan pears, of which the content of lactic acid is significantly higher than that of acetic acid. A small amount of acetic acid gives canned pears a unique sour aroma and taste, while the sour taste of lactic acid is softer. With the substantial increase in lactic acid, the acidity of the canned Dangshan pears after fermentation is moderate, and the taste is more rounded and rich.

[0088] 9. Detection method of volatile flavor substances content

[0089] Volatile compounds are one of the important factors that determine the flavor of food. As an indicator of bacterial fermentation pathways and sensory characteristics, lactic acid bacteria fermentation improves sensory quality by changing the spectrum of volatile compounds. The detection method is as follows: weigh 5g of homogenized canned food into a 20mL solid phase microextraction sampling bottle, add 1gNaCl, use deuterated chlorobenzene as the internal standard, incubate at 60℃ for 20min and then inject, and each sample is measured in 3 groups in parallel. The headspace injection method is adopted: the incubation temperature is 60℃; the incubation time is 20min; the injection volume is 500μL; the non-split injection mode; the incubation speed is 500r / min; the injection needle temperature is 85℃. GC conditions: the chromatographic column is a MXT-WAX capillary column (30m×0.53mm, 1.0μm); the chromatographic column temperature is 60℃; the carrier gas is high-purity nitrogen (purity ≥99.999%); program boost: the initial flow rate is 2.0mL / min and maintained for 2min, linearly increased to 10.0mL / min within 8min, linearly increased to 100.0mL / min within 10min, and maintained for 30min. The chromatographic running time is 50min; the injection port temperature is 80℃. IMS conditions: the ionization source is a tritium source; the migration tube length is 53mm; the electric field strength is 500V / cm; the migration tube temperature is 45℃; the drift gas is high-purity nitrogen (purity ≥99.999%); the flow rate is 75.0mL / min; positive ion mode.

[0090] The results are as follows Figure 8 , aroma substances are formed by the raw materials themselves and a series of microbial metabolisms during the fermentation process, such as lipolysis or oxidation of fatty acids, degradation of proteins and amino acids, etc. The proportion and types of alcohols, aldehydes and esters in the aroma components of Dangshan pear canned food are relatively large. After fermentation with Lactobacillus plantarum L3, the types and contents of volatile flavor substances in Dangshan pear canned food increased significantly. Ester compounds are the main source of floral and fruity aromas. The fermentation of Lactobacillus plantarum L3 significantly increased the content of ethyl butyrate and ethyl caproate in Dangshan pear canned food. Ethyl caproate is the main source of pear aroma, and ethyl butyrate has a pineapple fragrance, which provides a pleasant fruity aroma for Dangshan pear canned food; aldehyde substances can provide sweet aroma, plant aroma and fruit aroma. After fermentation with Lactobacillus plantarum L3, tetradecanal, lauric aldehyde, perilla aldehyde, etc. are significantly increased, making the fermented canned pears appear iris-like , violet, basil and other plant aromas; in addition, the content of 3-hydroxy-2-butanone increased significantly after fermentation with Lactobacillus plantarum L3, making the fermented canned pears have a creamy aroma; alcohols can not only bring special aromas to the product, but also help to present other aroma substances. After fermentation with Lactobacillus plantarum L3, the content of alcohols such as decanol, trans-nerolidol, geraniol, and n-heptanol in the canned Dangshan pears significantly increased, making the canned Dangshan pears have a rose, orange flower and other aromatic smells. Therefore, the fermentation of Lactobacillus plantarum L3 significantly improved the aroma of the canned Dangshan pears.

[0091] 10. Sensory evaluation.

[0092] The sensory evaluation of Dangshan pear canned food was carried out. Fig. 9 . After fermentation with Lactobacillus plantarum L3, the aroma, sweetness, acidity and taste scores of Dangshan pear canned products were significantly improved. The Dangshan pear pulp in the fermented Dangshan pear canned food is milky white, soft, juicy, and the soup is uniform without precipitation; the aroma of Dangshan pear, kumquat and lactic acid bacteria fermentation can be directly smelled, and the aroma is strong; the acidity and sweetness are moderate, and the taste is richer than that of unfermented Dangshan pear canned food.

Claims

1. A Lactobacillus plantarum, characterized in that The plant lactobacillus is Lactiplantibacillus plantarum L3, and the Lactiplantibacillus plantarum L3 was deposited in the China Center for Type Culture Collection on April 11, 2024, with a deposit number of CCTCC NO: M 2024663, and the deposit address is 202, Collection Center of Wuhan University, Wuhan City, Hubei Province.

2. A plant lactobacillus fermentation agent, characterized in that The starter is prepared by the Lactiplantibacillus plantarum L3 described in claim 1.

3. Application of a plant lactobacillus fermentation agent in the preparation of fermented canned food.

4. A method for preparing Dangshan pear canned food, characterized in that: The specific steps of the method are: Step 1: placing Dangshan pear pieces and sugar solution into a fermentation tank; the Dangshan pear pieces are pear pieces with a size of 2 to 3 cm; Step 2: adding the fermentation agent of claim 2 into a fermentation tank for fermentation; Step 3: After fermentation is completed, the fermented liquid and pear pieces are canned in a weight ratio of 1.5:1, and then auxiliary materials are added; Step 4: sealing the cans and sterilizing at high temperature, wherein the high temperature is 100-105° C. and maintained for 15-20 minutes to obtain canned Dangshan pears fermented by lactic acid bacteria.

5. The preparation method according to claim 4, characterized in that: The sugar solution is obtained by dissolving 15 to 16 parts by weight of white sugar in 100 to 110 parts by weight of pure water.

6. The preparation method according to claim 4, characterized in that: In the step 1, the mass ratio of the Dangshan pear pieces to the sugar solution is 1:1.

2.

7. The preparation method according to claim 4, characterized in that: The amount of the leavening agent added in step 2 is 2% by weight.

8. The preparation method according to claim 4, characterized in that: The fermentation conditions in step 2 are as follows: a temperature of 35-37° C., an ambient humidity of 50%-60%, and static fermentation for 22-24 hours.

9. The preparation method according to claim 4, characterized in that: The auxiliary materials in step 3 include kumquat, tremella and lily, and the weight ratios of the added amounts are 0.3%, 0.3% and 0.05% respectively.

10. A Dangshan pear canned food, characterized in that: The can is prepared by any one of claims 4-9.

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