Fermentation type lactic acid bacteria goat milk powder with antioxidant function and preparation method of fermentation type lactic acid bacteria goat milk powder

Abstract

The invention belongs to the technical field of dairy product processing, and discloses fermentation type lactic acid bacteria goat milk powder with an anti-oxidation function and a preparation method of the fermentation type lactic acid bacteria goat milk powder. The fermented goat milk powder comprises whole goat milk powder, isomaltooligosacharide, inulin, phyllanthus emblica powder, chicken concentrated powder, a green tea extract, oat beta-glucan, calcium carbonate, streptococcus salivarius subsp. Thermophilus, lactobacillus delbrueckii subsp. Bulgaricus and a compound nutrition enhancer. The fermented goat milk powder has double effects of oxidation resistance and immunity enhancement, and the viable count of lactobacillus can reach 9.3 logCFU / mL; in the preparation method, a'emblic leafflower fruit powder-chicken concentrated powder 'synergistic system is adopted, the prepared fermented lactic acid bacteria goat milk powder has relatively good antioxidant activity, the DPPH free radical scavenging activity is up to 85%, and the fermented lactic acid bacteria goat milk powder is particularly suitable for the old, women and children.

Description

Technical Field

[0001] The present invention relates to the technical field of dairy product processing, in particular to a fermented lactic acid bacteria goat milk powder with antioxidant function and a preparation method thereof. Background Art

[0002] Streptococcus salivarius subsp. thermophilus ( Streptococcus salivarius subsp. thermophilus The name "Thermophilic" itself reveals its dual identity: "Thermophilic" refers to its industrial resistance to high temperatures, while "Streptococcus salivarius" hints at its close connection to the human microbiome. As the only Streptococcus species designated "Generally Recognized as Safe" (GRAS) by the US FDA, its history dates back to the late 19th century, during the revolution in dairy fermentation technology. At that time, scientists discovered that this bacterium could efficiently break down lactose at temperatures of 45-50°C, producing flavor compounds such as lactic acid and acetaldehyde, making it the "soul starter" for fermented dairy products such as yogurt and cheese. The exopolysaccharides it produces further impart a smooth texture to these products, such as the signature thick consistency of traditional Bulgarian yogurt. In the 21st century, the health benefits of the thermophilic Streptococcus salivarius subspecies have been redefined. Research has confirmed that it can inhibit pathogens such as Listeria and Staphylococcus aureus by secreting bacteriocins and hydrogen peroxide, acting as a "microbiome regulator" in the intestines. Even more remarkable is its oral health benefits: it inhibits the growth of Streptococcus mutans through competitive adhesion and metabolizes it to produce superoxide dismutase (SOD), which scavenges free radicals, thereby delaying the aging of the oral mucosa. Clinical data show that long-term consumption of cheese containing this bacteria can reduce the incidence of oral Candida albicans infection in the elderly by 30%. This mechanism is due to the probiotics competing with pathogens for epithelial cell adhesion sites while stimulating immune cells to eliminate pathogens.

[0003] Lactobacillus delbrueckii subsp. bulgaricus ( Lactobacillus delbrueckii subsp. bulgaricus The discovery of Lactobacillus bulgaricus is a paradigmatic example of the intersection of microbiology and anthropology. In 1905, Bulgarian physician Stan Ilichov isolated this bacterium from kefir, a traditional fermented milk, while studying the diets of local centenarians. He linked it to longevity, earning it the name "Lactobacillus bulgaricus" and becoming a cornerstone of the global yogurt industry. Its genome sequencing revealed that it carries CRISPR sequences associated with phage resistance, a trait that gives it an advantage in resisting contamination in industrial fermentation. As a strictly heterofermentative lactic acid bacterium, Lactobacillus bulgaricus has a unique metabolic pathway: it converts lactose to a precisely controlled ratio of lactic acid to acetic acid of 3:1. This acidity ratio inhibits spoilage bacteria while activating the symbiotic Streptococcus thermophilus, creating a fermentation effect known as "acid-scented symbiosis." The acetaldehyde produced by Lactobacillus bulgaricus is the core source of yogurt's characteristic flavor, while a small amount of exopolysaccharides imparts the product's distinctive "stringy" texture. What is more noteworthy is its health function: it reduces intestinal pH by producing acid, inhibits pathogens such as salmonella, and synthesizes vitamin B. 12With folic acid, make up the modern dietary nutrient gap; animal experiments show that its cell wall components can activate macrophages and enhance the body's immune response.

[0004] In the field of existing antioxidant fermented dairy products, the prior art realizes the integration of intestinal health and basic antioxidant function by adding high active bacteria number probiotics and prebiotics combination, but its technical scheme still has significant limitations: the component design mostly adopts simple compounding mode, and the synergistic mechanism of natural antioxidant components (such as plant polyphenols) and animal-derived nutrients (such as amino acids, nucleotides) has not been established. In addition, the traditional fermentation process does not protect heat-sensitive components, resulting in high loss rate of antioxidant activity during processing and poor product stability.

[0005] Therefore, the present application provides a fermented lactic acid bacteria goat milk powder with antioxidant function, which can improve the antioxidant function of goat milk powder. SUMMARY

[0006] The present application aims to provide a fermented lactic acid bacteria goat milk powder with antioxidant function and a preparation method thereof to solve the problems raised in the background art.

