140 results about "Lactalbumin" patented technology

The invention belongs to the technical field of protein purification processes, and particularly relates to a method for separating and purifying alpha-lactalbumin in whey. Comprising the following steps: S1, obtaining skimmed milk; s2, performing microfiltration separation on the skimmed milk obtained in the step S1 to obtain whey protein liquid containing alpha-lactalbumin; s3, loading the whey protein liquid containing alpha-lactalbumin obtained in S2 into a balanced strong cation chromatographic column, and collecting a flow-through liquid to obtain separated and purified alpha-lactalbumin; according to the method, the SP Purose 6XL filler is combined with the specific 10-60mM acetic acid buffer solution with the pH value of 4-6, so that the method is particularly suitable for separating the alpha-lactalbumin from other proteins in the whey, and the alpha-lactalbumin is collected in a flow-through manner, so that large-volume sample loading can be realized, and more importantly, the obtained alpha-lactalbumin is high in yield and purity; in addition, the process is simple in extraction step and free of a tedious elution process, a large amount of time can be saved, the production cost is reduced, and industrial production is facilitated.

The invention discloses a protein separation method and related application thereof, and relates to the technical field of dairy product processing, the method comprises the following steps: heating a whey solution of which the pH value is adjusted to 3.5-4.2 by a citric acid solution, carrying out microfiltration on the heated product, carrying out beta-lactoglobulin and / or alpha-lactalbumin separation on permeate and trapped fluid obtained by microfiltration, the method is based on the membrane filtration technology, high-purity separation of beta-lactoglobulin and alpha-lactalbumin is achieved, the purity can reach 70%-90% or above, the method is compatible with whey from multiple sources, equipment is simple, the method has the advantages of being low in separation cost, high in efficiency, easy to implement, large in flux and the like, and a way is provided for large-scale industrial production of beta-lactoglobulin and alpha-lactalbumin.

A method for separating protein from a milk raw material, the method comprising separating beta-lactoglobulin and alpha-lactalbumin from the milk raw material, the method comprising: a whey separation step for separating whey protein from the milk raw material; a step of ion exchange treatment: adsorbing the whey protein by using strong anion exchange resin, then eluting by using an eluent, adsorbing the whey protein by using strong anion exchange resin to obtain a flow-through liquid, enriching alpha-lactalbumin in the flow-through liquid, and carrying out gradient elution by using the eluent to obtain an elution component, at least one of the elution components is enriched with beta-lactoglobulin; and purifying the flow-through liquid to obtain an alpha-lactalbumin solid, and purifying the elution component enriched with beta-lactoglobulin to obtain a beta-lactoglobulin solid.

The invention relates to the technical field of medicine, and discloses an artificial exosome and application thereof in drug delivery, the artificial exosome is prepared into an oil phase based on PLGA and DOTAP, and a water phase based on OCT4 protein and siTrim28; mixing the two phases to obtain a primary emulsion, and adding a PVA aqueous solution to obtain a double emulsion; stirring the double emulsion and volatilizing the solvent to form an emulsified solution, and centrifuging to obtain PLGA nanoparticles; the lipid mixture is prepared from lipid, DPPE-PEG2000, alpha-tocopherol and alpha-lactalbumin, and a lipid film is formed after a solvent is evaporated; the preparation method comprises the following steps: mixing PLGA nanoparticles, a lipid film and membrane protein, uniformly mixing and heating to obtain a film-coated solution, and finally extruding through a cellulose acetate film to obtain the artificial exosome. The artificial exosome disclosed by the invention combines the stability of the PLGA nanoparticles and the biocompatibility of the lipid membrane, and provides new possibility for a drug delivery system.

