Formula and superfine grinding processing method of multi-grain compounded corn fine powder

Abstract

The invention discloses multi-grain compound corn fine powder and a superfine grinding processing method, and belongs to the technical field of grain processing. The fine flour is prepared by compounding corn flour, quinoa flour, chia seed flour, highland barley flour, chickpea flour, fructo-oligosaccharide, inulin, lactobacillus plantarum powder, a rice bran dietary fiber extract, konjac glucomannan, purple sweet potato flour, flaxseed meal, cordyceps militaris powder, a vitamin complexing agent and a mineral complexing agent in proportion. The processing method comprises the steps of raw material pretreatment, superfine grinding and post-treatment. A three-dimensional nutrition system is constructed through scientific compounding, an innovative low-temperature superfine grinding technology and an inert gas protection technology are combined, the particle size of 98% or above particles is smaller than or equal to 25 microns, the heat-sensitive component retention rate is increased by 30% or above, the product shelf life is prolonged to 12 months or above through microencapsulation embedding, the survival rate of probiotics is larger than or equal to 80%, and the product quality guarantee period is prolonged to 12 months or above through microencapsulation embedding. The method is suitable for the fields of meal replacement food, senile nutritious food and the like, and is obviously superior to the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of grain processing, in particular to a multi-grain composite corn flour formula and an ultrafine grinding processing method. Background Art

[0002] With the improvement of people's health awareness, consumers' demand for processed grain products has shifted from simply satisfying their hunger to nutritionally balanced and multifunctional products. However, there are still significant limitations in the multi-grain compound products and processing technologies currently on the market, as follows:

[0003] First, the raw material combinations lack scientific basis and are mostly simply mixed, failing to achieve synergistic nutrient enhancement. For example, the ratio of protein to dietary fiber is unbalanced, and the content of functional fatty acids is insufficient, making it difficult to meet the precise nutritional needs of special populations.

[0004] Second, the processing technology is backward. Traditional pulverization technology mainly relies on single mechanical grinding. Due to the limitations of equipment performance, the particle size of the material can usually only reach 80-100μm. Not only does it have a rough taste, but the macromolecular nutrients are difficult to be fully digested and absorbed by the human body, with a bioavailability rate of less than 50%.

[0005] Third, heat-sensitive ingredients are severely lost. Frictional heat generated during mechanical pulverization causes the processing chamber temperature to rise to over 60°C, reducing the survival rate of active substances such as B vitamins and probiotics to less than 40%, and the oxidation rate of easily oxidized ingredients such as omega-3 fatty acids to over 30%, significantly reducing the functionality of the product.

[0006] Fourth, storage stability is poor. Due to the lack of effective protection measures, the shelf life of existing products at 25°C is generally less than 6 months. They are also prone to moisture absorption and agglomeration, and have excessive microbial growth, posing food safety risks.

[0007] Comparative document 1 (CN108771768A) discloses a multi-grain composite powder and a preparation method thereof. Its raw materials include six basic grains such as corn flour and buckwheat flour, and a single air flow milling process is used. This technology has the problems of few types of raw materials and single functional ingredients, and does not involve functional additives such as probiotics and active polysaccharides, and cannot meet precise nutritional needs; its grinding particle size is relatively coarse, resulting in a rough taste of the product, a digestion and absorption rate of less than 60%, and no low-temperature protection measures are adopted, resulting in a loss rate of heat-sensitive components exceeding 40%.

[0008] Comparative document 2 (CN112335642A) discloses a cereal compound powder containing probiotics, which adds lactic acid bacteria but does not use encapsulation technology. After traditional baking, the survival rate of probiotics is only 30%-40%, and the stability of easily oxidized ingredients such as Omega-3 fatty acids is not controlled. The acid value of the product increases by more than 50% after storage at 25°C for 3 months, and the shelf life is only 6 months. Its processing technology uses ordinary mechanical crushing, which does not solve the taste and digestion problems.

[0009] Comparative document 3 (CN109674219A) discloses a method for processing ultrafinely ground grain powder, which adopts two-stage grinding. However, the temperature is not controlled during the grinding process, resulting in a vitamin E retention rate of only 55%. In addition, the product is not microencapsulated, and the water holding capacity of dietary fiber is only 3-4g / g. The packaging uses ordinary polyethylene film and is not vacuum-treated. The product is prone to moisture absorption and agglomeration during storage, and the total number of microbial colonies is more than 5000 CFU / g.

[0010] Therefore, how to provide a multi-grain composite corn flour formula and ultrafine grinding processing method is a problem that those skilled in the art urgently need to solve. Summary of the Invention

[0011] One purpose of the present invention is to propose a multi-grain compound corn flour formula and an ultrafine grinding processing method. The present invention can achieve the technical effects of balanced nutrition, excellent quality, strong stability and high safety of the product through scientific raw material ratios and innovative processing technology.

