Infant standard yellow millet suitable for infants to eat and preparation method of infant standard yellow millet

Abstract

The invention relates to the technical field of food, in particular to infant standard yellow millet suitable for infants to eat and a preparation method of the infant standard yellow millet. The infant standard yellow millet is prepared by the method. The method comprises the following steps: cleaning selected qualified yellow millet, soaking in water, draining, crushing, and sieving with a 80-mesh sieve to obtain first rice flour; the first rice flour is subjected to first drying treatment and then subjected to first screening treatment, and second rice flour is obtained; uniformly mixing the second rice flour with nutrients according to the required dosage to obtain mixed rice flour; performing twin-screw extrusion treatment on the mixed rice flour to obtain recombinant yellow millet particles; the recombined yellow millet particles are subjected to second drying treatment and then subjected to second screening treatment, and the infant standard yellow millet is obtained. The prepared infant standard yellow millet is high in nutrition retention and low in nutrient loss rate in the shelf life, can always meet the GB 10769-2025 infant grain standard, and can be commercially and continuously produced.

Description

Technical Field

[0001] This invention relates to the field of food technology, and in particular to a type of infant-grade yellow millet suitable for infants and young children, and its preparation method. Background Technology

[0002] Yellow millet is renowned for its spleen-strengthening and stomach-nourishing properties, boasting a sweet, fragrant, soft, and smooth texture, making it a top choice for regulating the spleen and stomach during the complementary food stage. However, natural yellow millet has a low energy density, is deficient in essential fatty acids, and its key trace elements such as calcium, iron, zinc, and selenium are significantly different from the physiological needs of infants aged 0-36 months. Currently, there is a technological gap in fortified yellow millet, and no yellow millet products that meet infant standards are available on the market, creating a double gap of "technological and product gaps." Therefore, developing a yellow millet product that meets the regulatory requirements for infant complementary foods and has a high nutrient density is of urgent practical significance for filling the dual gaps in product and technology in the market and improving the matrix of cereal complementary foods for infants in my country.

[0003] Based on research, producing infant-grade yellow millet requires fortifying natural yellow millet with calcium, iron, zinc, vitamin B1, vitamin D, vitamin A, and vitamin C. Current fortified rice production processes include: 1) Soaking (i.e., immersion) method: Soak white rice in a weak acid or neutral solution containing nutrients for 2-4 hours, allowing the rice grains to absorb the nutrients, and then dry them with hot air. 2) Spraying (i.e. coating) method: Use vacuum spraying to "brush" the nutrient solution onto the surface of rice grains, and then apply edible film such as pectin-gum arabic-starch or collodion in 2 to 3 times to form a "protective layer"; 3) Ultrasonic-steam composite spraying method: Rice is first ultrasonically soaked in nutrient solution, then steamed and gelatinized, fluidized and air-dried, sprayed with nutrient solution a second time, and frozen, and then microwave dried; among them, the freezing step can slow down the oxidation of nutrients during storage. 4) Microencapsulation emulsion method: Easily oxidized nutrients such as vitamin A, vitamin D, and folic acid are made into microencapsulated emulsions and then coated on the surface, which maintains a good nutrient loss rate during shelf life. 5) Breeding enhancement method: Increase the iron, zinc and vitamin A content of rice itself through hybridization or gene editing, which complements the post-processing enhancement.

[0004] However, the aforementioned fortified rice processing technology also has shortcomings: 1) Although the soaking (i.e., immersion) method has simple equipment and low cost, the nutrient distribution is uneven, the nutrient loss rate after washing is extremely high, and it is easy to develop odors and discoloration. 2) The disadvantages of spraying (i.e. coating) method are that there are many processes and high costs. If the film is too thick, it will affect the overall flavor and make the overall flavor of the product poor. 3) The ultrasonic-vapor composite spraying method involves complex procedures, the technology is not mature enough, and the possibility of industrialization is low; 4) The microencapsulation emulsion method has high process costs and low industrial feasibility; 5) Breeding enhancement methods tend to focus on single nutrient enhancement, making it difficult to achieve multi-nutrient enhancement. Furthermore, breeding takes a long time and has a long development cycle.

