A soil Staphylococcus aureus H3 strain and its application

Abstract

The present invention discloses a soil Staphylococcus aureus ( Staphylococcus edaphicus ) H3, whose preservation number in Guangdong Province Microbiological Culture Collection Center is GDMCC No: 64958. The strain H3 of the present invention is used in the fermentation of meat products without adding nitrite. The soil staphylococcus H3 can promote the color of meat products. The soil staphylococcus H3 has strong antioxidant properties and can effectively inhibit lipid peroxidation. The soil staphylococcus H3 can produce polysaccharides, which also play an antioxidant role in the processing of meat products and help maintain the color of meat. When the strain H3 is inoculated to ferment sausages, the nitrite content in the sausages is significantly reduced, and the hardness, cohesion, elasticity and chewiness of the sausages are improved, which can make the sausages taste richer and increase the umami taste. The strain H3 of the present invention has no coagulation or hemolysis effects. As a food additive, it is safe and reliable and suitable for industrial production and market promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of applied microorganisms, and particularly relates to soil staphylococcus H3 and application thereof in the preparation of meat products. Background Art

[0002] Color is an important indicator of meat product quality. The color of meat products is mainly determined by the content and state of myoglobin. Traditional fermented meat products use nitrite as a pickling agent. Nitrite reacts with reducing substances to produce nitric oxide (NO). NO reacts with myoglobin to produce nitrosomyoglobin, which makes the meat products bright pink. However, after nitrite is ingested, it can react in the body to produce N-nitrosamines. N-nitrosamines are potential carcinogens that can cause health problems. The amount of N-nitrosamines added is strictly controlled and cannot meet the needs of green and safety in food manufacturing. Therefore, people are in urgent need of a new substance to replace the use of nitrite in meat processing. Summary of the invention

[0003] The present invention provides a soil Staphylococcus aureus ( Staphylococcus edaphicus ) H3, which was deposited in Guangdong Microbiological Culture Collection Center on May 11, 2024, with the deposit number GDMCC No: 64958, and the deposit address is: Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0004] Another object of the present invention is to convert the above-mentioned soil Staphylococcus aureus ( Staphylococcus edaphicus ) H3 is used in the fermentation preparation of meat products without adding nitrite. Soil Staphylococcus H3 has the effect of promoting the color of meat products. Soil Staphylococcus H3 has strong antioxidant properties and can effectively inhibit lipid peroxidation. Soil Staphylococcus H3 can produce polysaccharides, which also play an antioxidant role in the processing of meat products and help maintain the color of meat. When inoculated with strain H3 to ferment sausages, the nitrite content in the sausages is significantly reduced, which improves the hardness, cohesion, elasticity and chewiness of the sausages, making the sausages taste richer and increasing the umami taste.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] 1. Samples were collected from ham in Qujing City, Yunnan Province, cut into pieces, and homogenized in sterile 0.9% saline. After dilution, the samples were spread on MSA solid medium and cultured at 30°C for 48 hours. Single colonies were picked and separated and purified by streaking on MSA solid medium to obtain strain H3.

[0007] 2. Identification of strain H3

[0008] (1) Morphological characteristics of strain H3: On MSA solid culture medium, the colonies are protruding, round, white, opaque, and have a moist and smooth surface; the bacteria are Gram-positive and are arranged in single, double, quadruple, or grape-like shapes.