[0012] A multi-grain composite corn flour according to an embodiment of the present invention comprises, by weight percentage, the following raw materials:

[0013] Corn flour 35%-45%, quinoa flour 8%-12%, chia seed powder 3%-7%, barley flour 6%-10%, chickpea flour 5%-9%, oligofructose 2%-4%, inulin 1%-3%, Lactobacillus plantarum powder 0.5%-1.5%, rice bran dietary fiber extract 3%-5%, konjac glucomannan 1%-3%, purple sweet potato powder 4%-8%, flaxseed meal 3%-7%, cordyceps militaris powder 1%-3%, vitamin complex 0.05%-0.15%, mineral complex 0.03%-0.07%;

[0014] The vitamin complex is prepared by mixing 0.15mg-0.25mg of vitamin B1, 0.15mg-0.25mg of vitamin B2, and 0.3mg-0.5mg of vitamin E per 100g of multi-grain composite corn flour, wherein the vitamin B1, vitamin B2, and vitamin E are mixed in a mass ratio of 1:1:2 per 100g of multi-grain composite corn flour;

[0015] The mineral complex is prepared by mixing 0.3mg-0.5mg of zinc, 0.15mg-0.25mg of selenium and 0.5mg-0.7mg of magnesium per 100g of multi-grain compound corn flour, wherein the zinc, selenium and magnesium are mixed in a mass ratio of 2:1:3 in the multi-grain compound corn flour.

[0016] Furthermore, the corn flour is ultrafinely ground yellow corn flour with a particle size of ≤25 μm and an amylose content of 22%-28%.

[0017] Furthermore, the quinoa flour, chia seed flour, highland barley flour and chickpea flour are all ultrafinely ground, with a particle size of ≤25 μm, wherein the protein content of quinoa flour is ≥16%, the Omega-3 fatty acid content of chia seed flour is ≥18%, the β-glucan content of highland barley flour is ≥5%, and the protein content of chickpea flour is ≥20%.

[0018] Furthermore, the degree of polymerization of the oligofructose is 3-6, the degree of polymerization of the inulin is 2-60, and the number of viable bacteria of the Lactobacillus plantarum powder is ≥1.0×10^10 CFU / g.

[0019] Furthermore, the rice bran dietary fiber extract has a total dietary fiber content of ≥85%, a water holding capacity of ≥5 g / g, a konjac glucomannan purity of ≥90%, and a viscosity of ≥2000 mPa·s; the purple sweet potato powder is ultrafinely ground, has a particle size of ≤25 μm, and has an anthocyanin content of ≥0.2%; the flaxseed meal is ethanol-detoxified, has a cyanide content of ≤5 mg / kg; and the Cordyceps militaris powder is artificially cultivated, has an adenosine content of ≥0.05%, and a cordycepin content of ≥0.02%.

[0020] Furthermore, the zinc in the mineral complex is derived from zinc gluconate, the selenium is derived from selenium-enriched yeast, and the magnesium is derived from magnesium oxide.

[0021] A method for ultrafine grinding of multi-grain composite corn flour comprises the following steps:

[0022] S1. Raw material pretreatment

[0023] First, the raw materials are screened and unqualified raw materials are eliminated. Then, qualified raw materials are baked at low temperature, and the baked raw materials are subjected to enzymatic hydrolysis.

[0024] S2, ultrafine grinding

[0025] All the pretreated raw materials are mixed according to the ratio of claim 1 to form a mixed material, and then the material is crushed in sequence through a first-stage airflow crushing, a second-stage low-temperature rolling, and a third-stage ultrasonic-assisted ultrafine crushing, and 0.5% modified starch is added during the third-stage ultrasonic-assisted ultrafine crushing to achieve microencapsulation and embedding through the ultrasonic cavitation effect. Finally, nitrogen is introduced into the material in a double-helix conical mixer and mixed at 300±20 r / min for 15±2 minutes to achieve inert gas protection mixing;

[0026] S3, post-processing

[0027] The material is granulated at low temperature by a vacuum granulator to form 0.5-1 mm particles. The particles are then dried in a fluidized bed to a moisture content of 5-6%. Finally, the particles are packaged with a three-layer composite film, and the vacuum degree in the package is ≤1kPa through three pulse vacuums.

[0028] Furthermore, the specific method of low-temperature baking in step S1 is:

[0029] Corn, barley and chickpeas are baked using a gradient temperature increase, first baked at 60±2℃ for 30 minutes, then heated to 80±2℃ for 20 minutes, and finally baked at 100±2℃ for 10 minutes. Inert gas with a purity of ≥99.9% is introduced throughout the process, with a gas flow rate of 2-3L / min. Quinoa and chia seeds are placed in a vacuum baking equipment and baked at 60±2℃ and a pressure of -0.08±0.005MPa for 2 hours. The moisture content of all raw materials after baking must be controlled at 6-7%.

