Chinese yam, Chinese wolfberry fruit and cereal composite powder and process thereof

Abstract

The invention relates to the technical field of food, and discloses Chinese yam, Chinese wolfberry fruit and cereal composite powder which comprises the following components: Chinese yam powder, Chinese wolfberry fruit powder, cereal powder, probiotics and prebiotics, and the probiotics and the prebiotics are embedded through microcapsules. Wherein the probiotics and the prebiotics are embedded in the microcapsule wall material. By adopting a microcapsule embedding technology and chitosan coating treatment, the activity of probiotics in processing, storage and gastrointestinal tract environments is effectively protected; the microcapsule wall material comprises the following components: sodium alginate accounting for 1.5-3% of the total weight of the wall material; chitosan accounting for 0.5%-1% of the total weight of the wall material; gelatin accounting for 1-2% of the total weight of the wall material; the wall material is cross-linked through a cross-linking agent to form a stable microcapsule structure. The microcapsule wall material forms a physical barrier, so that the probiotics are prevented from being influenced by external adverse factors; and the chitosan coating further enhances the acid resistance of the microcapsule, so that the probiotics can smoothly pass through the erosion of gastric acid, and the survival rate and stability of the probiotics are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of food, in particular to a yam, wolfberry and grain composite powder and a process thereof. Background Art

[0002] With the improvement of people's living standards and the enhancement of health awareness, the market demand for functional foods is growing. Functional foods not only meet basic nutritional needs, but also have health benefits such as regulating body functions and preventing diseases. Among the many functional foods, yam, wolfberry and grains, as traditional nutritional ingredients, have attracted much attention due to their rich nutritional ingredients and health benefits.

[0003] Chinese yam is rich in mucin, polysaccharides, saponins, vitamins and minerals, and has the effects of nourishing the body, strengthening the spleen and stomach, and enhancing immunity. Chinese wolfberry contains Chinese wolfberry polysaccharides, carotene, vitamins and various trace elements, and has the effects of anti-oxidation, protecting the liver and improving eyesight, and enhancing immunity. Cereals such as rice, oats and millet provide rich dietary fiber, protein, B vitamins and minerals, which help improve the function of the digestive system and maintain cardiovascular health.

[0004] At present, there are compound powder products made of yam, wolfberry and grains on the market, which are made into convenient powdered foods through crushing, mixing and other processes. However, there is still room for improvement in the functionality and nutritional value of such products. In particular, with the increasing attention paid to intestinal health, probiotics and prebiotics, as important factors in regulating intestinal microecology, have been widely used in various functional foods.

[0005] Probiotics (such as lactic acid bacteria and bifidobacteria) can balance intestinal flora, promote nutrient absorption, and enhance immunity. However, probiotics are easily affected by external factors during processing, storage, and the gastrointestinal environment, resulting in reduced activity and limited functional effects. Prebiotics (such as oligofructose) as "food" for probiotics can promote the proliferation of probiotics and improve their colonization ability and functional activity.

[0006] In order to improve the stability and activity of probiotics, microencapsulation technology has been widely studied and applied. Microcapsules can protect probiotics from adverse external conditions and control their release in the intestine. However, traditional microencapsulation technology still has shortcomings in improving the gastric acid tolerance and controlled release performance of probiotics.

[0007] In this context, how to combine Chinese yam, wolfberry, and grains with probiotics and prebiotics and use advanced microencapsulation technology to prepare highly functional and stable composite powder products has become a research hotspot and technical challenge in this field. The existing technology mainly has the following problems: 1. Reduced activity of probiotics: During product processing and storage, probiotics are easily affected by factors such as temperature, humidity, and oxygen, which can lead to decreased activity and affect functional effects.

[0008] 2. Poor tolerance to gastric acid: Probiotics are easily killed by gastric acid when passing through the stomach, resulting in a significant reduction in the number of live bacteria reaching the intestines, affecting their colonization and proliferation in the intestines.

[0009] 3. Insufficient utilization of prebiotics: The addition and utilization of prebiotics in traditional products are insufficient, which cannot fully exert the synergistic effect of prebiotics and probiotics, limiting the functional improvement of the products.

[0010] 4. The sensory quality of the product needs to be improved: the unpleasant smell that probiotics and prebiotics may bring, as well as the roughness of the powder, affect the taste of the product and consumer acceptance.

[0011] 5. Short shelf life: During the storage process, the activity of probiotics decreases and the product quality stability is poor, which cannot meet the market demand for products with a long shelf life.

[0012] In response to the above problems, an improved technical solution is needed that can effectively protect the activity of probiotics, improve their colonization and function in the intestine, and at the same time combine them with nutrients such as yam, wolfberry, and cereals to prepare a composite powder product with high functionality, good sensory quality and long shelf life. Summary of the invention

[0013] In view of the shortcomings of the prior art, the present invention provides a yam and wolfberry grain composite powder and a process thereof, which solves the problem of how to effectively protect the activity and stability of probiotics in the yam and wolfberry grain composite powder, enhance their survival rate and functional performance in the gastrointestinal tract, and at the same time improve the nutritional value, sensory quality and shelf life of the product.

[0014] To achieve the above objectives, the present invention is implemented through the following technical scheme: a yam and wolfberry grain composite powder, the composite powder comprising the following components: Chinese yam powder, wolfberry powder, cereal powder, microencapsulated probiotics and prebiotics; Wherein, the probiotics and prebiotics are embedded in the microcapsule wall material.