[0009] (2) Molecular identification

[0010] The bacterial genomic DNA extraction kit was used to extract the genomic DNA of strain H3. The extracted genome was used as a template and 16S rDNA bacterial universal primers were used for PCR amplification. After the PCR product was sequenced, the sequencing results were compared with the sequences on NCBI. Combined with the morphological characteristics and molecular identification results, the strain was finally identified as soil Staphylococcus aureus ( Staphylococcus edaphicus );

[0011] 3. The present invention proves through safety evaluation experiments that strain H3 has no coagulation or hemolysis, does not contain heat-resistant deoxyribonuclease, and does not produce bioamines, and is safe as a food additive; through physiological and biochemical experiments, it is proved that strain H3 produces nitric oxide, has strong antioxidant properties, and can effectively inhibit lipid peroxidation; strain H3 can produce polysaccharides, which also have antioxidant effects;

[0012] 4. The strain H3 was used in sausage fermentation without adding nitrite. The experimental results showed that the redness value of sausage fermented with the inoculated strain H3 was ( a* There was no significant difference in the redness value of sausages fermented with or without sodium nitrite, and the nitrite content in sausages fermented with inoculated strain H3 was significantly reduced, which improved the hardness, cohesion, elasticity and chewiness of the sausages, making the sausages taste richer and increasing the umami flavor.

[0013] Therefore, the strain of the present invention can replace nitrite and serve as a fermentation agent in meat product processing.

[0014] Advantages and technical effects of the present invention:

[0015] The soil Staphylococcus H3 obtained by screening from traditional cured meat products in the present invention has nitric oxide synthase and can produce NO. During the fermentation of meat products, NO combines with myoglobin to form nitrosylmyoglobin (NO-Mb), making the meat products bright pink. It can replace nitrite in meat products to promote the color development of meat, and can be added to fermented meat products to achieve nitrite-free fermentation with a short production cycle. The method of the present invention avoids the introduction of nitrite and can meet customers' demands for green and safe food. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the colony morphology of soil Staphylococcus aureus H3 on MSA solid medium;

[0017] Figure 2 This is a schematic diagram of the morphology of soil Staphylococcus aureus H3 under a microscope;

[0018] Figure 3 This is the phylogenetic tree of soil Staphylococcus aureus H3;

[0019] Figure 4 This is a schematic diagram of the detection results of lipase production by soil Staphylococcus aureus H3;

[0020] Figure 5 The results of the test of acetoin production by soil Staphylococcus aureus H3 metabolites. The left test tube in the figure is added with H3, and the right test tube is not added with H3.

[0021] Figure 6 This is the NO fluorescence probe detection diagram in soil Staphylococcus;

[0022] Figure 7 The results of the test for the ability to transform metmyoglobin are shown in Figure 1. C is blank, N is the addition of sodium nitrite, and H3 is the addition of strain H3.

[0023] Figure 8 The diagram is a schematic diagram of the absorption peak results of proteins in the test experiment of the ability to transform metmyoglobin. In the figure, C is blank, N is the addition of sodium nitrite, H3 is the addition of strain H3, and the right figure is an enlarged schematic diagram of part of the absorption peaks in the left figure;

[0024] Fig. 9 This is a schematic diagram of the results of electron spin resonance (ESR) detection of myoglobin, in which C is blank, N is the addition of sodium nitrite, and H3 is the addition of strain H3;

[0025] Fig.10 Radar chart of effective taste indicators for fermented sausages. DETAILED DESCRIPTION

[0026] The technical scheme of the present invention is further described in detail below through examples, but the content of the present invention is not limited thereto. The methods in the present examples are conventional methods unless otherwise specified, and the materials and reagents used are obtained from commercial channels or prepared according to conventional methods unless otherwise specified;

[0027] The experiments in the following examples were repeated three times, and the results were expressed as mean ± standard deviation. The experimental data were statistically analyzed using Excel 2019 software to calculate the mean value, standard deviation, etc. of the data; SPSS 26.0 was used to perform one-way analysis of variance on the data.

[0028] Solid culture medium for producing bioamines: 0.5% yeast extract, 0.5% NaCl, 0.1% glucose, 0.05% Tween80, 0.02% MgSO4·7H2O, 0.01% CaCO3, 0.006% bromocresol purple, 0.005% MnSO4·4H20, 0.004% FeSO4·7H2O, 2% agar, 2% specific precursor amino acids (histidine, tyrosine, lysine or ornithine), pH value is adjusted to 5.3, sterilized at 121℃ for 15min; the color of the indicator in the culture medium is yellow at pH 5.3. If bioamines are produced after inoculation, the pH of the culture medium will increase, and the color of the indicator in the culture medium will change from yellow to lavender.

