Health-care food rich in zinc and selenium and preparation method thereof

Abstract

The invention relates to the technical field of health food research and development, in particular to a health food rich in zinc and selenium and a preparation method thereof, the health food comprises the following raw materials: egg white powder, yolk powder, zinc-rich micro powder and a mixed flavoring agent; the selenium-rich egg white liquid is firstly subjected to step-by-step ultrasonic treatment, and then the papain gradient enzymolysis is performed, so that the prepared egg white powder is low in caking rate and easy to brew; according to the preparation method disclosed by the invention, the egg yolk liquid of the selenium-rich eggs is firstly subjected to step-by-step ultrasonic treatment, and then is sequentially subjected to degreasing treatment, protective agent addition and alkaline protease enzymolysis treatment, so that the prepared egg yolk powder is high in solubility and lower in fat content; the mixed flavoring agent prepared from gordon euryale seeds, hawthorn fruits, Chinese dates and momordica grosvenori enables the prepared health-care food to have high contents of proteins, essential amino acids, vitamins, zinc, selenium and other trace elements, and to be low in fat and delicious.

Description

Technical Field

[0001] The invention relates to the technical field of health food research and development, in particular to a health food rich in zinc and selenium and a preparation method thereof. Background Art

[0002] Zinc and selenium are essential elements for human life and are necessary for maintaining normal metabolism of the body. Zinc and selenium deficiency can lead to various diseases. Zinc is a component of many metalloenzymes or an activator of enzymes. There are about 70-100 enzymes related to zinc. Studies have shown that zinc is necessary for the activity of RNA polymerase and DNA polymerase, and zinc can assist in the transport of glucose across the cell membrane. Zinc cannot be synthesized in the body, so it can only be obtained from outside the body. When the human body is zinc deficient, growth retardation may occur; juvenile dysplasia, taste disorders and slow wound healing, etc.; zinc deficiency in pregnant women may even cause fetal malformations. Insufficient zinc intake in food or too much fiber intake in the diet will affect zinc absorption and lead to zinc deficiency. Zinc deficiency in children is still common today.

[0003] Similarly, selenium is a component of glutathione peroxidase and phospholipid peroxidase in human red blood cells. Its main function is to participate in the synthesis of enzymes, protect the structure and function of cell membranes from excessive oxidation and interference, and has many important physiological functions. It has been confirmed that selenium is closely related to tumors, cardiovascular diseases and aging, which currently seriously affect human health. The main source of human selenium intake is also in vitro intake, while the selenium content in natural foods is generally low. The selenium content of fruits and vegetables is generally less than 0.01 mg / kg, and the selenium content of grains, marine animals and meat is slightly higher. Therefore, the selenium content in natural foods alone is generally not enough to meet the normal needs of the human body. The toxicological analysis of selenium salts shows that inorganic selenium is highly toxic and is generally only used in medicines rather than in food. Its scope of use and dosage are limited. However, studies have shown that organic selenium compounds are much less toxic than inorganic selenium compounds and have higher bioavailability. Therefore, only when inorganic selenium is converted into organic selenium can it have universal edible and health value.

[0004] Egg white hydrolysate can not only improve and change the functionality and palatability of food protein, meet the nutritional needs of various special groups of people, but also improve the foaming, solubility, viscosity, gelling, emulsification and other functions of the product. Hydrolysis can reduce the relative molecular mass of egg white, reduce allergenicity, and the resulting polypeptide mixture is more conducive to human absorption, and has physiological activities such as anti-oxidation, lowering blood lipids, and lowering blood pressure. For example, the enzymatic hydrolysis method of egg protein powder disclosed in patent technology document CN110452947B is as follows: add 10-20 times of water to the egg protein powder, stir and dissolve it, adjust the pH value to 6.8-7.2, add 2%-10% papain of the egg protein powder, stir and mix it, heat it to 55±2℃ for 3-12 hours, increase the enzymatic temperature to 65±2℃, keep it warm for 12-24 hours, heat it to above 80℃, make the unenzymatic protein fully denatured, filter it, and obtain the enzymolysate.

[0005] However, the enzymatic hydrolysis efficiency of these hydrolysis methods still needs to be improved. At the same time, these methods do not utilize both egg white and egg yolk at the same time, and the nutritional content of the prepared products is not rich enough.

[0006] Therefore, according to the above-mentioned related technologies, it is urgent to develop a health food rich in zinc and selenium and a preparation method thereof. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a zinc-selenium-rich health food and a preparation method thereof, so as to provide a zinc-selenium-rich, high-protein, low-fat, easy-to-brew health food.

[0008] Based on the above purpose, the present invention provides a health food rich in zinc and selenium and a preparation method thereof.