[0030] Furthermore, the enzymatic hydrolysis operation in step S1 is specifically as follows:

[0031] The baked highland barley and chickpeas are preliminarily crushed to achieve a 100-mesh sieve pass rate of ≥95%, and deionized water is added at a material-liquid ratio of 1:8. The pH is adjusted to 5.0±0.1, and 0.2% of a complex enzyme is added, wherein the complex enzyme is prepared by mixing cellulase and xylanase at a mass ratio of 1:1, wherein the cellulase activity is ≥5000U / g and the xylanase activity is ≥10000U / g. The mixture is enzymolyzed in a 50±2°C water bath for 30 minutes, and then the enzyme is inactivated in a 95°C water bath for 10 minutes. The mixture is cooled to room temperature and then centrifuged and dehydrated for later use.

[0032] Furthermore, in step S2, the first-stage air flow mill adopts a fluidized bed air flow mill, the compressed air pressure is 0.8±0.05MPa, the feed rate is 10-15kg / h, the crushing chamber temperature is controlled at -5±2°C, the material passes through a 150-mesh sieve, and the pass rate is ≥98%. The second-stage low-temperature rolling adopts a double-roll low-temperature rolling mill, liquid nitrogen refrigeration maintains the rolling chamber temperature at -10±2°C, the rolling roller speed is 300r / min, the rolling gap is 0.01±0.002mm, the material passes through a 300-mesh sieve, and the pass rate is ≥98%. The third-stage ultrasonic assisted The ultrafine grinding is assisted by an ultrasonic grinder with a probe diameter of 20 mm, an ultrasonic power of 500±50 W, an ultrasonic time of 20 minutes, an operating time of 5 seconds, an intermission of 3 seconds, a material-liquid ratio of 1:4, and a temperature controlled below 20±2°C. The final material is sieved through a 500-mesh sieve with a pass rate of ≥98% and a particle size of ≤25 μm. The modified starch is hydroxypropyl distarch phosphate with a degree of substitution of 0.02-0.04. The particle size after embedding is 1-5 μm and the embedding rate is ≥90%. The nitrogen in the double-helix conical mixer needs to be replaced 3 times, the residual oxygen is ≤1%, and the mixing uniformity is ≥95%.

[0033] The beneficial effects of the present invention are:

[0034] This invention achieves nutritional synergy through the scientific compounding of 15 raw materials, breaking through the nutritional limitations of single grains. It balances nutrients such as protein, dietary fiber, and omega-3 fatty acids, and combines the synergistic effects of probiotics and active ingredients to precisely meet the nutritional needs of special populations. A three-stage composite pulverization process is used to achieve an ultrafine particle size of more than 98% of particles ≤25μm. Combined with low temperature and inert gas protection technology, the nutrient retention rate is increased by more than 30% compared to traditional processes, significantly improving the product's taste and digestibility. Ultrasonic cavitation is used to achieve a microencapsulation rate of ≥90%, creatively extending the shelf life of easily oxidizable ingredients by 50% to more than 12 months, while ensuring a probiotic survival rate of ≥80%. This overcomes the industry's shortcoming of poor storage stability of processed grain products. Through full-process quantitative process control, extending from raw material screening to packaging, the product's total colony count is ensured to be ≤1000 CFU / g and coliform bacteria are undetectable. Strict food safety standards can be implemented throughout the entire production chain, significantly improving food safety and forming synergistic advantages in four dimensions: nutrition, process, stability, and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 This is a flow chart of the ultrafine grinding processing method for multi-grain composite corn flour proposed by the present invention. DETAILED DESCRIPTION

[0037] The present invention will now be described in further detail with reference to the accompanying drawings, which are simplified schematic diagrams that illustrate the basic structure of the present invention in a schematic manner.

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] The present invention discloses a multi-grain composite corn flour and an ultrafine grinding processing method. By scientifically proportioning a variety of grain raw materials and functional ingredients and combining a multi-stage ultrafine grinding process, the raw materials are ultrafinely processed and the active ingredients are retained. The resulting product is nutritionally balanced and easily absorbed, and is suitable for use in the fields of meal replacement foods, nutritional foods for the elderly, and the like.

[0040] Example 1

[0041] A multi-grain compound corn flour comprises, by weight percentage, 40% corn flour, 10% quinoa flour, 5% chia seed flour, 8% highland barley flour, 7% chickpea flour, 3% oligofructose, 2% inulin, 1% Lactobacillus plantarum powder, 4% rice bran dietary fiber extract, 2% konjac glucomannan, 6% purple sweet potato flour, 5% flaxseed meal, 2% cordyceps militaris powder, 0.1% vitamin complex, and 0.05% mineral complex.