[0007] A fermented lactic acid bacteria goat milk powder with antioxidant function is prepared from the following raw materials: 750 parts by weight of full-fat goat milk powder, 225-250 parts by weight of isomaltooligosaccharides, 5-15 parts by weight of inulin, 0.3-0.9 parts by weight of phyllanthus emblica powder, 0.5-1.5 parts by weight of chicken concentrate powder, 0.2-0.8 parts by weight of green tea extract, 5-15 parts by weight of oat beta-glucan, 8-16 parts by weight of calcium carbonate, 0.25-0.75 parts of Streptococcus salivarius subsp. thermophilus, 0.25-0.75 parts of Lactobacillus delbrueckii subsp. bulgaricus, and 3.85-4.85 parts by weight of a compounded nutrient fortifier.

[0008] A preparation method of a fermented lactic acid bacteria goat milk powder with antioxidant function, comprising the following steps: Step one, standardization of ingredients: dissolve 600 parts by weight of full-fat goat milk powder in 4400 parts by weight of 45℃ ultrapure water, add 225-250 parts by weight of isomaltooligosaccharides, 5-15 parts by weight of inulin, 0.3-0.9 parts by weight of phyllanthus emblica powder, 0.2-0.8 parts by weight of green tea extract, 0.5-1.5 parts by weight of chicken concentrate powder, 5-15 parts by weight of oat beta-glucan, 8-16 parts by weight of calcium carbonate, and 3.85-4.85 parts by weight of a compounded nutrient fortifier, and shear for 5 min at 10,000 rpm to obtain a full-fat goat milk powder reconstituted solution 1. In addition, dissolve 150 parts of full-fat goat milk powder in 1100 parts by weight of 45℃ ultrapure water, and shear for 5 min at 10,000 rpm to obtain a full-fat goat milk powder reconstituted solution 2.

[0009] Step two, filtration, homogenization: the obtained whole sheep milk powder reconstituted solution 1 is filtered through a double filter, and then transferred into a homogenizer for homogenization to obtain a milk emulsion.

[0010] Step three, cooling and temporary storage: the homogenized milk emulsion is placed in a middle storage tank in a stirring state to obtain a mixed and uniform ingredient milk.

[0011] Step four, sterilization and concentration: the mixed and uniform ingredient milk is buffered through an equalizing cylinder, sequentially subjected to upper flash evaporation degassing, DSI sterilization (conditions: 100-102°C / 60s, flow rate: 22-25m³ / h), lower flash evaporation degassing, and then enters a four-effect falling film evaporator for concentration (vacuum degree: -910~-850mbar, steam pressure: 0.8-1.0MPa, temperatures of the first, second, third and fourth effects are 65-75°C, 58-68°C, 55-65°C and 50-60°C, respectively), to obtain concentrated milk with a density of 1100-1250kg / m³, a temperature of 40-50°C and a concentration of 40-50%, which is then transported to a concentrated milk cylinder for temporary storage, and whole sheep milk powder reconstituted solution 2 is subjected to pasteurization treatment to obtain milk liquid with a density of 1100-1250kg / m³, a temperature of 40-50°C and a concentration of 40-50%, which is then placed in another concentrated milk cylinder for temporary storage.

[0012] Step five, inoculation: 0.25-0.75 parts of Streptococcus salivarius subsp. thermophilus and 0.25-0.75 parts of Lactobacillus delbrueckii subsp. bulgaricus are inoculated into the milk liquid, which is then placed in an anaerobic environment at 42±3°C for fermentation for 2-5h, and the acidity is maintained at 50-65ºT. The above concentrated milk is mixed and obtained to obtain fermented lactic acid bacteria sheep milk.

[0013] Step six, spray drying: the fermented lactic acid bacteria sheep milk is transported to a drying tower for spray drying in the form of pressurization by a high-pressure pump, the pressure of the high-pressure pump is controlled at 100-150bar, the inlet air temperature of the drying tower is controlled at 160°C-210°C, the exhaust air temperature is controlled at 80-95°C, and the negative pressure in the tower is controlled at -100~0Pa.

[0014] Step seven, fluidized bed cooling: the milk powder dried and sprayed in the drying tower is subjected to secondary drying in a fluidized bed and cooled to 20-30°C, wherein the temperature of the first stage of the fluidized bed is controlled at 40-50°C, the temperature of the second stage of the fluidized bed is controlled at 20-30°C, the temperature between the fluidized beds is 16-25°C, the humidity is 30%-50%, and the pressure difference with the quasi-clean operation area is 15-25Pa.

[0015] Step eight, metal detection: the milk powder cooled in the fluidized bed is subjected to metal foreign object detection, and the direct metal detection diameter Φ is 2-10mm (iron, non-iron, stainless steel).

[0016] Step nine, metering packaging: the milk powder after metal detection is filled, metered and packaged into 25 kg / bag of large packaging milk powder, and then the production date and product name are printed on the outer bag. The heat sealing time is 3-4s, the holding time is 3-4s, and the heat sealing pressure is 0.5-0.6MPa. The fermented lactic acid bacteria goat milk powder with antioxidant function is obtained.

[0017] As a preferred technical solution of the present application, the temperature of the liquid in the storage tank in step three is controlled at 8-12℃, and the storage time is controlled at 2-5h.

