A composite probiotic starter for camel milk fermentation and a preparation method thereof
Patent Information
- Application Number
- CN202611202827.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-10
- Publication Date
- 2026-09-29
AI Technical Summary
然而，由于驼乳与牛乳在蛋白质组成、乳糖含量、矿物质比例、缓冲能力以及天然抑菌活性物质含量等方面存在显著差异，使得现有牛乳发酵剂难以完全适应驼乳发酵体系
[0022]一、提高驼乳发酵体系的适应性。本发明针对驼乳中乳清蛋白含量较高、缓冲能力较强以及含有天然抑菌活性物质等特点，通过筛选适用于驼乳发酵体系的益生菌菌株，并采用嗜热链球菌、保加利亚乳杆菌、副干酪乳杆菌、鼠李糖乳杆菌、植物乳杆菌及双歧杆菌按照特定质量比例进行复配，使不同菌株能够在驼乳发酵环境中发挥协同作用，提高复合益生菌发酵剂对驼乳体系的适应能力，改善传统牛乳发酵剂应用于驼乳体系时存在的菌株适配性不足、发酵启动缓慢等问题，为驼乳发酵制品生产提供稳定的菌种基础。
Smart Images
Figure CN122832886A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dairy fermentation technology, and in particular to a compound probiotic starter for camel milk fermentation and its preparation method. Background Technology
[0002] In recent years, with the rapid development of the functional dairy product market, camel milk, rich in lactoferrin, immunoglobulins, lysozyme, unsaturated fatty acids, and various vitamins and minerals, has gained widespread attention from consumers due to its high nutritional and functional value. Camel milk not only possesses excellent nutritional and health benefits but also shows significant application potential in the fields of special diets and functional foods. Therefore, the research and development of fermented camel milk products has become an important direction for the dairy industry.
[0003] Currently, most camel milk fermented products are produced using cow's milk starter cultures. However, due to significant differences between camel milk and cow's milk in protein composition, lactose content, mineral ratio, buffering capacity, and the content of natural antibacterial active substances, existing cow's milk starter cultures are difficult to fully adapt to camel milk fermentation systems. In particular, camel milk has a higher proportion of whey protein, a unique casein micelle structure, and contains abundant lactoferrin and lysozyme, among other natural antibacterial components. These factors all affect the growth and reproduction of lactic acid bacteria and fermentation performance, resulting in poor performance of existing starter cultures in camel milk systems.
[0004] The existing technology has at least the following shortcomings: First, the compatibility between the strains and the camel milk system is insufficient, resulting in a slow fermentation start-up speed, a long acidification time, and low production efficiency; second, the growth performance of the microorganisms is poor, and the number of live bacteria is difficult to reach the ideal level, resulting in insufficient product quality stability; third, the flavor formation ability is limited, and it is impossible to effectively reduce the unique muttony smell of camel milk, affecting the sensory quality of the product and consumer acceptance; fourth, the gel structure after fermentation is relatively loose, and whey separation is prone to occur, resulting in a rough product taste and poor textural properties; fifth, the quality of the product fluctuates greatly between batches, which is not conducive to the large-scale and standardized production of camel milk fermented products.
[0005] Therefore, developing a compound probiotic starter specifically for camel milk fermentation systems and establishing corresponding preparation processes is of great practical significance and application value for improving camel milk fermentation efficiency, enhancing product flavor and texture, improving product stability, and promoting the industrialization of camel milk. Summary of the Invention
[0006] In order to at least solve one of the above-mentioned technical problems, the present invention aims to provide a compound probiotic starter for camel milk fermentation and its preparation method, so as to improve the fermentation efficiency of camel milk, improve the flavor and texture of the product, and enhance the stability of the product.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] A compound probiotic starter for camel milk fermentation, wherein the compound probiotic starter is composed of Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium. Based on the total mass of the six strains as 100%, the mass percentages of Streptococcus thermophilus are 25%–35%, Lactobacillus bulgaricus 20%–30%, Lactobacillus paracasei 10%–20%, Lactobacillus rhamnosus 10%–20%, Lactobacillus plantarum 5%–15%, and Bifidobacterium 5%–15%.
[0009] Preferably, the compound probiotic fermentation agent is a freeze-dried bacterial powder formulation.