[0005] It is evident that although there are many processes for fortified rice, they all have shortcomings and are not suitable for developing infant-labeled yellow millet products suitable for infants and young children.

[0006] Therefore, it is necessary to provide a suitable infant-labeled yellow millet and its preparation method to solve the technical problem of the dual gap of "technological gap and product gap" in infant-labeled yellow millet. Summary of the Invention

[0007] The purpose of this invention is to provide a baby-labeled yellow millet suitable for infants and young children, and its preparation method. The specific technical solution is as follows: In a first aspect, the present invention provides a method for preparing infant-labeled yellow millet suitable for infants and young children, comprising: Step S1: After washing the selected qualified yellow millet, soak it in water, drain it, and crush it through an 80-mesh sieve to obtain the first rice flour. Step S2: After the first rice flour undergoes a first drying process, it is then subjected to a first sieving process to obtain the second rice flour. Step S3: Mix the second rice flour with the nutrients according to the required amount to obtain mixed rice flour; wherein, in every 100 grams of the second rice flour, the nutrients and the amount added include: vitamin A added at 200~400 μgRE, vitamin D added at 10~30 μg, vitamin B1 added at 250~400 μg, vitamin C added at 35~50 mg, calcium carbonate added at 300~400 mg, ferrous fumarate added at 10~40 mg, and zinc gluconate added at 5~20 mg; Step S4: The mixed rice flour is processed by twin-screw extrusion to obtain reconstituted yellow millet granules; Step S5: After the recombinant yellow millet particles undergo a second drying process, they are then subjected to a second sieving process to obtain infant-grade yellow millet.

[0008] Optionally, the soaking time for the soaking treatment is 4 to 6 hours.

[0009] Optionally, the first drying process uses a drying temperature of 60~70 ℃, and dries the rice flour until the moisture content is less than 12%.

[0010] Optionally, the parameters used in the twin-screw extrusion process include: screw diameter of 30~50 mm, screw length-to-diameter ratio of 10:1~15:1, screw speed of 100~200 rpm, barrel temperature of 60~100 ℃, die temperature of 60~110 ℃, feed rate of 50~100 kg / h, and cutting speed of 500~1000 rpm.

[0011] Optionally, the moisture content of the mixed rice flour needs to be controlled to be 20%~24% during the twin-screw extrusion process.

[0012] Optionally, the second drying process uses a drying temperature of 60~80 ℃, a drying time of 30~60 min, an air velocity of 1~2 m / s, and dries until the moisture content of the recombinant yellow millet grains is less than 12%.

[0013] Optionally, the first screening process is completed using a 20-60 mesh vibrating screen; the second screening process is completed using a 20-60 mesh vibrating screen.

[0014] Optionally, the preparation method of the infant-labeled yellow millet suitable for infants and young children further includes step S6, which involves mixing the infant-labeled yellow millet with selected qualified yellow millet at a mass ratio of 1:2 to 1:1, and then packaging it after vacuuming to obtain the improved infant-labeled yellow millet product.

[0015] Optionally, the qualified yellow millet is natural yellow millet that is free from mold and insect infestation.

[0016] In a second aspect, the present invention provides a yellow millet labeled for infants and young children, which is prepared by the aforementioned method for preparing yellow millet labeled for infants and young children.

[0017] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The present invention provides a method for preparing infant-labeled yellow millet suitable for infants and young children. The prepared infant-labeled yellow millet has high nutrient retention and low nutrient loss rate during shelf life, and can always meet the GB 10769-2025 infant cereal standard. It can be commercially produced continuously, which is of urgent practical significance for filling the market gap in both products and technology and improving the matrix of infant cereal supplementary foods in my country. Specifically, the present invention uses soaking treatment on qualified yellow millet to make it fully absorb water, which is conducive to the "pre-swelling" of starch macromolecules, promotes the physical change of starch macromolecule structure, and thus enhances the chelation strength between yellow millet and various nutrients during subsequent twin-screw extrusion processing. This not only increases the nutrient content, but also reduces the nutrient loss rate during shelf life. In addition, soaking treatment can also increase the phytic acid content in the infant-labeled yellow millet product, thereby increasing its chelated Zn. 2+ Fe 3+ and Ca2+ This ability further increases nutrient content and reduces nutrient loss during shelf life.

