Preparation method of dry-cured beef fermented by lactic acid bacteria and sauce-flavor distiller's grains

Abstract

The application provides a preparation method of dry-cured beef fermented by sauce-flavor wine lees and lactic acid bacteria, and belongs to the technical field of food processing. The method is characterized by adding sauce-flavor wine lees and lactic acid bacteria starter in the curing process, and controlling the fermentation temperature and time, so that the flavor substances in the wine lees and the metabolic products of lactic acid bacteria synergistically act to improve the flavor level and nutritional value of the dry-cured beef. The unique flavor components of the sauce-flavor wine lees and the fermentation characteristics of the lactic acid bacteria are utilized to effectively improve the problem of single taste and insufficient flavor of traditional dry-cured beef, and the prepared product has the characteristics of rich sauce-flavor, compact meat, moderate saltiness and balanced nutrition, realizes high-value utilization of the wine lees, and also endows the dry-cured beef with unique sauce-flavor and rich nutrition, which has important economic and social benefits.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for preparing air-dried beef using fermentation of soy sauce-flavored liquor lees in conjunction with lactic acid bacteria. Background Technology

[0002] Air-dried beef is a traditional meat product rich in nutrients and with a unique flavor, and it is very popular among consumers. Traditional air-dried beef production relies heavily on natural air drying and simple curing, which has problems such as long production cycles, limited flavor, and difficulty in controlling microbial safety. With the development of the food industry, fermentation technology has been widely applied to meat product processing. Microbial fermentation can improve product flavor, extend shelf life, and enhance nutritional value.

[0003] Soy sauce-flavored distiller's grains are a byproduct of baijiu (Chinese liquor) brewing, rich in dietary fiber, amino acids, vitamins, and various flavor compounds. However, they are currently mostly treated as waste, resulting in low resource utilization. Lactic acid bacteria, as a commonly used fermentation agent, can inhibit the growth of spoilage bacteria and improve texture and flavor in meat product fermentation. However, there are currently no reports on the synergistic application of soy sauce-flavored distiller's grains and lactic acid bacteria in the fermentation of dried beef. Combining soy sauce-flavored distiller's grains with lactic acid bacteria could not only achieve high-value utilization of the distiller's grains but also impart a unique soy sauce flavor and rich nutrition to dried beef, yielding significant economic and social benefits. Summary of the Invention

[0004] To address the problems of monotonous flavor, long production cycle, and low resource utilization in existing air-dried beef preparation technologies, this invention provides a method for preparing air-dried beef fermented with soy sauce-flavored lees and lactic acid bacteria. This method enables the resource utilization of soy sauce-flavored lees, improves the flavor quality and nutritional characteristics of air-dried beef, and shortens the production cycle.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing fermented and dried beef with a soy sauce aroma and synergistic lactic acid bacteria fermentation includes the following steps: S1. Raw material pretreatment: Select beef hind leg meat, remove tendons and fat, cut into strips with a thickness of 2-3cm, rinse with clean water and drain to obtain beef strips; S2. Processing of distiller's grains: Dry the soy sauce-flavored distiller's grains to obtain distiller's grains powder; S3. Preparation of pickling liquid: Water, distiller's grains powder, lactic acid bacteria powder, salt, white sugar, and spices are mixed evenly to obtain the pickling liquid; S4. Tumbling and marinating: Weigh 95%-98% of the cut and drained meat strips, add 2%-5% of the marinade, and tumble them. S5. Fermentation and air drying: Ferment and air dry the marinated beef strips; S6. Packaging and sterilization: After vacuum packaging, sterilize at 105℃ for 15 minutes, and then cool to obtain the finished product.

[0006] Preferably, in step S2, the drying temperature is 50-60℃, the drying time is 4-6 hours, and the powder is passed through an 80-100 mesh sieve to obtain distiller's grains powder.

[0007] Preferably, in step S3, the pickling liquid comprises the following components by weight: 50%-70% water, 5.5%-9.0% distiller's grains powder, 0.3%-0.5% lactic acid bacteria powder, 15%-20% salt, 3.4%-5.2% white sugar, and 3.0%-4.8% spices, which are mixed evenly to obtain the pickling liquid.

[0008] Preferably, in step S3, the lactic acid bacteria powder is selected from one or more of Lactobacillus plantarum, Lactobacillus sakei, Pediococcus pentosaceus, Lactobacillus curvaturei, Lactobacillus casei, and Pediococcus lactis.