The invention discloses a method for enriching whey protein main monomers from cow milk. According to the method, whey protein subjected to membrane separation is taken as a raw material, interaction between main monomers of the whey protein and other milk proteins is weakened by adopting a pH conversion technology and an ultrasonic technology, mineral substances, lactose, bovine serum albumin and residual casein are removed through ion exchange chromatography, the main monomers of the whey protein are enriched, and the high-purity whey protein is obtained. And drying the alpha-lactalbumin and the beta-lactoglobulin to obtain a milk protein product rich in two main monomers of the whey protein, and the total content of the two monomers is up to 85% or above. According to the technology, cow milk serves as a raw material, efficient enrichment of two main monomers of whey protein can be achieved only through membrane separation, pH conversion, ultrasonic assistance and ion exchange chromatography, only pH needs to be adjusted in the separation process, other chemical reagents are not added, and the process is environmentally friendly, simple, easy to implement and suitable for large-scale processing; the prepared milk protein base material rich in the whey protein main monomer can be used as a main material and a base material of infant food, and is high in nutritional value and wide in application prospect.

The invention discloses a nutritional composition for promoting neurodevelopment and application, and provides a nutritional composition for promoting neurodevelopment, which comprises the following necessary components: a sialylated substance component comprising one or more of N-acetylneuraminic acid, sialylated oligosaccharide, sialylated protein and sialylated lipid; the whey protein component comprises alpha-lactalbumin; and a peptide component from casein, including a hydrolysate of casein; the nutritional composition comprises a sialylated substance component, a whey protein component and a casein-derived peptide component, and the mass ratio of the sialylated substance component, the whey protein component and the casein-derived peptide component in the nutritional composition is (0.5-10): (300-1): (100-0.5). The nutritional composition provided by the invention can promote brain development and cognitive functions, and can significantly promote neurodevelopment by scientifically matching the sialylated substance component, the whey protein component and the peptide component from casein.

The invention provides a milk powder composition containing breast milk oligosaccharide and easy to digest and absorb. The milk powder composition comprises the breast milk oligosaccharide, OPN, galactooligosaccharide, lactoferrin, alpha-whey protein, multivitamins, lactose, vegetable oil and compound minerals, wherein the weight ratio of the lactoferrin to the OPN to the breast milk oligosaccharide to the galactooligosaccharide is 1: (2-4): (2-50): (4-100). The composition can effectively recover and improve the intestinal barrier function caused by inflammatory factors, can be well absorbed by infants with poor digestion and absorption functions, reduces diarrhea and promotes skeletal development.

The invention discloses a method for extracting a target product from a milk raw material, and relates to the technical field of food processing. According to the method, before strong anion exchange chromatography is carried out, a synergistic pretreatment step of ultrafiltration and conductivity adjustment is introduced, so that acceleration, synergism, quality improvement and cost reduction of the chromatography process are realized, and the technical bottlenecks of low speed, easiness in pollution, instability and the like of the traditional ion exchange chromatography during treatment of milk raw materials are overcome; and a solution is provided for high-efficiency, high-purity and large-scale production of the beta-lactoglobulin and the alpha-lactalbumin. According to the method, strong anion exchange chromatography and weak anion exchange chromatography can be combined, so that the extraction purity of beta-lactoglobulin and alpha-lactalbumin can be further improved; in addition, the method can synchronously realize high-efficiency extraction of various target substances such as casein micelles, lactose and milk mineral salts, so that the additional value and resource utilization efficiency of milk source byproducts are greatly improved.

The invention discloses a method for preparing low-bitterness micromolecular bovine colostrum protein peptide powder by adopting a multi-stage membrane separation and enzyme membrane coupling combined technology, and belongs to the technical field of food processing. The preparation method comprises the following steps: firstly, dividing a colostrum component into components to be hydrolyzed by adopting a multi-stage membrane separation technology, namely casein intercepted by ceramic membrane microfiltration and lactoglobulin and lactalbumin filtered by an ultrafiltration membrane, and non-hydrolytic components, namely immune globulin and lactoferrin; the preparation method comprises the following steps: firstly, separating bovine coloctrum, then deeply hydrolyzing the separated lactoglobulin, milky white and casein flocculate with the molecular weight of less than 50kDa by adopting an enzyme membrane coupling technology, mixing with unhydrolyzed immunoglobulin and lactoferrin, and freeze-drying, so that the peptide content in the treated bovine coloctrum is more than 40%, the peptide content of 200-1000Da is more than 30%, the peptide content of 200-1000Da is more than 30%, and the peptide content of 200-1000Da is more than 30%. The preparation method is simple, the preparation dispersion time is within 10 s, no obvious bitter taste exists, the retention rate of immune globulin in bovine coloctrum reaches 90% or above, and the preparation method is suitable for large-scale industrial popularization.