[0018] (2) The present invention uses specific parameters in the twin-screw extrusion process to promote the partial degradation of tannins and phytic acid in millet, reduce astringency, and promote the breakage of starch chains in millet to produce a small amount of maltose and glucose, resulting in a noticeable sweet aftertaste, thus making it sweeter than natural millet. In addition, twin-screw extrusion processing can also improve the overall cooking quality of the improved infant-label yellow millet product. Specifically, compared with natural yellow millet, the improved infant-label yellow millet product has a lower water absorption rate. This is because twin-screw extrusion processing causes partial gelatinization of the starch inside the millet, resulting in a relatively lower water absorption rate during cooking. Compared with natural yellow millet, the improved infant-label yellow millet product has a lower cooking loss rate. This is related to the microstructure of the millet. The internal structure of natural yellow millet is loose, which is prone to disintegration during cooking, leading to the dissolution of more components. However, twin-screw extrusion processing makes the internal structure of the millet more compact, and the components have good adhesion, which reduces the cooking loss rate of the improved infant-label yellow millet product and improves the taste and flavor of the millet. Compared with natural yellow millet, the improved infant-label yellow millet product has a lower expansion rate. This is because the starch in the improved infant-label yellow millet undergoes partial gelatinization during twin-screw extrusion before cooking, and the internal structure is relatively compact and dense, resulting in a lower water absorption rate and a lower expansion rate during cooking.

[0019] (3) The improved product of infant-labeled yellow millet prepared by the present invention, due to the addition of a suitable proportion of qualified natural yellow millet, can make up for the loss of flavor and taste of the reconstituted yellow millet particles due to twin-screw extrusion processing, thereby giving the improved product of infant-labeled yellow millet a good flavor and taste. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example: A method for preparing infant-labeled yellow millet suitable for infants and young children includes: Step S1: After washing the selected qualified yellow millet with clean water to remove surface dust and impurities, soak it in water, drain it, and then use a hammer mill to crush the soaked yellow millet through an 80-mesh sieve to obtain the first rice flour. Step S2: After the first rice flour undergoes a first drying process, it is then subjected to a first sieving process to obtain the second rice flour. Step S3: According to GB 10769-2025 standard, the second rice flour and nutrients are mixed in the required amounts using a three-dimensional motion mixer to obtain mixed rice flour; wherein, in every 100 grams of the second rice flour, the nutrients and their added amounts include: vitamin A added amount of 200~400 μgRE, vitamin D added amount of 10~30 μg, vitamin B1 added amount of 250~400 μg, vitamin C added amount of 35~50 mg, calcium carbonate added amount (i.e., the calcium added amount in Table 1, expressed as calcium (mg / 100g)) of 300~400 mg, ferrous fumarate added amount (i.e., the iron added amount in Table 1, expressed as iron (mg / 100g)) of 10~40 mg, and zinc gluconate added amount (i.e., the zinc added amount in Table 1, expressed as zinc (mg / 100g)) of 5~20 mg; the specific added amount of each nutrient is shown in Table 1; Step S4: The mixed rice flour is processed by twin-screw extrusion to obtain reconstituted yellow millet granules; Step S5: The recombinant yellow millet particles are evenly spread on a drying tray and dried for a second time, and then sieved for a second time to obtain infant-labeled yellow millet. Step S6: Mix the infant-labeled yellow millet with the selected qualified yellow millet at a mass ratio of 1:2 to 1:1 (specifically 1:1), and then package the mixture using a three-dimensional motion mixer. After vacuuming, the mixture is packaged to obtain the improved infant-labeled yellow millet product.