[0009] A health food rich in zinc and selenium, comprising the following raw materials in parts by weight: 72-75 parts of egg white powder, 18-20 parts of egg yolk powder, 0.06-0.07 parts of zinc-rich micropowder, and 7-8 parts of mixed flavor enhancer; The egg white powder is obtained by first subjecting selenium-enriched egg white liquid to step-by-step ultrasonic treatment and then to gradient enzymatic hydrolysis with papain; The gradient enzymatic hydrolysis is first performed at 55-60°C for 5-8h, then at 60-65°C for 5-8h, then at 70-78°C for 1-3h, and finally at 95-100°C for 30-45min; The egg yolk powder is obtained by first subjecting selenium-enriched egg yolk liquid to step-by-step ultrasonic treatment, and then sequentially undergoing defatting treatment, adding a protective agent, and alkaline protease enzymolysis treatment; The step-by-step ultrasonic treatment comprises first ultrasonicating the selenium-enriched egg white liquid at 60-70W and 40-45kHz for 10-15min, then ultrasonicating the selenium-enriched egg white liquid at 80-90W and 40-45kHz for 10-15min, and finally ultrasonicating the selenium-enriched egg white liquid at 150-170W and 40-45kHz for 5-10min. The protective agent is obtained by mixing maltodextrin, trehalose and mannitol; The mixed flavor enhancer is prepared from euryale ferox, hawthorn, jujube and momordica grosvenori.

[0010] Preferably, the preparation method of the egg white powder is as follows: Step A1: subjecting the selenium-enriched egg white liquid to ultrasonic treatment step by step at 10-15° C. to obtain a pretreated egg white liquid; Step A2: Mix the pretreated egg white liquid with deionized water and adjust the pH to 6.8-7.2, then add papain, mix well, perform gradient enzymolysis, spray dry, and sieving in sequence to obtain egg white protein powder.

[0011] Preferably, the usage ratio of the pretreated egg white solution, deionized water and papain in step A2 is 150 g: 700-1000 mL: 3-7.5 g.

[0012] Preferably, during the spray drying process in step A2, the feed flow rate is 600-700 mL / h and the inlet air temperature is 100-140° C.; The sieve mesh size during the sieving process in step A2 is 15-30 μm.

[0013] Preferably, the preparation method of the egg yolk powder is as follows: Step B1: at 5-10° C., after gradually ultrasonically treating the selenium-enriched egg yolk liquid, adding 95%-98% ethanol and stirring for 1-2 hours, then repeatedly adding 600-800 mL of deionized water and filtering for 3-5 times, and then centrifuging to obtain defatted egg yolk powder; Step B2: adding defatted egg yolk powder, maltodextrin, trehalose and mannitol to deionized water and mixing them evenly, adjusting the pH to 9-9.5, heating to 53-57° C., adding alkaline protease and performing enzymolysis for 0.5-1 h to obtain an enzymolysis solution; Step B3: The pH of the enzymatic hydrolysate is adjusted to 6.5-7.5, and then vacuum freeze-drying, freezing ball friction, microwave sterilization and sieving are performed in sequence to obtain egg yolk powder.

[0014] Preferably, the ratio of the selenium-enriched egg yolk liquid to ethanol in step B1 is 50-60 g: 300-360 mL; In step B1, the rotation speed during the centrifugal treatment is 10000-12000 r / min, the temperature during the centrifugal treatment is 4-5° C., and the duration of the centrifugal treatment is 20-30 min; The usage ratio of deionized water, defatted egg yolk powder, maltodextrin, trehalose, mannitol and alkaline protease in step B2 is 70-100 mL: 25-30 g: 0.7-1 g: 0.3-0.5 g: 1-1.5 g: 0.2-0.25 g; The vacuum freeze-drying treatment in step B3 is to first balance at -7--5°C for 30-40 minutes, then cool to -25--20°C and freeze for 8-10 hours, and then dry at -60--55°C and 5-8Pa for 22-25 hours; The temperature of the frozen ball milling treatment in step B3 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 30-45min; The power of the microwave sterilization treatment in step B3 is 25-40KW, the frequency of the microwave treatment is 2300-2450Hz, and the duration of the microwave treatment is 0.5-1min; The sieve mesh size during the sieving process in step B3 is 15-30 μm.

[0015] Preferably, the zinc-rich micropowder is any one of zinc gluconate and zinc lactate.

[0016] Preferably, the preparation method of the mixed flavor enhancer is as follows: Step E1: drying the monk fruit until the water content is 55%-60%, then sequentially subjecting it to microwave treatment and cryo-ball milling treatment, and then extracting it with a 0.05%-0.10% calcium hydroxide solution under stirring at room temperature for 2-5 hours, filtering, and centrifuging to obtain an extract; Step E2: introducing carbon dioxide gas into the extract while stirring, and filtering and nanofiltration are performed in sequence after the pH value is adjusted to 7.5-9.0, and the nanofiltration membrane retentate is then concentrated under reduced pressure and spray-dried to obtain the monk fruit extract; Step E3: Peeling and removing the core of Euryale ferox, hawthorn and jujube, and then freeze-drying them in vacuum, and then freezing ball-milling and sieving them, and then mixing them with Monk Fruit Extract to obtain a mixed flavor enhancer.

