Use of lactobacillus sake smf-l5 in micro-fermented poultry food products

Abstract

This invention relates to the field of food processing technology. It provides the application of *Lactobacillus sakei* SMF-L5 in micro-fermented poultry products and in improving their quality, wherein the mass ratio of *Lactobacillus sakei* SMF-L5 to poultry meat during micro-fermentation is 0.25-0.35:1000. This invention also provides a method for preparing micro-fermented poultry products, which utilizes the metabolic activity of *Lactobacillus sakei* SMF-L5 to alter the micro-fermentation environment, thereby effectively improving the texture, flavor, and other quality characteristics of the poultry products, producing livestock and poultry meat products with novel properties.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to the application of Lactobacillus sakei SMF-L5 in micro-fermented poultry products. Background Technology

[0002] Fermentation agents refer to live or dormant microbial preparations. Currently, fermentation agents for livestock and poultry fermented meat products mainly fall into two categories: one is lactic acid bacteria, which are Gram-positive microorganisms, primarily including Lactobacillus, Pediococcus, Streptococcus, and Lactococcus. The main role of lactic acid bacteria in the meat fermentation process is to promote a rapid decrease in pH, thereby inhibiting adverse changes caused by putrefactive microorganisms or non-microbial reactions, stabilizing the product and extending its shelf life. They can also alter the product's color and texture. The other category includes Staphylococcus and Micrococcus, which are also widely used in fermented meat product production. They primarily improve product color and enhance meat flavor by releasing lipases and proteases.

[0003] However, the current fermentation agents have not shown significant effects in improving the flavor, color, and texture of fermented meat products from livestock and poultry. Summary of the Invention

[0004] The purpose of this invention is to provide an application of Lactobacillus sakei SMF-L5 in micro-fermented poultry products. By using Lactobacillus sakei SMF-L5 for wet fermentation, the texture, flavor and other quality characteristics of poultry products can be effectively improved through the metabolic action of microorganisms.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides the application of Lactobacillus sakei SMF-L5 in micro-fermented poultry products.

[0007] Preferably, the mass ratio of Lactobacillus sakei SMF-L5 to poultry meat during micro-fermentation is 0.25-0.35:1000.

[0008] This invention provides the application of Lactobacillus sakei SMF-L5 in improving the quality of poultry products.

[0009] This invention also provides a method for preparing micro-fermented poultry meat products, comprising the following steps:

[0010] (1) Mix poultry meat with brine and inoculate with Lactobacillus sakei SMF-L5 for micro-fermentation to obtain semi-finished poultry meat;

[0011] (2) The obtained semi-finished poultry meat is dried and packaged to obtain the finished product.

[0012] Preferably, the mass concentration of the brine in step (1) is 2-6%, and the mass ratio of the brine to the poultry meat is 2:4-6.

[0013] Preferably, the micro-fermentation time in step (1) is 3-7 days, and the micro-fermentation temperature is 8-15℃.

[0014] Preferably, the initial viable count of the Lactobacillus sakei SMF-L5 is 1.2-2.5 × 10⁻⁶. 11 cfu / g; the mass ratio of the inoculated Lactobacillus sakei SMF-L5 to the poultry meat is 0.25-0.35:1000.

[0015] Preferably, the drying method includes natural air drying or temperature-controlled drying.

[0016] Preferably, when the drying method is natural air drying, the drying time is 5-15 days; when the drying method is temperature-controlled drying, the drying time is 4-6 hours and the drying temperature is 50-70℃.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects:

[0018] 1. This invention utilizes Lactobacillus sakei SMF-L5 for wet fermentation. Due to its strong acid-producing properties, it can effectively reduce the pH of the fermentation system, thereby significantly inhibiting the growth of putrefactive and pathogenic bacteria and reducing the production of harmful substances, thus improving product safety.

[0019] 2. In this invention, the addition of salt water during the micro-fermentation process can inhibit the growth of spoilage bacteria and other miscellaneous bacteria to a certain extent. Furthermore, Lactobacillus sakei SMF-L5 has a high salt tolerance, and this strain dominates the fermentation process, which is beneficial for shortening the fermentation time and improving product quality.