[0015] Preferably, the microcapsule wall material comprises the following components: Sodium alginate, accounting for 1.5% to 3% of the total weight of the wall material; Chitosan, accounting for 0.5% to 1% of the total weight of the wall material; Gelatin, accounting for 1% to 2% of the total weight of the wall material; The wall material is cross-linked by a cross-linking agent to form a stable microcapsule structure.

[0016] Preferably, the cross-linking agent is a 0.1M to 0.3M calcium chloride solution, which is used to undergo a cross-linking reaction with sodium alginate during the preparation of the microcapsules.

[0017] Preferably, the probiotics include: strains of the genus Lactobacillus, Lactobacillus acidophilus; strains of the genus Bifidobacterium, Bifidobacterium longum; The viable count of the probiotics in the microencapsulated powder reaches 10¹ 0 CFU / g and above.

[0018] Preferably, the prebiotics are oligosaccharides that can promote the proliferation of probiotics, including: Fructo-oligosaccharide, purity ≥95%; Inulin, purity ≥90%; The amount of the prebiotic added to the microcapsule wall material is 5% to 10% of the weight of the wall material.

[0019] Preferably, the cereal flour is composed of one or more of the following components: Rice flour, oat flour, barley flour, millet flour; The grains are roasted before being ground.

[0020] Preferably, the weight percentage of each component is: Yam powder: 30%; Wolfberry powder: 20%; Cereal flour: 40%; Microencapsulated probiotic and prebiotic powders: 10%.

[0021] A preparation process of yam and wolfberry grain composite powder comprises the following steps: (1) Raw material pretreatment: Yam processing: Wash and peel the yam, slice it and dry it at 60℃ for 6 hours until the moisture content is reduced to ≤8%, then crush it through a 100-mesh sieve to obtain yam powder; Wolfberry treatment: wash the wolfberries, dry them at 50°C for 4 hours, reduce the moisture content to ≤12%, and grind them through a 100-mesh sieve to obtain wolfberry powder; Grain processing: Wash the grains, bake at 150°C for 5 minutes, and then grind through a 100-mesh sieve after cooling to obtain grain flour; (2) Preparation of probiotic / prebiotic microcapsules: Probiotic culture and concentration: The probiotic strains were cultured anaerobically in MRS medium at 37°C for 24 hours, the cells were collected by centrifugation, washed and concentrated to a bacterial concentration of 10¹ 0 CFU / mL; Preparation of wall material solution: prepare 2% sodium alginate solution, add prebiotics, stir evenly, and degas; Microcapsule formation: The probiotic bacterial solution and the wall material solution were mixed at a volume ratio of 1:4, and an emulsion was formed in the oil phase by an emulsification-gelation method. A 0.2 M CaCl2 solution was added for cross-linking for 30 minutes, and the microcapsules were collected, washed, and freeze-dried to obtain microcapsule powder; (3) Mixing of composite powder: Add yam powder, wolfberry powder and cereal powder into a mixer according to the proportion and mix for 10 minutes; Add microcapsule powder and mix at low speed for 5 minutes. The mixing temperature is controlled at ≤40℃ to obtain uniform yam and wolfberry grain composite powder. Preferably, during the formation of microcapsules, chitosan is used to coat the microcapsules to improve the survival rate of probiotics in a gastric acid environment. The specific steps are: The initially formed sodium alginate microcapsules were suspended in 1% chitosan solution and stirred for 30 min; The microcapsules were collected, washed and dried.

[0022] Preferably, the composite powder is packaged in an aluminum foil bag sealed with nitrogen and stored in a cool, dry, light-proof place with a shelf life of 12 months.

[0023] The present invention provides a yam and wolfberry grain composite powder and its process, which has the following beneficial effects: 1. The present invention effectively protects the activity of probiotics during processing, storage and gastrointestinal environment by adopting microcapsule embedding technology and chitosan coating treatment. The microcapsule wall material forms a physical barrier to prevent the probiotics from being affected by adverse external factors; the chitosan coating further enhances the acid resistance of the microcapsule, allowing the probiotics to pass through the erosion of gastric acid smoothly, significantly improving the survival rate and stability of the probiotics.

[0024] 2. The addition of prebiotics in the present invention provides a high-quality nutrient source for probiotics, and promotes the proliferation and colonization of probiotics in the intestine. The synergistic effect of prebiotics and probiotics helps to regulate the balance of intestinal microecology, enhance intestinal health functions, and improve immunity.

[0025] 3. The yam, wolfberry and cereals of the present invention are rich in various bioactive substances, such as mucin, polysaccharides, vitamins and minerals. Combining the functions of probiotics and prebiotics, the product has excellent performance in antioxidant activity, short-chain fatty acid production, etc., which helps to reduce oxidative stress, promote digestion and absorption, and prevent chronic diseases.

[0026] 4. The invention uses ultrafine grinding and microencapsulation to make the product powder fine and uniform, smooth in taste, and free of roughness. The microencapsulation technology masks the odor that may be brought by probiotics, and the baking of grains adds natural fragrance, which improves the flavor of the product and consumer acceptance as a whole.