[0029] Example 1: Isolation and identification of soil Staphylococcus aureus H3

[0030] 1. Screening and Isolation of Strain H3

[0031] Samples were collected from homemade ham collected from farmers in Qujing, Yunnan, cut into several small pieces, 25 g of the sample was added to 225 mL of sterile 0.9% saline, homogenized, diluted with 0.9% saline, spread on MSA solid culture medium, and cultured at 30°C for 48 h; a single colony was picked and continued to be streaked on MSA solid culture medium for separation and purification to obtain strain H3;

[0032] 2. Identification of strain H3

[0033] (1) Morphological identification

[0034] The colonies of purified strain H3 on MSA solid medium were round, white, opaque, and moist and smooth ( Figure 1 ); The bacteria are Gram-positive cocci, arranged in single, double, quadruple, and grape-like beads ( Figure 2 ).

[0035] (2) 16S rDNA molecular biological identification

[0036] The bacterial genomic DNA extraction kit (Solebo) was used to extract the genomic DNA of strain H3. The genomic DNA of strain H3 was extracted according to the operating instructions of the kit. The extracted genome was used as a template and 16S rDNA bacterial universal primers (27F: 5'-AGAGTTGATCCTGGCTCAG-3'; 1429R: 5'-GGTTACCTTGTTACGACTT-3') were used for PCR amplification. The PCR product was entrusted to Sangon Biotech (Shanghai) Co., Ltd. for sequencing; the sequence is shown in SEQ ID NO: 1. The 16S rDNA sequence measured by the strain was compared and analyzed in the GenBank database using BLAST, and related sequences with higher homology were selected to construct a phylogenetic tree and analyze the evolutionary relationship using MAGE 11.0.11 software ( Figure 3 ); The 16S rDNA sequence of strain H3 isolated and purified by the present invention is Staphylococcus edaphicus (NR_156818.1) had a 100% homology and the closest evolutionary distance; combined with morphological characteristics and molecular identification results, the strain H3 was finally identified as soil Staphylococcus aureus ( Staphylococcus edaphicus ).

[0037] Example 2: Safety assessment of soil Staphylococcus aureus H3

[0038] Plasma coagulation experiment: Add 0.5 mL of sterile saline to the vial containing freeze-dried rabbit plasma to completely dissolve it, add 0.3 mL of soil Staphylococcus aureus H3 bacterial suspension, mix thoroughly, and culture at 30°C. Observe every half an hour for 6 hours. No coagulation phenomenon occurs.

[0039] Hemolysis experiment: Take soil Staphylococcus aureus H3 cultured in nutrient broth (NB) medium, streak it on the blood plate, and observe it after culturing at 30℃ for 24 hours. It was observed that soil Staphylococcus aureus H3 did not produce a hemolysis circle and had no hemolytic effect.

[0040] Heat-resistant deoxyribonuclease experiment: Take soil Staphylococcus aureus H3 cultured in NB liquid medium, streak it on toluidine blue-DNA agar medium, culture it at 30℃ for 24h, and observe that the area around the colony does not turn into rose red, indicating that soil Staphylococcus aureus H3 does not contain heat-resistant deoxyribonuclease.

[0041] Bioamine production experiment: Take soil Staphylococcus aureus H3 cultured in NB liquid culture medium, streak it on bioamine-producing solid culture medium, culture it at 30°C for 24-48h, and observe that the culture medium turns yellow and does not turn purple, indicating that H1 does not produce bioamines.