[0020] 3. This invention utilizes a micro-fermentation method to effectively improve the texture, flavor, and other quality characteristics of poultry meat products, producing livestock and poultry meat products with novel properties. The examples also clearly demonstrate that there are significant differences in the content and types of flavor-related volatile substances in unfermented and micro-fermented laying hen products, indicating that *Lactobacillus sakei* has the effect of improving the flavor and quality of chicken meat. Attached Figure Description

[0021] Figure 1 Three-dimensional response surface plot of the interaction of fermentation process parameters ( Figure 1 In the figure, A represents the relationship between the amount of Lactobacillus sake bacteria added and the concentration of saline solution. Figure 1 In the graph, B represents the relationship between drying temperature and brine concentration. Figure 1 C in the graph represents the relationship between drying time and brine concentration. Figure 1 D in the graph represents the relationship between drying temperature and the amount of Lactobacillus added to sake. Figure 1 E in the graph represents the relationship between drying time and the amount of Lactobacillus sake added. Figure 1 (F in the figure represents the relationship between drying time and drying temperature).

[0022] Figure 2 Gas chromatographic ion migration spectra of unfermented and slightly fermented laying hen groups ( Figure 2 (The left side of the image shows the unfermented laying hen group, and the right side shows the slightly fermented laying hen group).

[0023] Figure 3 Gas chromatographic ion migration spectrum differences between the unfermented and slightly fermented laying hen groups ( Figure 3 (The left side of the image shows the unfermented laying hen group, and the right side shows the slightly fermented laying hen group).

[0024] Figure 4 Fingerprint spectra of volatile substances in unfermented and slightly fermented laying hen groups ( Figure 4 (The left side of the image shows the unfermented laying hen group, and the right side shows the slightly fermented laying hen group).

[0025] Figure 5 The textural properties of the unfermented and slightly fermented laying hen groups are shown. Detailed Implementation

[0026] This invention provides an application of Lactobacillus sakei SMF-L5 in micro-fermented poultry products.

[0027] In this invention, the taxonomic name of the *Lactobacillus sakei* SMF-L5 is *Lactobacillus sakei*, which was deposited on December 7, 2020, at the Guangdong Provincial Microbiological Culture Collection Center, located at the Guangdong Institute of Microbiology, Building 59, No. 100 Xianlie Middle Road, Guangzhou, with accession number GDMCC NO:61345. The *Lactobacillus sakei* SMF-L5 described in this invention exhibits strong acid-producing and salt-tolerant properties, and also shows good antibacterial effects against pathogens such as *Escherichia coli*, *Staphylococcus aureus*, *Staphylococcus saprophyticus*, and *Pseudomonas syringae*.

[0028] In this invention, the mass ratio of Lactobacillus sakei SMF-L5 to poultry meat during micro-fermentation is preferably 0.25-0.35:1000, more preferably 0.29-0.32:1000, and even more preferably 0.303:1000.

[0029] This invention provides the application of Lactobacillus sakei SMF-L5 in improving the quality of poultry products.

[0030] This invention also provides a method for preparing micro-fermented poultry meat products, comprising the following steps:

[0031] (1) Mix poultry meat with brine and inoculate with Lactobacillus sakei SMF-L5 for micro-fermentation to obtain semi-finished poultry meat;

[0032] (2) The obtained semi-finished poultry meat is dried and packaged to obtain the finished product.

[0033] In this invention, the poultry meat is selected from frozen, viscera-free carcasses. Before being mixed with brine, the poultry meat needs to be thawed, washed, and have any remaining feathers trimmed from its surface. The thawing temperature is 3-5°C, and the thawing is carried out in a cold storage facility. The washing is done with tap water, and the trimming method involves using scissors.

[0034] In this invention, the micro-fermentation is carried out in a fermentation tank. The preferred mass ratio of brine to poultry meat is 2:4-6, more preferably 2:5-5.8, and even more preferably 2:5.5; the preferred mass concentration of the brine is 2-6%, more preferably 3.5-5%, and even more preferably 4.38%. The preferred micro-fermentation time is 3-7 days, more preferably 4-6.5 days, and even more preferably 5-6 days; the preferred micro-fermentation temperature is 8-15℃, more preferably 9-12℃, and even more preferably 10℃. Adding brine during fermentation in this invention can inhibit the growth of putrefactive bacteria and other miscellaneous bacteria to a certain extent; the low-pH fermentation system formed by the growth and metabolism of *Lactobacillus sakei* SMF-L5 can effectively inhibit the growth of putrefactive and pathogenic bacteria and reduce the production of harmful substances, thereby improving the safety of the micro-fermented product of this invention.