[0027] 5. The microcapsule embedding and chitosan coating of the present invention not only protect the activity of probiotics, but also improve the resistance of the product to environmental factors. Combined with moisture-proof and oxidation-proof packaging materials and nitrogen-filled sealing technology, the product maintains stable quality within a shelf life of 12 months, meeting the market demand for products with a long shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1: Please see attached Figure 1 The embodiment of the present invention provides a yam and wolfberry grain composite powder and a process thereof, comprising the following steps: 1. Raw material preparation 1. Raw material selection In this embodiment, the following raw materials are selected: Yam: Choose fresh iron stick yam, which is white in appearance, free of mold and insect infestation, and weighs about 10 kg.

[0031] Wolfberry: Choose Ningxia wolfberry, which is dry, bright red in color, free of impurities, and weighs about 5 kg.

[0032] Cereals: Choose rice, oats and millet, 3 kg each, for a total of 9 kg.

[0033] Probiotics: Choose Lactobacillus acidophilus and Bifidobacterium longum, freeze-dried bacterial powder, 50 grams each.

[0034] Prebiotics: Fructooligosaccharides (FOS), purity ≥95%, 500 g.

[0035] Microcapsule wall material: 2 kg of food grade sodium alginate, 500 g of chitosan.

[0036] 2. Raw material pretreatment 2.1 Yam processing In this embodiment: Cleaning: Place 10 kg of yam in a cleaning machine and rinse with clean water for 5 minutes to remove dirt and impurities.

[0037] Peeling: Use a peeler to remove the skin of the yam, leaving the white fleshy part.

[0038] Slicing: Cut the peeled yam into thin slices about 3 mm thick.

[0039] Anti-browning treatment: Immediately soak the yam slices in 0.1% (w / v) citric acid solution for 5 minutes.

[0040] dry: Equipment: Hot air circulation dryer.

[0041] Parameters: temperature set to 60°C, wind speed 1.5 m / s, drying time 6 hours.

[0042] End point control: moisture content drops to ≤8% (detected by moisture meter).

[0043] Crushing: Equipment: Ultrafine pulverizer (such as air flow pulverizer).

[0044] Parameters: feed rate 2 kg / h, crushing pressure 0.8 MPa.

[0045] Particle size: crushed to D90≤50 microns.

[0046] Sieving: Use a 100-mesh (pore size about 150 microns) vibrating screen to sift to obtain fine yam powder.

[0047] 2.2 Lycium barbarum processing In this embodiment: Selection: 5 kg of wolfberries are hand-selected to remove impurities and damaged fruits.

[0048] Cleaning: Rinse the wolfberries gently in clean water for 2 minutes, then quickly remove and drain.

[0049] dry: Equipment: Vacuum dryer.

[0050] Parameters: temperature 50°C, vacuum degree -0.08 MPa, drying time 4 hours.

[0051] End point control: moisture content drops to ≤12%.

[0052] Crushing: Equipment: Ultrafine pulverizer.

[0053] Parameters: Same as yam crushing parameters.

[0054] Particle size: crushed to D90≤50 microns.

[0055] Sieve: Sieve using a 100-mesh vibrating sieve to obtain wolfberry powder.

[0056] 2.3 Grain handling In this embodiment: Washing: Wash rice, oats and millet separately in clean water to remove dust and impurities, and drain.

[0057] Baking: Equipment: Baking oven.

[0058] Parameters: temperature 150°C, time 5 minutes.

[0059] Purpose: To enhance the aroma of cereals.

[0060] Cooling: Spread out the roasted cereal and let it cool to room temperature.

[0061] Crushing: Equipment: Ultrafine pulverizer.

[0062] Parameters: Same as yam crushing parameters.

[0063] Particle size: crushed to D90≤50 microns.

[0064] Sieve: Sieve using a 100-mesh vibrating sieve to obtain grain flour.

[0065] 2. Preparation of probiotic / prebiotic microcapsules 1. Probiotic culture and concentration In this embodiment: Bacteria activation: Culture medium: Prepare MRS culture medium (as follows): Peptone: 10g Beef paste: 10g Yeast extract: 5g Glucose: 20g Triammonium citrate: 2g Potassium hydrogen phosphate: 2g Magnesium sulfate: 0.2 g Manganese sulfate: 0.05g Tween 80: 1mL Add water to 1000 mL and autoclave at 121°C for 15 minutes.

[0066] Inoculation: Inoculate 50 g of freeze-dried Lactobacillus acidophilus powder into 500 mL of MRS medium and culture anaerobically at 37°C for 24 hours.

[0067] Expanded cultivation: Inoculation amount: Inoculate 1% of the activated bacterial solution into 5 L of MRS medium and culture anaerobically at 37°C for 18 hours until the bacterial concentration reaches 10^9 CFU / mL.

[0068] Bacteria collection: Centrifuge: 8000 rpm, 4°C, 10 min to collect the bacteria.

[0069] Washing: Wash the cells twice with sterile saline (0.85% NaCl solution).

[0070] Concentration: Suspend the bacteria in 200 mL of sterile saline to a bacterial concentration of approximately 10^10 CFU / mL.

[0071] Note: The cultivation and treatment of Bifidobacterium longum are the same as above. The two bacteria are finally mixed.

[0072] 2. Preparation of microcapsule wall material solution In this embodiment: Sodium alginate solution: Preparation: Dissolve 2 kg of sodium alginate in 98 kg of purified water to obtain a 2% (w / v) solution.

[0073] Stirring: Using a stirrer, stir at room temperature for 2 hours until completely dissolved.

[0074] Degassing: In a vacuum degassing machine, the negative pressure is 0.08 MPa, and degassing is carried out for 15 minutes.

[0075] Adding prebiotics: Add 500 grams of oligofructose to the sodium alginate solution and stir well.