[0009] Preferably, in step S4, the tumbling is vacuum tumbling for 60-80 minutes. After tumbling, the mixture is poured into a container and marinated at 0-4°C for 18-24 hours.

[0010] Preferably, in step S5, the order is fermentation followed by air drying. The fermentation temperature is 15-20℃, the relative humidity is 50-60%, and the time is 6-10h; the air drying temperature is 50-65℃, and the time is 20-24h.

[0011] Preferably, in step S2, the soy sauce-flavored lees are vacuum desorbed at 35-45°C and 8-20 kPa absolute pressure for 20-50 minutes, and the desorbed gas is condensed to obtain lees aroma condensate and deodorized lees; the deodorized lees are mixed with water, and cellulase and neutral protease are added for enzymatic hydrolysis. After enzyme inactivation, the mixture is filtered to obtain lees enzymatic hydrolysate. The lees enzymatic hydrolysate is dried to obtain lees powder.

[0012] Preferably, the moisture content of the soy sauce-flavored lees is 55% to 70%, and it is crushed to a particle size of ≤5mm before vacuum desorption; the condensation includes a first-stage condensation at 5 to 12℃ and a second-stage condensation at -5 to 2℃, and the condensates from the two stages are combined as the aroma condensate of the lees.

[0013] Preferably, the mass ratio of deodorized lees to water is 1:2 to 1:4. First, 0.10% to 0.30% of cellulase relative to the dry weight of the deodorized lees is added, and enzymatic hydrolysis is carried out at 48 to 52°C and pH 4.8 to 5.2 for 40 to 80 minutes. Then, the pH is adjusted to 6.5 to 7.2, and 0.05% to 0.20% of neutral protease relative to the dry weight of the deodorized lees is added, and enzymatic hydrolysis is carried out at 42 to 48°C for 30 to 60 minutes.

[0014] Preferably, in step S3, no lactic acid bacteria powder is added to the marinade, and in step S5, Lactobacillus sakei is inoculated into the marinated beef strips for fermentation.

[0015] Preferably, the fermentation in step S5 is divided into two stages. The marinated beef strips are inoculated with Lactobacillus sakei for the first stage of fermentation. When the pH of the center of the beef strips drops to 5.0-5.2, Lactobacillus plantarum is inoculated for the second stage of fermentation. Fermentation ends when the pH of the center of the beef strips is 4.7-4.9.

[0016] Preferably, the inoculation amount of *Lactobacillus sakei* is such that the viable bacterial count in the beef strips reaches 1 × 10⁻⁶. 6 ~5×10 7 CFU / g, the first stage fermentation conditions were 20-24℃ and 88%-95% relative humidity; the inoculum size of *Lactobacillus plantarum* was such that the viable count in the beef reached 5 × 10⁻⁶. 5 ~1×10 7 CFU / g, the second-stage fermentation conditions are 14–18℃ and 80%–90% relative humidity. In the first stage, Lactobacillus sakei, which is tolerant to the curing environment of meat products and suitable for low-temperature fermentation, establishes the dominant bacterial community. After the fermentation system is acidified and putrefactive bacteria and pathogenic bacteria are inhibited, in the second stage, Lactobacillus plantarum, which is acid-resistant and metabolically adaptable, is inoculated to continue acidification using the fermentable substrate in the sake lees hydrolysate, improve fermentation stability, and form metabolic flavor.

[0017] Preferably, in step S5, after fermentation is completed, the encapsulated aroma liquid is applied to the surface of the beef strips. The encapsulated aroma liquid is obtained by mixing the fermented lees aroma condensate and β-cyclodextrin at a mass ratio of 1:1.5 to 1:3.0.

[0018] Preferably, the aroma condensate of the fermented lees is mixed with β-cyclodextrin and stirred at 20-30°C for 30-90 min; the amount of the aroma condensate is 0.8-2.0% of the mass of the fermented beef strips, and after coating, it is left to stand at 8-12°C for 1-3 h.

[0019] Preferably, in step S5, the air drying process involves first air drying at 28–34°C and 70%–82% relative humidity until the water activity at the center of the beef strip is 0.90–0.93, and then air drying at 38–45°C and 45%–60% relative humidity until the water activity at the center of the beef strip is 0.76–0.82.