The present invention discloses a lactoferrin composition and its application for improving immunity by regulating macrophage immune activity, and belongs to the technical field of functional compositions. The present invention obtains a lactoferrin composition with regulating macrophage immune activity by compounding lactoferrin, α-lactalbumin, N-acetylneuraminic acid and yeast β-glucan in a specific ratio, the raw material of the composition is easy to obtain, and four components work together to significantly enhance its phagocytic activity without changing the activity of macrophages, regulate the polarization state of macrophages in inflammatory response, inhibit macrophages from polarizing to pro-inflammatory M1 type, and promote macrophages to polarize to anti-inflammatory M2 type; At the same time, the composition can also enhance the antigen presentation ability of macrophages and the activation of immune T cells, and improve body immunity. Therefore, the composition provided by the present invention can be used to prepare health products, food or medicines, etc. that improve immunity.

The invention discloses a method for simultaneously separating and purifying alpha-lactalbumin and serum albumin from camel milk, which comprises the following steps: taking camel milk, and separating to obtain camel milk whey protein by adopting isoelectric precipitation and water system filter membrane filtration methods; sequentially flushing the anion exchange column with a pre-prepared alpha-lactalbumin separation buffer solution and a serum albumin separation buffer solution, and flushing the anion exchange column with a pre-prepared whey combination buffer solution until an ultraviolet absorption base line and a conductive base line are stable; loading a sample of camel milk whey protein into an anion exchange column, and flushing the anion exchange column with whey combined with a buffer solution to elute non-target protein in camel milk whey; washing the anion exchange column by adopting an alpha-lactalbumin separation buffer solution, and eluting and collecting an elution peak of the alpha-lactalbumin; and flushing the anion exchange column by using a serum albumin separation buffer solution, and eluting and collecting an elution peak of the serum albumin. The separation and purification method provided by the invention is simpler in process, lower in cost and more suitable for industrial production.

The utility model relates to the technical field of cow milk protein separation and purification, and provides a cow milk protein component synchronous separation system. Comprising a milk bin, a fat separator, a first cation exchange device, a first membrane filtration module, a casein solution treatment branch, a second membrane filtration module, a second cation exchange device, a first anion exchange device, a second anion exchange device, a purification and sterilization treatment branch and a product production line. Membrane filtration and a chromatographic technology are combined, and different active proteins are separated by using the molecular weight, the charged property, the hydrophobic interaction and the like of the proteins. Main active protein in milk can be separated, beta-casein, alpha-lactalbumin, immune globulin and lactoferrin can be sequentially separated and purified from raw milk, drying or sterile filling is carried out, different products are prepared while natural nutritional ingredients are reserved, and in addition, the product quality is improved. The separated milk can still be processed into sterilized milk or milk beverages.

The invention relates to an aptamer specifically combined with beta-lactoglobulin and application of the aptamer, and belongs to the technical field of biological detection. According to the aptamer and the preparation method thereof, a binding domain base, participating in recognition, of the aptamer is predicted through molecular docking firstly, then the binding domain base is subjected to directional mutation, the aptamer with the recognition performance improved is obtained, the affinity of the aptamer to beta-lactoglobulin is 10.6 nM, and the aptamer has no recognition capacity on alpha-lactalbumin, casein, bovine serum albumin, immune globulin G, lactose and the like and can be used for preparing the aptamer with the recognition performance improved. Therefore, the aptamer disclosed by the invention has good sensitivity and specificity on the beta-lactoglobulin. On the basis, a fluorescence polarization method is directly constructed by utilizing the characteristic that the beta-lactoglobulin is a biomacromolecule, when the beta-lactoglobulin exists, an aptamer marked by a fluorophore FAM recognizes the beta-lactoglobulin to form an aptamer beta-lactoglobulin compound, and the fluorescence polarization value is relatively large, so that the beta-lactoglobulin compound can be used for identifying the beta-lactoglobulin. Therefore, the specific detection of the low-concentration beta-lactoglobulin is realized.