[0017] Preferably, the power of the microwave treatment in step E1 is 45-70KW, the frequency of the microwave treatment is 2300-2450Hz, and the duration of the microwave treatment is 5-8min; The temperature of the frozen ball milling treatment in step E1 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 45-60min; The pore size of the filter membrane during the filtration treatment in step E2 is 0.2-1 μm; In step E2, the molecular weight cutoff of the nanofiltration membrane during nanofiltration is 3000-5000Da, the filtration pressure is 0.1-0.3Mpa, and the temperature during nanofiltration is 10-15°C; The mass ratio of the extracts of Euryale ferox, hawthorn, jujube and monk fruit in step E3 is 3-3.5:2-2.2:2-2.3:0.2-0.5; The vacuum freeze-drying treatment in step E3 is to first balance at -7--5°C for 30-40 minutes, then cool to -25--20°C and freeze for 8-10 hours, and then dry at -60--55°C and 5-8Pa for 22-25 hours; The temperature of the frozen ball milling treatment in step E3 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 30-45min; The aperture size of the sieve during the sieving process in step E3 is 15-30 μm.

[0018] A method for preparing a health food rich in zinc and selenium, the method for preparing the health food rich in zinc and selenium is as follows: Egg white powder, egg yolk powder, zinc-rich micropowder and mixed flavor enhancer are evenly mixed to obtain a health food rich in zinc and selenium.

[0019] Beneficial effects of the present invention: The invention provides a zinc-selenium-rich health food and a preparation method thereof. The invention performs step-by-step ultrasonic treatment of specific parameters on egg white liquid and egg yolk powder before enzymolysis when preparing egg white powder and egg yolk powder, thereby maximally improving the solubility and dispersion stability of egg white and egg yolk, making the particle sizes of egg white and egg yolk powder smaller and reducing the power consumption to the maximum extent. The invention performs gradient enzymolysis of specific temperature on the pretreated protein liquid with papain after the step-by-step ultrasonic treatment, thereby maximally improving the enzymolysis efficiency and dispersibility of egg white powder and further reducing the particle size of egg white powder. Similarly, the egg yolk powder is defatted and enzymolyzed after the step-by-step ultrasonic treatment, thereby maximally improving the defatting rate and solubility of the egg yolk powder. The invention adds a protective agent to the defatted egg yolk before vacuum freeze drying, thereby improving the solubility of the egg yolk powder. The invention adopts microwave sterilization, thereby greatly reducing the possibility of agglomeration during the sterilization process, and the invention subsequently performs screening treatment. Therefore, the sterilization process will not only not reduce the solubility of the egg yolk powder, but also improve the solubility of the egg yolk powder; the addition of the mixed flavor enhancer of the present invention can greatly improve the flavor and taste of the zinc-selenium-rich health food, and can also improve its satiety, heat-clearing and lung-moistening ability and digestion-promoting ability, thereby alleviating the side effects such as indigestion caused by a large amount of high-protein intake. DETAILED DESCRIPTION

[0020] In order to make the objectives, 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.

