Preparation method of infant rice flour

Abstract

The invention provides a preparation method of infant rice flour. The preparation method comprises the following steps: crushing rice and sieving to 100 meshes; the preparation method comprises the following steps: weighing a rice flour base material with a certain dry basis mass, adding distilled water to prepare slurry with a substrate concentration of 20-40%, pre-gelatinizing for 10-15 minutes, putting into a water bath of 45-65 DEG C, adding alpha-amylase when the temperature of the slurry is reduced to a set value, magnetically stirring for 25-40 minutes, and deactivating enzyme at 85-95 DEG C for 10-15 minutes to obtain an enzymolysis sample; and diluting the sample until the substrate concentration is 20%, and controlling the water content of the product to be 4-6% by adopting a spray drying mode to obtain the infant rice flour. The starch structure is regulated through enzymolysis, and an efficient drying process is combined, so that the solubility, the reconstituability and the digestibility of the rice flour are remarkably improved, the taste and the dispersity are improved, and the preparation method is suitable for processing infant nutritional foods.

Description

Technical Field

[0001] This invention relates to the field of infant food processing technology, and in particular to a method for preparing infant rice cereal. Background Technology

[0002] With the continuous expansion of the infant rice cereal market and the increasing demands of consumers, highly digestible, quick-dissolving, hypoallergenic, and finely textured infant rice cereals have become a research hotspot and development trend in recent years. Infant rice cereal is mainly made from rice, and it is rich in nutrients, easy to store and carry, making it an important component of infant complementary food. However, existing infant rice cereals generally suffer from problems such as low digestibility, poor dispersibility, easy clumping during preparation, high viscosity, and difficulty in nutrient absorption and feeding for infants.

[0003] During the drying process of rice flour, starch granules undergo a series of structural changes, such as the destruction of crystalline regions and the increase of amorphous regions. These changes significantly affect the gelatinization characteristics, retrogradation rate, and final taste and texture of the starch. Traditional drum drying or hot air drying processes are greatly affected by high temperatures, easily leading to starch aging, uneven gelatinization, clumping, and sticking to the walls. Simultaneously, a hard crust easily forms on the surface of the rice flour, affecting the product's solubility and taste. Furthermore, prolonged high-temperature treatment may cause oxidative denaturation of some nutrients, reducing the safety and nutritional value of infant food.

[0004] Therefore, it is necessary to provide an improved method to address the issues of starch structure changes and quality degradation during the drying process of infant rice cereal, so as to achieve a gentle and controllable drying process while ensuring product safety and nutritional value, thereby improving the dispersibility, solubility, and digestibility of infant rice cereal and enhancing the overall quality and stability of the product. Summary of the Invention

[0005] In view of the aforementioned technical problems with infant rice cereal in traditional drying and processing, such as poor reconstitution properties, high clumping rate, low solubility, and easy loss of nutrients, a method for preparing infant rice cereal is provided.

[0006] This invention primarily utilizes α-amylase to controllably hydrolyze rice flour base materials, moderately hydrolyzing starch molecules—the main component of rice flour—and regulating their chain length distribution, branching degree, and spatial conformation. This alters the particle morphology, crystallinity and crystal form, molecular weight distribution, short-range ordered structure, and hydrogen bond network of starch molecules, thereby improving rice flour solubility, reducing clumping rate, and lowering viscosity. It significantly improves the reconstitution properties of rice flour, maximizing digestibility, swelling power, gel properties, and product quality. This invention employs a spray-drying process, rapidly and uniformly dehydrating the rice flour to form a uniformly sized infant rice flour product with stable moisture content. This preserves the nutritionally active ingredients while improving solubility, reconstitution properties, and texture.