The invention relates to a method for inducing pichia pastoris to express human alpha-lactalbumin by using ethanol, and belongs to the technical field of genetic engineering. Recombinant pichia pastoris using ethanol as an inducer for heterologous expression of human alpha-lactalbumin is constructed, three different expression vectors are used in the construction process, the first expression vector uses an ethanol inducible promoter to express fusion polypeptide of DNA binding protein and a transcription activator, and the second expression vector uses an ethanol inducible promoter to express fusion polypeptide of human alpha-lactalbumin. The second expression vector sequentially expresses a protein binding sequence, a methanol inducible promoter, an alpha signal peptide and human alpha-lactalbumin, the third expression vector overexpresses a signal recognition particle subunit participating in a protein targeting endoplasmic reticulum, and the yield of the constructed recombinant pichia pastoris shake flask fermentation human alpha-lactalbumin is 23.3 mg / L; the yield of the human alpha-lactalbumin reaches 1.1 g / L in a 3L fermentation tank, and methanol is not required to be added as an inducer in the fermentation process, so that the problems of toxicity and safety possibly caused by methanol are avoided, and efficient production of the human alpha-lactalbumin is realized.

The invention discloses a preparation method and application of an anti-continuous cropping microbial fertilizer, and aims to solve the problems of aggravation of crop diseases and insect pests and reduction of yield and quality caused by continuous cropping planting. The preparation method comprises the following steps: activating and uniformly mixing bacillus subtilis and bacillus licheniformis, and adding an alpha-lactalbumin solution and a calcium chloride solution to prepare a bacillus aggregate; adding bentonite into the polytrehalose solution, and performing ultrasonic treatment on the mixture and the humic acid solution to prepare a modified polytrehalose-bentonite compound; uniformly mixing acremonium terricola, trichoderma harzianum and a bacillus aggregate, and adding a wall material solution to prepare a compound bacterium microcapsule preparation; and finally, mixing the microcapsules with the corn straw biochar, the chitosan oligosaccharide and the like to obtain a finished product. Through calcium ion induction and humic acid modified embedding, the strain stability and viable count are improved, soil organic matter and nitrogen phosphorus and potassium nutrients can be activated, pathogenic bacteria are inhibited, the crop rhizosphere environment is improved, the growth index and quality of red kidney beans and potatoes are effectively improved, and the method is suitable for continuous cropping resistant planting of crops.

The invention relates to the technical field of gene engineering, in particular to a method for reducing acetic acid accumulation in the process of ethanol-induced expression of alpha-lactalbumin by regulating pichia pastoris. According to the recombinant yeast strain provided by the invention, the accumulation amount of acetic acid is greatly reduced in the process of inducing expression of target protein by adopting ethanol, acetic acid can be basically not accumulated, relatively high biomass and target protein yield can be achieved, and the highest yield of human alpha-lactalbumin up to now is achieved; and a strain resource and a foundation are provided for application of an ethanol-induced pichia pastoris expression system and development of bioengineering milk protein. The invention provides a method for solving the problem of acetic acid accumulation of pichia pastoris in the process of inducing expression of the target protein by using ethanol, and the method provides an effective strategy for popularization and application of an ethanol-induced expression system and improvement of the yield of the target protein induced and expressed by using the ethanol. The method has important significance on production of proteins such as alpha-lactalbumin and the like.