[0010] Preferably, the freeze-dried bacterial powder further includes a food-grade preservative, which includes one or more of skim milk powder, trehalose, fructooligosaccharides, and ascorbic acid.
[0011] Preferably, the amount of the food-grade preservative added is 5% to 15% of the mass of the compound bacterial solution.
[0012] A method for preparing a compound probiotic starter for camel milk fermentation includes the following steps:
[0013] S1. Screening, purifying, and activating probiotic strains;
[0014] S2. Each strain after activation culture is further cultured to allow it to grow to a stable growth phase.
[0015] S3. Mix the strains according to the preset ratio to obtain a compound bacterial solution;
[0016] S4. Add a food-grade preservative to the compound bacterial solution to protect the bacterial cells;
[0017] S5. The composite bacterial solution is freeze-dried using a freeze-drying process to obtain freeze-dried bacterial powder.
[0018] S6. Vacuum package and low-temperature storage of the freeze-dried bacterial powder to obtain a compound probiotic starter for camel milk fermentation.
[0019] Preferably, in S2, each strain is cultured at 35–42°C for 12–24 hours until it reaches a stable growth period before being compounded.
[0020] Preferably, in step S5, a vacuum freeze-drying process is used, where the product is pre-frozen at -40 to -50°C for 8 to 12 hours and then freeze-dried for 18 to 36 hours.
[0021] The present invention has the following beneficial effects:
[0022] I. Improving the Adaptability of Camel Milk Fermentation Systems. This invention addresses the characteristics of camel milk, such as its high whey protein content, strong buffering capacity, and presence of natural antibacterial active substances. By screening probiotic strains suitable for camel milk fermentation systems, and using a specific mass ratio of Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium, different strains can exert synergistic effects in the camel milk fermentation environment. This improves the adaptability of the compound probiotic starter culture to the camel milk system, addressing the problems of insufficient strain compatibility and slow fermentation start-up that exist when traditional cow milk starter cultures are applied to camel milk systems. This provides a stable microbial foundation for the production of camel milk fermented products.
[0023] II. Improving Camel Milk Fermentation Efficiency. This invention utilizes a rationally designed compound ratio of six probiotic strains to enable *Streptococcus thermophilus* and *Lactobacillus bulgaricus* to rapidly produce acid. Simultaneously, the combination of *Lactobacillus paracasei*, *Lactobacillus rhamnosus*, *Lactobacillus plantarum*, and *Bifidobacterium* regulates the fermentation environment, promoting the growth, reproduction, and metabolic activities of the strains within the camel milk system, thereby increasing the conversion efficiency of lactose to lactic acid. Furthermore, by separately activating and expanding the culture of each strain, and then compounding them during the stable growth phase, high strain activity is maintained, thus improving the stability and production efficiency of the camel milk fermentation process.
[0024] III. Improving the Flavor and Quality of Fermented Camel Milk Products. This invention employs a multi-strain synergistic fermentation method, allowing different probiotics to participate in lactose metabolism, protein decomposition, and flavor compound formation during fermentation. Specifically, *Lactobacillus paracasei*, *Lactobacillus rhamnosus*, *Lactobacillus plantarum*, and *Bifidobacterium* can assist in regulating the composition of fermentation metabolites, improving the flavor profile of fermented camel milk products, reducing the adverse effects of camel milk's unique flavor on the product's sensory quality, and resulting in fermented products with a milder milky aroma and better taste.
[0025] IV. Improving the texture and stability of fermented products. This invention promotes changes in camel milk protein structure and gel network formation through the synergistic fermentation effect among various probiotics, which helps to improve the viscosity, fineness, and texture stability of fermented products. It also improves problems such as loose gel structure and whey separation that may exist in traditional camel milk fermented products, thereby improving the overall quality of the product.
[0026] V. Improving the survival rate and storage stability of probiotics. This invention uses a freeze-dried bacterial powder formulation and adds one or more food-grade preservatives selected from skim milk powder, trehalose, fructooligosaccharides, and ascorbic acid during the freeze-drying process. Through the protective effect of the preservatives on the bacterial cells and the combination of the vacuum freeze-drying process, the activity loss of the strains during freezing and drying is reduced, improving the stability of the freeze-dried bacterial powder and giving the resulting compound probiotic starter good transport and storage performance.