[0042] The corn flour is ultrafinely ground yellow corn flour with a particle size of ≤25 μm and an amylose content of 25%;

[0043] Quinoa flour, chia seed flour, highland barley flour, and chickpea flour are all ultrafinely ground to a particle size of ≤25μm. Quinoa flour has a protein content of 17%, chia seed flour has an Omega-3 fatty acid content of 19%, highland barley flour has a β-glucan content of 6%, and chickpea flour has a protein content of 21%.

[0044] The degree of polymerization of oligofructose is 4, the degree of polymerization of inulin is 30; the number of viable Lactobacillus plantarum powder is 1.2×10^10 CFU / g;

[0045] Rice bran dietary fiber extract contains 86% total dietary fiber and a water-holding capacity of 5.2g / g; konjac glucomannan has a purity of 92% and a viscosity of 2200mPa·s; purple sweet potato powder is ultrafinely ground to a particle size of ≤25μm and contains 0.3% anthocyanin; flaxseed meal is detoxified with 70% ethanol and has a cyanide content of 4mg / kg; Cordyceps militaris powder is artificially cultivated and contains 0.06% adenosine and 0.03% cordycepin.

[0046] The vitamin complex is prepared by mixing 0.2 mg of vitamin B1, 0.2 mg of vitamin B2 and 0.4 mg of vitamin E per 100 g of multi-grain compound corn flour;

[0047] The mineral complex is composed of 0.4 mg of zinc from zinc gluconate, 0.2 mg of selenium from selenium-enriched yeast and 0.6 mg of magnesium from magnesium oxide per 100 g of multi-grain compound corn flour.

[0048] Example 2

[0049] A multi-grain compound corn flour comprises, by weight percentage, 35% corn flour, 12% quinoa flour, 3% chia seed flour, 10% highland barley flour, 5% chickpea flour, 4% oligofructose, 1% inulin, 1.5% Lactobacillus plantarum powder, 5% rice bran dietary fiber extract, 1% konjac glucomannan, 8% purple sweet potato flour, 3% flaxseed meal, 3% cordyceps militaris powder, 0.15% vitamin complex, and 0.03% mineral complex.

[0050] The corn flour is ultrafinely ground yellow corn flour with a particle size of ≤25 μm and an amylose content of 22%;

[0051] Quinoa flour, chia seed flour, highland barley flour, and chickpea flour are all ultrafinely ground to a particle size of ≤25μm. Quinoa flour contains 16% protein, chia seed flour contains 18% Omega-3 fatty acids, highland barley flour contains 5% β-glucan, and chickpea flour contains 20% protein.

[0052] The degree of polymerization of oligofructose is 6, the degree of polymerization of inulin is 2; the number of viable Lactobacillus plantarum powder is 1.0×10^10 CFU / g;

[0053] Rice bran dietary fiber extract contains 85% total dietary fiber and has a water-holding capacity of 5g / g; konjac glucomannan is 90% pure and has a viscosity of 2000mPa·s; purple sweet potato powder is ultrafinely ground to a particle size of ≤25μm and contains 0.2% anthocyanin; flaxseed meal is detoxified with 70% ethanol and has a cyanide content of 5mg / kg; Cordyceps militaris powder is artificially cultivated and contains 0.05% adenosine and 0.02% cordycepin.

[0054] The vitamin complex is prepared by mixing 0.25 mg of vitamin B1, 0.25 mg of vitamin B2 and 0.5 mg of vitamin E per 100 g of multi-grain compound corn flour;

[0055] The mineral complex is a mixture of 0.5 mg of zinc, 0.25 mg of selenium and 0.7 mg of magnesium per 100 g of multi-grain compound corn flour.

[0056] Example 3

[0057] A multi-grain compound corn flour comprises, by weight percentage, 45% corn flour, 8% quinoa flour, 7% chia seed flour, 6% highland barley flour, 9% chickpea flour, 2% oligofructose, 3% inulin, 0.5% Lactobacillus plantarum powder, 3% rice bran dietary fiber extract, 3% konjac glucomannan, 4% purple sweet potato flour, 7% flaxseed meal, 1% cordyceps militaris powder, 0.05% vitamin complex, and 0.07% mineral complex.

[0058] The corn flour is ultrafinely ground yellow corn flour with a particle size of ≤25 μm and an amylose content of 28%;

[0059] Quinoa flour, chia seed flour, highland barley flour, and chickpea flour are all ultrafinely ground to a particle size of ≤25μm. Quinoa flour has a protein content of 18%, chia seed flour has an Omega-3 fatty acid content of 20%, highland barley flour has a β-glucan content of 7%, and chickpea flour has a protein content of 22%.