[0020] Compared with the prior art, the beneficial effects of the present invention are: (1) This invention utilizes the fermentation of soy sauce-flavored lees with lactic acid bacteria to prepare air-dried beef, realizing the resource utilization of lees, reducing production costs, and at the same time giving the product a unique soy sauce flavor and enriching the flavor layers.

[0021] (2) Through lactic acid bacteria fermentation, the growth of spoilage bacteria is effectively inhibited, the microbial safety of the product is improved, and the shelf life is extended.

[0022] (3) Lactobacillus sakei first establishes the dominant bacterial community, and Lactobacillus plantarum is then inoculated at a pH of 5.0-5.2. The pH of the beef strip center is used as the fermentation endpoint. This can balance the excessive or insufficient acidification during the fermentation process of the beef strip, improve the fermentation safety and batch stability, and help to form a richer and more harmonious flavor.

[0023] (4) The organic acids and enzymes produced during fermentation can improve the texture of beef, making the product more tender and improving the utilization rate of nutrients such as protein and amino acids.

[0024] (5) Compared with the traditional natural air drying process, the present invention shortens the production cycle and improves production efficiency. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0026] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0027] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention are commercially available or can be prepared by existing methods.

[0028] Example 1 A method for preparing soy sauce-flavored fermented beef with lactic acid bacteria: S1. Raw material pretreatment: Select beef hind leg meat, remove tendons and fat, cut into strips with a thickness of 2.0cm, rinse with clean water and drain to obtain beef strips; S2. Processing of distiller's grains: Dry the soy sauce-flavored distiller's grains at 50℃ for 3 hours and at 60℃ for 4 hours respectively. After crushing, pass the powder through an 80-mesh sieve to obtain distiller's grains powder. S3. Preparation of pickling liquid: By weight percentage, 70% water, 7.8% distiller's grains powder, 0.3% lactic acid bacteria powder, 15% salt, 3.4% white sugar, and 3.5% spices are mixed evenly to obtain the pickling liquid. S4. Tumbling and marinating: Weigh 97% of the cut and drained meat strips, add 3% of the marinating liquid, pour into a tumbling machine, vacuum tumble for 60 minutes, then pour into a marinating vat and place in a low-temperature warehouse at 0-4℃ for 18 hours. S5. Fermentation and air drying: Place the marinated beef strips in a fermentation room with the parameters set at 15℃ and 50% relative humidity for 6 hours; then carry out the air drying stage at 60℃ for 22 hours. S6. Packaging and sterilization: After vacuum packaging, sterilize at 105℃ for 15 minutes, and then cool to obtain the finished product.

[0029] Example 2 A method for preparing soy sauce-flavored fermented beef with lactic acid bacteria: S1. Raw material pretreatment: Select beef hind leg meat, remove tendons and fat, cut into strips with a thickness of 2.5cm, rinse with clean water and drain to obtain beef strips; S2. Processing of distiller's grains: Dry the soy sauce-flavored distiller's grains at 55℃ for 2.5 hours and at 60℃ for 4 hours respectively. After crushing, pass the powder through a 90-mesh sieve to obtain distiller's grains powder. S3. Preparation of pickling liquid: By weight percentage, 70% water, 7.9% distiller's grains powder, 0.2% lactic acid bacteria powder, 15% salt, 3.3% white sugar, and 3.6% spices are mixed evenly to obtain the pickling liquid. S4. Tumbling and marinating: Weigh 98% of the cut and drained meat strips, add 2% of the marinating liquid, pour into a tumbling machine, vacuum tumble for 60 minutes, then pour into a marinating vat and place in a low-temperature warehouse at 0-4℃ for 18 hours. S5. Fermentation and air drying: Place the marinated beef strips in a fermentation room with the parameters set at 18℃ and 60% relative humidity for 6 hours; then carry out the air drying stage at 60℃ for 24 hours. S6. Packaging and sterilization: After vacuum packaging, sterilize at 105℃ for 15 minutes, and then cool to obtain the finished product.