The invention relates to a detection method, in particular to a method for rapidly detecting alpha and beta-lactoglobulin in auxiliary material lactose based on a microarray chip technology. On the basis of an indirect competitive enzyme-linked immunosorbent assay principle and a silver enhanced developing technology, a high-sensitivity microarray chip detection platform is successfully constructed by virtue of a biological chip scanner, and rapid quantitative analysis of alpha-lactalbumin and beta-lactoglobulin in the auxiliary material lactose for injection is realized. According to the method, an antigen-antibody specific recognition mechanism and a nano-silver signal amplification mechanism are integrated, and the detection efficiency and sensitivity are remarkably improved through the high-throughput layout of the microarray chip. In the aspect of methodology performance, the technology has the remarkable advantages of simple and convenient operation process, short detection time, high sample treatment flux, excellent specificity (CRlt; 1%) and the like.

The present invention provides a method of predicting the outcome of a treatment of a cancer or a metabolism-related disease in a subject, the treatment comprising administering to the subject a complex comprising a polypeptide having a naturally occurring alpha-lactalbumin sequence, or a functional variant thereof; or a peptide comprising up to 50 amino acids of the alpha-helical domain of the polypeptide; and a fatty acid or lipid or a salt thereof; wherein the method comprises the steps of: a) evaluating the regulation of cancer genes in the subject after administration of the complex, and b) correlating the regulation of the genes to the outcome of the treatment wherein the positive outcome of the treatment is negatively correlated to the level of regulation of those genes.

The invention relates to the field of nutritional compositions, methods for providing them and uses thereof. More in particular, it relates to ready-to-feed and powdered infant or growing up milk formulas showing desirable gastric digestion properties. Provided is a nutritional composition comprising casein, whey proteins comprising α-lactalbumin (aLAc) and β-lactoglobulin (bLac), and protein-coated fat droplets, wherein (i) the protein content of the composition is 5 to 20% (w / w), preferably 7-16 w %, based on total solids; (ii) the aLac+bLac content is at least 25% (w / w) based on the total protein level; (iii) the fat content is in the range of 10% to 50% (w / w) based on total solids; and (iv) the fat droplets are coated with an average protein load of 2-10 mg / m2 and wherein the weight ratio of casein:(aLac+bLac) on the fat droplets is at least 4 times higher, preferably at least 4.5 times higher, than the weight ratio of casein:whey protein in the total composition.

The invention provides a yoghurt fermentation composition and application thereof in preparation of yoghurt with antioxidant activity, and belongs to the technical field of fermented food. The yoghourt fermentation composition comprises the following raw materials: maltodextrin, whey protein concentrate, a lactobacillus paracasei strain A21151, a lactobacillus rhamnosus strain A21149, a phytobacterium plantarum strain A21246, a bifidobacterium animalis subsp. Lactis strain B21247 and a phytobacterium plantarum strain SLB01. The yoghourt is prepared by utilizing the yoghourt fermentation composition, the shelf life of the fermentation composition is longer than that of commercially available yoghourt, and the prepared yoghourt has an antioxidant effect, is high in viable count of probiotics, is simple and convenient to process and low in cost, and has a wide market prospect.

The present invention provides a method for preparing a bioactive complex, the method comprising dissolving a mixture of a polypeptide component in the form of a powdered complex, such as alpha-lactalbumin or a fragment thereof, and oleic acid or a pharmaceutically acceptable salt thereof, which is also in solid form, in an aqueous solution containing a mixture of at least two salts, preferably three salts; wherein the method is carried out at a moderate temperature. Since the preparation process does not require a large amount of heating, the operation is simple and effective.

The present invention discloses a method for preparing milk-derived angiotensin-converting enzyme inhibitory peptides by fermentation with composite strains, which belongs to the fields of microbial technology and fermentation. The ratio of whey protein hydrolysate with a molecular weight below 1000 Da and the angiotensin-converting enzyme inhibition rate in the milk-based fermentation broth are used as evaluation indicators. The composite strain Lactobacillus helveticus ( Lactobacillus helveticus , CICC: 20289), composite strain Pediococcus dilactici ( Pediococcus acidilactici , CICC:20719) were rescreened to obtain strains with excellent whey protein hydrolysis performance and high angiotensin-converting enzyme inhibitory peptide production capacity. The two composite strains obtained from the rescreening were enriched and cultured separately, and then inoculated into skim milk powder culture medium at a specific compound ratio. Through composite fermentation, the angiotensin-converting enzyme inhibitory peptide content in the milk-based fermentation product was increased. The process of this invention is rationally designed and highly operable. It provides a reference for further increasing the content of small molecule functional peptides in fermented dairy products, efficiently preparing milk-derived angiotensin-converting enzyme inhibitory peptides, and improving the nutritional value of dairy products, and has great application prospects.