[0021] Example 1: A method for preparing a zinc-selenium-rich health food is as follows: S1: At 10°C, the selenium-enriched egg white liquid was first sonicated at 60W and 40kHz for 10 minutes, then sonicated at 80W and 40kHz for 10 minutes, and finally sonicated at 150W and 40kHz for 5 minutes to obtain a pretreated egg white liquid; S2: 150 g of pretreated egg white liquid was mixed with 700 mL of deionized water and the pH was adjusted to 6.8, then 3 g of papain was added, and after mixing, the mixture was first enzymolyzed at 55°C for 5 h, then at 60°C for 5 h, then at 70°C for 1 h, and finally at 95°C for 30 min; then, the mixture was spray dried at a feed rate of 600 mL / h and an inlet air temperature of 100°C; and then, the mixture was sieved with a sieve with an aperture of 15 μm to obtain egg white powder; S3: At 5°C, 50 g of selenium-enriched egg yolk liquid was ultrasonicated once at 60W and 40kHz for 10 min, then ultrasonicated twice at 80W and 40kHz for 10 min, and finally ultrasonicated three times at 150W and 40kHz for 5 min; then 300 mL of 95% pure ethanol was added and stirred for 1 h, then 600 mL of deionized water was repeatedly added and filtered for 3 times, and then centrifuged at 10000 r / min for 20 min at 4°C to obtain defatted egg yolk powder; S4: Add 25 g defatted egg yolk powder, 0.7 g maltodextrin, 0.3 g trehalose, and 1 g mannitol to 70 mL deionized water and mix well. Adjust the pH to 9, then heat to 53° C. and add 0.2 g alkaline protease to perform enzymolysis for 0.5 h to obtain an enzymolysis solution. S5: The pH of the enzymatic hydrolysate was adjusted to 6.5, and then the solution was balanced at -7°C for 30 minutes, then cooled to -25°C and frozen for 8 hours, and then dried at -60°C and 5Pa for 22 hours; then the solution was frozen and ball-milled at -15°C and 500 r / min for 30 minutes, and then microwaved for 0.5 minutes at a power of 25 kW and a frequency of 2300 Hz, and finally sieved with a sieve with an aperture of 15 μm to obtain egg yolk powder; S6: drying the monk fruit until the moisture content is 55%, then subjecting it to microwave treatment at a power of 45 kW and a frequency of 2300 Hz for 5 min, then subjecting it to cryo-ball milling at -15°C and 500 rpm for 45 min, then extracting it with a 0.05% calcium hydroxide solution at room temperature for 2 h, filtering it, and centrifuging it to obtain an extract; S7: introducing carbon dioxide gas into the extract while stirring, and after the pH value is adjusted to 7.5, filtering with a filter membrane with a pore size of 0.2 μm, and then filtering with a nanofiltration membrane with a molecular weight cutoff of 3000-5000Da at 0.1Mpa at 10°C, and concentrating the nanofiltration membrane retentate under reduced pressure and spray drying to obtain a monk fruit extract; S8: 3g of Euryale ferox, 2g of hawthorn and 2g of jujube were peeled and pitted, then balanced at -7°C for 30min, then cooled to -25°C and frozen for 8h, and then dried at -60°C and 5Pa for 22h; then, ball milled at -15°C and 500r / min for 30min, then sieved with a sieve with a pore size of 15μm, and finally mixed with 0.2g of monk fruit extract to obtain a mixed flavor enhancer; S9: 72 g of egg white powder, 18 g of egg yolk powder, 0.06 g of zinc gluconate, and 7 g of mixed flavor enhancer are mixed evenly to obtain a health food rich in zinc and selenium; Example 2: A method for preparing a zinc-selenium-rich health food is as follows: S1: At 12°C, the selenium-enriched egg white liquid was first sonicated at 65W and 43kHz for 12 minutes, then sonicated at 85W and 43kHz for 12 minutes, and finally sonicated at 155W and 43kHz for 7 minutes to obtain the pretreated egg white liquid; S2: 150 g of pretreated egg white liquid was mixed with 800 mL of deionized water and the pH was adjusted to 6.9, then 4.5 g of papain was added, and after mixing, the mixture was first enzymolyzed at 57°C for 6 h, then at 62°C for 6 h, then at 73°C for 1.5 h, and finally at 97°C for 35 min; then, the mixture was spray dried at a feed rate of 630 mL / h and an inlet air temperature of 120°C; and then, the mixture was sieved with a sieve with an aperture of 21 μm to obtain egg white powder; S3: At 7°C, 53 g of selenium-enriched egg yolk liquid was first sonicated at 63 W and 42 kHz for 12 min, then sonicated at 83 W and 42 kHz for 12 min, and finally sonicated at 155 W and 42 kHz for 7 min; then 320 mL of 95% pure ethanol was added and stirred for 1.3 h, then 670 mL of deionized water was repeatedly added and filtered 4 times, and then centrifuged at 4.5°C at a speed of 10500 r / min for 23 min to obtain defatted egg yolk powder; S4: Add 27 g defatted egg yolk powder, 0.8 g maltodextrin, 0.4 g trehalose, and 1.3 g mannitol to 80 mL deionized water and mix well. Adjust the pH to 9.3, then heat to 55°C and add 0.23 g alkaline protease to perform enzymolysis for 0.8 h to obtain an enzymolysis solution. S5: The pH of the enzymatic hydrolysate was adjusted to 7, and then the solution was balanced at -6°C for 35 minutes, then cooled to -23°C and frozen for 9 hours, and then dried at -57°C and 7Pa for 24 hours; then the solution was frozen and ball-milled at -13°C and 550 r / min for 40 minutes, and then microwaved for sterilization at a power of 30 kW and a frequency of 2350 Hz for 0.8 minutes, and finally sieved with a sieve with an aperture of 21 μm to obtain egg yolk powder; S6: drying the monk fruit until the moisture content is 58%, then subjecting it to microwave treatment at a power of 60 kW and a frequency of 2400 Hz for 7 min, then subjecting it to cryo-ball milling at -13°C and 550 r / min for 55 min, then extracting it with a 0.08% calcium hydroxide solution at room temperature for 3 h under stirring, filtering, and centrifuging to obtain an extract; S7: introducing carbon dioxide gas into the extract while stirring, and after the pH value is adjusted to 8.0, filtering with a filter membrane with a pore size of 0.5 μm, and then filtering with a nanofiltration membrane with a molecular weight cutoff of 3000-5000Da at 13°C at 0.2Mpa, and the nanofiltration membrane retentate is then concentrated under reduced pressure and spray-dried to obtain a monk fruit extract; S8: 3.3 g Euryale ferox, 2.1 g Hawthorn, and 2.1 g jujube are peeled and pitted, then balanced at -6°C for 35 min, then cooled to -23°C and frozen for 9 h, and then dried at -57°C and 7 Pa for 24 h; then, they are frozen ball-milled at -13°C and 550 r / min for 40 min, then sieved with a sieve with a pore size of 21 μm, and finally mixed with 0.3 g Momordica grosvenori extract to obtain a mixed flavor enhancer; S9: 73 g of egg white powder, 19 g of egg yolk powder, 0.07 g of zinc gluconate, and 7.5 g of mixed flavor enhancer are mixed evenly to obtain a health food rich in zinc and selenium; Example 3: A method for preparing a zinc-selenium-rich health food is as follows: S1: At 15°C, the selenium-enriched egg white liquid was first sonicated at 70W and 45kHz for 15 