[0076] 3. Mixing of probiotics / prebiotics and wall materials In this embodiment: Mixing: Slowly add 200 mL of probiotic solution (including Lactobacillus acidophilus and Bifidobacterium longum) into 800 mL of sodium alginate-prebiotic solution, stirring gently to avoid bubbles.

[0077] 4. Microcapsule Formation In this embodiment: Oil phase preparation: Oil phase: Take 1 L of edible grade vegetable oil (such as soybean oil).

[0078] Emulsifier: Add 10 mL Span 80 (sorbitan monooleate) and stir well.

[0079] Emulsification process: Equipment: High speed mixer.

[0080] Stirring speed: initially 600 rpm.

[0081] Emulsification: Add the probiotic-wall material mixture into the oil phase at a rate of 1 mL / min, increase the stirring speed to 800 rpm, and continue stirring for 20 minutes to form a stable W / O emulsion.

[0082] Cross-linking curing: Cross-linking agent: 0.2 M CaCl2 solution.

[0083] Add: Add 100 mL of CaCl2 solution to the emulsion at a rate of 0.5 mL / min, continue stirring for 30 minutes, and react at room temperature.

[0084] Microcapsule collection: Centrifuge: 3000 rpm, 10 min to separate microcapsules.

[0085] Washing: Wash three times with sterile saline to remove the oil phase and residual cross-linking agent.

[0086] 5. Chitosan coating (optional) In this embodiment: Chitosan solution: Preparation: Dissolve 500 g of chitosan in 50 L of 1% (v / v) acetic acid solution to obtain a 1% (w / v) chitosan solution.

[0087] Coating treatment: Suspension: The collected microcapsules were suspended in chitosan solution and stirred for 30 minutes.

[0088] Collection: Centrifuge at 3000 rpm for 10 minutes to collect microcapsules.

[0089] Washing: Wash twice with sterile saline to remove excess chitosan.

[0090] 6. Microcapsule drying In this embodiment: Freeze drying: Prefreezing: Place the moist microcapsules in a stainless steel dish and place in a -40°C freezer for 2 hours.

[0091] Freeze-dried: Equipment: Freeze dryer.

[0092] parameter: Vacuum degree: 0.1 mbar.

[0093] Plate temperature: from -40°C to 25°C at a rate of 1°C / hour.

[0094] Drying time: 24 hours.

[0095] Collect and save: Collection: Collect the dried microcapsule powder with a sterile spoon.

[0096] Storage: Place in a dry sterile container, seal and refrigerate at 4°C.

[0097] 3. Mixing of composite powder 1. Formula ratio In this embodiment, the weight ratio of each component is: Yam powder: 30% (10 kg x 30% = 3 kg) Wolfberry powder: 20% (5 kg x 20% = 1 kg) Cereal flour: 40% (9 kg x 40% = 3.6 kg) Microcapsule powder: 10% (total amount of microcapsules is about 1 kg) 2. Mixing process In this embodiment: Equipment: Two-dimensional motion mixer, capacity 20 L.

[0098] Mixing steps: Feeding: Add 3 kg of yam powder, 1 kg of wolfberry powder and 3.6 kg of grain powder into the mixer in sequence.

[0099] Initial mixing: Start mixer and mix for 10 minutes at 15 rpm.

[0100] Add microcapsule powder: turn off the mixer, open the feeding port, and evenly sprinkle 1 kg of microcapsule powder.

[0101] Mix again: Start mixer and mix at low speed (10 rpm) for 5 minutes.

[0102] Temperature control: During the mixing process, both the ambient temperature and the material temperature should be ≤40℃.

[0103] 3. Mixing uniformity test In this embodiment: Sampling: Randomly take 5 samples from different locations in the mixture, each sample is about 10 grams.

[0104] Detection: Determine the content of yam polysaccharides in the sample using ultraviolet spectrophotometer.

[0105] Result determination: Calculate the relative standard deviation (RSD), which should be ≤5%, indicating uniform mixing.

[0106] 4. Product packaging and storage 1. Packaging In this embodiment: Inner Packing: Material: Aluminum foil bag, thickness 70 microns, with high barrier properties.

[0107] Specifications: Net content of each bag is 50 grams.

[0108] Packaging process: Environmental requirements: temperature 20-25℃, relative humidity ≤50%, cleanliness meets GMP standards.

[0109] Equipment: Automatic quantitative packaging machine, accuracy ±0.5g.

[0110] Nitrogen-filled packaging: Nitrogen is filled during the packaging process, and the oxygen content is ≤1%.

[0111] Sealing: heat sealing machine, sealing temperature 170℃, pressure 0.3 MPa, time 1 second.

[0112] 2. Label identification In this embodiment, the label content includes: Product name: Chinese yam, wolfberry, grain and probiotics compound powder Ingredients: Chinese yam powder, wolfberry powder, cereal powder (rice powder, oatmeal powder, millet powder), microcapsule probiotics, oligofructose Net content: 50g Production date: XXXX Shelf life: 12 months Storage conditions: cool, dry, dark place How to use: Take one bag (50g) of this product, add 200ml warm water (≤40℃), stir well and drink. Nutritional composition table: Lists the energy, protein, fat, carbohydrates, sodium, dietary fiber, etc. per 100 grams of product 3. Storage conditions In this embodiment: Environmental requirements: temperature ≤25℃, relative humidity ≤60%.