[0042] Example 3: Detection of functional properties of soil Staphylococcus aureus H3

[0043] 1. Catalase test

[0044] Use an inoculation loop to smear the bacterial solution cultured overnight at 30°C on a glass slide with 3% H2O2, and observe the results immediately. If bubbles appear, it means that the soil Staphylococcus aureus H3 catalase is positive.

[0045] 2. Lipase activity detection

[0046] Soil Staphylococcus aureus H3 was inoculated into NB liquid medium and cultured at 200 rpm for 14-18 h. 10 μL of bacterial solution was spotted on tributyrin agar medium. After 72 h of culture, a hydrolysis zone appeared around the colony on the plate ( Figure 4 ), indicating extracellular lipase activity.

[0047] 3. Acetoin production experiment

[0048] Inoculate soil Staphylococcus aureus H3 into acetoin detection medium, take the culture medium and mix it with 10% NaOH in equal amounts, add a little creatine, and the culture medium reacts quickly and turns dark red ( Figure 5 ), indicating that H3 produces acetoin.

[0049] 4. Nitric Oxide Production Experiment

[0050] NO in soil Staphylococcus aureus H3 cells was detected by DAF-FM DA (NO-specific fluorescent probe); the third-generation cultured soil Staphylococcus aureus H3 bacterial solution was centrifuged at 7000 g for 10 min to obtain the bacterial cells, and the bacteria were resuspended in NOS detection buffer to keep the bacteria at 2×10 6 -1×10 8 Then, DA-FM DA fluorescent probe was added and incubated at 37°C in the dark for 0.5-1h. Obvious green fluorescence signal was observed under a fluorescence microscope (Leica GM2500) at 100x oil immersion. Figure 6 ), the results showed that strain H3 produced nitric oxide.

[0051] 5. Antioxidant capacity test

[0052] (1) Determination of the DPPH scavenging ability of soil Staphylococcus aureus H3

[0053] The strain H3 cultured overnight in NB liquid medium was centrifuged at 5000g for 10 min to collect the cells, washed 3 times with PBS, suspended in PBS, adjusted to OD600nm = 1.0±0.05, took 0.5mL of the test bacterial suspension, added 0.5mL of DPPH solution with a final concentration of 0.2mmol / L, mixed evenly, reacted at room temperature in the dark for 30min, centrifuged at 7000rpm for 5min, and measured its absorbance at 517nm, with 3 replicates for each sample;

[0054] The clearance rate was calculated according to the following formula: Clearance rate % = [1-(A 样品 -A 空白 ) / A 对照 ]×100.

[0055] In the blank group, DPPH was replaced by an equal volume of anhydrous ethanol; in the control group, the sample solution (bacterial suspension) was replaced by an equal volume of PBS.

[0056] The results showed that the DPPH clearance rate of strain H3 was 58.97%.

[0057] (2) Determination of the ability of soil Staphylococcus aureus H3 to scavenge hydroxyl radicals (OH)

[0058] The hydroxyl radical scavenging ability test kit (purchased from Beijing Solebow Technology Co., Ltd., catalog number: BC1320) was used for determination. The H3 bacterial suspension in step (1) was taken and the determination was performed according to the kit operation steps. The H3 hydroxyl radical scavenging rate was measured to be 91.72%, indicating that soil Staphylococcus aureus H3 has strong antioxidant activity and can effectively inhibit lipid peroxidation.

[0059] 6. Detection of polysaccharide production ability of soil Staphylococcus aureus H3

[0060] (1) Polysaccharide extraction and determination

[0061] According to the inoculation amount of 1% (v / v), the activated H3 bacterial liquid was inoculated into the MRS liquid medium containing 5% (w / v) sucrose, cultured at 30℃ for 48 hours, and 10mL of the culture liquid was centrifuged at 4℃ and 7000g for 10 minutes. The supernatant was collected and added with a trichloroacetic acid solution with a volume of 1 / 15 and a mass volume concentration of 80%, magnetic stirring for two hours, centrifuged to remove protein, and the supernatant was placed in a dialysis bag for 36 hours. Anhydrous ethanol 3 times the volume of the dialysate was added to the dialysate, refrigerated at 4℃ overnight, and the polysaccharide precipitated in a flocculent state. Centrifuged at 4℃ and 8000g for 20 minutes, the supernatant was discarded, and the precipitated polysaccharide was obtained. The precipitated polysaccharide was dissolved in 10mL of distilled water, and the mass concentration of soil Staphylococcus H3 polysaccharide was measured by phenol-sulfuric acid method to be 391.96mg / L.