minutes, then sonicated at 90W and 45kHz for 15 minutes, and finally sonicated at 170W and 45kHz for 10 minutes to obtain the pretreated egg white liquid; S2: 150 g of pretreated egg white liquid was mixed with 1000 mL of deionized water and the pH was adjusted to 7.2, then 7.5 g of papain was added, and after mixing, enzymolysis was first performed at 60° C. for 8 h, then at 65° C. for 8 h, then at 78° C. for 3 h, and finally at 100° C. for 45 min; then spray drying was performed at a feed rate of 700 mL / h and an inlet air temperature of 140° C.; and then the egg white powder was obtained after sieving with a sieve with an aperture size of 30 μm; S3: At 10°C, 60 g of selenium-enriched egg yolk liquid was first sonicated at 70W and 45kHz for 15 minutes, then sonicated at 90W and 45kHz for 15 minutes, and finally sonicated at 170W and 45kHz for 10 minutes; then 360 mL of 98% pure ethanol was added and stirred for 2 hours, then 800 mL of deionized water was repeatedly added and filtered for 5 times, and then centrifuged at 12000 r / min for 30 minutes at 5°C to obtain defatted egg yolk powder; S4: Add 30 g defatted egg yolk powder, 1 g maltodextrin, 0.5 g trehalose, and 1.5 g mannitol to 100 mL deionized water and mix well. Adjust the pH to 9.5, then heat to 57° C. and add 0.25 g alkaline protease for 1 h of enzymolysis to obtain an enzymolysis solution. S5: The pH of the enzymatic hydrolysate was adjusted to 7.5, and then the solution was balanced at -5°C for 40 minutes, then cooled to -20°C and frozen for 10 hours, and then dried at -55°C and 8Pa for 25 hours; then the solution was subjected to a freezing ball milling treatment at -10°C and 600 r / min for 45 minutes, and then subjected to a microwave sterilization treatment at a power of 40 kW and a frequency of 2450 Hz for 1 minute, and finally sieved with a sieve with an aperture of 30 μm to obtain the egg yolk powder; S6: drying the monk fruit until the water content is 60%, then subjecting it to microwave treatment at a power of 70 kW and a frequency of 2450 Hz for 8 min, then subjecting it to cryo-ball milling at -10°C and 600 r / min for 60 min, then extracting it with a 0.10% calcium hydroxide solution at room temperature for 5 h, filtering it, and centrifuging it to obtain an extract; S7: introducing carbon dioxide gas into the extract while stirring, and after the pH value is adjusted to 9.0, filtering with a filter membrane with a pore size of 1 μm, and then filtering with a nanofiltration membrane with a molecular weight cutoff of 3000-5000Da at 0.3Mpa at 15°C, and concentrating the nanofiltration membrane retentate under reduced pressure and spray drying to obtain a monk fruit extract; S8: 3.5 g of Euryale ferox, 2.2 g of hawthorn, and 2.3 g of jujube were peeled and pitted, then balanced at -5°C for 40 min, then cooled to -20°C and frozen for 10 h, and then dried at -55°C and 8 Pa for 25 h; then, they were frozen ball-milled at -10°C and 600 r / min for 45 min, and then sieved with a sieve with a pore size of 30 μm, and finally mixed with 0.5 g of monk fruit extract to obtain a mixed flavor enhancer; S9: 75 g of egg white powder, 20 g of egg yolk powder, 0.06 g of zinc lactate, and 8 g of mixed flavor enhancer are mixed evenly to obtain a health food rich in zinc and selenium; Comparative Example 1: Compared with Example 1, this comparative example only replaces the following in the process of preparing the pretreated egg white liquid: "At 10°C, the selenium-enriched egg white liquid is first ultrasonicated at 60W and 40kHz for 10 minutes, then ultrasonicated at 80W and 40kHz for 10 minutes, and finally ultrasonicated at 150W and 40kHz for 5 minutes to obtain the pretreated egg white liquid" with "At 10°C, the selenium-enriched egg white liquid is first ultrasonicated at 60W and 40kHz for 10 minutes, then ultrasonicated at 150W and 40kHz for 15 minutes to obtain the pretreated egg white liquid", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 2: Compared with Example 1, this comparative example only replaces the process of preparing the pretreated egg white liquid with "at 10°C, first ultrasonically treat the selenium-enriched egg white liquid at 60W and 40kHz for 10 minutes, then ultrasonically treat the selenium-enriched egg white liquid at 80W and 40kHz for 10 minutes, and finally ultrasonically treat the selenium-enriched egg white liquid at 150W and 40kHz for 5 minutes to obtain the pretreated egg white liquid" with "at 10°C, ultrasonically treat the selenium-enriched egg white liquid at 150W and 40kHz for 25 minutes to obtain the pretreated egg white liquid", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 3: Compared with Example 1, this comparative example only replaces the "150g pre-treated egg white liquid" added in the egg white powder preparation process with "150g selenium-enriched egg white liquid", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 4: Compared with Example 1, this comparative example only replaces the step of "enzymolyzing at 55°C for 5h after mixing, then enzymolyzing at 60°C for 5h, then enzymolyzing at 70°C for 1h, and finally treating at 95°C for 30min" in the egg white powder preparation process with "enzymolyzing at 55°C for 5h after mixing, then enzymolyzing at 65°C for 6h, and finally treating at 95°C for 30min", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 5: Compared with Example 1, this comparative example only changes the process of preparing defatted egg yolk powder in which "50 g of selenium-enriched egg yolk liquid was ultrasonicated at 60 W and 40 kHz for 10 min at 5 ° C, then ultrasonicated at 80 W and 40 kHz for 10 min twice, and finally ultrasonicated at 150 W and 40 kHz for 5 min three times; then 300 mL of 95% pure ethanol was added and stirred for 1 h, then 600 mL of deionized water was repeatedly added and filtered for 3 times, and then ultrasonicated at 10 ° C at 4 ° C for 5 min. 000r / min speed for 20min centrifugation to obtain defatted egg yolk powder" is replaced by "adding 300mL of 95% purity ethanol to 50g of selenium-enriched egg yolk liquid and stirring for 1h, then repeatedly adding 600mL of deionized water and filtering for 3 times, and then centrifuging at a speed of 10000r / min for 20min at 4°C to obtain defatted egg yolk powder", and the remaining steps and parameters are the same, and this comparative example will not be repeated, and finally a health food rich in zinc and selenium is obtained; Comparative Example 6: Compared with Example 1, this comparative example only replaces the following in the process of preparing the pre-treated egg white liquid: "At 5°C, 50g of selenium-enriched egg yolk liquid is first ultrasonicated at 60W and 40kHz for 10min, then ultrasonicated at 80W and 40kHz for 10min twice, and finally ultrasonicated at 150W and 40kHz for 5min three times; then 300mL of 95% purity ethanol is added and stirred for 1h, then 600mL of deionized water is repeatedly added and filtered three times, and then