[0035] In this invention, the initial viable count of the Lactobacillus sakei SMF-L5 is preferably 1.2-2.5 × 10⁻⁶. 11 cfu / g, further preferably 1.8-2.3×10 11 cfu / g, and even more preferably 2×10 11 cfu / g. The preferred mass ratio of Lactobacillus sakei SMF-L5 inoculated with poultry meat to the mass of poultry meat in this invention is 0.25-0.35:1000, more preferably 0.29-0.32:1000, and even more preferably 0.303:1000.

[0036] In this invention, the obtained semi-finished poultry meat is removed, hung to air dry, and then dried. The drying method in this invention includes natural air drying or temperature-controlled drying. When natural air drying is used, the drying time is preferably 5-15 days, more preferably 6-13 days, and even more preferably 9-11 days. When temperature-controlled drying is used, the drying time is preferably 4-6 hours, more preferably 5-5.8 hours, and even more preferably 5.6 hours; the drying temperature is preferably 50-70°C, more preferably 55-65°C, and even more preferably 60°C.

[0037] In this invention, the dried semi-finished poultry meat is vacuum-packed and then further packaged to obtain the finished poultry meat product.

[0038] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0039] Example 1

[0040] A method for preparing micro-fermented poultry meat products includes the following steps:

[0041] (1) Place frozen, visceral-free poultry carcasses in a 4°C cold storage to thaw. After thawing, wash the surface of the thawed poultry with tap water, trim any remaining feathers on the surface of the poultry with scissors, and drain.

[0042] (2) The drained poultry meat was placed in a fermentation tank and mixed with 4.38% brine at a ratio of 2:5.5. It was then inoculated with *Lactobacillus sakei* SMF-L5 at a ratio of 0.303:1000. The mixture was micro-fermented at 10°C for 5 days to obtain semi-finished poultry meat, with an initial viable count of 2 × 10⁻⁶ *Lactobacillus sakei* SMF-L5. 11 cfu / g;

[0043] (3) Take out the obtained semi-finished poultry meat, hang it to dry, and dry it at 60℃ for 5.6 hours. Then vacuum pack and outer packaging are carried out in sequence to obtain finished poultry meat products.

[0044] Example 2

[0045] A method for preparing micro-fermented poultry meat products includes the following steps:

[0046] (1) Place frozen, visceral-free poultry carcasses in a 4°C cold storage to thaw. After thawing, wash the surface of the thawed poultry with tap water, trim any remaining feathers on the surface of the poultry with scissors, and drain.

[0047] (2) The drained poultry meat was placed in a fermentation tank and mixed with 2% brine at a ratio of 2:4 (brine to poultry meat). It was then inoculated with *Lactobacillus sakei* SMF-L5 at a ratio of 0.25:1000 (poultry meat to sakei). The mixture was micro-fermented at 8°C for 3 days to obtain semi-finished poultry meat, with an initial viable count of 2.5 × 10⁻⁶ *Lactobacillus sakei* SMF-L5. 11 cfu / g;

[0048] (3) Take out the obtained semi-finished poultry meat, hang it to dry, and dry it at 50℃ for 6 hours. Then vacuum pack and outer packaging are carried out in sequence to obtain finished poultry meat products.

[0049] Example 3

[0050] A method for preparing micro-fermented poultry meat products includes the following steps:

[0051] (1) Place frozen, visceral-free poultry carcasses in a 4°C cold storage to thaw. After thawing, wash the surface of the thawed poultry with tap water, trim any remaining feathers on the surface of the poultry with scissors, and drain.

[0052] (2) The drained poultry meat was placed in a fermentation tank and mixed with 6% brine at a mass ratio of 2:6. It was then inoculated with *Lactobacillus sakei* SMF-L5 at a mass ratio of 0.35:1000. The mixture was micro-fermented at 15℃ for 7 days to obtain semi-finished poultry meat, with a final effective viable count of 1.2 × 10⁻⁶ *Lactobacillus sakei* SMF-L5. 11 cfu / g;

[0053] (3) Take out the obtained semi-finished poultry meat, hang it to dry, and dry it at 70℃ for 4 hours. Then vacuum pack and outer packaging are carried out in sequence to obtain finished poultry meat products.

[0054] Experimental Example 1

[0055] Based on Example 1, the micro-fermentation process was optimized using Anhui white goose as raw material.