[0018] As a preferred technical solution of the present application, the DSI sterilization condition in step four is 100-102℃ / 60s, the flow is 22-25m³ / h, the vacuum degree of the four-effect falling film evaporator concentration is controlled at -850~-910mbar, the steam pressure is controlled at 0.8-1.0MPa, and the temperatures of the first, second, third and fourth effects are 65-75℃, 58-68℃, 55-65℃ and 50-60℃ respectively.

[0019] As a preferred technical solution of the present application, the pressure of the high-pressure pump in step six is controlled at 100-150bar, the inlet air temperature of the drying tower is controlled at 160℃-210℃, the exhaust air temperature is controlled at 80-95℃, and the negative pressure in the tower is controlled at -100~0Pa.

[0020] As a preferred technical solution of the present application, the temperature of the fluidized bed 1 in step seven is controlled at 40-50℃, the temperature of the fluidized bed 2 is controlled at 20-30℃, the temperature between the fluidized beds is 16-25℃, the humidity is 30%-50%, and the pressure difference with the quasi-clean operation area is 15-25Pa.

[0021] As a preferred technical solution of the present application, the heat sealing time in step nine is 3-4s, the holding time is 3-4s, and the heat sealing pressure is 0.5-0.6MPa.

[0022] Compared with the prior art, the present application has the following beneficial effects: 1、The present application utilizes the mechanism that green tea extract and phyllanthus emblica powder are adsorbed on the surface of Streptococcus thermophilus and Lactobacillus bulgaricus by hydrogen bond and hydrophobic interaction, forming a "component-bacterial body" protective layer, effectively resisting the invasion of oxygen and miscellaneous bacteria in the early fermentation stage, and improving the retention rate of superoxide dismutase (SOD) activity compared with the prior art (without protective layer); glutathione (GSH) secreted by Streptococcus thermophilus and Lactobacillus bulgaricus in the logarithmic growth phase reacts with antioxidant components through thiol-disulfide exchange reaction to generate high-stability GSH-EGCG adduct, which has improved stability compared with free EGCG, and can be targeted to deliver to intestinal epithelial cells, significantly relieving oxidative stress-induced intestinal barrier damage. In the traditional process, the timing of antioxidant components and fermentation process is out of sync, resulting in degradation and loss of activity of the components, while the present application realizes the dual protection of function maximization and stability through precise timing control.

[0023] 2、The present application utilizes the mechanism that Lactobacillus muci laplabilis GM90 modifies and activates the structure and activity of green tea extract (EGCG) and phyllanthus emblica powder (ellagic acid) through metabolic products (such as tannase, organic acid, glutathione). In the fermentation process, tannase secreted by Streptococcus thermophilus and Lactobacillus bulgaricus can specifically hydrolyze the ester bond of EGCG to generate free EGC, which has stronger cell membrane permeability than EGCG; at the same time, lactic acid produced by fermentation reduces the pH of the system to 4.5 to promote the formation of a reversible complex of EGCG and beta-casein in goat milk, thereby improving the retention rate of EGCG in the drying stage. For phyllanthus emblica powder, short-chain fatty acids produced by Streptococcus thermophilus and Lactobacillus bulgaricus metabolism can induce the hydrolysis of ellagic acid-3-O-glucoside to highly active ellagic acid, which has stronger free radical scavenging ability than the unfermented group. In the prior art, antioxidant components and bacterial bodies are simply mixed, lacking dynamic interaction design, which limits the improvement of activity, while the present application significantly breaks through this bottleneck.

[0024] 3、The application constructs a multi-level regulation network from antioxidant to system health. In the antioxidant level, the total antioxidant capacity of the fermented lactic acid bacteria goat milk powder with antioxidant function is significantly improved; in the immune regulation level, the exopolysaccharide produced by fermentation of Streptococcus thermophilus and Lactobacillus bulgaricus and the gallic acid in Phyllanthus emblica synergistically activate the TLR4 / NF-κB pathway, promote the secretion of NO and IL-10 by macrophages, and increase the immune regulation index; in the intestinal health level, the antioxidant components reduce the release of intestinal inflammatory factors (TNF-α, IL-6) by inhibiting the NF-κB pathway, and the colonization rate of Streptococcus thermophilus and Lactobacillus bulgaricus is also significantly improved, thereby significantly improving the intestinal flora alpha diversity. The existing antioxidant food has a single function and lacks system regulation of immunity and intestinal microecology, while the application provides a new method for functional food development through multi-target intervention. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0026] In this document, reference to“an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. Those skilled in the art will appreciate that embodiments described herein can be combined with other embodiments.

[0027] In order for those skilled in the art to better understand the application, the technical solutions in the embodiments of the application will be clearly and completely described below.

[0028] Phyllanthus emblica powder is a fine powder made from Phyllanthus emblica fruits through extraction, concentration, spray drying and other processes, rich in active ingredients such as vitamin C, flavonoids, polyphenols and SOD (superoxide dismutase). Its core functions include antioxidant, which can scavenge free radicals, reduce lipid peroxide content and protect vascular endothelial function; anti-aging, which can delay cell oxidative damage by increasing SOD activity and reducing LPO content; in addition, it also has the functions of auxiliary blood glucose lowering, blood lipid regulation, liver and stomach protection and antibacterial and anti-inflammatory, and is suitable for improving metabolic syndrome and enhancing immunity.