[0030] Example 3 A method for preparing soy sauce-flavored fermented beef with lactic acid bacteria: S1. Raw material pretreatment: Select beef hind leg meat, remove tendons and fat, cut into strips with a thickness of 3.0cm, rinse with clean water and drain to obtain beef strips; S2. Processing of distiller's grains: Dry the soy sauce-flavored distiller's grains at 60℃ for 7 hours, then pulverize them and pass them through a 100-mesh sieve to obtain distiller's grains powder. S3. Preparation of pickling liquid: By weight percentage, 70% water, 7.9% distiller's grains powder, 0.2% lactic acid bacteria powder, 15% salt, 3.3% white sugar, and 3.6% spices are mixed evenly to obtain the pickling liquid. S4. Tumbling and marinating: Weigh 95% of the cut and drained meat strips, add 5% of the marinating liquid, pour into a tumbling machine, vacuum tumble for 60 minutes, then pour into a marinating vat and place in a low-temperature warehouse at 0-4℃ for 18 hours. S5. Fermentation and air drying: Place the marinated beef strips in a fermentation room with the parameters set at 20℃ and 60% relative humidity for 6 hours; then carry out the air drying stage at 60℃ for 24 hours. S6. Packaging and sterilization: After vacuum packaging, sterilize at 105℃ for 15 minutes, and then cool to obtain the finished product.

[0031] Example 4 A method for preparing soy sauce-flavored fermented beef with lactic acid bacteria: S1. Raw material pretreatment: Select beef hind leg meat, remove tendons and fat, cut into strips with a thickness of 3.0cm, rinse with clean water and drain to obtain beef strips; S2. Processing of Distillers' Grains: Take fresh soy sauce-flavored distillers' grains with a moisture content of approximately 62%, crush them to a particle size of no more than 5mm, place them in a jacketed vacuum desorber, and process them at 40℃ and 12kPa absolute pressure for 35 minutes. The desorbed gas is passed sequentially through 8℃ and 0℃ condensers, and the condensates are combined to obtain distillers' grains aroma condensate; the material in the container is de-aromaized distillers' grains. Add water to the deodorized lees at a mass ratio of 1:3, adjust the pH to 5.0, add 0.20% cellulase based on the dry weight of the deodorized lees, and react at 50℃ for 60 min; adjust the pH to 6.8, add 0.10% neutral protease, and react at 45℃ for 45 min. Heat to 90℃ and hold for 10 min to inactivate the enzyme, filter by pressure to obtain the lees enzymatic hydrolysate, and dry the hydrolysate at 50℃ for 3 h and at 60℃ for 4 h respectively. Pulverize and pass through an 80-mesh sieve to obtain lees powder. S3. Preparation of the pickling liquid: By weight percentage, 70.3% water, 7.8% distiller's grains powder, 15% salt, 3.4% white sugar, and 3.5% spices are mixed evenly to obtain the pickling liquid.

[0032] S4. Tumbling and Marinating: Weigh 97% of the cut and drained meat strips, add 3% of the marinade, and perform 4 pulse vacuum tumbling cycles at 4℃. Each cycle is tumbling for 10 minutes under -80kPa gauge pressure and then standing at normal pressure for 6 minutes. Then, stand at 4℃ for 8 hours.

[0033] S5. Fermentation and Drying: Inoculate with Lactobacillus sakei until the viable bacterial count in the meat reaches 1×10⁻⁶. 7 CFU / g, fermented at 22℃ and 92% relative humidity with monitoring of the core pH; when the core pH dropped to 5, *Lactobacillus plantarum* was inoculated until the viable count in the meat reached 5 × 10⁻⁶. 6Fermentation continued at 16℃ and 85% relative humidity until the core pH reached 4.8. (CFU / g)

[0034] Mix the fermented lees aroma condensate with β-cyclodextrin at a mass ratio of 1:2 and stir at 25℃ for 60 min to obtain an encapsulated aroma liquid; apply 1% of the fermented beef strip mass to the liquid and mix well, then let it stand at 10℃ for 2 h.

[0035] The meat strips were air-dried at 31℃ and 76% relative humidity until the central water activity was 0.92; then air-dried at 42℃ until the central water activity reached 0.79 and the difference between the surface and central water activities was ≤0.06.

[0036] S6. Packaging and sterilization: After vacuum packaging, sterilize at 105℃ for 15 minutes, and then cool to obtain the finished product.

[0037] Comparative Example 1 The difference from Example 1 is that no soy sauce-flavored fermented rice powder is added to the marinade, while the lactic acid bacteria powder, salt, white sugar, spices and their proportions remain unchanged, and water is added to 100%; all other steps and parameters are the same as in Example 1.