[0113] Shelf life: Under the above conditions, the product shelf life is 12 months.

[0114] 5. Quality Control and Testing 1. Sensory testing In this embodiment: Appearance: The powder is light yellow, uniform and fine, without lumps.

[0115] Smell: It has the natural fragrance of yam and wolfberry, without any peculiar smell.

[0116] Feel: dry and loose.

[0117] 2. Physical and chemical index testing In this embodiment: Moisture Content: Method: Oven method, 105℃, dry to constant weight.

[0118] Result: The moisture content is 6.5%, which meets the requirement of ≤8%.

[0119] Ash content: Method: High temperature calcination method, 550℃, to constant weight.

[0120] Result: The ash content is 2.5%.

[0121] 3. Microbiological index detection In this embodiment: Total colony count: Method: According to GB 4789.2-2016 “National Food Safety Standard Food Microbiology Examination Determination of Total Colony Count”.

[0122] Results: The total colony count was 2.0×10^3 CFU / g, which met the standard of ≤1.0×10^4 CFU / g.

[0123] Coliform bacteria: Method: According to GB 4789.3-2016.

[0124] Result: Not detected (<3 MPN / g).

[0125] Molds and yeasts: Method: According to GB 4789.15-2016.

[0126] Result: The total number of molds and yeasts was 20 CFU / g, which met the standard of ≤50 CFU / g.

[0127] Pathogens: Methods: Salmonella, Staphylococcus aureus, etc. were detected according to relevant national standards.

[0128] Result: None detected.

[0129] 4. Probiotic live bacteria count detection In this embodiment: Sample preparation: Take 10 g of the product, add 90 mL of sterile saline and mix thoroughly.

[0130] Serial dilution: Perform 10-fold serial dilutions to 10^-7 times.

[0131] Inoculation culture: Culture medium: MRS agar medium.

[0132] Conditions: Anaerobic culture at 37°C for 48 hours.

[0133] Count: The number of live bacteria was calculated and the result was 1.5×10^9 CFU / g, which meets the requirement that the number of live probiotic bacteria per gram of product should be ≥1.0×10^8 CFU / g.

[0134] Embodiment 2: This embodiment is based on the first embodiment, and only one variable is changed, that is, the probiotic microcapsules are not subjected to chitosan coating treatment. The specific steps are as follows: 1. Raw material preparation 1. Raw material selection In this embodiment, the same raw materials as those in Embodiment 1 are selected: Yam: Iron stick yam, 10 kg.

[0135] Wolfberry: Ningxia wolfberry, 5 kg.

[0136] Cereals: rice, oats and millet, 3 kg each, 9 kg in total.

[0137] Probiotics: Lactobacillus acidophilus and Bifidobacterium longum, 50g each.

[0138] Prebiotics: Fructooligosaccharide, purity ≥95%, 500g.

[0139] Microcapsule wall material: 2 kg of food grade sodium alginate.

[0140] 2. Raw material pretreatment The steps of washing, peeling, slicing, drying, crushing and screening the raw materials are the same as those in Example 1 and will not be repeated here.

[0141] 2. Preparation of probiotic / prebiotic microcapsules 1. Probiotic culture and concentration In this embodiment, the steps of culturing and concentrating probiotics are the same as those in Embodiment 1: The steps of strain activation, expansion culture, bacterial cell collection, washing and concentration were all carried out according to Example 1.

[0142] 2. Preparation of microcapsule wall material solution In this embodiment: Sodium alginate solution: A 2% (w / v) sodium alginate solution was prepared, and the stirring and degassing steps were the same as in Example 1.

[0143] Prebiotics addition: Add 500g of oligofructose and stir well.

[0144] 3. Mixing of probiotics / prebiotics and wall materials Similar to Example 1, the probiotic solution and the sodium alginate-prebiotic solution were mixed at a volume ratio of 1:4 and gently stirred.

[0145] 4. Microcapsule Formation In this embodiment: Preparation of oil phase: same as in Example 1.

[0146] Emulsification process: same as in Example 1.

[0147] Cross-linking and curing: Same as in Example 1, using 0.2 M CaCl2 solution.

[0148] Microcapsule collection: The centrifugation and washing steps are the same as those in Example 1.

[0149] 5. Microcapsule drying In this embodiment: Freeze drying: The pre-freezing and freeze-drying parameters are the same as those in Example 1.

[0150] Collection and storage: Place the dried microcapsule powder in a sterile container, seal it, and refrigerate it at 4°C.

[0151] Note: Chitosan coating was not performed in this example.

[0152] 3. Mixing of composite powder 1. Formula ratio Same as in Example 1, the weight ratio of each component is: Yam powder: 3 kg Wolfberry powder: 1 kg Cereal flour: 3.6 kg Microcapsule powder: 1 kg 2. Mixing process The mixing equipment and steps are the same as those in Example 1.

[0153] Temperature control: During the mixing process, both the ambient temperature and the material temperature should be ≤40℃.

[0154] 3. Mixing uniformity test The method and results are the same as those of Example 1.

[0155] 4. Product packaging and storage 1. Packaging The inner packaging materials, specifications and packaging process are the same as those in Example 1.

[0156] 2. Label identification The label content is the same as that of the first embodiment.

[0157] 3. Storage conditions The environmental requirements and shelf life are the same as those of Example 1.

[0158] 5. Quality Control and Testing 1. Sensory testing The appearance, smell and feel are similar to those of Example 1.