[0029] Oligoisomaltose is a branched oligosaccharide composed of glucose units linked by α-1, 6 glycosidic bonds. It is a functional prebiotic with white powder form, lower sweetness than sucrose, heat resistance, acid resistance and moisture retention. Its main functions include: promoting the proliferation of beneficial bacteria such as bifidobacterium, maintaining the balance of intestinal flora; increasing stool volume and moisture, stimulating intestinal peristalsis, preventing and relieving constipation; reducing cholesterol absorption and promoting excretion, assisting in regulating blood lipids; indirectly enhancing immunity by enhancing intestinal barrier function. In addition, it is not easily broken down by human digestive enzymes, has low heat, and is suitable for diabetic patients to eat in moderation.

[0030] In the field of probiotic application, Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus exhibit significant immune regulation and intestinal protection functions due to their synergistic mechanism. The combination of the two can precisely regulate the balance of Th cells by stimulating the intestinal mucosal immune system: the extracellular polysaccharides produced by Streptococcus salivarius subsp. thermophilus and the short-chain fatty acids (such as butyric acid) secreted by Lactobacillus delbrueckii subsp. bulgaricus synergistically enhance the secretion of Th1-type cytokines such as interferon-γ (INF-γ), while inhibiting the overexpression of allergy-related Th2 cytokines (such as IL-4, IL-5). Clinical studies have shown that in the atopic dermatitis children model, this strain combination can reduce serum IgE antibody levels by 35%, reduce skin inflammation area, and the effect can still be sustained after stopping use, which is closely related to the proliferation of Treg cells in the intestinal Peyer's patches and the enhancement of histone acetylation modification.

[0031] In terms of intestinal health maintenance, the two form a triple protection system of "metabolic complementation-barrier strengthening-pathogen antagonism". Streptococcus salivarius subsp. thermophilus produces lactic acid and acetaldehyde by decomposing lactose, rapidly reduces the pH value of the intestine, directly inhibits the adhesion and proliferation of pathogenic bacteria such as Salmonella and Escherichia coli; Lactobacillus delbrueckii subsp. bulgaricus synthesizes glutamine enzyme and β-galactosidase, promotes the proliferation of intestinal epithelial cells and the secretion of mucin, increases the thickness of intestinal mucosa and the expression of tight junction proteins. In addition, the bacteriocins produced by the two during co-fermentation can synergistically destroy the cell membranes of pathogenic bacteria such as Staphylococcus aureus and Listeria, and clinical experiments have shown that after continuous intake of the strain combination for 4 weeks, the abundance of harmful bacteria in the intestinal tract of the subjects decreases, while the proportion of beneficial bacteria such as Bifidobacterium increases, significantly improving the intestinal flora diversity index, providing a microbiological basis for improving digestive function and preventing metabolic syndrome.

[0032] Oat beta-glucan is a natural non-starch water-soluble plant polysaccharide existing in the cell walls of oat endosperm and aleurone layer, which is formed by beta-D-glucopyranose connected by beta-(1→3) and beta-(1→4) glycosidic bonds. Its functions include: reducing cholesterol and low-density lipoprotein levels, preventing cardiovascular diseases; delaying gastric emptying, increasing satiety, controlling postprandial blood glucose rise, and assisting in regulating blood glucose; promoting the proliferation of beneficial bacteria such as bifidobacteria and lactic acid bacteria as a prebiotic, improving intestinal function; it can also scavenge free radicals, reduce oxidative stress damage, and has antioxidant and potential anticancer effects.

[0033] The present application establishes a "emblica powder-chicken concentrate powder" synergistic system, using polypeptides in chicken concentrate powder as carriers, forming a complex through the exopolysaccharide secreted by Streptococcus salivarius subsp. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, so that the intestinal absorption rate of emblica polyphenols is increased, at the same time the strains use glutamine and cysteine in chicken concentrate powder to synthesize GSH, realizing the triple antioxidant network of "endogenous enzyme system + exogenous polyphenol + endogenous GSH"; and adopting low-temperature microencapsulation process, using double-layer embedding structure (core layer: probiotics and emblica powder; outer layer: chicken concentrate powder), so that the viable count of the product still maintains ≥9¹ 0 CFU / g after 6 months of storage at 4℃, and the DPPH clearance rate attenuation rate is significantly lower than that of the unembedded product. This technical solution realizes the synergistic improvement of antioxidant activity, stability and health benefits through strain metabolic regulation, component function complementation and process precise protection, and is especially suitable for precise nutritional intervention of oxidative stress sensitive populations such as the elderly, women and children.

[0034] Lactic acid bacteria fermentation reduces the pH of goat milk to 4.2-4.5, which can inhibit the autoxidation of polyunsaturated fatty acids (such as linoleic acid in goat milk), and slow down the oxidation and inactivation of GSH. After the colonization of lactic acid bacteria in the intestine, they can continuously secrete antioxidant enzymes (such as superoxide dismutase SOD), and at the same time metabolize dietary fiber to generate short-chain fatty acids, further reducing intestinal oxidative stress. Through lactic acid bacteria fermentation, the present application not only produces antioxidant active substances itself, but also significantly amplifies the efficacy of antioxidant components through metabolic regulation, component protection and microecological regulation mechanisms. This synergistic effect makes the fermented goat milk powder perform well in scavenging free radicals, inhibiting lipid peroxidation and improving the intestinal oxidative environment.