[0060] The degree of polymerization of oligofructose is 3, the degree of polymerization of inulin is 60; the number of viable Lactobacillus plantarum powder is 1.5×10^10 CFU / g;

[0061] Rice bran dietary fiber extract contains 88% total dietary fiber and 5.5g / g water holding capacity; konjac glucomannan is 95% pure and has a viscosity of 2500mPa·s; purple sweet potato powder is ultrafinely ground to a particle size of ≤25μm and contains 0.4% anthocyanin; flaxseed meal is detoxified with 70% ethanol and has a cyanide content of 3mg / kg; Cordyceps militaris powder is artificially cultivated and contains 0.07% adenosine and 0.04% cordycepin.

[0062] The vitamin complex is prepared by mixing 0.15 mg of vitamin B1, 0.15 mg of vitamin B2 and 0.3 mg of vitamin E per 100 g of multi-grain compound corn flour;

[0063] The mineral complex is a mixture of 0.3 mg of zinc, 0.15 mg of selenium and 0.5 mg of magnesium per 100 g of multi-grain compound corn flour.

[0064] Example 4

[0065] See also Figure 1 A method for ultrafine grinding of multi-grain composite corn flour based on Example 1 comprises the following steps:

[0066] S1. Raw material pretreatment

[0067] First, the raw materials are screened to remove unqualified raw materials such as moldy kernels in corn, barley, and chickpeas, empty kernels in quinoa and chia seeds, rotten parts in purple sweet potatoes, and agglomerated impurities in flaxseed meal.

[0068] The qualified raw materials were then baked at low temperature. Corn, barley, and chickpeas were baked at a gradient temperature of 60°C for 30 minutes (moisture 13%) → 80°C for 20 minutes (moisture 9%) → 100°C for 10 minutes (moisture 6.5%), with nitrogen (purity 99.9%, flow rate 2.5L / min) flowing throughout the process. Quinoa and chia seeds were baked at 60°C and -0.08MPa vacuum conditions for 2 hours (moisture 6.5%).

[0069] The baked highland barley and chickpeas were subjected to an enzymatic hydrolysis operation. The highland barley and chickpeas were crushed after baking, and the passing rate of the crushed materials on a 100-mesh sieve was 96%. Deionized water was added according to a material-liquid ratio of 1:8, the pH was adjusted to 5.0, and 0.2% of a complex enzyme was added. The complex enzyme was prepared by mixing 5000U / g of cellulase and 10000U / g of xylanase in a ratio of 1:1. The mixture was then enzymolyzed at 50°C for 30 minutes, inactivated at 95°C for 10 minutes, and dehydrated by centrifugation at 3000r / min for 10 minutes.

[0070] S2, ultrafine grinding

[0071] All the pretreated raw materials were mixed according to the proportions in Example 1 to form a mixed material;

[0072] The material is then crushed in sequence through the first stage of air flow crushing, the second stage of low-temperature rolling and the third stage of ultrasonic-assisted ultrafine grinding. The first stage of air flow crushing adopts a fluidized bed air flow crusher with a pressure of 0.8 MPa, a temperature of -5°C, a feed of 12 kg / h, and a 150-mesh sieve pass rate of 98%; the second stage of low-temperature rolling adopts a double-roller low-temperature rolling machine with a temperature of -10°C, a speed of 300 r / min, a gap of 0.01 mm, and a 300-mesh sieve pass rate of 98%; the third stage of ultrasonic-assisted ultrafine grinding adopts an ultrasonic crusher with a probe diameter of 20 mm, a power of 500 W, a time of 20 minutes, a working time of 5 seconds, a rest time of 3 seconds, a material-liquid ratio of 1:4, a temperature of 20°C, a 500-mesh sieve pass rate of 98%, and a particle size of 22 μm.

[0073] In the third stage of ultrasonic-assisted ultrafine grinding, 0.5% hydroxypropyl distarch phosphate modified starch is added to achieve microencapsulation through ultrasonic cavitation effect, with an embedding rate of 92% and a particle size of 3 μm.

[0074] Finally, the materials were introduced into a double-screw conical mixer with nitrogen and replaced three times, with a residual oxygen content of 0.8%. The materials were mixed at 300 r / min for 15 minutes to achieve inert gas protection mixing, and the mixing uniformity reached 96%;

[0075] S3, post-processing

[0076] The material is granulated at low temperature by a vacuum granulator to produce 0.8 mm particles;

[0077] The granules were then fluid-bed dried to a moisture content of 5.5%;

[0078] Finally, the particles were packaged with a three-layer composite film, and the vacuum degree inside the package was 0.8 kPa by three pulse vacuums (-0.06 MPa→-0.08 MPa→-0.1 MPa, each holding pressure for 3 seconds).

