Modified glutinous rice flour and its preparation method and application

Abstract

The present invention discloses a modified glutinous rice flour, a preparation method and application thereof, and belongs to the technical field of food raw material modification. The present invention discloses a method for preparing a modified glutinous rice flour, comprising the following steps: adding polyphenols and vitamins to a glutinous rice flour slurry, followed by pre-gelatinization, and vacuum drying to obtain the modified glutinous rice flour. The present invention provides a method for preparing a modified glutinous rice flour, which improves the processing performance of the glutinous rice flour, reduces the sedimentation value and water separation rate of the glutinous rice flour, thereby improving the anti-aging performance and water holding capacity, i.e., freeze-thaw stability, of the glutinous rice flour. The present invention provides a method for preparing a modified glutinous rice flour, which uses natural plant pigments and vitamins to treat the glutinous rice flour, has a simple process, low cost, and is safe, green, and environmentally friendly. Moreover, the polyphenols and vitamins themselves are beneficial to human health and can enhance the nutritional value of the glutinous rice flour.

Description

Technical Field

[0001] The invention belongs to the technical field of food raw material modification, and particularly relates to modified glutinous rice flour and a preparation method and application thereof. Background Art

[0002] Glutinous rice flour is widely used in pastry making. However, glutinous rice pastries are prone to aging, moisture loss, and hardening during storage and transportation, which seriously affects the nutritional value and sensory quality of glutinous rice pastries and shortens their shelf life.

[0003] Currently, food additives are often used to address issues such as hardening, cracking, and aging in glutinous rice flour products. For example, emulsifiers like monoglycerides and thickeners like guar gum, xanthan gum, and sodium carboxymethyl cellulose are added to improve product quality. However, this modification approach is inconsistent with the current demand for green, healthy, and additive-free foods. Therefore, better modification methods are urgently needed. Summary of the Invention

[0004] In order to solve the above problems in the prior art, the present invention provides a modified glutinous rice flour and a preparation method and application thereof.

[0005] One object of the present invention is to address the deficiencies in the prior art and provide a method for modifying glutinous rice flour that is simple in process, low in cost, and conforms to the concept of healthy green food; in addition, another object of the present invention is to use the modified glutinous rice flour prepared by the present invention to prepare glutinous rice flour products with high sensory evaluation and good texture characteristics.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is a method for preparing modified glutinous rice flour, comprising the following steps: adding polyphenols and vitamins to glutinous rice flour slurry, then pre-gelatinizing, and vacuum drying to obtain the modified glutinous rice flour.

[0008] Furthermore, the preparation method of the glutinous rice flour slurry is: mixing glutinous rice flour and water according to a mass volume ratio of 1g: (0.8-1.2)mL.

[0009] Furthermore, the mass volume ratio of glutinous rice flour to water is preferably 1 g:1 mL.

[0010] Furthermore, the polyphenolic substance includes one of proanthocyanidins, tea polyphenols and buckwheat polyphenols.

[0011] Furthermore, the polyphenolic substance is preferably proanthocyanidin.

[0012] Furthermore, the vitamin substance includes one of vitamin A, vitamin C and vitamin E.

[0013] Furthermore, the vitamin substance is preferably vitamin A.

[0014] Furthermore, the mass ratio of the polyphenols to the vitamins is 1:(1-2).

[0015] Furthermore, the mass ratio of the polyphenols to the vitamins is preferably 1:1.5.

[0016] Furthermore, the total added amount of the polyphenols and vitamins is 0.05% to 0.4% of the mass of the glutinous rice flour.

[0017] Furthermore, the total amount of the polyphenols and vitamins added is preferably 0.2% of the mass of the glutinous rice flour.

[0018] Furthermore, the pre-gelatinization temperature is 60-70° C. and the time is 25-35 minutes.

[0019] Furthermore, the vacuum drying temperature is 40-60° C., the vacuum degree is 93.3-98.6 KPa, and the time is 2-5 hours.

[0020] The second technical solution of the present invention: the modified glutinous rice flour prepared by the above-mentioned preparation method of the modified glutinous rice flour.

[0021] The third technical solution of the present invention: application of the modified glutinous rice flour in the preparation of glutinous rice flour products.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention provides a method for preparing modified glutinous rice flour, which improves the processing performance of glutinous rice flour, reduces the sedimentation value and water separation rate of glutinous rice flour, thereby improving the anti-aging performance and water holding capacity, i.e., freeze-thaw stability, of glutinous rice flour.