A method for producing a gold colloid-labeled antibody suspension, comprising: a labeling step of obtaining a mixture by mixing a gold colloid solution and an antibody solution to obtain a gold colloid-labeled antibody in the mixture; a centrifugation step of centrifugating the mixture to obtain a precipitate of the gold colloid-labeled antibody and removing the supernatant containing antibody that does not have gold colloid adsorbed; and a suspension step of suspending the precipitate of the gold colloid-labeled antibody in a suspension solution containing lactalbumin to obtain a gold colloid-labeled antibody suspension.

The invention relates to the technical field of sports nutrition food, in particular to a product capable of providing muscle nutrition support and a preparation method thereof. The method sequentially comprises the following steps: (1) premixing concentrated / separated / hydrolyzed whey protein, bovine colostrum powder, alpha-lactalbumin, calcium silicate and compound sweet system dry powder at the temperature of less than or equal to 25 DEG C; (2) intermittently spraying the aqueous phase bonding liquid into a multi-section fluidized bed under the conditions that the temperature is 35-40 DEG C and the pressure is 0.3-0.5 MPa, and synchronously introducing supercritical CO2 under the pressure of 6-8 MPa and the temperature is 35-40 DEG C to realize pulse atomization and instantaneous foaming, so as to obtain wet particles with the true porosity of more than or equal to 60% and the water content of less than or equal to 8%; (3) step pressure reduction and 40-45 DEG C hot air drying until the water content is less than or equal to 4%; and (4) carrying out two-stage vibration classification, and recycling 180-300 microns of main materials. The method has the characteristics of low-temperature keep-alive, open pore structure and excellent flow instant solubility, and is suitable for large-scale production.

The invention discloses a flora double-layer capsule with long-term storage stability and a preparation method thereof, and belongs to the technical field of flora double-layer capsules, and the preparation method comprises the following steps: mixing probiotic freeze-dried powder and composite lysozyme, and reacting with alpha-lactalbumin to obtain probiotic-loaded nanoparticles; mixing the nano-particles loaded with the probiotics with sodium alginate to prepare an alginic acid capsule, and carrying out surface modification on the alginic acid capsule by using oxidized starch to obtain a flora single-layer capsule; and mixing the flora single-layer capsule and the hovenia acerba methanol extract to serve as a core material, and taking a chitosan acetic acid solution as a wall material to prepare the flora double-layer capsule. The lysozyme nano-particles can be adhered to the intestinal tract through interaction with mucus, and the lysozyme nano-particles can penetrate through a mucus barrier to be absorbed by epithelial villus, so that the absorption of intestinal flora is improved; the alpha-lactalbumin is coated on the surfaces of the nano-particles, and the alpha-lactalbumin is compounded with the lysozyme nano-particles, so that intestinal mucus can be more effectively penetrated.

The invention belongs to the technical field of protein purification, and particularly relates to a chromatography medium, a preparation method of the chromatography medium and application of the chromatography medium to extraction of alpha-lactalbumin. The chromatography medium provided by the invention takes agarose as a matrix, and the surface of the chromatography medium is modified by a ligand through a glucan spacer arm; wherein the molecular weight of the glucan is 20 kDa to 500 kDa, the ligand comprises propylene diamine, and the density of the ligand in the chromatography medium is 200 [mu] mol / mL to 300 [mu] mol / mL. The invention also provides a preparation method of the material, and the material can be obtained by sequentially carrying out epoxy activation, glucan modification, secondary activation and ligand bonding on the matrix. When the chromatography medium provided by the invention is used for extracting alpha-lactalbumin from whey, the chromatography medium has the advantages of high loading capacity, high loading flow rate and efficient regeneration, and meets the requirements of industrial production.