[0027] VI. Improving the standardization of the preparation process of compound probiotic fermentation agents. This invention establishes a preparation process that includes strain screening, purification and activation, scale-up culture, proportional compounding, protective treatment, freeze-drying, and vacuum packaging preservation. This process ensures better standardization and repeatability in the production of compound probiotic fermentation agents, which helps reduce performance differences between different production batches and improves product quality stability.
[0028] VII. Enhancing the overall performance of multi-strain synergistic fermentation. This invention combines probiotics with different metabolic characteristics in a specific ratio, enabling acid-producing strains, flavor-regulating strains, and probiotic functional strains to work synergistically to promote acidification, improve flavor, optimize texture, and enhance stability during camel milk fermentation, thereby increasing the application value of compound probiotic starter in the field of camel milk fermentation. Attached Figure Description
[0029] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts. Wherein:
[0030] Figure 1 This is a process flow diagram of an embodiment of the present invention. Detailed Implementation
[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the implementation cases of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0032] The camel milk used in the following examples is fresh camel milk, which is screened and filtered to remove impurities before use. The camel milk meets the relevant food safety standards. Specifically, the camel milk has a milk fat content of 3.0%–6.0%, a protein content of 2.5%–5.0%, and a lactose content of 3.5%–5.0%.
[0033] Before conducting the fermentation experiment, the camel milk was pretreated by pasteurization to reduce the number of bacteria in the raw material and minimize the adverse effects on the main nutrients and functional components of the camel milk.
[0034] The *Streptococcus thermophilus*, *Lactobacillus bulgaricus*, *Lactobacillus paracasei*, *Lactobacillus rhamnosus*, *Lactobacillus plantarum*, and *Bifidobacterium* used in the following examples are all food-grade probiotic strains. Each strain was screened, purified, and activated, and cultured to a stable growth phase before being used in the preparation of the compound probiotic starter.
[0035] The culture medium used is a food-grade medium suitable for the growth of lactic acid bacteria. During the culture process, the culture temperature is controlled at 35-42℃ and the culture time is 12-24h to maintain the good growth activity of each strain.
[0036] like Figure 1 As shown, specific embodiments of the present invention are as follows:
[0037] Example 1
[0038] This embodiment provides a compound probiotic fermentation agent for camel milk fermentation.
[0039] The compound probiotic starter is composed of Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium.
[0040] Based on the total mass of the six strains being 100%, of which:
[0041] Thermophilic Streptococcus accounted for 25% of the total mass.
[0042] The mass percentage of Lactobacillus bulgaricus was 20%.
[0043] The mass percentage of Lactobacillus paracasei was 20%.
[0044] The mass percentage of Lactobacillus rhamnosus was 15%.
[0045] The mass percentage of Lactobacillus plantarum is 10%.
[0046] Bifidobacteria accounted for 10% of the total mass.
[0047] The compound probiotic fermentation agent is in the form of freeze-dried bacterial powder.
[0048] Its preparation method includes the following steps:
[0049] S1. Select food-grade Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium strains for screening, purification, and activation culture.
[0050] S2. The six activated strains were cultured at 37°C for 12 hours to allow each strain to grow to a stable growth phase.
[0051] S3. Mix the six strains according to the above proportions to obtain a compound bacterial solution.
[0052] S4. Add a food-grade preservative composed of trehalose and skim milk powder to the compound bacterial solution. The amount of the food-grade preservative added is 5% of the mass of the compound bacterial solution, to protect the bacterial cells.
[0053] S5. The composite bacterial solution was freeze-dried using a vacuum freeze-drying process, wherein the pre-freezing temperature was -40℃, the pre-freezing time was 8h, and the freeze-drying time was 18h to obtain freeze-dried bacterial powder.
[0054] S6. Vacuum package the obtained freeze-dried bacterial powder and store it at 4°C to obtain a compound probiotic starter for camel milk fermentation.
[0055] Testing showed that the freeze-dried bacterial powder obtained in this embodiment has good storage stability, with a viable bacterial count of 1×10⁻⁶. 10 CFU / g or higher.