[0079] Example 5

[0080] An ultrafine grinding processing method for multi-grain composite corn flour based on Example 2 comprises the following steps:

[0081] S1. Raw material pretreatment

[0082] First, the raw materials are screened and unqualified raw materials are removed, as in Example 4, to ensure that the rejection rate of unqualified raw materials is ≥99%;

[0083] The qualified raw materials were then baked at low temperature: corn, barley, and chickpeas were baked at 62°C for 30 minutes (moisture 14%) → 82°C for 20 minutes (moisture 10%) → 102°C for 10 minutes (moisture 7%), with a nitrogen flow rate of 3 L / min; quinoa and chia seeds were vacuum baked at 62°C and -0.075 MPa for 2 hours (moisture 7%).

[0084] The roasted highland barley and chickpeas were subjected to enzymatic hydrolysis. After crushing, the highland barley and chickpeas had a 100-mesh sieve pass rate of 95%. The pH value was 5.1 and the enzymatic hydrolysis temperature was 52°C for 30 minutes. The residual enzyme activity after enzyme inactivation was 5U / g.

[0085] S2, ultrafine grinding

[0086] All the pretreated raw materials were mixed according to the ratio of Example 2 to form a mixed material;

[0087] The material is then crushed in sequence through the first stage of air flow milling, the second stage of low-temperature rolling and the third stage of ultrasonic-assisted ultrafine grinding. The first stage of air flow milling adopts a fluidized bed air flow mill at 0.85MPa, -3℃, and a feed of 15kg / h; the second stage of low-temperature rolling adopts a double-roller low-temperature rolling mill at -8℃ and a gap of 0.012mm; the third stage of ultrasonic-assisted ultrafine grinding adopts an ultrasonic mill at 550W, 18℃, and a particle size of 24μm.

[0088] In the third stage of ultrasonic-assisted ultrafine grinding, 0.5% hydroxypropyl distarch phosphate modified starch is added to achieve microencapsulation through ultrasonic cavitation effect, with an embedding rate of 90% and a particle size of 5 μm.

[0089] Finally, nitrogen was introduced into the materials in a double-screw conical mixer and mixed at 320 r / min for 17 minutes to achieve inert gas protection mixing, and the mixing uniformity was 95%;

[0090] S3, post-processing

[0091] The material is granulated at low temperature by a vacuum granulator to produce 0.5 mm particles;

[0092] The granules were then dried in a fluidized bed to a moisture content of 6%;

[0093] Finally, the particles were packaged with a three-layer composite film, and the vacuum degree inside the package was 0.9 kPa through three pulse vacuums.

[0094] Example 6

[0095] An ultrafine grinding processing method for multi-grain composite corn flour based on Example 3 comprises the following steps:

[0096] S1. Raw material pretreatment

[0097] First, the raw materials were screened and unqualified raw materials were removed, as in Example 4;

[0098] The qualified raw materials were then baked at low temperature: corn, barley, and chickpeas were baked at 58°C for 30 minutes (moisture 12%) → 78°C for 20 minutes (moisture 8%) → 98°C for 10 minutes (moisture 6%), with a nitrogen flow rate of 2 L / min; quinoa and chia seeds were vacuum baked at 58°C and -0.085 MPa for 2 hours (moisture 6%).

[0099] The roasted highland barley and chickpeas were subjected to enzymatic hydrolysis. After crushing, the highland barley and chickpeas had a 100-mesh sieve pass rate of 97%. The pH value was 4.9 and the enzymatic hydrolysis temperature was 48°C for 30 minutes. The residual enzyme activity after enzyme inactivation was 3U / g.

[0100] S2, ultrafine grinding

[0101] All the pretreated raw materials were mixed according to the proportions in Example 3 to form a mixed material;

[0102] The material is then crushed in sequence through the first stage of airflow crushing, the second stage of low-temperature rolling and the third stage of ultrasonic-assisted ultrafine grinding. The first stage of airflow crushing adopts a fluidized bed airflow crusher at 0.75MPa, -7℃, and a feed of 10kg / h; the second stage of low-temperature rolling adopts a double-roller low-temperature rolling machine at -12℃ and a gap of 0.008mm; the third stage of ultrasonic-assisted ultrafine grinding adopts an ultrasonic crusher at 450W, 22℃, and a particle size of 20μm.

[0103] In addition, 0.5% modified starch is added during the third stage of ultrasonic-assisted ultrafine grinding to achieve microencapsulation and embedding through ultrasonic cavitation effect;

[0104] Finally, nitrogen was introduced into the materials in a double-screw conical mixer and mixed at 280 r / min for 13 minutes to achieve inert gas protection mixing, and the mixing uniformity reached 97%;

[0105] S3, post-processing

[0106] The material is granulated at low temperature by a vacuum granulator to produce 1mm particles;

[0107] The granules were then dried in a fluidized bed to a moisture content of 5%;

[0108] Finally, the particles were packaged with a three-layer composite film, and the vacuum degree inside the package was 0.7 kPa through three pulse vacuums.