centrifuged at 4°C at a speed of 10000r / min for 20min to obtain defatted egg yolk powder" with "At 5°C, 50g of selenium-enriched egg yolk liquid is first ultrasonicated at 60W and 40kHz for 10min, then ultrasonicated at 80W and 40kHz for 10min twice, and finally ultrasonicated at 150W and 40kHz for 5min three times to obtain defatted egg yolk powder", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 7: Compared with Example 1, this comparative example does not add maltodextrin, trehalose and mannitol during the preparation of the enzymatic hydrolyzate, and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 8: Compared with Example 1, this comparative example only replaces the "0.7g maltodextrin, 0.3g trehalose, and 1g mannitol" added in the preparation process of the enzymatic hydrolyzate with "0.5g trehalose and 1.5g mannitol", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 9: Compared with Example 1, this comparative example only replaces the step of "further performing microwave sterilization at a power of 25KW and a frequency of 2300Hz for 0.5min" in the egg yolk powder preparation process with "further performing sterilization at 95°C for 5min", and the remaining steps and parameters are the same, which will not be repeated in this comparative example, and finally a health food rich in zinc and selenium is obtained; Comparative Example 10: Compared with Example 1, this comparative example does not add a mixed flavor enhancer during the preparation of the zinc-selenium-rich health food, and the remaining steps and parameters are the same, which will not be repeated in this comparative example. Finally, a zinc-selenium-rich health food is obtained; Performance Testing: Determination of zinc content: Referring to the determination standard of GB5009.14-2017 "Determination of Zinc in Foods of National Food Safety Standard", the zinc content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 10 was determined; Determination of selenium content: Referring to GB5009.93 "National Food Safety Standard - Determination of Selenium in Food", the selenium content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 and Comparative Examples 1 to 10 of the present invention was determined; Determination of protein content: Referring to the determination standard of GB5009.5-2016 "Determination of Protein in Foods of National Food Safety Standard", the protein content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 10 was determined; Determination of fat content: With reference to the determination standard of GB5009.6-2016 "Determination of Fat in Foods of National Food Safety Standard", the fat content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 10 was determined; Determination of moisture content: Referring to the determination standard of GB5009.3-2016 "Determination of Water in Foods in National Food Safety Standard", the water content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 10 was determined; Determination of ash content: With reference to GB5009.4-2016 "National Food Safety Standard - Determination of Ash in Food", the ash content of the zinc-selenium-rich health foods prepared in Examples 1 to 3 and Comparative Examples 1 to 10 of the present invention was determined; Sensory evaluation: Take 50g of zinc-selenium-rich health food and mix it with 300mL of drinking water at 60°C, then stir for 3min, observe the tissue state under natural light, smell it, rinse your mouth with warm water, and taste it. Then perform sensory evaluation on the smell, taste, and presence of lumps after brewing. According to this method, the zinc-selenium-rich health food prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 10 was subjected to sensory evaluation; the evaluation results are shown in Table 1; Table 1 Data Analysis: As can be seen from Table 1, the zinc-selenium-rich health food prepared by the present invention has higher zinc, selenium and protein contents; lower fat, moisture and ash contents; and better solubility and flavor; This may be because the present invention first performs step-by-step ultrasonic treatment of specific parameters on the egg white liquid and the egg yolk powder before enzymolysis when preparing the egg white powder and the egg yolk powder, which can maximize the solubility and dispersion stability of the egg white and the egg yolk, so that the particle size of the egg white and the egg yolk powder is smaller, and the power consumption is minimized; and the present invention performs a gradient enzymolysis of a specific temperature on the pretreated protein liquid with papain after the step-by-step ultrasonic treatment, which can maximize the enzymolysis efficiency and the dispersibility of the egg white powder, and further reduce the particle size of the egg white powder; similarly, defatting and enzymolysis of the egg yolk powder after the step-by-step ultrasonic treatment can also maximize the degreasing rate and solubility of the egg yolk powder; The protective agent is added to the defatted egg yolk before vacuum freeze drying to reduce the aggregation of egg yolk protein caused by freezing and the destruction of the natural structure of lipoprotein by dehydration due to drying; at the same time, the addition of the protective agent prepared in a specific ratio can also make the egg yolk powder particles smaller, the particle size distribution more uniform, and reduce the hydrophobicity of the egg yolk powder, thereby improving its solubility and the retention rate of biologically active proteins; High temperature sterilization will cause the egg yolk powder to aggregate due to heat and form granules, which will lead to poor solubility of defatted egg yolk powder. However, the present invention uses microwave sterilization to greatly reduce the possibility of agglomeration, while reducing the moisture content in the egg yolk powder to improve the storage capacity of the zinc-selenium-rich health food, and the present invention subsequently performs a screening process. Therefore, the sterilization process will not only not reduce the solubility of the egg yolk powder, but also improve the storage stability and solubility of the egg yolk powder; The addition of the mixed flavor enhancer prepared from Euryale ferox, hawthorn, jujube and monk fruit in the present invention can greatly improve the flavor and taste of the zinc-selenium-rich health food, and can also improve its satiety, heat-clearing and lung-moistening ability and digestion-promoting ability, thereby alleviating the side effects such as indigestion caused by a large amount of high protein intake. In the preparation process of the monk fruit extract, the present invention further improves the extraction rate of its effective components to the greatest extent, and uses it to replace sweeteners such as sucrose to improve the taste, so that the sweet taste of the zinc-selenium-rich health food is more natural and soft, while also reducing the calorie intake.