[0024] (2) The present invention provides a method for preparing modified glutinous rice flour, which uses natural plant pigments (polyphenols) and vitamins to treat glutinous rice flour. The process is simple, the cost is low, and it is safe, green and environmentally friendly. Moreover, polyphenols and vitamins themselves are beneficial to human health and can enhance the nutritional value of glutinous rice flour.

[0025] (3) The present invention provides a method for preparing a modified glutinous rice flour, and the glutinous rice flour product prepared therefrom has good texture and sensory properties and is not significantly different from the existing glutinous rice flour. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 These are photos of the appearance of glutinous rice balls A and B made in an application example of the present invention, where (a) is a photo of the appearance of glutinous rice balls A, and (b) is a photo of the appearance of glutinous rice balls B. DETAILED DESCRIPTION

[0028] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0029] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0030] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0031] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0032] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0033] Example 1

[0034] 1) 200 g of glutinous rice flour was mixed with 200 mL of deionized water to obtain a glutinous rice flour slurry;

[0035] 2) adding 0.05 g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.05 g of vitamin A, vitamin C or vitamin E (vitamins) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and grinding through a 120-mesh sieve to obtain modified glutinous rice flour;

[0036] The pre-gelatinization temperature is 65°C and the time is 30 minutes; the vacuum drying temperature is 60°C, the vacuum degree is 93.3 KPa, and the time is 4 hours.

[0037] Effect verification:

[0038] The modified glutinous rice flour prepared in Example 1 was tested for sedimentation value and water separation rate. The test results are shown in Table 1 (the sedimentation value is related to the anti-aging property of starch. The smaller the sedimentation value, the better the anti-aging property. The water separation rate reflects the water holding capacity of glutinous rice flour. The lower the water separation rate, the stronger the water holding capacity and the better the freeze-thaw stability).

[0039] Determination of sedimentation value:

[0040] Accurately weigh 2g of glutinous rice flour and add 200g of deionized water to prepare a 10g / L suspension emulsion. Place the paste in a 10mL graduated tube and shake well. The volume of the lower layer of paste after sedimentation for 24h is the sedimentation value.

[0041] Determination of water separation rate:

[0042] Accurately weigh 2 g of glutinous rice flour, add 200 g of deionized water to prepare a 10 g / L suspension emulsion, and mix evenly with a glass rod; take 15 mL of starch paste and pour it into three 50 mL centrifuge tubes, freeze them in a -18 °C freezer for 24 h, then take them out, thaw them to room temperature, and centrifuge them in a centrifuge at a speed of 5000 r / min for 20 min. After filtering out excess water, weigh the centrifuge tubes and sediment, and calculate the water separation rate (R) according to the following formula.

[0043] R=[(m1-m2) / (m1-m0)]×100%

[0044] Where: m0 is the mass of the centrifuge tube / g; m1 is the total mass of the centrifuge tube and sample after thawing / g; m2 is the total mass of the centrifuge tube and sediment after centrifugation / g.

[0045] Table 1 Sedimentation value (mL) and water separation rate (%)

[0046]

[0047] Example 2

[0048] The only difference from Example 1 is that step 2) is to add 0.04 g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.06 g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0049] Effect verification:

[0050] The modified glutinous rice flour prepared in Example 2 was tested for sedimentation value and water separation rate. The test results are shown in Table 2.

[0051] Table 2 Sedimentation value (mL) and water separation rate (%)

[0052]

[0053]

[0054] Example 3

[0055] The only difference from Example 1 is that step 2) is to add 0.03g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.07g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0056] Effect verification:

[0057] The modified glutinous rice flour prepared in Example 3 was tested for sedimentation value and water separation rate. The test results are shown in Table 3.

[0058] Table 3 Sedimentation value (mL) and water separation rate (%)

[0059]

[0060] Example 4

[0061] The only difference from Example 1 is that step 2) is to add 0.2 g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.2 g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0062] Effect verification:

[0063] The modified glutinous rice flour prepared in Example 4 was tested for sedimentation value and water separation rate. The test results are shown in Table 4.

[0064] Table 4 Sedimentation value (mL) and water separation rate (%)

[0065]

[0066] Example 5

[0067] The only difference from Example 1 is that step 2) is to add 0.16g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.24g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0068] Effect verification:

[0069] The modified glutinous rice flour prepared in Example 5 was tested for sedimentation value and water separation rate. The test results are shown in Table 5.

[0070] Table 5 Sedimentation value (mL) and water separation rate (%)

[0071]

[0072] Example 6

[0073] The only difference from Example 1 is that step 2) is to add 0.13g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.27g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0074] Effect verification:

[0075] The modified glutinous rice flour prepared in Example 6 was tested for sedimentation value and water separation rate. The test results are shown in Table 6.