[0062] (2) Antioxidant capacity test of polysaccharides

[0063] The total antioxidant capacity (T-AOC) kit (BC1310, Solarbio, Beijing, China) was used to measure the total antioxidant capacity of polysaccharides in step (1). The total antioxidant capacity calculated based on the polysaccharide concentration was 538.46 μmol / g, which plays an antioxidant role in the processing of meat products and helps maintain the color of meat.

[0064] Example 4: Detection of the ability of soil Staphylococcus aureus H3 to transform metmyoglobin

[0065] 1. Inoculate soil Staphylococcus aureus H3 in NB liquid culture medium containing 2 mg / mL metmyoglobin, add a layer of sterile paraffin oil on the surface, culture at 30°C for 20 h, centrifuge at 4°C and 7000 rpm for 10 min, take the supernatant, and measure the color value with a colorimeter; use a UV-visible spectrophotometer to perform spectral scanning on the red pigment extract, with a scanning range of 350-700 nm and a scanning interval of 1 nm to determine the characteristic absorption peak of the red pigment, and set up a blank control group (C, without adding bacteria and nitrite) and a nitrite control group (N, adding 60 ppm sodium nitrite, containing the reducing agent NADPH);

[0066] Depend on Figure 7 As shown, the medium containing metmyoglobin after adding sodium nitrite and inoculating soil Staphylococcus aureus H3 changed from brown to bright red, while the medium of the blank group maintained its original brown color;

[0067] from Figure 8 It can be seen that the blank group has obvious absorption peaks at 503nm and 635nm, which are the characteristic absorption peaks of metmyoglobin; in the culture solution of adding sodium nitrite and strain H3, metmyoglobin decreased significantly; the absorption peak of nitrosylmyoglobin in the sodium nitrite group is more obvious, and its characteristic absorption peaks are 395nm, 540nm, and 580nm. After inoculating soil Staphylococcus aureus H3, the characteristic absorption peak is consistent with the absorption peak of nitrosomyoglobin; this shows that inoculating soil Staphylococcus aureus H3 produces nitrosomyoglobin in the myoglobin model.

[0068] 2. Electron spin resonance (ESR) detection of metmyoglobin

[0069] ESR can analyze the lone pair electrons in NO and distinguish between two myoglobin derivatives: oxygenated myoglobin (MbO2) and nitrosyl myoglobin (NO-Mb). The test method is as follows: take 0.2mL of supernatant and put it into a nuclear magnetic tube for ESR spectral analysis. The detection conditions are: scan width: 223 mT-423mT, microwave frequency: 1mW, modulation amplitude: 0.25mT, receiver modulation frequency: 100kHz, temperature 150K. The calculation formula of the spectrum splitting factor (g value) is as follows: g = 0.07145×γ / H (where: γ is the microwave frequency (MHz), H is the resonance field (mT)).

[0070] The results are as follows Fig. 9As shown, both the nitrite group (addition amount 100ppm) and the inoculated strain H3 group produced signals of paramagnetic field substances. The spectrum of the fermentation group inoculated with soil Staphylococcus aureus H3 was consistent with the addition of sodium nitrite. The g value of the peak of the H3 group (g1=2.0325, g2=2.2.0177, g3=1.9986) was very similar to the previously reported NO-Mb, further proving that NO-Mb was produced by adding strain H3 to fermented meat. This shows that the principle of soil Staphylococcus aureus H3 forming a stable red color with nitrite is the same, indicating the feasibility of strain H3 replacing nitrite.