[0022] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0023] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A health food rich in zinc and selenium, characterized in that: The method comprises the following raw materials in parts by weight: 72-75 parts of egg white powder, 18-20 parts of egg yolk powder, 0.06-0.07 parts of zinc-rich micropowder, and 7-8 parts of mixed flavor enhancer; The egg white powder is obtained by first subjecting selenium-enriched egg white liquid to step-by-step ultrasonic treatment and then to gradient enzymatic hydrolysis with papain; The gradient enzymatic hydrolysis is first performed at 55-60°C for 5-8h, then at 60-65°C for 5-8h, then at 70-78°C for 1-3h, and finally at 95-100°C for 30-45min; The egg yolk powder is obtained by first subjecting selenium-enriched egg yolk liquid to step-by-step ultrasonic treatment, and then sequentially undergoing defatting treatment, adding a protective agent, and enzymolysis treatment with alkaline protease; The step-by-step ultrasonic treatment comprises first ultrasonicating the selenium-enriched egg white liquid at 60-70W and 40-45kHz for 10-15min, then ultrasonicating the selenium-enriched egg white liquid at 80-90W and 40-45kHz for 10-15min, and finally ultrasonicating the selenium-enriched egg white liquid at 150-170W and 40-45kHz for 5-10min. The protective agent is obtained by mixing maltodextrin, trehalose and mannitol; The mixed flavor enhancer is prepared from euryale ferox, hawthorn, jujube and momordica grosvenori.