[0076] Table 6 Sedimentation value (mL) and water separation rate (%)

[0077]

[0078] Example 7

[0079] The only difference from Example 1 is that step 2) is to add 0.40g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.40g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0080] Effect verification:

[0081] The modified glutinous rice flour prepared in Example 7 was tested for sedimentation value and water separation rate. The test results are shown in Table 7.

[0082] Table 7 Sedimentation value (mL) and water separation rate (%)

[0083]

[0084] Example 8

[0085] The only difference from Example 1 is that step 2) is to add 0.32g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.48g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0086] Effect verification:

[0087] The modified glutinous rice flour prepared in Example 8 was tested for sedimentation value and water separation rate. The test results are shown in Table 8.

[0088] Table 8 Sedimentation value (mL) and water separation rate (%)

[0089]

[0090] Example 9

[0091] The only difference from Example 1 is that step 2) is to add 0.27g of proanthocyanidins, tea polyphenols or buckwheat polyphenols (polyphenols) and 0.53g of vitamin A, vitamin C or vitamin E (vitamin substances) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and crushing through a 120-mesh sieve to obtain modified glutinous rice flour.

[0092] Effect verification:

[0093] The modified glutinous rice flour prepared in Example 9 was tested for sedimentation value and water separation rate. The test results are shown in Table 9.

[0094] Table 9 Sedimentation value (mL) and water separation rate (%)

[0095]

[0096] It can be seen from the data in Tables 1 to 9 above that when proanthocyanidins are used as polyphenols, vitamin A is used as vitamins, the mass ratio of proanthocyanidins to vitamin A is 1:1.5, and the total amount of proanthocyanidins and vitamin A added is 0.2% of the mass of glutinous rice flour, the lowest sedimentation value and water separation rate are obtained, that is, the best anti-aging performance and water holding capacity are obtained.

[0097] Comparative Example 1

[0098] 1) 200 g of glutinous rice flour was mixed with 200 mL of deionized water to obtain a glutinous rice flour slurry;

[0099] 2) pre-gelatinizing the glutinous rice flour obtained in step 1), vacuum drying, and grinding through a 120-mesh sieve to obtain modified glutinous rice flour;

[0100] The pre-gelatinization temperature is 65°C and the time is 30 minutes; the vacuum drying temperature is 60°C, the vacuum degree is 93.3 KPa, and the time is 4 hours.

[0101] Comparative Example 2

[0102] 1) 200 g of glutinous rice flour was mixed with 200 mL of deionized water to obtain a glutinous rice flour slurry;

[0103] 2) adding 0.4 g of proanthocyanidins (polyphenols) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and grinding through a 120-mesh sieve to obtain modified glutinous rice flour;

[0104] The pre-gelatinization temperature is 65°C and the time is 30 minutes; the vacuum drying temperature is 60°C, the vacuum degree is 93.3 KPa, and the time is 4 hours.

[0105] Comparative Example 3

[0106] 1) 200 g of glutinous rice flour was mixed with 200 mL of deionized water to obtain a glutinous rice flour slurry;

[0107] 2) adding 0.4 g of vitamin A (vitamin-like substance) to the glutinous rice flour slurry obtained in step 1), followed by pre-gelatinization, vacuum drying, and grinding through a 120-mesh sieve to obtain modified glutinous rice flour;

[0108] The pre-gelatinization temperature is 65°C and the time is 30 minutes; the vacuum drying temperature is 60°C, the vacuum degree is 93.3 KPa, and the time is 4 hours.

[0109] Comparative Example 4

[0110] 1) 200 g of glutinous rice flour was mixed with 200 mL of deionized water to obtain a glutinous rice flour slurry;

[0111] 2) adding 0.16 g of proanthocyanidins (polyphenols) and 0.24 g of vitamin A (vitamin) to the glutinous rice flour slurry obtained in step 1), followed by vacuum drying and grinding through a 120-mesh sieve to obtain modified glutinous rice flour (i.e., omitting pre-gelatinization);

[0112] The vacuum drying temperature was 60°C, the vacuum degree was 93.3 KPa, and the drying time was 4 h.

[0113] Effect verification:

[0114] The glutinous rice flour prepared in Comparative Examples 1 to 3 was tested for sedimentation value and water separation rate. The test results are shown in Table 10.