[0022] The soaking treatment involves a soaking time of 4 to 6 hours (specifically 5 hours).

[0023] The first drying process uses a drying temperature of 60~70 ℃ (specifically 65 ℃) to dry the rice flour until the moisture content is less than 12%.

[0024] The twin-screw extrusion process is completed in a twin-screw extruder, and the parameters used include: screw diameter of 30~50 mm (specifically 35 mm), screw length-to-diameter ratio of 10:1~15:1 (specifically 12:1), screw speed of 100~200 rpm (specifically 160 rpm), barrel temperature of 60~100 ℃ (specifically 70 ℃), die temperature of 60~110 ℃ (specifically 80 ℃), feed rate of 50~100 kg / h (specifically 85 kg / h), and cutting speed of 500~1000 rpm (specifically 600 rpm).

[0025] In the twin-screw extrusion process, the moisture content of the mixed rice flour needs to be controlled at 20% to 24%.

[0026] The second drying process is completed in a microwave dryer, with a drying temperature of 60~80 ℃ (specifically 65 ℃), a drying time of 30~60 min, and a wind speed of 1~2 m / s (specifically 1 m / s), until the moisture content of the recombinant yellow millet grains is less than 12%.

[0027] The first screening process is completed using a 20-60 mesh (specifically 40 mesh) vibrating screen to remove coarse particles and impurities; the second screening process is completed using a 20-60 mesh (specifically 60 mesh) vibrating screen.

[0028] The qualified yellow millet is natural yellow millet that is free from mold and insect infestation.

[0029] Comparative example: Unlike the previous embodiment, the soaking treatment is omitted in step S1; the twin-screw extrusion treatment in step S4 is replaced with ordinary extrusion treatment; specifically, the ordinary extrusion treatment is completed in a single-screw extruder, and the parameters used include: screw diameter of 30 mm, screw length-to-diameter ratio of 18:1, screw speed of 90 rpm, barrel temperature of 80°C in zone I, 90°C in zone II, and 100°C in zone III, die temperature of 110°C, feed rate of 35 kg / h, melt pressure of 5 MPa, and cutting speed of 650 rpm.

[0030] Samples of the improved infant-labeled yellow millet products prepared in the examples and comparative examples were taken and the content of each nutrient was tested. The process loss rate of each nutrient compared to the actual addition was calculated. The test results are shown in Table 1.

[0031] The methods for detecting the content of each nutrient are as follows: Vitamin A was determined using the first method of GB 5009.82-2016; Vitamin D was determined using Method IV of GB 5009.82-2016; Vitamin B1 was determined using the first method of GB 5009.84-2016; Vitamin C was determined using the first method of GB 5009.86-2016; Calcium was determined using the first method of GB 5009.92; Iron was detected using the first method of GB 5009.90; Zinc was determined using the first method of GB 5009.14.

[0032] The calculation methods for the processing loss rate of each nutrient are as follows: Nutrient loss rate during processing = [(Actual amount of nutrient added - Actual value of nutrient detected) / Actual amount of nutrient added] × 100%.

[0033] Table 1. Actual addition amount and test results of each nutrient As shown in Table 1, the improved infant-grade yellow millet product prepared by the present invention meets the requirements of GB 10769-2025 infant cereal standard for nutrient content, and the process loss rate is maintained at about 10%, which is convenient for commercial production. Compared with ordinary extruded yellow millet that has not been soaked before pretreatment, the nutrient loss rate under this process is lower, indicating that this method is superior to the ordinary method.

[0034] Each of the improved infant-labeled yellow millet products prepared in the examples and comparative examples was randomly and equally packaged into 10 portions. After vacuum packaging, the portions were placed in a constant temperature and humidity chamber at 37 ℃ and 75% relative humidity for 10 weeks (i.e., a shelf life of 10 weeks). Samples were taken weekly to test the content of each nutrient and to calculate the shelf-life loss rate of each nutrient. The test results are shown in Tables 2 and 3 (data for weeks 1, 2, 4, 5, and 7 in Table 2 are not shown).