[0159] 2. Physical and chemical index testing The test results of moisture content and ash content are similar to those of Example 1 and meet the standard requirements.

[0160] 3. Microbiological index detection The test results of total colony count, coliform group, mold and yeast, and pathogenic bacteria all meet the national food safety standards.

[0161] 4. Probiotic live bacteria count detection In this embodiment: Live bacteria count: Through testing, the live bacteria count of probiotics in the product is 1.2×10^9 CFU / g, which meets the requirements.

[0162] Comparative test: 1. Purpose The survival rates of the probiotics in Example 1 and Example 2 in a simulated gastrointestinal environment, as well as the differences in product functionality, were compared to verify the effect of chitosan coating treatment on product performance.

[0163] 2. Materials and Methods 2.1 Sample preparation Sample A (Example 1): Chinese yam and wolfberry grain composite powder containing probiotic microcapsules treated with chitosan coating.

[0164] Sample B (Example 2): Chinese yam and wolfberry grain composite powder containing probiotic microcapsules without chitosan coating treatment.

[0165] 2.2 Preparation of simulated gastric and intestinal fluid Simulated gastric fluid: Take 0.1 M hydrochloric acid solution and add 2.0 g / L pepsin (pH 1.5).

[0166] Simulated intestinal fluid: Take 0.05 M phosphate buffer (pH 7.4), add 10 g / L bile salts and 5.0 g / L pancreatic enzyme.

[0167] 2.3 Experimental steps (1) Survival rate test of probiotics in simulated gastric fluid Sampling: Take 1 g of sample A and sample B respectively, add them into 9 mL of simulated gastric fluid, and oscillate at a constant temperature (100 rpm) at 37°C.

[0168] Time points: samples were taken at 0, 30, 60, 90 and 120 minutes.

[0169] Detection method: The plate count method was used to determine the number of viable probiotics.

[0170] (2) Release and survival rate test of probiotics in simulated intestinal fluid Transfer: After 120 minutes of simulated gastric fluid treatment, transfer the sample into 9 mL of simulated intestinal fluid and shake at a constant temperature of 37°C.

[0171] Time points: samples were taken at 0, 2, 4 and 6 hours.

[0172] Detection method: The plate count method was also used to determine the number of viable probiotics.

[0173] (3) Functional index test Antioxidant activity determination: The DPPH free radical scavenging ability method was used to determine the antioxidant activity of the samples.

[0174] In vitro fermentation experiment: The samples were added to a simulated intestinal fermentation system to measure the production of short-chain fatty acids (SCFAs).

[0175] 3. Data processing The survival rate, release rate and functional indexes of probiotics were calculated, and statistical software was used for data analysis. The results were expressed as mean ± standard deviation.

[0176] Results Analysis 1. Comparison of probiotic survival rate In simulated gastric fluid: The survival rate of probiotics in sample A was significantly higher than that in sample B. After 120 minutes, the survival rate of sample A was still 73.3%, while that of sample B was only 10%.

[0177] Reason: The probiotic microcapsules in sample A are coated with chitosan, which forms a stable film under acidic conditions to protect the probiotics from erosion by gastric acid.

[0178] 2. Comparison of probiotic release and survival rate In simulated intestinal fluid: The number of live probiotics in sample A gradually increased, and the release rate was higher than that in sample B.

[0179] Reason: The chitosan coating dissolves under alkaline conditions, allowing probiotics to be released and proliferate in the intestinal environment.

[0180] 3. Comparison of functional indicators Antioxidant Activity: The DPPH removal rate of sample A was 70%, which was higher than 60% of sample B, indicating that chitosan coating treatment was helpful in retaining the active and functional components of probiotics.

[0181] SCFAs production: The total amount of short-chain fatty acids produced by sample A in in vitro fermentation was 55 mM, which was higher than 45 mM of sample B.

[0182] Significance: Higher SCFAs levels help maintain intestinal health and prevent intestinal diseases.

[0183] IV. Conclusion Through comparative tests, the following conclusions were drawn: Chitosan coating treatment significantly improved the survival rate of probiotics in simulated gastric fluid and enhanced the ability of probiotics to reach the intestine smoothly.

[0184] The product of Example 1 is superior to that of Example 2 in terms of functionality, as reflected in higher antioxidant activity and SCFAs production.

[0185] By changing only one variable (whether or not chitosan coating was performed), the difference in product performance can be clearly seen, proving the positive impact of chitosan coating on product quality.

[0186] Table 1 Survival rate of probiotics in simulated gastric fluid Table 2 Release and survival rate of probiotics in simulated intestinal fluid.

[0187] Release rate = (current number of live bacteria / initial number of live bacteria) × 100%.

[0188] Table 3 Comparison of functional indicators The probiotic survival rate and functional indicators are superior to those of Example 2.

[0189] Chitosan coating treatment, as a key step, is of great significance to improving product quality.

[0190] In actual production, it is recommended to adopt the process of Example 1 to obtain higher quality products and meet consumers' demand for functional foods.

[0191] Embodiment three: This embodiment is based on the first embodiment, and only one variable is changed, that is, no prebiotics are added to the microcapsule wall material solution, and specifically includes the following steps: 1. Raw material preparation 1. Raw material selection In this embodiment, the same raw materials as those in Embodiment 1 are selected: Yam: Iron stick yam, 10 kg.

[0192] Wolfberry: Ningxia wolfberry, 5 kg.

[0193] Cereals: rice, oats and millet, 3 kg each, 9 kg in total.