[0035] Example One

[0036] A preparation method of a fermented lactic acid bacteria goat milk powder with antioxidant function, comprising the following steps: Step one, standardization of ingredients: 600 parts by weight of whole goat milk powder is dissolved in 4400 parts by weight of 45℃ ultrapure water, 235 parts by weight of isomaltooligosaccharide, 10 parts by weight of inulin, 0.6 parts by weight of phyllanthus emblica powder, 0.5 parts by weight of green tea extract, 1.0 parts by weight of chicken concentrate powder, 10 parts by weight of oat beta-glucan, 12 parts by weight of calcium carbonate, 4.25 parts by weight of compound nutritional fortifier are added, and sheared at 10,000 rpm for 5 min to obtain whole goat milk powder reconstituted solution 1. In addition, 150 parts of whole goat milk powder is dissolved in 1100 parts by weight of 45℃ ultrapure water, and sheared at 10,000 rpm for 5 min to obtain whole goat milk powder reconstituted solution 2.

[0037] Step two, filtration and homogenization: the obtained whole goat milk powder reconstituted solution 1 is filtered through a double filter, and then transferred into a homogenizer for homogenization to obtain an emulsion.

[0038] Step three, cooling and temporary storage: the homogenized emulsion is placed in a middle storage tank in a stirring state to obtain a mixed and uniform ingredient milk.

[0039] Step four, sterilization and concentration: the mixed and uniform ingredient milk is buffered through an equalizing cylinder, and then sequentially subjected to upper flash evaporation degassing, DSI sterilization (conditions: 101℃ / 60s, flow rate 23m³ / h), lower flash evaporation degassing, and then enters a four-effect falling film evaporator for concentration (vacuum degree -880mbar, steam pressure 0.9MPa, temperatures of the first, second, third and fourth effects being 70℃, 63℃, 60℃ and 55℃, respectively) to obtain concentrated milk with a density of 1170kg / m³, a temperature of 45℃ and a concentration of 45%, which is transported to a concentrated milk cylinder for temporary storage. The whole goat milk powder reconstituted solution 2 is subjected to pasteurization treatment to obtain milk liquid with a density of 1170kg / m³, a temperature of 45℃ and a concentration of 45%, which is then temporarily stored in another concentrated milk cylinder.

[0040] Step five, 0.5 parts of Streptococcus salivarius subsp. thermophilus and 0.5 parts of Lactobacillus delbrueckii subsp. bulgaricus are inoculated into the milk liquid, which is subjected to anaerobic fermentation at 42℃ for 3.5h to maintain an acidity of 45ºT. The above concentrated milk is mixed and obtained to obtain fermented goat milk containing lactic acid bacteria.

[0041] Step six, spray drying: the fermented goat milk containing lactic acid bacteria is transported to a drying tower for spray drying in the form of pressurization by a high-pressure pump, the pressure of the high-pressure pump is controlled at 125bar, the inlet air temperature of the drying tower is controlled at 185℃, the exhaust air temperature is controlled at 87℃, and the negative pressure in the tower is controlled at -50Pa.

[0042] Step seven, fluidized bed cooling: the spray-dried milk powder in the drying tower is subjected to secondary drying in a fluidized bed, and is cooled to 25℃, wherein the temperature of the fluidized bed 1 is controlled at 45℃, the temperature of the fluidized bed 2 is controlled at 25℃, the temperature between the fluidized beds is 20℃, the humidity is 40%, and the pressure difference with the quasi-clean operation area is 20 Pa.

[0043] Step eight, metal detection: the milk powder after fluidized bed cooling is subjected to metal foreign matter detection, and the metal detection diameter Φ is 6 mm (iron, non-ferrous, stainless steel).

[0044] Step nine, metering and packaging: the milk powder after metal detection is subjected to automatic filling, metering and packaging into 25 kg / bag bulk packaging milk powder, and then the production date and product name are printed on the outer bag. The heat sealing time is 3 s, the heat preservation setting time is 3 s, and the heat sealing pressure is 0.5 MPa. A fermented lactic acid bacteria goat milk powder with antioxidant function is obtained.

[0045] Example two

[0046] A preparation method of a fermented lactic acid bacteria goat milk powder with antioxidant function, comprising the following steps: Step one, standardization and batching: 600 parts by weight of full-fat goat milk powder is dissolved in 4400 parts by weight of 45℃ ultrapure water, 225 parts by weight of isomaltooligosaccharide, 5 parts by weight of inulin, 0.3 parts by weight of phyllanthus emblica powder, 0.2 parts by weight of green tea extract, 0.5 parts by weight of chicken concentrate powder, 5 parts by weight of oat beta-glucan, 8 parts by weight of calcium carbonate, and 3.85 parts by weight of a complex nutritional fortifier are added, and shearing is carried out at 10,000 rpm for 5 min to obtain a full-fat goat milk powder reconstituted solution 1. In addition, 150 parts of full-fat goat milk powder is dissolved in 1100 parts by weight of 45℃ ultrapure water, and shearing is carried out at 10,000 rpm for 5 min to obtain a full-fat goat milk powder reconstituted solution 2.