The invention provides a composition for chronic wound treatment and a preparation method thereof, and relates to the field of medicines. The mask is prepared from the following raw materials in percentage by mass: 20 to 30 percent of methacrylic acid hyaluronic acid, 20 to 30 percent of metacrylic acid ester modified silk fibroin, 40 to 50 percent of carboxymethyl chitosan, 1 to 2 percent of photoinitiator and 5 to 10 percent of hydrogen sulfide sustained-release microspheres, the hydrogen sulfide sustained-release microsphere is a core-shell microsphere which takes GYY4137-PLGA (poly (lactic-co-glycolic acid)) nanoparticles as a core layer and EGCG (epigallocatechin gallate)-whey protein as a shell layer. The composition provided by the invention can slowly release H2S gas, promote angiogenesis of chronic wounds and promote wound healing.

The invention provides a Lactobacillus casei DS31 microcapsule for improving irritable bowel syndrome and a preparation method thereof, the Lactobacillus casei DS31 microcapsule loaded with DS31 is prepared by using the Lactobacillus casei DS31 as a water phase, DHA algal oil as an oil phase, thermally denatured whey protein as solid particles and chitosan oligosaccharide as a stabilizer by adopting a Pickering emulsion technology, and the microcapsule loaded with DS31 is prepared by using the Lactobacillus casei DS31 as a water phase, DHA algal oil as an oil phase and chitosan oligosaccharide as a stabilizer. The obtained microcapsule can resist the severe environment of gastrointestinal tracts and help strains to be planted in the intestinal tracts better, and the strain effect of the strains is achieved. The emulsion in the microcapsule has the advantages of small droplet size, high surface area, good physical stability, simplicity in operation, safety, no toxicity, high probiotic content and the like.

The invention discloses an improved test method for detecting a dairy cow ketone body and application, and relates to the technical field of dairy product detection, and the method comprises the following steps: a lactalbumin detection step: pretreating a dairy cow sample, mixing the pretreated dairy cow sample with sodium nitroprusside-sodium carbonate composite powder, ammonium sulfate and anhydrous sodium carbonate according to a preset ratio, and determining the lactalbumin content through reaction color development; a urinary ketone detection step: pretreating a dairy cow urine sample, mixing the pretreated dairy cow urine sample with sodium nitroprusside-sodium carbonate composite powder, ammonium sulfate and anhydrous sodium carbonate in proportion, and judging the content of urinary ketone by prolonging the reaction time and adjusting the dosage of ammonium sulfate; the kit covers rapid screening of dairy farms, clinical stage diagnosis of veterinarians and raw material quality control of dairy enterprises, and is compatible with sample and urine sample detection. Through an accurate reagent system and parameter optimization, high-sensitivity, low-cost and fast detection is realized, and a technical support is provided for ketosis prevention and control.

The present invention relates to the field of nutritional compositions, methods of providing nutritional compositions and uses thereof. More particularly, the present invention relates to a ready-to-eat powdered infant formula or ready-to-eat powdered growth formula exhibiting desirable gastric digestion characteristics. There is provided a nutritional composition comprising casein, whey protein comprising alpha-lactalbumin (aLac) and beta-lactoglobulin (bLac), and protein-coated fat droplets wherein the composition has a protein content of from 5% to 20% (w / w) based on total solids; the bLac content is at least 3% (w / w) based on the total protein level, and the aLac + bLac content is at least 25% (w / w) based on the total protein level; the fat content is in the range of 10% to 50% (w / w) based on total solids; the fat droplets are coated with an average protein load of 2 to 10 mg / m2, and wherein the weight ratio of casein: (aLacc + bLac) on the fat droplets is at least 4 times the weight ratio of casein: (aLacc + bLac) in the total composition; the level of sphingomyelin per 100 g of the composition is between 70 mg and 200 mg; the level of phospholipids per 100 g of the composition is between 280 mg and 950 mg.