[0109] The multi-grain composite corn flour obtained in Examples 4 to 6 was tested, and the test results are shown in Table 1:

[0110] Table 1 Quality test results of multi-grain composite corn flour in different embodiments

[0111]

[0112] As shown in Table 1, the particle size of the multi-grain composite corn flour obtained in Examples 4 to 6 of the present invention is ≥98%, and the particle size is ≤25 μm. Among them, the particle size of Example 6 is the best, and 99.0% of the particles reach the ultrafine standard, which is more conducive to improving the digestion and absorption rate of the product than 98.5% of Example 4 and 98.2% of Example 5. The protein content in the nutrients is ≥15%, and Example 6 leads with a protein content of 17.0%. Examples 4 and 5 are 16.2% and 15.5% respectively, all of which meet the needs of a high-protein diet. The dietary fiber content is ≥8%, and the 9.0% of Example 6 is significantly higher than the other two groups, which can effectively promote intestinal health. The omega-3 fatty acid content is ≥1%, and the 1.5% of Example 6 has a more nutritional advantage than the 1.2% of Example 4 and the 1.0% of Example 5, which is beneficial to cardiovascular health.

[0113] In terms of microbial indicators, the total colony count of the three groups of examples was ≤1000 CFU / g, with 780 CFU / g of Example 6 being the lowest, indicating the best microbial control effect, and no coliform bacteria were detected, meeting food safety standards. The shelf life was ≥12 months when sealed and stored at 25°C. Example 6 had the longest shelf life of 15 months, while Example 4 was 14 months and Example 5 was 12 months, indicating that the packaging and processing technology of the present invention can effectively extend the shelf life of the product. The probiotic survival rate was ≥80%, with Example 6 having the highest survival rate of 85%, while Examples 4 and 5 were 82% and 80% respectively, reflecting the protective effect of microencapsulation technology on the activity of probiotics.

[0114] Overall, all three groups of examples met the quality standards set by the present invention, among which Example 6 performed best in terms of particle size, nutritional content, microbial control and shelf life. This is closely related to the higher proportion of chickpea flour and chia seed flour and the finer ultrasonic grinding parameters in this example, verifying the synergistic effectiveness of the formula and process of the present invention.

[0115] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A multi-grain composite corn flour, characterized in that: Calculated by weight percentage, the raw material composition includes: Corn flour 35%-45%, quinoa flour 8%-12%, chia seed powder 3%-7%, barley flour 6%-10%, chickpea flour 5%-9%, oligofructose 2%-4%, inulin 1%-3%, Lactobacillus plantarum powder 0.5%-1.5%, rice bran dietary fiber extract 3%-5%, konjac glucomannan 1%-3%, purple sweet potato powder 4%-8%, flaxseed meal 3%-7%, cordyceps militaris powder 1%-3%, vitamin complex 0.05%-0.15%, mineral complex 0.03%-0.07%; The vitamin complex is prepared by mixing 0.15mg-0.25mg of vitamin B1, 0.15mg-0.25mg of vitamin B2, and 0.3mg-0.5mg of vitamin E per 100g of multi-grain composite corn flour, wherein the vitamin B1, vitamin B2, and vitamin E are mixed in a mass ratio of 1:1:2 per 100g of multi-grain composite corn flour; The mineral complex is prepared by mixing 0.3mg-0.5mg of zinc, 0.15mg-0.25mg of selenium and 0.5mg-0.7mg of magnesium per 100g of multi-grain compound corn flour, wherein the zinc, selenium and magnesium are mixed in a mass ratio of 2:1:3 in the multi-grain compound corn flour.

2. A method for ultrafine grinding of multi-grain composite corn flour, characterized in that: The following steps are involved: S1. Raw material pretreatment First, the raw materials are screened and unqualified raw materials are eliminated. Then, qualified raw materials are baked at low temperature, and the baked raw materials are subjected to enzymatic hydrolysis. S2, ultrafine grinding All the pretreated raw materials are mixed according to the ratio of claim 1 to form a mixed material, and then the material is crushed in sequence through a first-stage airflow crushing, a second-stage low-temperature rolling, and a third-stage ultrasonic-assisted ultrafine crushing, and 0.5% modified starch is added during the third-stage ultrasonic-assisted ultrafine crushing to achieve microencapsulation and embedding through the ultrasonic cavitation effect. Finally, nitrogen is introduced into the material in a double-helix conical mixer and mixed at 300±20 r / min for 15±2 minutes to achieve inert gas protection mixing; S3, post-processing The material is granulated at low temperature by a vacuum granulator to form 0.5-1 mm particles. The particles are then dried in a fluidized bed to a moisture content of 5-6%. Finally, the particles are packaged with a three-layer composite film, and the vacuum degree in the package is ≤1kPa through three pulse vacuums.