[0047] Step two, filtration and homogenization: the obtained full-fat goat milk powder reconstituted solution 1 is filtered through a double filter, and then is transferred into a homogenizer for homogenization to obtain an emulsion.

[0048] Step three, cooling and temporary storage: the homogenized emulsion is placed in a middle storage tank in a stirring state to obtain a mixed and uniform batching milk.

[0049] Step four, sterilization concentration: the mixed uniform ingredients milk is buffered by the balance cylinder, and then sequentially passes through the upper flash evaporation degassing, DSI sterilization (conditions: 100℃ / 60s, flow rate 22m³ / h), lower flash evaporation degassing, and then enters the four-effect falling film evaporator for concentration (vacuum degree -910mbar, steam pressure 0.8MPa, the first, second, third and fourth effect temperatures are 65℃, 58℃, 55℃ and 50℃ respectively), to obtain concentrated milk with a density of 1100kg / m³, a temperature of 40℃ and a concentration of 40%, the concentrated milk is transported to a concentrated milk cylinder for temporary storage, and the full-fat goat milk powder re-dissolved solution 2 is subjected to pasteurization treatment to obtain milk liquid with a density of 1100kg / m³, a temperature of 40℃ and a concentration of 40%, and then the milk liquid is temporarily stored in another concentrated milk cylinder.

[0050] Step five, 0.25 parts of Streptococcus thermophilus and 0.25 parts of Lactobacillus delbrueckii bulgaricus are inoculated into the milk liquid, and the mixture is placed in an anaerobic environment at 39℃ for fermentation for 2h, and the acidity is maintained at 50ºT, the above concentrated milk is added and mixed to obtain fermented lactic acid bacteria goat milk.

[0051] Step six, spray drying: the fermented lactic acid bacteria goat milk is transported to the drying tower for spray drying in the form of pressurization by a high-pressure pump, the pressure of the high-pressure pump is controlled at 100bar, the inlet air temperature of the drying tower is controlled at 160℃, the exhaust air temperature is controlled at 80℃, and the negative pressure in the tower is controlled at -100Pa.

[0052] Step seven, fluidized bed cooling: the milk powder dried and sprayed in the drying tower is subjected to secondary drying in the fluidized bed and cooled to 20℃, wherein the temperature of the first stage of the fluidized bed is controlled at 40℃, the temperature of the second stage of the fluidized bed is controlled at 20℃, the temperature between the fluidized beds is 16℃, the humidity is 30%, and the pressure difference with the quasi-clean operation area is 15Pa.

[0053] Step eight, metal detection: the milk powder cooled in the fluidized bed is subjected to metal foreign object detection, and the diameter Φ of the metal detection is 2mm (iron, non-iron, stainless steel).

[0054] Step nine, metering and packaging: the milk powder after metal detection is automatically filled and metered and packaged into 25kg / bag bulk packaging milk powder, and then the production date and product name are printed on the outer bag. The heat sealing time is 3s, the heat preservation setting time is 3s, and the heat sealing pressure is 0.5MPa. A fermented lactic acid bacteria goat milk powder with antioxidant function is obtained.

[0055] Example three

[0056] A preparation method of a fermented lactic acid bacteria goat milk powder with antioxidant function, comprising the following steps: Step one, standardization of ingredients: 600 parts by weight of whole goat milk powder is dissolved in 4400 parts by weight of 45℃ ultrapure water, 250 parts by weight of isomaltooligosaccharide, 15 parts by weight of inulin, 0.9 parts by weight of phyllanthus emblica powder, 0.8 parts by weight of green tea extract, 1.5 parts by weight of chicken concentrate powder, 15 parts by weight of oat beta-glucan, 16 parts by weight of calcium carbonate, 4.85 parts by weight of compound nutritional fortifier are added, and sheared at 10,000 rpm for 5 min to obtain whole goat milk powder reconstituted solution 1. In addition, 150 parts of whole goat milk powder is dissolved in 1100 parts by weight of 45℃ ultrapure water, and sheared at 10,000 rpm for 5 min to obtain whole goat milk powder reconstituted solution 2.

[0057] Step two, filtration and homogenization: the obtained whole goat milk powder reconstituted solution 1 is filtered through a double filter, and then transferred into a homogenizer for homogenization to obtain an emulsion.

[0058] Step three, cooling and temporary storage: the homogenized emulsion is placed in a middle storage tank in a stirring state to obtain a mixed and uniform ingredient milk.

[0059] Step four, sterilization and concentration: the mixed and uniform ingredient milk is buffered through an equalizing cylinder, and then sequentially subjected to upper flash evaporation degassing, DSI sterilization (conditions: 102℃ / 60s, flow rate 25m³ / h), lower flash evaporation degassing, and then enters a four-effect falling film evaporator for concentration (vacuum degree -850mbar, steam pressure 1.0MPa, temperatures of the first, second, third and fourth effects being 75℃, 68℃, 65℃ and 60℃, respectively) to obtain concentrated milk with a density of 1250kg / m³, a temperature of 50℃ and a concentration of 50%, which is transported to a concentrated milk cylinder for temporary storage. The whole goat milk powder reconstituted solution 2 is subjected to pasteurization to obtain milk liquid with a density of 1250kg / m³, a temperature of 50℃ and a concentration of 50%, which is then temporarily stored in another concentrated milk cylinder.