[0007] The technical means employed in this invention are as follows: A method for preparing infant rice cereal includes the following steps: Step 1: Raw material pretreatment: Grind the rice and sieve it to 100 mesh; Step 2, α-amylase hydrolysis: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 20%-40%, pregelatinize the slurry for 10-15 minutes, place it in a water bath at 45-65℃, add a certain mass of α-amylase when the temperature of the slurry drops to the set value, and continue to stir magnetically for 25-40 minutes. Then, inactivate the enzyme in the slurry to obtain the enzymatically hydrolyzed rice flour slurry sample. Step 3: Drying treatment: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%, and use spray drying process to obtain dried infant rice cereal.

[0008] Furthermore, the amount of α-amylase added is 0.1%-0.5% of the dry weight of the rice flour base.

[0009] Furthermore, α-amylase is added when the temperature of the slurry drops to 60°C.

[0010] Furthermore, the enzyme inactivation is achieved by placing the slurry in a water bath at 85-95°C for 10-15 minutes.

[0011] Furthermore, the parameters for spray drying are as follows: air inlet temperature is 160-180℃, fan speed is 1000-1200L / h, liquid flow rate is 20-40ml / min, and the moisture content of the dried infant rice cereal is 4%-6%.

[0012] Compared with the prior art, the present invention has the following advantages: 1. This invention uses α-amylase to controllably hydrolyze rice flour base material, causing starch molecules to break down and rearrange appropriately, regulating their chain length distribution, branching degree and spatial conformation, improving crystallinity and molecular ordered structure, thereby significantly improving the solubility and dispersibility of rice flour, and reducing the clumping rate and system viscosity.

[0013] 2. This invention carries out enzymatic hydrolysis under mild conditions of 45-65℃. Through moderate hydrolysis and timely enzyme inactivation, it not only achieves starch structure regulation, but also effectively avoids the destruction of nutritional components (such as vitamins, minerals and some proteins) by high temperature, thus ensuring the nutritional integrity and safety of infant rice cereal.

[0014] 3. This invention uses a spray drying process to atomize the slurry into micron-sized droplets, which then come into instantaneous contact with hot air to dehydrate the slurry, forming rice cereal powder with fine particles and stable moisture content. This process has a fast drying speed and low energy consumption, and the resulting infant rice cereal particles are evenly distributed, have good flowability, and excellent instant solubility.

[0015] 4. The infant rice cereal prepared by this invention can be quickly dispersed in water without clumping. After mixing, the paste is delicate and smooth with a mild taste, which is suitable for infants to swallow and digest. At the same time, the water-holding capacity of the powder is enhanced, and the consistency is stable after mixing, making it less prone to separation or sedimentation.

[0016] In summary, this invention systematically solves the problems of poor reconstitution, high clumping rate, low solubility, and serious nutrient loss in traditional drying processes of infant rice cereal through a combined process of "controllable enzymatic hydrolysis of α-amylase-spray drying". It achieves comprehensive improvement in solubility, digestibility, texture, and nutrient retention of infant rice cereal, providing an efficient and stable technical path for the development of infant nutritional foods. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 Comparison of the sedimentation properties of rice flour processed by different methods (RF, HAD, WHAD, SD).

[0019] Figure 2 A comparison of the transparency of rice flour processed using different methods (RF, HAD, WHAD, SD).

[0020] Figure 3 Comparison of clumping rates of rice noodles processed using different methods (RF, HAD, WHAD, SD).

[0021] Figure 4 Comparison of dispersion time of rice flour processed by different methods (RF, HAD, WHAD, SD). Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0023] Example 1 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry basis mass of rice flour base material. The dry basis mass refers to the mass calculated based on the dry matter content of the rice flour, which is used to ensure the accuracy of substrate concentration and enzyme addition. Add distilled water to prepare a slurry with a substrate concentration of 20%, pregelatinize for 10 minutes, and quickly place it in a 60℃ water bath. Use a thermometer to measure the temperature of the sample. When the solution temperature drops to 60℃, add 0.1% α-amylase by dry basis mass and start timing. Stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes. Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 160℃, fan speed 1000L / h, and liquid flow rate 20ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD1.