[0038] Comparative Example 2 The difference from Example 1 is that no lactic acid bacteria powder is added to the pickling liquid, and the proportions of distillers' grains powder, salt, white sugar, spices and so on remain unchanged, and water is added to 100%; after tumbling and pickling, there is no fermentation stage, and the product is directly air-dried. All other steps and parameters are the same as in Example 1.

[0039] Comparative Example 3 The difference from Example 4 is that in step S5, instead of segmented inoculation, *Lactobacillus sakei* and *Lactobacillus plantarum* are simultaneously inoculated into the marinated beef strips in one go, with a total viable count of 1.5 × 10⁻⁶. 7 The ratio of live bacteria of Lactobacillus sakei to Lactobacillus plantarum was 2:1. Fermentation was carried out at 22°C and 92% relative humidity until the pH of the center of the beef strips dropped to 4.8. All other steps and parameters were the same as in Example 4.

[0040] Table 1. Summary of Results of Examples 1-4 and Comparative Examples 1-3 Note: 1. The detection of lactic acid bacteria in Comparative Example 2 may be due to endogenous flora in the raw materials or introduction from the environment.

[0041] 1. Nitrite residue was determined according to GB 5009.33; viable lactic acid bacteria count was determined according to GB 4789.35; sensory evaluation was conducted independently by 10 trained tasters, and the average score was taken (scoring criteria: 1-3 points unacceptable, 4-6 points fair, 7-8 points good, 9-10 points excellent). Acidity acceptability refers to whether the product's acidity is harmonious and does not mask other flavors; a higher score indicates a more moderate acidity and better integration with the overall flavor.

[0042] The results of Example 1 and Comparative Example 1 (without lees) show that the soy sauce aroma score of Comparative Example 1 is only 5.2 points, which is much lower than the 8.7 points of Example 1, indicating that soy sauce aroma lees are the main source of the characteristic soy sauce aroma of the product.

[0043] The residual nitrite content in Comparative Example 1 (5.6 mg / kg) was higher than that in Example 1 (4.2 mg / kg), indicating that the reducing substances in the lees have an auxiliary effect in promoting the degradation of nitrite or inhibiting its formation.

[0044] The results of comparing Example 1 and Comparative Example 2 (without lactic acid bacteria) showed that the number of viable lactic acid bacteria in Comparative Example 2 (3.8 log CFU / g) was significantly lower than that in Example 1 (7.2 log CFU / g), and the central pH (5.3) was significantly higher, indicating that the exogenous addition of lactic acid bacteria is the key to dominant fermentation and rapid pH reduction.

[0045] The nitrite residue in Comparative Example 2 (6.8 mg / kg) was the highest among all groups, indicating that the acidic environment and reducing metabolites produced by lactic acid bacteria fermentation can effectively reduce nitrite residue and improve product safety.

[0046] The tenderness score of Comparative Example 2 (6.5) was lower than that of Example 1 (8.2), indicating that the protease produced by lactic acid bacteria fermentation improved the texture of the beef and made the product more tender.

[0047] Comparative Example 4 and Comparative Example 3 (simultaneous inoculation with Lactobacillus sakei and Lactobacillus plantarum) showed that the pH at the end of fermentation in Comparative Example 3 was 4.6, which was lower than that in Example 4 (4.7), indicating that Comparative Example 3 produced acid faster and had a higher total acid production. However, this rapid acidification had adverse effects: (1) The sourness acceptance score was significantly lower: the sourness acceptance score of Comparative Example 3 was only 6.5 points, which was much lower than that of Example 4 (9.2 points). The tasters generally reported that the sourness of Comparative Example 3 was too strong and sharp, and the soy sauce aroma was obviously masked by the sourness, resulting in its soy sauce aroma score (7.8 points) being significantly lower than that of Example 4 (9.6 points). This indicates that segmented inoculation helps to accumulate sourness gently and avoids flavor imbalance caused by excessive acid production at one time. (2) The nitrite residue was higher: the nitrite residue of Comparative Example 3 was 4.5 mg / kg, which was higher than that of Example 4 (3.2 mg / kg). Simultaneous inoculation in Comparative Example 3 resulted in excessively rapid acid production in the early stage and premature drop in pH to below 4.6, which inhibited the activity of enzymes capable of reducing nitrite. In contrast, the phased pH gradient of segmented inoculation was more conducive to the metabolic synergy of different strains, thus enabling more complete degradation of nitrite.