[0056] (1) Yield (Y1) = [Weight of micro-fermented Wanxi white goose / Weight of Wanxi white goose raw material] × 100%

[0057] (2) Sensory evaluation (Y2) Sensory evaluation standard: 10 points are used, color (2.5 points), smell (2.5 points), taste (2.5 points) and flavor (2.5 points). A sensory evaluation group of 10 people is established to steam-cook the slightly fermented Anhui white goose products and then conduct sensory evaluation, taking the sum of color, smell, taste and flavor values.

[0058] (3) The formula for calculating the overall score is as follows:

[0059] Y = Normalized yield value × 0.5 + Normalized sensory score value × 0.5

[0060] Note: The formula for calculating yield and sensory evaluation normalization value is D = (d i -d min ) / (d max -d min )

[0061] Based on the Box-Behnken experimental design principle, a four-factor, three-level response surface methodology was conducted, taking into account saline concentration, amount of Lactobacillus sago added, drying temperature, and drying time. A total of 29 experiments were carried out, as detailed in Tables 1 and 2.

[0062] Table 1. Factors and levels in response surface methodology experiments

[0063]

[0064] Table 2 Response Surface Experimental Design

[0065]

[0066]

[0067] Based on the experimental results in Table 2, a regression model was established and an analysis of variance was performed. Using Design Expert 12 software, the regression analysis yielded the following prediction model: Y = 0.78822 - 0.0093A + 0.0675833B + 0.085925C + 0.0262083D - 0.117225AB - 0.04435AC + 0.005925AD - 0.014325BC + 0.13625BD - 0.06955CD - 0.0724225A 2 -0.239697B 2 -0.27671C 2 -0.055335D 2 The regression equation results of the model are shown in Table 3.

[0068] Table 3 Regression Equation Analysis of the Model

[0069]

[0070]

[0071] Note: * indicates P<0.05, significant effect; ** indicates P<0.01, highly significant effect.

[0072] As shown in Table 3, the selected model has a P-value < 0.01, indicating a highly significant impact and a good fit to the actual situation. The lack-of-fit term has a P-value > 0.05, indicating an insignificant impact and minimal interference from unknown factors on the experimental results, suggesting that the model selection was appropriate. In conclusion, the regression model exhibits a high degree of fit and is usable.

[0073] The response surface analysis plot, derived from the regression equation, is a three-dimensional graph representing the three-dimensional spatial surface formed by the response values ​​against the experimental factors. When the experimental factors interact, the three-dimensional surface plot visually illustrates the changing trends of the response values, such as... Figure 1 As shown. By Figure 1 It can be seen that with the increase of brine concentration and the amount of *Lactobacillus sakei* added, the increase of brine concentration and drying temperature, the increase of *Lactobacillus sakei* added and drying temperature, the increase of *Lactobacillus sakei* added and drying temperature, and the increase of drying temperature and drying time, the overall score showed a trend of first increasing and then decreasing. Among them, the amount of *Lactobacillus sakei* added and the drying temperature had a significant impact on the overall score, while the brine concentration and drying time had no significant impact on the overall score (P<0.05), which is consistent with the results of the model regression equation analysis.

[0074] Analysis using Design Expert 12 software revealed the optimal process parameters to be: brine concentration 4.38%, *Lactobacillus sakei* addition 0.303‰, drying temperature 60.3℃, and drying time 5.57 h. Considering practical operational issues, the selected parameters were: brine concentration 4.38%, *Lactobacillus sakei* addition 0.303‰, drying temperature 60℃, and drying time 5.6 h. The corresponding response surface methodology predicted a comprehensive score of 0.7926. To verify the feasibility of the response surface methodology optimization experiment, the experiment was repeated three times, resulting in a comprehensive score of 0.7882 for the cured goose. This score differed from the predicted value by less than 1%, indicating that the optimal preparation process for cured goose is feasible.

[0075] Experimental Example 2

[0076] Based on the preparation method of Example 1, two-year-old laying hens were used as raw materials and divided into an unfermented (without inoculation with Lactobacillus sakei SMF-L5) treatment group and a fermented (inoculated with Lactobacillus sakei SMF-L5) treatment group to explore the flavor differences of laying hens between the two treatment groups. (one)

[0078] Accurately weigh 1g of sample meat and place it in a 20mL headspace vial. Tighten the cap and place the vial on the GC-IMS headspace sampler (set 3 parallel samples for each stage).