3. The multi-grain composite corn flour according to claim 1, characterized in that: The corn flour is ultrafinely ground yellow corn flour with a particle size of ≤25 μm and an amylose content of 22%-28%.

4. The multi-grain composite corn flour according to claim 1, characterized in that: The quinoa flour, chia seed flour, highland barley flour and chickpea flour are all ultrafinely ground, with a particle size of ≤25 μm. The protein content of quinoa flour is ≥16%, the Omega-3 fatty acid content of chia seed flour is ≥18%, the β-glucan content of highland barley flour is ≥5%, and the protein content of chickpea flour is ≥20%.

5. The multi-grain composite corn flour according to claim 1, characterized in that: The polymerization degree of the oligofructose is 3-6, the polymerization degree of the inulin is 2-60; and the number of viable bacteria of the Lactobacillus plantarum powder is ≥1.0×10^10 CFU / g.

6. The multi-grain composite corn flour according to claim 1, characterized in that: The rice bran dietary fiber extract has a total dietary fiber content of ≥85%, a water holding capacity of ≥5g / g, a konjac glucomannan purity of ≥90%, and a viscosity of ≥2000mPa·s. The purple sweet potato powder is ultrafinely ground to have a particle size of ≤25μm and an anthocyanin content of ≥0.2%. The flaxseed meal is ethanol-detoxified to have a cyanide content of ≤5mg / kg. The Cordyceps militaris powder is artificially cultivated and has an adenosine content of ≥0.05% and a cordycepin content of ≥0.02%.

7. The multi-grain composite corn flour according to claim 1, characterized in that: The zinc in the mineral complex is derived from zinc gluconate, the selenium is derived from selenium-enriched yeast, and the magnesium is derived from magnesium oxide.

8. The ultrafine grinding processing method of multi-grain composite corn flour according to claim 2, characterized in that: The specific method of low-temperature baking in step S1 is: Corn, barley and chickpeas are baked using a gradient temperature increase, first baked at 60±2℃ for 30 minutes, then heated to 80±2℃ for 20 minutes, and finally baked at 100±2℃ for 10 minutes. Inert gas with a purity of ≥99.9% is introduced throughout the process, with a gas flow rate of 2-3L / min. Quinoa and chia seeds are placed in a vacuum baking equipment and baked at 60±2℃ and a pressure of -0.08±0.005MPa for 2 hours. The moisture content of all raw materials after baking must be controlled at 6-7%.

9. The ultrafine grinding processing method of multi-grain composite corn flour according to claim 2, characterized in that: The enzymatic hydrolysis operation in step S1 is specifically as follows: The baked highland barley and chickpeas are preliminarily crushed to achieve a 100-mesh sieve pass rate of ≥95%, and deionized water is added at a material-liquid ratio of 1:

8. The pH is adjusted to 5.0±0.1, and 0.2% of a complex enzyme is added, wherein the complex enzyme is prepared by mixing cellulase and xylanase at a mass ratio of 1:1, wherein the cellulase activity is ≥5000U / g and the xylanase activity is ≥10000U / g. The mixture is enzymolyzed in a 50±2°C water bath for 30 minutes, and then the enzyme is inactivated in a 95°C water bath for 10 minutes. The mixture is cooled to room temperature and then centrifuged and dehydrated for later use.

10. The ultrafine grinding processing method of multi-grain composite corn flour according to claim 2, characterized in that: In the step S2, the first-stage air flow pulverization adopts a fluidized bed air flow pulverizer, the compressed air pressure is 0.8±0.05MPa, the feed rate is 10-15kg / h, the pulverization chamber temperature is controlled at -5±2°C, the material passes through a 150-mesh sieve, and the pass rate is ≥98%. The second-stage low-temperature rolling adopts a double-roller low-temperature rolling machine, liquid nitrogen refrigeration is used to maintain the rolling chamber temperature at -10±2°C, the rolling roller speed is 300r / min, the rolling gap is 0.01±0.002mm, the material passes through a 300-mesh sieve, and the pass rate is ≥98%. The third-stage ultrasonic assisted ultrafine grinding is carried out. The pulverization adopts an ultrasonic pulverizer with a probe diameter of 20 mm, an ultrasonic power of 500±50 W, an ultrasonic time of 20 minutes, an operating time of 5 seconds, an intermission of 3 seconds, a material-liquid ratio of 1:4, and a temperature controlled below 20±2°C. The final material passes through a 500-mesh sieve with a pass rate of ≥98% and a particle size of ≤25 μm. The modified starch is hydroxypropyl distarch phosphate with a substitution degree of 0.02-0.

04. The particle size after embedding is 1-5 μm and the embedding rate is ≥90%. The nitrogen in the double-helix conical mixer needs to be replaced 3 times, the residual oxygen is ≤1%, and the mixing uniformity is ≥95%.

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