[0115] Table 10 Sedimentation value (mL) and water separation rate (%)

[0116] Sedimentation value Water separation rate Comparative Example 1 2.53 80.33 Comparative Example 2 1.87 77.02 Comparative Example 3 1.89 77.95 Comparative Example 4 1.63 67.98

[0117] Further analysis of the data in Tables 1-10 indicates that polyphenols and vitamins each have a certain promoting effect on the anti-aging and water-holding capacity of glutinous rice flour. Furthermore, polyphenols and vitamins exhibit a synergistic effect, effectively enhancing the anti-aging and water-holding properties of glutinous rice flour. The study suggests that the amount of polyphenols and vitamins added significantly influences the anti-aging and water-holding properties of glutinous rice flour. Excessive or insufficient addition of polyphenols and vitamins increases sedimentation and water extraction rates, negatively impacting these properties. The study also suggests that when polyphenols and vitamins exhibit synergistic effects, their ratio significantly influences the final anti-aging and water-holding properties. Only when the optimal ratio is achieved can the sedimentation and water extraction rates be significantly reduced, ultimately improving the anti-aging and water-holding properties of glutinous rice flour. The study shows that whether or not to use pre-gelatinization has a certain degree of influence on the sedimentation value and water separation rate, but the influence is not significant. The pre-gelatinization treatment mainly affects the texture characteristics of glutinous rice flour products.

[0118] Application Examples

[0119] The modified glutinous rice flour prepared by adding 0.16g of proanthocyanidins and 0.24g of vitamin A in Example 5 and the glutinous rice flour prepared in Comparative Example 1 were respectively made into glutinous rice balls (50 pieces, general production methods, not protected by the present invention, and will not be described here), the former is glutinous rice ball A, and the latter is glutinous rice ball B.

[0120] The appearance photos of glutinous rice balls A and B are as follows Figure 1 As shown, (a) is the appearance photo of glutinous rice ball A, and (b) is the appearance photo of glutinous rice ball B.

[0121] The texture characteristics of glutinous rice balls A and B were tested using a texture analyzer, including hardness, adhesion, elasticity, chewiness, stickiness, cohesion, and resilience.

[0122] The texture analyzer was used as follows: After cooking the glutinous rice balls, the texture characteristics were analyzed using a TA.XTPLUS texture analyzer. A P / 50 cylindrical probe was used for measurement. The test conditions were a pre-measurement speed of 2 mm / s, a test speed of 1 mm / s, a post-measurement speed of 1 mm / s, a compression ratio of 50%, a dwell time of 5 seconds between compressions, and the probe compression site was the center of the glutinous rice balls.

[0123] The test results are shown in Table 11.

[0124] Table 11 Texture characteristics

[0125] Tangyuan A Tangyuan B hardness 684.16±16.24 560.77±15.54 Adhesion -17.89±4.07 -15.38±4.33 elasticity 0.85±0.01 0.86±0.07 chewability 451.16±6.63 385.99±11.73 Adhesion 533.44±10.48 473.59±7.60 Cohesion 0.98±0.01 0.86±0.06 Resilience 0.50±0.00 0.48±0.05

[0126] Depend on Figure 1 From the data in Table 11, it can be found that there is no significant difference in appearance or texture characteristics between the glutinous rice balls made from the modified glutinous rice flour of the present invention and the glutinous rice balls made from the glutinous rice flour without any treatment (Comparative Example 1). Therefore, the modified glutinous rice flour prepared by the present invention can replace the existing glutinous rice flour to prepare glutinous rice products.

[0127] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for preparing modified glutinous rice flour, characterized in that: The following steps are involved: Adding polyphenols and vitamins to a glutinous rice flour slurry, followed by pre-gelatinization and vacuum drying to obtain the modified glutinous rice flour; the glutinous rice flour slurry is prepared by mixing glutinous rice flour and water at a mass volume ratio of 1 g: (0.8-1.2) mL; The polyphenolic substances include one of proanthocyanidins, tea polyphenols and buckwheat polyphenols; The vitamin substance includes one of vitamin A, vitamin C and vitamin E; The mass ratio of the polyphenols to the vitamins is 1:(1-2); The total added amount of the polyphenols and vitamins is 0.05% to 0.4% of the mass of the glutinous rice flour.

2. The method for preparing modified glutinous rice flour according to claim 1, wherein The pre-gelatinization temperature is 60-70° C. and the pre-gelatinization time is 25-35 minutes.

3. The method for preparing modified glutinous rice flour according to claim 1, wherein The vacuum drying temperature is 40-60° C., the vacuum degree is 93.3-98.6 KPa, and the time is 2-5 hours.

4. Modified glutinous rice flour prepared by the method for preparing the modified glutinous rice flour according to any one of claims 1 to 3.

5. Use of the modified glutinous rice flour according to claim 4 in preparing glutinous rice flour products.

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