[0048] Example 4 was significantly better than Examples 1-3 in terms of soy sauce flavor (9.6 points) and tenderness (9.0 points), indicating that the combination of the fermented grains aroma recovery and addition technology, the segmented inoculation fermentation and the gradient air drying process produced a synergistic effect.

[0049] The nitrite residue in Example 4 (3.2 mg / kg) was the lowest among all groups, while the number of viable lactic acid bacteria (7.8 logCFU / g) was the highest, further verifying the safety and quality advantages of the preferred technical solution of the present invention.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a soy sauce-flavored fermented beef product with lactic acid bacteria, characterized in that, Includes the following steps: S1. Raw material pretreatment: Select beef hind leg meat, cut it into strips, rinse and drain the water to obtain beef strips; S2. Processing of distiller's grains: Dry the soy sauce-flavored distiller's grains to obtain distiller's grains powder; S3. Preparation of pickling liquid: Water, distiller's grains powder, lactic acid bacteria powder, salt, white sugar, and spices are mixed evenly to obtain the pickling liquid; S4. Tumbling and marinating: Weigh 95%-98% of the cut and drained meat strips, add 2%-5% of the marinade, and tumble them. S5. Fermentation and air drying: Ferment and air dry the marinated beef strips; S6. Packaging and sterilization: After vacuum packaging, sterilization is performed, and the finished product is obtained after cooling.

2. The preparation method according to claim 1, characterized in that, In step S2, the drying temperature is 50-60℃, the drying time is 4-6 hours, and after pulverization, the product is passed through an 80-100 mesh sieve to obtain distiller's grains powder.

3. The preparation method according to claim 1, characterized in that, In step S3, the pickling liquid comprises the following components by weight: 50%-70% water, 5.5%-9.0% distiller's grains powder, 0.3%-0.5% lactic acid bacteria powder, 15%-20% salt, 3.4%-5.2% white sugar, and 3.0%-4.8% spices, which are mixed evenly to obtain the pickling liquid.

4. The preparation method according to claim 1, characterized in that, In step S4, the tumbling is vacuum tumbling for 60-80 minutes. After tumbling, the mixture is poured into a container and marinated at 0-4℃ for 18-24 hours.

5. The preparation method according to claim 1, characterized in that, In step S5, the order is fermentation followed by air drying. The fermentation temperature is 15-20℃, the relative humidity is 50-60%, and the time is 6-10h. The air drying temperature is 50-65℃, and the time is 20-24h.

6. The preparation method according to claim 1, characterized in that, In step S2, the soy sauce-flavored lees are vacuum desorbed at 35-45℃ and 8-20kPa absolute pressure for 20-50 minutes, and the desorbed gas is condensed to obtain lees aroma condensate and de-fragrant lees; the de-fragrant lees are mixed with water, enzymes are added for enzymatic hydrolysis, the enzymes are inactivated and filtered to obtain lees enzymatic hydrolysate, and the lees enzymatic hydrolysate is dried to obtain lees powder.

7. The preparation method according to claim 6, characterized in that, In step S3, no lactic acid bacteria powder is added to the marinade. In step S5, Lactobacillus sakei is inoculated into the marinated beef strips for fermentation.

8. The preparation method according to claim 7, characterized in that, The fermentation described in step S5 is divided into two stages. The marinated beef strips are inoculated with Lactobacillus sakei for the first stage of fermentation. When the pH of the center of the beef strips drops to 5.0-5.2, Lactobacillus plantarum is inoculated for the second stage of fermentation. Fermentation ends when the pH of the center of the beef strips is 4.7-4.

9.

9. The preparation method according to claim 8, characterized in that, In step S5, after fermentation is completed, the encapsulated aroma liquid is applied to the surface of the beef strips. The encapsulated aroma liquid is obtained by mixing the fermented lees aroma condensate and β-cyclodextrin at a mass ratio of 1:1.5 to 1:3.

0.

10. The preparation method according to claim 9, characterized in that, In step S5, the air drying process involves first air drying at 28–34°C and 70%–82% relative humidity until the water activity at the center of the beef strip is 0.90–0.93, and then air drying at 38–45°C and 45%–60% relative humidity until the water activity at the center of the beef strip is 0.76–0.82.

Images