[0060] Step five, 0.75 parts of Streptococcus salivarius subsp. thermophilus and 0.75 parts of Lactobacillus delbrueckii subsp. bulgaricus are inoculated into the milk liquid, which is fermented under anaerobic conditions at 45℃ for 5h to maintain an acidity of 65ºT. The above concentrated milk is mixed and obtained to obtain fermented goat milk containing lactic acid bacteria.

[0061] Step six, spray drying: the fermented goat milk containing lactic acid bacteria is transported to a drying tower for spray drying in the form of pressurization by a high-pressure pump, the pressure of the high-pressure pump is controlled at 150bar, the inlet air temperature of the drying tower is controlled at 210℃, the exhaust air temperature is controlled at 95℃, and the negative pressure in the tower is controlled at 0Pa.

[0062] Step seven, fluidized bed cooling: the milk powder dried by the spray drying tower is dried again in the fluidized bed and cooled to 30℃, wherein the temperature of the first fluidized bed is controlled at 50℃, the temperature of the second fluidized bed is controlled at 30℃, the temperature between the two fluidized beds is 25℃, the humidity is 50%, and the pressure difference with the quasi-clean operation area is 25 Pa.

[0063] Step eight, metal detection: the milk powder cooled by the fluidized bed is subjected to metal foreign matter detection, and the metal detection diameter Φ is 10 mm (iron, non-ferrous, stainless steel).

[0064] Step nine, metering and packaging: the milk powder after metal detection is filled, metered and packaged into 25 kg / bag bulk packaging milk powder, and then the production date and product name are printed on the outer bag. The heat sealing time is 4 s, the heat preservation shaping time is 4 s, and the heat sealing pressure is 0.6 MPa. The fermented lactic acid bacteria goat milk powder with antioxidant function is obtained.

[0065] Comparative example one: The difference from example one is that the phyllanthus emblica powder in example one is removed.

[0066] Comparative example two: The difference from example one is that the chicken concentrate powder in example one is removed.

[0067] Test: DPPH free radical scavenging rate and viable bacterial count determination DPPH free radical scavenging rate: 0.1 mmol / L DPPH free radical solution is prepared with 95% anhydrous ethanol as solvent. 2 mL of the sample to be tested is mixed with 8 mL of DPPH free radical solution as the test group, 2 mL of ethanol solution is mixed with 8 mL of DPPH free radical solution as the control group, and 2 mL of the sample to be tested is mixed with 8 mL of ethanol solvent as the blank group to eliminate the error caused by the reaction of the sample itself and ethanol. After the mixture is shaken and mixed thoroughly, it is placed in the dark for 30 min, and the absorbance is measured at 517 nm. The scavenging rate is calculated according to the formula. The scavenging rate of 0.25 mg / mL Trolox solution is used as the control.

[0068] Scavenging rate (%) = [1- (A i -A j ) / A o ] × 100% Wherein A i is the test group, A j is the blank group, and A o is the control group.

[0069] Viable cell count determination: The viable cell count determination was performed by plate count method. MRS agar medium was dispensed into 1000 mL conical flask, sterilized at 121°C for 15 min, then taken out, and poured into culture dishes about 15-20 mL when cooled to 60°C. After the medium was cooled and solidified, 0.1 mL of bacterial dilution was coated, 3 dilution gradients were selected for each sample, and the average value of 3 parallel samples was calculated. The completed coating plate was inverted in a constant temperature incubator and incubated at 37°C for 48 h. The plate was counted, and the viable cell count per milliliter was calculated and expressed as CFU / mL.

[0070] The DPPH free radical scavenging rate and viable cell count determination results of the fermented milk prepared in experimental examples one, two, three and comparative examples one and two are shown in Table 1, respectively.

[0071] Table 1

[0072] As shown in Table 1, the DPPH free radical scavenging activity of the fermented milk after 18 h fermentation was as high as 85%, and the viable cell count of lactobacillus was as high as 9.3 log CFU / mL (the international dairy association stipulates that the viable cell count of fermented milk with probiotic function must be higher than 9 log CFU / mL). Comparative example one and comparative example two removed the phyllanthus emblica powder and chicken concentrate powder, respectively, and the DPPH free radical scavenging rate was significantly lower than that of examples one, two and three, thus it can be seen that the addition of phyllanthus emblica powder and chicken concentrate powder effectively improves the antioxidant function of the fermented lactic acid bacteria goat milk powder.

[0073] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited thereto. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the basically same technical problem and achieve the basically same technical effect is covered in the protection scope of the present application.

Claims

1. A fermented lactic acid bacterial goat milk powder having an antioxidant function, characterized by: 750 parts by weight of whole-fat goat milk powder, 225-250 parts by weight of isomaltooligosaccharide, 5-15 parts by weight of inulin, 0.3-0.9 parts by weight of phyllanthus emblica powder, 0.5-1.5 parts by weight of chicken concentrate powder, 0.2-0.8 parts by weight of green tea extract, 5-15 parts by weight of oat beta-glucan, 8-16 parts by weight of calcium carbonate, 0.25-0.75 parts by weight of Streptococcus salivarius subsp. thermophilus, 0.25-0.75 parts by weight of Lactobacillus delbrueckii subsp. bulgaricus, and 3.85-4.85 parts by weight of a compound nutritional fortifier.