[0056] In this embodiment, *Streptococcus thermophilus* and *Lactobacillus bulgaricus* can rapidly produce acid, promoting acidification of the camel milk system. *Lactobacillus paracasei*, *Lactobacillus rhamnosus*, *Lactobacillus plantarum*, and *Bifidobacterium* can synergistically interact with the acid-producing strains, helping to improve their growth status in the camel milk system and promoting stable fermentation. By combining these six strains in a specific ratio, the adaptability of the compound probiotic starter to the camel milk system is improved.
[0057] Example 2
[0058] This embodiment provides a compound probiotic starter for camel milk fermentation, the preparation method of which is basically the same as that of Example 1, except that each strain is compounded in a preferred proportion within the scope of the claims.
[0059] Based on the total mass of the six strains being 100%:
[0060] Thermophilic Streptococcus accounted for 30% of the total mass.
[0061] The percentage of Lactobacillus bulgaricus in the sample is 25%.
[0062] The percentage of Lactobacillus paracasei was 15%.
[0063] The percentage of Lactobacillus rhamnosus in the total mass was 15%.
[0064] The percentage of Lactobacillus plantarum in the total mass was 7.5%.
[0065] Bifidobacteria accounted for 7.5% of the total sample.
[0066] The food-grade preservative is composed of trehalose, fructooligosaccharides and ascorbic acid, and its addition amount is 10% of the mass of the compound bacterial solution.
[0067] Each strain was cultured at 39℃ for 18 hours to reach a stable growth period before being compounded.
[0068] The process was carried out using a vacuum freeze-drying process, with a pre-freezing temperature of -45℃, a pre-freezing time of 10 hours, and a freeze-drying time of 24 hours.
[0069] The obtained freeze-dried bacterial powder was tested and found to have good viable bacterial retention capacity.
[0070] To verify the application effect of the compound probiotic fermentation agent obtained in this embodiment, the obtained compound probiotic fermentation agent was inoculated into pretreated camel milk at 0.05% of the camel milk mass and fermented at 40°C.
[0071] After fermentation, the resulting fermented camel milk product was subjected to sensory evaluation. The results showed that the product had good viscosity and a delicate texture, the unique flavor of camel milk was improved to a certain extent, and the milk aroma and fermentation aroma were more harmonious.
[0072] The reason for its technical effect is that this embodiment uses an optimized combination of the proportion of each strain, culture conditions and freeze-drying process parameters, which enables the six strains to form a better synergistic fermentation effect, which helps to improve the acidification efficiency of camel milk, promote the formation of protein gel structure and improve the texture of fermented products.
[0073] Example 3
[0074] This embodiment provides a compound probiotic starter for camel milk fermentation, the preparation method of which is basically the same as that of Example 1, except that the process parameters are adopted at higher values within the scope of the claims.
[0075] With the total mass of the six strains as 100%, the mass percentage of each strain is as follows:
[0076] Streptococcus thermophilus 35%;
[0077] Lactobacillus bulgaricus 30%;
[0078] Lactobacillus paracasei 10%;
[0079] Lactobacillus rhamnosus 10%;
[0080] Lactobacillus plantarum 5%;
[0081] Bifidobacteria 10%.
[0082] The food-grade preservative is a composite system composed of skim milk powder, trehalose, fructooligosaccharides and ascorbic acid, and its addition amount is 15% of the mass of the composite bacterial solution.
[0083] Each strain was cultured at 42℃ for 24 hours until it reached a stable growth period before being combined with another strain.
[0084] The vacuum freeze-drying process was adopted, and the sample was pre-frozen at -50℃ for 12 hours and then freeze-dried for 36 hours.
[0085] Testing showed that the obtained freeze-dried bacterial powder had good viable cell retention capacity, with a viable cell count reaching 1.5 × 10⁻⁶. 10 CFU / g.
[0086] In this embodiment, increasing the amount of food-grade preservative and optimizing freeze-drying conditions helps reduce the loss of bacterial activity during freeze-drying and improves the storage stability of the compound probiotic starter. Simultaneously, a higher proportion of *Streptococcus thermophilus* and *Lactobacillus bulgaricus* enhances the system's acid-producing capacity, which is beneficial for improving camel milk fermentation efficiency.