[0024] Example 2 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 30%, pregelatinize for 10 minutes, quickly remove and place in a 60℃ water bath, use a thermometer to measure the sample temperature, wait for the solution temperature to drop to 60℃, add 0.3% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 170℃, fan speed 1000L / h, and liquid flow rate 30ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD2.

[0025] Example 3 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 30%, pregelatinize for 15 minutes, quickly remove and place in a 60℃ water bath, measure the sample temperature with a thermometer, and wait for the solution temperature to drop to 60℃, add 0.5% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 180℃, fan speed 1000L / h, and liquid flow rate 40ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD3.

[0026] Example 4 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 40%, pregelatinize for 10 minutes, quickly remove and place in a 60℃ water bath, use a thermometer to measure the sample temperature, wait for the solution temperature to drop to 60℃, add 0.4% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 160℃, fan speed 1100L / h, and liquid flow rate 30ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD4.

[0027] Example 5 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 20%, pregelatinize for 15 minutes, quickly remove and place in a 60℃ water bath, use a thermometer to measure the sample temperature, wait for the solution temperature to drop to 60℃, add 0.3% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 170℃, fan speed 1200L / h, and liquid flow rate 40ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD5.

[0028] Example 6 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 40%, pregelatinize for 15 minutes, quickly remove and place in a 60℃ water bath, measure the sample temperature with a thermometer, and wait for the solution temperature to drop to 60℃, add 0.5% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%. Spray drying parameters are: inlet air temperature 170℃, fan speed 1100L / h, and liquid flow rate 40ml / min to obtain infant rice cereal with a moisture content of about 5%, denoted by the English letters SD6.

[0029] Comparative Example 1 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 30%, pregelatinize for 10 minutes, and dry in an oven until the moisture content is 5%. The sample is represented by the English letters RF.

[0030] Comparative Example 2 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 30%, pregelatinize for 10 minutes, quickly remove and place in a 60℃ water bath, use a thermometer to measure the sample temperature, wait for the solution temperature to drop to 60℃, add 0.3% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Hot air drying (HAD): The enzymatically hydrolyzed sample is spread evenly on a tray, with a material thickness not exceeding 5 mm, and placed in a forced-air drying oven to dry at a temperature of 70℃ for 8 hours, resulting in infant rice cereal with a moisture content of about 5%, which is represented by the English letters HAD.

[0031] Comparative Example 3 This invention provides a method for preparing infant rice cereal, comprising the following steps: Step 1: Raw material pretreatment: Grind the rice into powder and sieve it through a 100-mesh sieve; Step 2: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 30%, pregelatinize for 25 minutes, quickly remove and place in a 60℃ water bath, measure the sample temperature with a thermometer, and wait for the solution temperature to drop to 60℃, add 0.3% dry weight of α-amylase and start timing, stir magnetically for 25 minutes, and then immediately place the sample in a 95℃ water bath to inactivate the enzyme for 10 minutes; Step 3: Microwave-hot air drying (MHAD): The enzymatically hydrolyzed sample is spread evenly on a tray, with a material thickness not exceeding 5 mm. It is then placed in a microwave oven at a power of 4 W / g for a total drying time of 4 minutes, with a 3-minute interval between 1-minute microwave cycles. The sample is then dried in a forced-air drying oven at 70℃ for 3 hours, yielding infant rice cereal with a moisture content of approximately 5%, denoted by the letters MHAD.

[0032] Application Example 1 The sedimentation, transparency, agglomeration rate, dispersion time, and solubility of the samples obtained in Examples 1-6 were measured respectively, as shown in Table 1.

[0033] Table 1

[0034] As shown in Table 1, there are significant differences in the physical properties and reconstitution performance of the infant rice cereal samples from different embodiments. The overall trend indicates that after moderate enzymatic hydrolysis with α-amylase and combined with spray drying, the rice cereal exhibits low sedimentation, high transparency, low agglomeration rate, and fast dispersion speed, demonstrating good solubility and dispersion characteristics.