[0071] The above results show that using soil Staphylococci that have NOS, produce NO and produce polysaccharides as colorants can improve the color of meat products, thereby achieving the effect of replacing nitrite for color development.

[0072] Example 5: Soil Staphylococcus aureus H3 as a coloring agent for fermentation of minced meat

[0073] 1. Preparation of soil Staphylococcus aureus H3 bacterial suspension

[0074] The activated soil Staphylococcus aureus H3 was inoculated into a nutrient broth medium with an inoculation amount of 1% to 3% (v / v), and cultured on a shaker at 200 rpm and 30°C for 18 hours, and the culture was continuously transferred for 3 times to obtain the third-generation fermentation broth; the third-generation fermentation broth was centrifuged at 4°C and 7000g for 10 minutes, the precipitate was taken, the precipitate was washed 3 times with sterile saline, and the precipitate was resuspended to obtain an H3 bacterial suspension.

[0075] 2. Preparation of fermented minced meat

[0076] (1) Mince pork at 4°C to make minced meat, and add 2% salt;

[0077] (2) Add H3 bacterial suspension as a coloring agent to the minced meat. The inoculation amount of soil Staphylococcus aureus H3 is 10 6 -10 8 CFU / g;

[0078] (3) After fermentation at 25 ± 2°C for 1 day, the mixture was matured at 18°C ​​for 6 days to obtain the fermented minced meat product;

[0079] At the same time, a blank control group was set up: 2% salt was added, no strain H3 was added, and an equal volume of sterile saline was added;

[0080] Comparative Example 1: The strain H3 in the above step 2 is replaced with a Staphylococcus aureus suspension;

[0081] The color value of the fermented minced meat in the above experimental group was tested, and samples were taken on the 1st, 2nd, 7th and 14th days of fermentation for redness value. a *The results are shown in Table 1. During the entire fermentation process, the chromaticity value of the inoculated strain H3 group was significantly higher than that of the blank control group and the inoculated Staphylococcus aureus group ( P <0.05).

[0082] Table 1 Redness values ​​of fermented minced meat in different treatment methods a * contrast

[0083]

[0084] Note: Different lowercase letters indicate significant differences among different treatment groups at the same fermentation time ( P <0.05, different capital letters indicate significant differences in fermentation time in the same treatment group ( P <0.05).

[0085] Example 6: Application of soil Staphylococcus aureus H3 in sausage fermentation

[0086] 1. Sausage production

[0087] Purchase pork hind leg meat (fat-to-lean ratio of 2:8), remove the fascia, mince and set aside; add 2.5% salt and 1% glucose to the meat and mix well; set up the H3 fermentation group: inoculate the H3 bacterial suspension and ensure that the total number of viable bacteria in the sausage reaches 10 7 CFU / g; the control group was not inoculated with H3 bacterial suspension, and an equal volume of sterile saline was added; the nitrite group was added with 100 mg / kg sodium nitrite and an equal volume of sterile saline.

[0088] After mixing, fill the intestines and ferment at 30℃ and relative humidity of 75%-80% for 24 hours; mature at 15℃ and relative humidity of 60%-65% for 6-7 days.

[0089] 2. The fermented mature sausages of the above experimental groups were evaluated for nitrite, nitrosoerythrin, texture, color difference and sensory evaluation

[0090] (1) Determination of nitrite content

[0091] The determination was carried out according to the spectrophotometric method in the national standard 5009.33-2016 "National Food Safety Standard Determination of Nitrite and Nitrate in Food". The standard curve of nitrite is y = 0.0345x + 0.0438, R 2 = 0.998. The results of nitrite detection in sausages of each experimental group are shown in Table 2. The nitrite content in the H3 fermentation group was significantly lower than that in the nitrite group and the control group ( P <0.05);

[0092] Table 2 Nitrite content in sausages

[0093]

[0094] Note: Different lowercase letters in the same row indicate significant differences ( P <0.05).