2. The zinc-selenium-rich health food according to claim 1, characterized in that: The preparation method of described egg white powder is as follows: Step A1: subjecting the selenium-enriched egg white liquid to ultrasonic treatment step by step at 10-15° C. to obtain a pretreated egg white liquid; Step A2: The pretreated egg white liquid is mixed with deionized water and the pH is adjusted to 6.8-7.2, and then papain is added. After mixing, gradient enzymatic hydrolysis, spray drying and sieving are performed in sequence to obtain egg white powder.

3. The zinc-selenium-rich health food according to claim 2, characterized in that: The usage ratio of the pretreated egg white solution, deionized water and papain in step A2 is 150 g: 700-1000 mL: 3-7.5 g.

4. The zinc-selenium-rich health food according to claim 2, characterized in that: During the spray drying process in step A2, the feed flow rate is 600-700 mL / h and the inlet air temperature is 100-140° C.; The sieve mesh size during the sieving process in step A2 is 15-30 μm.

5. The zinc-selenium-rich health food according to claim 1, characterized in that: The preparation method of the egg yolk powder is as follows: Step B1: at 5-10° C., after gradually ultrasonically treating the selenium-enriched egg yolk liquid, adding 95%-98% ethanol and stirring for 1-2 hours, then repeatedly adding 600-800 mL of deionized water and filtering for 3-5 times, and then centrifuging to obtain defatted egg yolk powder; Step B2: adding defatted egg yolk powder, maltodextrin, trehalose and mannitol to deionized water and mixing them evenly, adjusting the pH to 9-9.5, heating to 53-57° C., adding alkaline protease and performing enzymolysis for 0.5-1 h to obtain an enzymolysis solution; Step B3: The pH of the enzymatic hydrolysate is adjusted to 6.5-7.5, and then vacuum freeze-drying, freezing ball friction, microwave sterilization and sieving are performed in sequence to obtain egg yolk powder.

6. The zinc-selenium-rich health food according to claim 5, characterized in that: The ratio of the selenium-enriched egg yolk liquid to ethanol in step B1 is 50-60 g: 300-360 mL; In step B1, the rotation speed during the centrifugal treatment is 10000-12000 r / min, the temperature during the centrifugal treatment is 4-5° C., and the duration of the centrifugal treatment is 20-30 min; The usage ratio of deionized water, defatted egg yolk powder, maltodextrin, trehalose, mannitol and alkaline protease in step B2 is 70-100 mL: 25-30 g: 0.7-1 g: 0.3-0.5 g: 1-1.5 g: 0.2-0.25 g; The vacuum freeze-drying treatment in step B3 is to first balance at -7--5°C for 30-40 minutes, then cool to -25--20°C and freeze for 8-10 hours, and then dry at -60--55°C and 5-8Pa for 22-25 hours; The temperature of the frozen ball milling treatment in step B3 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 30-45min; The power of the microwave sterilization treatment in step B3 is 25-40KW, the frequency of the microwave treatment is 2300-2450Hz, and the duration of the microwave treatment is 0.5-1min; The sieve mesh size during the sieving process in step B3 is 15-30 μm.

7. The zinc-selenium-rich health food according to claim 1, characterized in that: The zinc-rich micropowder is any one of zinc gluconate and zinc lactate.

8. The zinc-selenium-rich health food according to claim 1, characterized in that: The preparation method of the mixed flavor enhancer is as follows: Step E1: drying the monk fruit until the water content is 55%-60%, then sequentially subjecting it to microwave treatment and cryo-ball milling treatment, and then extracting it with a 0.05%-0.10% calcium hydroxide solution under stirring at room temperature for 2-5 hours, filtering, and centrifuging to obtain an extract; Step E2: introducing carbon dioxide gas into the extract while stirring, and filtering and nanofiltration are performed in sequence after the pH value is adjusted to 7.5-9.0, and the nanofiltration membrane retentate is then concentrated under reduced pressure and spray-dried to obtain the monk fruit extract; Step E3: Peeling and removing the core of Euryale ferox, hawthorn and jujube, and then freeze-drying them in vacuum, and then freezing ball-milling and sieving them, and then mixing them with Monk Fruit Extract to obtain a mixed flavor enhancer.

9. The zinc-selenium-rich health food according to claim 8, characterized in that: The power of the microwave treatment in step E1 is 45-70KW, the frequency of the microwave treatment is 2300-2450Hz, and the duration of the microwave treatment is 5-8min; The temperature of the frozen ball milling treatment in step E1 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 45-60min; The pore size of the filter membrane during the filtration treatment in step E2 is 0.2-1 μm; In step E2, the molecular weight cutoff of the nanofiltration membrane during nanofiltration is 3000-5000Da, the filtration pressure is 0.1-0.3Mpa, and the temperature during nanofiltration is 10-15°C; The mass ratio of the extracts of Euryale ferox, hawthorn, jujube and monk fruit in step E3 is 3-3.5:2-2.2:2-2.3:0.2-0.5; The vacuum freeze-drying treatment in step E3 is to first balance at -7--5°C for 30-40 minutes, then cool to -25--20°C and freeze for 8-10 hours, and then dry at -60--55°C and 5-8Pa for 22-25 hours; The temperature of the frozen ball milling treatment in step E3 is -15--10°C, the ball milling speed is 500-600r / min, and the ball milling time is 30-45min; The aperture size of the sieve during the sieving process in step E3 is 15-30 μm.

10. A method for preparing a zinc-selenium-rich health food according to any one of claims 1 to 9, characterized in that: The preparation method of the zinc-selenium-rich health food is as follows: Egg white powder, egg yolk powder, zinc-rich micropowder and mixed flavor enhancer are evenly mixed to obtain a health food rich in zinc and selenium.

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