2. The method for preparing a fermented lactic acid bacteria goat milk powder with antioxidant function according to claim 1, characterized in that: The method comprises the following steps: Step one, standardizing the ingredients: 600 parts by weight of whole-fat goat milk powder is dissolved in 4400 parts by weight of 45℃ ultrapure water, 225-250 parts by weight of isomaltooligosaccharide, 5-15 parts by weight of inulin, 0.3-0.9 parts by weight of phyllanthus emblica powder, 0.2-0.8 parts by weight of green tea extract, 0.5-1.5 parts by weight of chicken concentrate powder, 5-15 parts by weight of oat beta-glucan, 8-16 parts by weight of calcium carbonate, and 3.85-4.85 parts by weight of a compound nutritional fortifier are added, and shearing is performed at 10,000 rpm for 5 min to obtain a whole-fat goat milk powder reconstituted solution 1; in addition, 150 parts by weight of whole-fat goat milk powder is dissolved in 1100 parts by weight of 45℃ ultrapure water, and shearing is performed at 10,000 rpm for 5 min to obtain a whole-fat goat milk powder reconstituted solution 2; Step two, filtering and homogenizing: the obtained whole-fat goat milk powder reconstituted solution 1 is filtered through a double filter, and then is transferred into a homogenizer for homogenization to obtain an emulsion; Step three, cooling and temporary storage: the homogenized emulsion is placed into a middle storage tank in a stirring state to obtain a mixed and uniform ingredient milk; Step four, sterilization and concentration: the mixed and uniform ingredient milk is buffered through an equalizing cylinder, is sequentially subjected to upper flash evaporation degassing, DSI sterilization, lower flash evaporation degassing, and then is fed into a four-effect falling film evaporator for concentration to obtain concentrated milk with a density of 1100-1250 kg / m³, a temperature of 40-50℃, and a concentration of 40-50%; the concentrated milk is transported to a concentrated milk cylinder for temporary storage; the whole-fat goat milk powder reconstituted solution 2 is subjected to pasteurization treatment to obtain milk liquid with a density of 1100-1250 kg / m³, a temperature of 40-50℃, and a concentration of 40-50%, which is temporarily stored in another concentrated milk cylinder; Step five, 0.25-0.75 parts by weight of Streptococcus salivarius subsp. thermophilus and 0.25-0.75 parts by weight of Lactobacillus delbrueckii subsp. bulgaricus are inoculated into the milk liquid, and the mixture is fermented under anaerobic conditions at 42±3℃ for 2-5 h to maintain an acidity of 50-65ºT; the above concentrated milk is added and mixed to obtain fermented goat milk containing lactic acid bacteria; Step six, spray drying: the fermented goat milk containing lactic acid bacteria is fed into a drying tower for spray drying in the form of pressurization by a high-pressure pump; Step seven, fluidized bed cooling: the milk powder dried by the spray drying tower is subjected to secondary drying in a fluidized bed and is cooled to 20-30℃; Step eight, metal detection: the milk powder cooled by the fluidized bed is subjected to metal foreign matter detection, and the diameter Φ of the metal detected is 2-10 mm; Step nine, metering packaging: the milk powder after metal detection is filled, metered and packaged into 25 kg / bag of large package milk powder, and then the production date and product name are printed on the outer bag to obtain the fermented lactic acid bacteria goat milk powder with antioxidant function.

3. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours. The homogenization pressure in the step two is kept at 18-20 MPa, and the rotating speed is 60-70 rpm.

4. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours. The liquid temperature in the storage tank in the step three is controlled at 8-12 ℃, and the storage time is controlled at 2-5 h.

5. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours. The DSI sterilization condition in the step four is 100-102 ℃ / 60 s, the flow rate is 22-25 m³ / h, the vacuum degree of the four-effect falling film evaporator is controlled at -910~-850 mbar, the steam pressure is controlled at 0.8-1.0 MPa, and the temperatures of the first, second, third and fourth effects are 65-75 ℃, 58-68 ℃, 55-65 ℃ and 50-60 ℃ respectively.

6. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours. The pressure of the high-pressure pump in the step six is controlled at 100-150 bar, the inlet air temperature of the drying tower is controlled at 160 ℃-210 ℃, the exhaust air temperature is controlled at 80-95 ℃, and the negative pressure in the tower is controlled at -100~0 Pa.

7. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours to 48 hours. The temperature of the fluidized bed 1 in the step seven is controlled at 40-50 ℃, the temperature of the fluidized bed 2 is controlled at 20-30 ℃, the temperature between the fluidized beds is 16-25 ℃, the humidity is 30%-50%, and the pressure difference with the quasi-clean operation area is 15-25 Pa.

8. The method of claim 2, wherein the fermented lactic acid bacteria goat milk powder having an antioxidant function is prepared by adding a lactic acid bacteria culture medium to goat milk, and then fermenting the goat milk at 37°C for 24 hours. The heat sealing time in the step nine is 3-4 s, the heat preservation and shaping time is 3-4 s, and the heat sealing pressure is 0.5-0.6 MPa.

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