[0194] Probiotics: Lactobacillus acidophilus and Bifidobacterium longum, 50g each.

[0195] Microcapsule wall material: 2 kg of food grade sodium alginate, 500 g of chitosan.

[0196] No prebiotics (fructoligosaccharides) were used in this example.

[0197] 2. Raw material pretreatment The steps of washing, peeling, slicing, drying, crushing and screening the raw materials are the same as those in Example 1 and will not be repeated here.

[0198] 2. Preparation of probiotic microcapsules 1. Probiotic culture and concentration In this embodiment, the steps of culturing and concentrating probiotics are the same as those in Embodiment 1: The steps of strain activation, expansion culture, bacterial cell collection, washing and concentration were all carried out according to Example 1.

[0199] 2. Preparation of microcapsule wall material solution In this embodiment: Sodium alginate solution: A 2% (w / v) sodium alginate solution was prepared, and the stirring and degassing steps were the same as in Example 1.

[0200] No prebiotics added: In this embodiment, no prebiotics are added to the wall material solution.

[0201] 3. Mixing of probiotics and wall materials Mixing: Slowly add 200 mL of probiotic solution into 800 mL of sodium alginate solution, stirring gently to avoid creating bubbles.

[0202] 4. Microcapsule Formation In this embodiment: Preparation of oil phase: same as in Example 1.

[0203] Emulsification process: same as in Example 1.

[0204] Cross-linking and curing: Same as in Example 1, using 0.2 M CaCl2 solution.

[0205] Microcapsule collection: The centrifugation and washing steps are the same as those in Example 1.

[0206] 5. Chitosan coating treatment In this embodiment, the chitosan coating treatment steps are the same as those in Embodiment 1: Chitosan solution: 1% (w / v), dissolved in 1% acetic acid.

[0207] Coating treatment: suspend the microcapsules in chitosan solution and stir for 30 minutes.

[0208] Collection and washing: Collection by centrifugation, washing twice.

[0209] 6. Microcapsule drying In this embodiment: Freeze drying: The pre-freezing and freeze-drying parameters are the same as those in Example 1.

[0210] Collection and storage: Place the dried microcapsule powder in a sterile container, seal it, and refrigerate it at 4°C.

[0211] 3. Mixing of composite powder 1. Formula ratio In this embodiment, the weight ratio of each component is: Yam powder: 30% (3 kg) Wolfberry powder: 20% (1 kg) Cereal flour: 40% (3.6 kg) Microcapsule powder: 10% (1 kg) Since no prebiotics were added, the weight of prebiotics was not included in the formula ratio.

[0212] 2. Mixing process The mixing equipment and steps are the same as those in Example 1.

[0213] Temperature control: During the mixing process, both the ambient temperature and the material temperature should be ≤40℃.

[0214] 3. Mixing uniformity test The method and results are the same as those of Example 1.

[0215] 4. Product packaging and storage 1. Packaging The inner packaging materials, specifications and packaging process are the same as those in Example 1.

[0216] 2. Label identification In this embodiment, the label content is the same as that of the first embodiment, but the ingredient list does not contain prebiotics (fructoligosaccharides).

[0217] 3. Storage conditions The environmental requirements and shelf life are the same as those of Example 1.

[0218] 5. Quality Control and Testing 1. Sensory testing The appearance, smell and feel are similar to those of Example 1.

[0219] 2. Physical and chemical index testing The test results of moisture content and ash content are similar to those of Example 1 and meet the standard requirements.

[0220] 3. Microbiological index detection The test results of total colony count, coliform group, mold and yeast, and pathogenic bacteria all meet the national food safety standards.

[0221] 4. Probiotic live bacteria count detection In this embodiment: Live bacteria count: Through testing, the live bacteria count of probiotics in the product is 1.4×10^9 CFU / g, which meets the requirements.

[0222] Comparative test: The proliferation ability of probiotics in Example 1 (prebiotics added) and Example 3 (prebiotics not added) in the simulated intestinal environment and the functional differences of the products were compared to verify the effect of prebiotics addition on product performance.

[0223] Materials and Methods Sample A (Example 1): Chinese yam, wolfberry, cereal and probiotic composite powder containing prebiotics.

[0224] Sample C (Example 3): Chinese yam, wolfberry, cereal and probiotics composite powder without added prebiotics.

[0225] The experimental steps are similar to the previous comparative tests, but the focus is on the proliferation and functional indicators of probiotics in simulated intestinal fluid.

[0226] Comparison of probiotic proliferation ability The probiotics in sample A proliferated rapidly in the simulated intestinal fluid, increasing 8 times within 6 hours.

[0227] The probiotics in sample C had a lower proliferation rate, which was 1.79 times within 6 hours.

[0228] Reason: Sample A contains prebiotics, which serve as a carbon source and energy source for probiotics and promote the proliferation of probiotics.

[0229] Comparison of functional indicators Antioxidant Activity: The DPPH removal rate of sample A was 70%, which was higher than that of sample C (65%).

[0230] SCFAs production: The total SCFAs production in sample A was 55 mM and in sample C was 48 mM.

[0231] The presence of prebiotics promotes the metabolic activity of probiotics, increases the production of SCFAs, and is beneficial to intestinal health.

[0232] Through comparative tests, the following conclusions were drawn: The addition of prebiotics significantly promoted the proliferation of probiotics in the intestine and improved the function of probiotics.