[0087] Example 4
[0088] This embodiment uses the compound probiotic starter prepared in Example 1 to prepare fermented camel milk products.
[0089] Fresh camel milk that meets food safety standards is selected as the fermentation raw material. After impurity removal and filtration, it is pasteurized at 75℃ for 20 minutes and then cooled to 40℃ for later use.
[0090] The freeze-dried compound probiotic starter prepared in Example 1 was added to the pretreated camel milk at 0.05% of the camel milk mass, and after thorough mixing, it was fermented at 40°C for 8 hours.
[0091] After the fermentation system forms a gel structure, the resulting fermented camel milk product is stored at 4°C.
[0092] Observations showed that the fermented camel milk products had a good texture, a relatively uniform curd structure, less whey separation, and a good fermented milk aroma, with improved camel milk flavor.
[0093] In this embodiment, Streptococcus thermophilus and Lactobacillus bulgaricus can promote the acidification of the camel milk system and promote the formation of gel structure, while Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum and Bifidobacterium can help regulate the metabolic environment during the fermentation process and jointly improve the flavor and texture of the fermented product.
[0094] Example 5
[0095] This embodiment uses the compound probiotic starter prepared in Example 2 to prepare fermented camel milk products.
[0096] Fresh camel milk was selected as the raw material, and after being pasteurized at 80℃ for 15 minutes, it was cooled to 42℃.
[0097] Add the freeze-dried compound probiotic starter prepared in Example 2 at 0.08% of the camel milk mass, mix well, and ferment at 42°C for 6 hours.
[0098] After fermentation, the product is refrigerated to obtain fermented camel milk products.
[0099] The test results showed that the product had good viscosity and stability, a relatively dense gel structure, less whey separation, and good flavor harmony.
[0100] In this embodiment, optimizing the inoculum size and fermentation temperature helps promote the growth and metabolism of the complex microbial community, thereby improving the fermentation efficiency of camel milk. Simultaneously, metabolic complementarity between different strains results in a better balance in terms of acidity, flavor, and texture of the product.
[0101] Example 6
[0102] This embodiment is used to verify the effect of the preferred ratio of compound strains on the fermentation effect of camel milk.
[0103] The compound probiotic starter prepared in Example 3, wherein six strains were selected according to:
[0104] Streptococcus thermophilus 35%;
[0105] Lactobacillus bulgaricus 30%;
[0106] Lactobacillus paracasei 10%;
[0107] Lactobacillus rhamnosus 10%;
[0108] Lactobacillus plantarum 5%;
[0109] Bifidobacteria 10%.
[0110] The proportions are mixed.
[0111] The compound probiotic starter was inoculated into pasteurized camel milk at 0.1% of the camel milk mass and fermented at 37°C for 12 hours.
[0112] The resulting fermented camel milk products have good maturity, a mild sour taste without obvious irritating sourness, and retain good milky aroma characteristics.
[0113] This embodiment demonstrates that adjusting the ratio of the six bacterial strains can improve the fermentation performance of the complex microbial community in camel milk systems. Specifically, *Streptococcus thermophilus* and *Lactobacillus bulgaricus* promote rapid acidification, while *Lactobacillus paracasei*, *Lactobacillus rhamnosus*, *Lactobacillus plantarum*, and *Bifidobacterium* help improve flavor and texture, resulting in fermented products with better overall performance in terms of acidity, flavor, and texture.
[0114] Comparative Example 1
[0115] This comparative example uses conventional cow's milk starter culture from the prior art to ferment camel milk, and is used to compare it with the compound probiotic starter culture of the present invention, in order to verify the differences in fermentation performance of different starter cultures in the camel milk system.
[0116] The specific method is as follows:
[0117] Fresh camel milk raw material, the same as in Example 4, was selected, and after being pasteurized in the same way, commercially available cow milk yogurt starter was added. The amount of starter was 0.05% of the camel milk mass, and fermentation was carried out at 40°C for 8 hours.
[0118] After fermentation, the texture, flavor characteristics, and whey separation of the fermented camel milk products were observed.
[0119] The results showed that fermented camel milk products prepared using conventional cow milk yogurt starter had issues such as relatively slow fermentation initiation, loose gel structure, significant whey separation, and insufficient improvement in the unique flavor of camel milk.