[0035] Among them, Example 2 showed the best overall performance: the sedimentation rate was 7.11 ml, the transparency (absorbance) was the lowest at 0.76, indicating that the solution was highly clear; the agglomeration rate was the lowest at 4.21%, the dispersion time was the longest and most stable at 40.32 s, and the solubility was the highest at 20.61%, indicating that Example 2 was evenly dispersed in water and formed a stable suspension.

[0036] Examples 3, 5, and 6 showed inferior performance, indicating that the product's reconstitution properties and solubility would decrease slightly under different enzymatic hydrolysis conditions or drying parameters.

[0037] Application Example 2 The average values ​​of sedimentation, transparency, agglomeration rate, and dispersion time of the samples obtained in Examples 1-6 were compared with those of the samples obtained in Comparative Examples 1-3. The results are as follows: Figures 1-4 The figures show the various indicators of infant rice cereal samples obtained by oven drying (RF), hot air drying (HAD), microwave-hot air drying (WHAD), and spray drying (SD).

[0038] In terms of sedimentation, the RF sample showed the highest sedimentation rate, while the SD sample showed the lowest, indicating that spray drying can significantly reduce sedimentation in the suspended system and improve system stability. In terms of transparency, the HAD sample showed the highest absorbance and was the most turbid, while the SD sample showed the lowest, indicating that the rice flour paste obtained by spray drying had the best clarity. In terms of agglomeration rate, the SD sample showed the lowest agglomeration rate (approximately 4%), while the HAD sample showed the highest, indicating that rapid atomization drying helps prevent the aggregation of starch particles. In terms of dispersion time, the WHAD sample dispersed the fastest, while the SD sample dispersed slightly faster, but both were better than RF and HAD, indicating that combined drying and spray drying are beneficial for improving the dispersion rate in water.

[0039] In summary, the infant rice cereal samples produced using the spray drying (SD) process of this invention exhibited optimal performance in terms of sedimentation, transparency, and caking rate, demonstrating that this process effectively improves the product's dispersibility, solubility, and reconstitution stability. This further verifies the significant advantages of the "α-amylase-controlled enzymatic hydrolysis-spray drying" process in improving the quality of infant rice cereal. The method of this invention can significantly improve the reconstitution, dispersibility, and clarity of rice cereal while maintaining nutritional stability, reducing caking and sedimentation rates. The resulting product has a uniform powder texture, delicate taste, and is easily absorbed, making it suitable for infants and young children. This provides an efficient and reliable technical approach for the industrial production of infant rice cereal.

[0040] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing infant rice cereal, characterized in that, Includes the following steps: Step 1: Raw material pretreatment: Grind the rice and sieve it to 100 mesh; Step 2, α-amylase hydrolysis: Weigh a certain dry weight of rice flour base material, add distilled water to prepare a slurry with a substrate concentration of 20%-40%, pregelatinize the slurry for 10-15 minutes, place it in a water bath at 45-65℃, add a certain mass of α-amylase when the temperature of the slurry drops to the set value, and continue to stir magnetically for 25-40 minutes. Then, inactivate the enzyme in the slurry to obtain the enzymatically hydrolyzed rice flour slurry sample. Step 3: Drying treatment: Dilute the enzymatically hydrolyzed sample with a certain amount of distilled water to a substrate concentration of 20%, and use spray drying process to obtain dried infant rice cereal.

2. The method for preparing infant rice cereal according to claim 1, characterized in that, The amount of α-amylase added is 0.1%-0.5% of the dry weight of the rice flour base.

3. The method for preparing infant rice cereal according to claim 1, characterized in that, α-Amylase is added when the temperature of the slurry drops to 60°C.

4. The method for preparing infant rice cereal according to claim 2, characterized in that, The enzyme inactivation is achieved by placing the slurry in a water bath at 85-95℃ for 10-15 minutes.

5. The method for preparing infant rice cereal according to claim 1, characterized in that, The parameters for spray drying are as follows: air inlet temperature is 160-180℃, fan speed is 1000-1200L / h, liquid flow rate is 20-40ml / min, and the moisture content of the dried infant rice cereal is 4%-6%.

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