[0233] The product of Example 1 is superior to that of Example 3 in terms of functionality, as reflected in higher probiotic proliferation multiples, antioxidant activity and SCFAs production.

[0234] By changing only one variable (whether or not to add prebiotics), the difference in product performance can be clearly seen, proving the positive impact of prebiotic addition on product quality.

[0235] Table 4 Comparison of the proliferation times of probiotics in simulated intestinal fluid Table 5 Comparison of the proliferation times of probiotics in simulated intestinal fluid The probiotics proliferation ability and functional indicators are superior to those of Example 3.

[0236] The addition of prebiotics, as a key step, is of great significance to improving product quality.

[0237] In actual production, it is recommended to adopt the process of Example 1 and add prebiotics to obtain higher quality products and meet consumers' demand for functional foods.

[0238] By comparing this example with Example 1, it can be clearly seen that the addition of prebiotics has a positive impact on product performance. Prebiotics not only promote the proliferation of probiotics in the intestines, improve the function of probiotics, but also enhance the antioxidant activity and intestinal health function of the product.

[0239] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A Chinese yam and wolfberry grain composite powder, characterized in that: The composite powder comprises the following components: Chinese yam powder, wolfberry powder, cereal powder, microencapsulated probiotics and prebiotics; Wherein, the probiotics and prebiotics are embedded in the microcapsule wall material.

2. The Chinese yam and wolfberry grain composite powder according to claim 1, characterized in that: The microcapsule wall material comprises the following components: Sodium alginate, accounting for 1.5% to 3% of the total weight of the wall material; Chitosan, accounting for 0.5% to 1% of the total weight of the wall material; Gelatin, accounting for 1% to 2% of the total weight of the wall material; The wall material is cross-linked by a cross-linking agent to form a stable microcapsule structure.

3. The Chinese yam and wolfberry grain composite powder according to claim 2, characterized in that: The cross-linking agent is a 0.1M to 0.3M calcium chloride solution, which is used to undergo a cross-linking reaction with sodium alginate during the preparation of microcapsules.

4. The Chinese yam and wolfberry grain composite powder according to claim 1, characterized in that: The probiotics include: strains of the genus Lactobacillus, Lactobacillus acidophilus; strains of the genus Bifidobacterium, Bifidobacterium longum; The viable count of the probiotics in the microencapsulated powder reaches 10¹ 0 CFU / g and above.

5. The Chinese yam and wolfberry grain composite powder according to claim 1, characterized in that: The prebiotics are oligosaccharides that can promote the proliferation of probiotics, including: Fructo-oligosaccharide, purity ≥95%; Inulin, purity ≥90%; The amount of the prebiotic added to the microcapsule wall material is 5% to 10% of the weight of the wall material.

6. The Chinese yam and wolfberry grain composite powder according to claim 1, characterized in that: The cereal flour is composed of one or more of the following components: Rice flour, oat flour, barley flour, millet flour; The grains are roasted before being ground.

7. The Chinese yam and wolfberry grain composite powder according to claim 1, characterized in that: The weight percentage of each component is: Yam powder: 30%; Wolfberry powder: 20%; Cereal flour: 40%; Microencapsulated probiotic and prebiotic powders: 10%.

8. A process for preparing yam and wolfberry grain composite powder, characterized in that: The following steps are involved: (1) Raw material pretreatment: Yam processing: Wash and peel the yam, slice it and dry it at 60℃ for 6 hours until the moisture content is reduced to ≤8%, then crush it through a 100-mesh sieve to obtain yam powder; Wolfberry treatment: wash the wolfberries, dry them at 50°C for 4 hours, reduce the moisture content to ≤12%, and grind them through a 100-mesh sieve to obtain wolfberry powder; Grain processing: Wash the grains, bake at 150°C for 5 minutes, and then grind through a 100-mesh sieve after cooling to obtain grain flour; (2) Preparation of probiotic / prebiotic microcapsules: Probiotic culture and concentration: The probiotic strains were cultured anaerobically in MRS medium at 37°C for 24 hours, the cells were collected by centrifugation, washed and concentrated to a bacterial concentration of 10¹ 0 CFU / mL; Preparation of wall material solution: prepare 2% sodium alginate solution, add prebiotics, stir evenly, and degas; Microcapsule formation: The probiotic bacterial solution and the wall material solution were mixed at a volume ratio of 1:4, and an emulsion was formed in the oil phase by an emulsification-gelation method. A 0.2 M CaCl2 solution was added for cross-linking for 30 minutes, and the microcapsules were collected, washed, and freeze-dried to obtain microcapsule powder; (3) Mixing of composite powder: Add yam powder, wolfberry powder and cereal powder into a mixer according to the proportion and mix for 10 minutes; Add the microcapsule powder and mix at a low speed for 5 minutes, with the mixing temperature controlled at ≤40°C to obtain a uniform yam and wolfberry grain composite powder.

9. The process for preparing the yam and wolfberry grain composite powder according to claim 8, characterized in that: During the microcapsule formation process, chitosan is used to coat the microcapsules to improve the survival rate of probiotics in the gastric acid environment. The specific steps are as follows: The initially formed sodium alginate microcapsules were suspended in 1% chitosan solution and stirred for 30 min; The microcapsules were collected, washed and dried.

10. The process for preparing the yam and wolfberry grain composite powder according to claim 8, characterized in that: The composite powder is packaged in an aluminum foil bag filled with nitrogen and sealed, and is stored in a cool, dry, light-proof place with a shelf life of 12 months.

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