[0120] The reason may be that the strains in conventional milk starter cultures are mainly screened and optimized for milk fermentation systems. Their growth and metabolic characteristics are different from those of camel milk systems. Camel milk has characteristics such as high whey protein content, strong buffering capacity, and natural antibacterial active substances, which may affect the growth, reproduction and acid production performance of some strains, thus affecting fermentation efficiency and product quality.
[0121] In contrast, this invention, tailored to the characteristics of the camel milk system, screens Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium, and combines them in a specific ratio to create a synergistic effect between different strains. This helps to improve the adaptability of the compound probiotic starter to the camel milk environment, and improves fermentation efficiency, product flavor, and texture stability.
[0122] Example Effect Analysis
[0123] As can be seen from the above embodiments and comparative examples, the compound probiotic starter for camel milk fermentation provided by the present invention can adapt well to the camel milk fermentation system, and improve the acidification performance, product texture and flavor quality during the camel milk fermentation process through the synergistic effect of multiple strains.
[0124] Among them, Streptococcus thermophilus and Lactobacillus bulgaricus have good acid-producing capacity, which can promote the acidification of camel milk system and help the formation of gel structure; Lactobacillus paracasei and Lactobacillus rhamnosus can participate in the metabolic regulation during fermentation and improve the stability of complex flora in camel milk system; Lactobacillus plantarum and Bifidobacterium can assist in regulating fermentation metabolic process and help improve the flavor characteristics of fermented products.
[0125] By rationally combining six strains, different strains can play complementary roles in the fermentation process of camel milk, thereby improving the overall fermentation performance of the compound probiotic starter and improving the acidity, taste, texture and storage stability of fermented camel milk products.
[0126] Compared with conventional milk yogurt starter cultures, the compound probiotic starter culture of this invention has undergone strain screening and ratio optimization for camel milk systems, which can improve the matching degree between strains and camel milk fermentation environment. It helps to improve the problems of insufficient acidification efficiency, poor flavor coordination and insufficient gel stability in existing camel milk fermentation processes, and has good application value.
[0127] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.
Claims
1. A compound probiotic starter for camel milk fermentation, characterized in that, The compound probiotic starter is composed of Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus plantarum, and Bifidobacterium. Based on the total mass of the six strains (100%), the mass percentages are as follows: Streptococcus thermophilus 25%–35%, Lactobacillus bulgaricus 20%–30%, Lactobacillus paracasei 10%–20%, Lactobacillus rhamnosus 10%–20%, Lactobacillus plantarum 5%–15%, and Bifidobacterium 5%–15%.
2. The compound probiotic starter for camel milk fermentation according to claim 1, characterized in that, The compound probiotic fermentation agent is a freeze-dried bacterial powder formulation.
3. The compound probiotic starter for camel milk fermentation according to claim 2, characterized in that, The freeze-dried bacterial powder also includes food-grade preservatives, which include one or more of skim milk powder, trehalose, fructooligosaccharides, and ascorbic acid.
4. The compound probiotic starter for camel milk fermentation according to claim 3, characterized in that, The amount of the food-grade preservative added is 5% to 15% of the mass of the compound bacterial solution.
5. A method for preparing a compound probiotic starter for camel milk fermentation according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Screening, purifying, and activating probiotic strains; S2. Each strain after activation culture is further cultured to allow it to grow to a stable growth phase. S3. Mix the strains according to the preset ratio to obtain a compound bacterial solution; S4. Add a food-grade preservative to the compound bacterial solution to protect the bacterial cells; S5. The composite bacterial solution is freeze-dried using a freeze-drying process to obtain freeze-dried bacterial powder. S6. Vacuum package and low-temperature storage of the freeze-dried bacterial powder to obtain a compound probiotic starter for camel milk fermentation.
6. The preparation method according to claim 5, characterized in that, In S2, each strain is cultured at 35–42°C for 12–24 hours until it reaches a stable growth period before being compounded.
7. The preparation method according to claim 5, characterized in that, In step S5, a vacuum freeze-drying process is adopted. After pre-freezing at -40 to -50°C for 8 to 12 hours, the freeze-drying process is carried out for 18 to 36 hours.