[0035] The methods for calculating the shelf-life loss rate of each nutrient are as follows: Shelf life loss rate = [(Week 0 detection value - Week 10 detection value) / Week 0 detection value] * 100%. Wherein, the Week 0 detection value is the real-time detection value of the products in the examples and comparative examples when they were manufactured.

[0036] Table 2. Changes in the content of various nutrients during shelf life and the shelf-life loss rate of each nutrient (twin-screw extrusion) Table 3. Changes in the content of various nutrients during shelf life and the shelf-life loss rate of each nutrient (ordinary extrusion). As shown in Table 2, the improved infant-label yellow millet product prepared using the embodiments of the present invention meets the requirements of GB 10769-2025 infant cereal standards for both nutrient content and nutrient loss rate during shelf life. As shown in Table 3, the nutrient loss rates of the finished product without soaking and ordinary extrusion treatment are higher than those of the product obtained by combining soaking and twin-screw extrusion treatments. This indicates that the combined use of soaking and twin-screw extrusion treatments in the embodiments of the present invention can synergistically improve nutrient content, reduce nutrient loss rate during shelf life, and ensure that the improved infant-label yellow millet product prepared meets the requirements of GB 10769-2025 infant cereal standards for both nutrient content and nutrient loss rate during shelf life.

[0037] Twelve trained food professionals served as sensory evaluators, conducting sensory evaluations on cooked and uncooked twin-screw extruded infant-label yellow millet (example), conventionally extruded infant-label yellow millet (comparative), and natural yellow millet. The training of the sensory evaluators and the sensory evaluation standards referenced the national standard GB / T 15682-2008, "Sensory Evaluation Method for the Cooking and Edibility of Rice and Grain (Grain and Oil Inspection)". The evaluation results are shown in Table 4.

[0038] Table 4 Evaluation Results Table 4 shows that before cooking, the flavor score of twin-screw extruded baby-labeled yellow millet was approximately 0.4 points lower than that of natural yellow millet, but approximately 2 points higher than that of ordinary extruded baby-labeled yellow millet. After cooking, the overall flavor score of twin-screw extruded baby-labeled yellow millet was approximately 1.2 points higher than that of natural yellow millet, and approximately 1.4 points higher than that of ordinary extruded baby-labeled yellow millet. This indicates that the overall cooking quality of the improved baby-labeled yellow millet product is higher than that of both natural yellow millet and ordinary extruded baby-labeled yellow millet, exhibiting excellent flavor and texture.

[0039] Equal weights of twin-screw extruded infant-label yellow millet (example), ordinary extruded infant-label yellow millet (comparative example), and natural yellow millet were selected and subjected to cooking quality tests. Specifically, cooking loss rate, water absorption rate, expansion rate, and iodine blue value were tested. The cooking quality test results are shown in Table 5.

[0040] The test method for cooking loss rate is as follows: Weigh 3.00 g (m0) of millet sample into a 100 mL beaker, add 50 mL of pure water, heat in a boiling water bath for 10 minutes, and then pour the rice water into a container that has been pre-weighed (m0). 1) The sample was dried in a beaker at 105°C to constant weight (m2). The measurement was repeated three times, and the average value was taken.

[0041] Cooking loss rate (%) = [((m2-m1) / m0]*100%. The test method for water absorption rate is as follows: Weigh 5.00g (m0) of millet sample into a rice steamer, add 20mL of pure water, and steam in a steamer for 10min. After cooling, transfer to a pre-weighed centrifuge tube (m1) for centrifugation, and weigh the total mass of the centrifuge tube and precipitate (m2).

[0042] Water absorption rate (%) = [((m2-m1) / m0]*100%. The test method for expansion rate is as follows: Weigh 5.00g (m0) of millet sample into a graduated test tube and read the volume V1. Add 5mL of pure water, steam in a steamer for 10min, and then put it into a graduated test tube and read the volume V2.