[0079] Headspace sampling conditions: incubation temperature 40℃, incubation time 20min, injection needle temperature 85℃, injection volume 500μL, vibration speed 500r / min.

[0080] Chromatographic conditions: FS-SE-54-CB-1 column, ID: 0.53 mm, column temperature 40℃, analysis time 40 min. Carrier gas: high-purity N2, flow rate settings: 0–2 min (2 mL / min), 2–10 min (2–15 mL / min), 10–20 min (15–80 mL / min), 20–25 min (100–130 mL / min), 25–40 min (130–145 mL / min).

[0081] Ion mobility spectrometry (IMS) conditions: high-purity N2 as drift gas, flow rate 150 mL / min, IMS detector temperature 45 °C. GC-IMS data was transmitted to the computer via a wired network in positive ion mode. Each spectrum was scanned an average of 32 times, using a grid pulse width of 100 μs, a repetition rate of 21 ms, and a sampling frequency of 150 kHz. The instrument's built-in LAV (Laboratory Analytical Viewer) and GC-IMS Library Search software were used for fingerprint analysis and qualitative analysis of volatile substances in the samples.

[0082] The results are as follows Figure 2-4As shown, the volatile matter content of micro-fermented laying hen products is higher than that of unfermented laying hen products. Unfermented laying hen products contain higher levels of substances such as pentanal, hexanal, heptanal, 5-methylfurfural, Bornyl acetate, hexylacetate, 1,8-cineole, Maltol, 2-pentanone, and triethylamine. 1-pentanol, 1-Hexanol, 2-Hexen-1-ol, 1-Heptanol, 1-Octen-3-ol, 2-Butoxyethanol, E-2-Hexen- in micro-fermented laying hen products 1-ol, Phenol, 2-Butanone, 2-Hexanone, 2-heptanone, 1-octen-3-one, 6-Methyl-5-hepten-2-one, butanal, E 2-pentenal,E 2-heptenal,E_E-2_4-Heptadienal,2_4-heptadienal,E 2-octenal,Octanal,E-2-nonenal,E_E-2_4-nonadienal,Decanal,2-Decenal,E_E-2_4-decadienal,E-2-undecenal,Benzaldehyde,ethyl Acetate, Butyl The content of substances such as acetate, 2,5-dimethylpyrazine, 2-pentylfuran, and propylsulfide is relatively high. Therefore, Lactobacillus sakei has the effect of improving the flavor and quality of chicken. (two)

[0084] Chicken breast meat was taken from chicken samples and cut into 10mm×10mm×10mm pieces for texture measurement. Texture parameters were measured using a TA-XT2i texture analyzer in TPA mode. Measurement parameters were: probe: P / 36R; pre-test speed: 2.0mm / s, test speed: 1.0mm / s, post-test speed: 5.0mm / s; compression ratio: 40%; time interval between two compressions: 5.0s. The results were evaluated using hardness, springiness, chewiness, and resilience parameters to assess the texture characteristics of the samples.

[0085] The results are as follows Figure 5 As shown, compared with the unfermented group, the fermented group (chicken breast) showed improvements in elasticity, chewiness, and resilience, while reducing the product's hardness, resulting in a superior texture.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a micro-fermented poultry food product, characterized in that, It comprises the following steps: (1) mixing poultry meat with brine and inoculating Lactobacillus sakei SMF-L5 for micro-fermentation to obtain semi-finished poultry meat; (2) drying the obtained semi-finished poultry meat, packaging to obtain finished product; The mass concentration of the brine in step (1) is 2-6%, and the mass ratio of the brine to poultry meat is 2:4-6; The micro-fermentation time in step (1) is 3-7 days, and the micro-fermentation temperature is 8-15℃; The initial viable cell count of the Lactobacillus saki SMF-L5 is 1.2-2.5 x 10 11 cfu / g; The mass ratio of the inoculated Lactobacillus sakei SMF-L5 to poultry meat is 0.25-0.35:1000.

2. The production method according to claim 1, characterized by, The drying mode comprises natural air drying or temperature-controlled drying.

3. The preparation method according to claim 2, characterized in that, When the drying mode is natural air drying, the drying time is 5-15 days; When the drying mode is temperature-controlled drying, the drying time is 4-6 hours, and the drying temperature is 50-70℃.

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