[0095] (2) Using a texture analyzer to test the texture of fermented mature sausages

[0096] The fermented mature sausage was cut into 1 cm thick slices. The force sensing unit had a range of 500 N and the probe used in the experiment was a 7.5 cm diameter disc. The probe took the sample platform as the displacement zero point and moved downward at a rate of 60 mm / min. When the probe touched the sausage sample (i.e., when the trigger force reached 0.75 N), it was pressed downward at a rate of 60 mm / min. After the sample was deformed by 50%, the probe was lifted at a rate of 60 mm / min and returned to the sample surface. Then, the extrusion was repeated once. The results are shown in Table 3.

[0097] The hardness, cohesiveness and chewiness of the H3 fermentation group were significantly higher than those of the nitrite group and the control group ( P <0.05), adding H3 increased the hardness, cohesion and elasticity of the sausage, and the chewiness also improved, making the sausage's tissue structure more compact. Inoculation of H3 fermentation effectively improved the sausage's texture;

[0098] Table 3 Effects of different treatments on sausage texture

[0099]

[0100] Note: Different lowercase letters in the same column indicate significant differences ( P <0.05).

[0101] (3) Using a desktop colorimeter to measure the color of fermented sausage

[0102] The fermented sausage was cut into slices about 1 cm thick and the brightness of the sample was measured using a colorimeter ( L* )、Redness value( a* ) and yellowness value ( b* ), select the reflection mode, calibrate the instrument using the built-in standard white plate, and measure the brightness ( L* )、Redness( a* )、Yellowness( b* ) values, color difference comparison is shown in Table 4;

[0103] The results showed that the fermented sausages were inoculated with strain H3 a* The value was significantly higher than that of naturally fermented sausage ( P <0.05), and there was no significant difference with the nitrite group ( P >0.05), therefore, the addition of soil Staphylococcus aureus H3 could replace nitrite as a chromogenic agent;

[0104] Table 4 Chromaticity of fermented sausage

[0105]

[0106] Note: Different lowercase letters in the same row indicate significant differences ( P <0.05).

[0107] (4) Electronic tongue is an effective means of analyzing flavor substances. It can simulate human taste perception and detect the flavor of fermented sausages in different treatment groups using electronic tongue.

[0108] Weigh 50g of sausage sample and put it in a food processor. Add pure water at a mass ratio of 1:5 to homogenize. After filtering, take the filtrate for SA402B Plus taste analysis system test. The reference solution used in the experiment is composed of potassium chloride and tartaric acid. Tasteless represents the output (tasteless point) of the reference solution. The tasteless point of each index is 0. Based on this, when the taste value of the sample is lower than Tasteless, it means that the sample has no taste, otherwise it has.

[0109] The results are as follows Fig.10 As shown in the figure, the main taste indexes of fermented sausages are bitterness, saltiness, umami, umami aftertaste and bitter aftertaste. The saltiness value of the fermentation group inoculated with H3 is the lowest; the bitterness, umami, umami aftertaste and bitter aftertaste of the fermentation group inoculated with H3 are higher than those of the natural fermentation group and the sodium nitrite group. The bitterness, umami and umami aftertaste reflect the richness of the taste; this shows that fermentation by inoculating with H3 can make the sausage taste richer and increase the umami taste.

Claims

1. A soil Staphylococcus aureus ( Staphylococcus edaphicus )H3, its deposit number in Guangdong Microbiological Culture Collection Center is GDMCC No:64958.

2. Use of the soil Staphylococcus aureus H3 according to claim 1 in the preparation of fermented meat products.

3. The use according to claim 2, characterized in that: No nitrite is added during the fermentation preparation of meat products. Soil Staphylococcus H3 has the effect of coloring fermented meat products, reducing nitrite content, and improving sausage texture.

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