[0043] Expansion rate (%) = (V2 - V1) / m0 * 100%. The method for testing iodine blue value is as follows: Weigh 3.00g of cooked millet sample into a 50mL colorimetric tube, add water to 25mL, incubate in a 40℃ water bath and shake for 60min, add water to make up to 50mL, centrifuge, take 5mL of supernatant, add 0.5mL of KI-I2 solution and 0.5mL of 0.1mol / L HCl solution, and make up to 50mL of pure water. After standing for 15min, measure the absorbance at 620nm. Perform a blank test according to the above method. The iodine blue value is expressed as the measured absorbance value.

[0044] Table 5 Results of Cooking Quality Test As shown in Table 5, the cooking loss rate, water absorption rate, expansion rate, and iodine blue value of twin-screw extruded infant-labeled yellow millet are all lower than those of ordinary extruded infant-labeled yellow millet and natural yellow millet. This indicates that the cooking quality of twin-screw extruded infant-labeled yellow millet is superior to that of natural yellow millet and ordinary extruded infant-labeled yellow millet. Therefore, it can be considered that its market acceptance is no less than that of natural yellow millet, and this method is superior to ordinary extrusion.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made using the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A method for preparing infant-labeled yellow millet suitable for infants and young children, characterized in that, include: Step S1: After washing the selected qualified yellow millet, soak it in water, drain it, and crush it through an 80-mesh sieve to obtain the first rice flour. Step S2: After the first rice flour undergoes a first drying process, it is then subjected to a first sieving process to obtain the second rice flour. Step S3: Mix the second rice flour with the nutrients according to the required amount to obtain mixed rice flour; wherein, in every 100 grams of the second rice flour, the nutrients and the amount added include: vitamin A added at 200~400 μgRE, vitamin D added at 10~30 μg, vitamin B1 added at 250~400 μg, vitamin C added at 35~50 mg, calcium carbonate added at 300~400 mg, ferrous fumarate added at 10~40 mg, and zinc gluconate added at 5~20 mg; Step S4: The mixed rice flour is processed by twin-screw extrusion to obtain reconstituted yellow millet granules; Step S5: After the recombinant yellow millet particles undergo a second drying process, they are then subjected to a second sieving process to obtain infant-grade yellow millet.

2. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, The soaking time for the soaking treatment is 4 to 6 hours.

3. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, The first drying process uses a drying temperature of 60~70 ℃, and the rice flour is dried until the moisture content is less than 12%.

4. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, The parameters used in the twin-screw extrusion process include: screw diameter of 30~50 mm, screw length-to-diameter ratio of 10:1~15:1, screw speed of 100~200 rpm, barrel temperature of 60~100 ℃, die temperature of 60~110 ℃, feed rate of 50~100 kg / h, and cutting speed of 500~1000 rpm.

5. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, In the twin-screw extrusion process, the moisture content of the mixed rice flour needs to be controlled at 20% to 24%.

6. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, The second drying process uses a drying temperature of 60~80 ℃, a drying time of 30~60 min, and an air speed of 1~2 m / s, until the moisture content of the recombinant yellow millet grains is less than 12%.

7. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, The first screening process is completed using a 20-60 mesh vibrating screen; the second screening process is completed using a 20-60 mesh vibrating screen.

8. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 1, characterized in that, It also includes step S6, which involves mixing the infant-labeled yellow millet with selected qualified yellow millet at a mass ratio of 1:2 to 1:1, and then packaging the mixture after vacuuming to obtain the improved infant-labeled yellow millet product.

9. The method for preparing infant-labeled yellow millet suitable for infants and young children as described in claim 8, characterized in that, The qualified yellow millet is natural yellow millet that is free from mold and insect infestation.

10. A type of infant-labeled yellow millet suitable for infants and young children, characterized in that, It is prepared by the method for preparing infant-grade yellow millet suitable for infants and young children as described in any one of claims 1 to 9.

Images