Indica rice treasure as well as preparation method and application thereof

Abstract

The invention relates to indica rice treasure as well as a preparation method and application thereof, the indica rice treasure is extracted from indica rice by using a rice milling machine, and the preparation method comprises the following steps: (1) first milling: milling rice husks; (2) secondary rolling: rolling out peels; (3) third grinding: grinding out seed coats; (4) fourth grinding: grinding out no more than 25% of aleurone layer to obtain a ground-out object 4; (5) fifth grinding: grinding out the residual aleurone layer to obtain a ground object 5; (6) collecting the rolled-out object 5, or the rolled-out object 5 and the rolled-out object 4; and (7) sieving with a 30-45-mesh sieve to obtain the traditional Chinese medicine composition. The indica rice treasure disclosed by the invention has very good blood glucose reducing and anti-oxidation effects, can be used for preparing blood glucose reducing and / or anti-oxidation biological agents, including medicines, foods, health-care products and the like, and improves the utilization rate of rice resources.

Description

Technical Field

[0001] The invention belongs to the technical field of rice pearl production, and particularly relates to indica rice pearls and a preparation method and application thereof. Background Art

[0002] Rice is one of the three major food crops in the world and is also widely grown in my country. Indica rice (Oryza sativa L. subsp. sativa) is a type of rice, with about 20% amylose, and is medium-viscosity. Indica rice originated in the subtropics and is planted in tropical and subtropical regions. It has a short growing season and can mature several times a year in places with a long frost-free period. After being husked, it becomes indica rice, which has a slender appearance and low transparency.

[0003] According to statistics, 60% of my country's grain is rice and its processed products, which is one of the most important food crops. Rice is the main processed product of rice. Excessive processing and washing make the nutrition of rice less than 30% of that of rice. However, rice bran, which accounts for 6% to 8% of the total weight of rice and is a by-product of rice processing, accounts for 64% of the nutritional content of rice. Traditional rice bran consists of a protective cortex and rice treasures, containing a variety of bioactive substances, such as phenolic compounds (tocotrienols, tocopherols, etc.), phytosterols, oryzanol, etc. In addition, rice bran contains more than 90% of essential elements for the human body and is a "natural nutrient treasure house". Despite this, due to insufficient research on its specific components, rice bran has always been only a low-value-added product of rice and is mostly used in the feed industry. At this stage, most studies only take rice bran as the object, and study the protective cortex and rice treasures as a whole, while there is less research on rice treasures with high nutritional content.

[0004] Rice jelly accounts for 5% to 9% of the total weight of rice grains. It is a natural nutrient made from the endosperm and embryo of rice. Due to the limitations of rice milling technology, the processing technology of rice jelly is immature, the product quality is low, and different processing technologies will also affect the nutritional content of rice jelly products. Therefore, rice jelly has always been regarded as a cheap by-product of rice processing, which greatly reduces the economic value of rice. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a kind of indica rice treasure and its preparation method and application, and the indica rice treasure has good hypoglycemic and anti-oxidation effects.

[0006] The first aspect of the present invention is to provide a method for preparing indica rice pearls, which uses a rice mill to extract rice pearls from indica rice, comprising the following steps:

[0007] (1) First grinding: grinding out the rice husks;

[0008] (2) Second grinding: grinding out the peel;

[0009] (3) Third grinding: grinding out the seed coat;

[0010] (4) Fourth grinding: grinding out no more than 25% of the aleurone layer to obtain grinding product 4;

[0011] (5) Fifth grinding: grinding out the remaining aleurone layer to obtain grinding product 5;

[0012] (6) collecting the milled product 5, or the milled product 5 and the milled product 4;

[0013] (7) Pass through a 30-45 mesh sieve.

[0014] In some embodiments, the sieve is 40-45 mesh.

[0015] In some embodiments, the milled product 5 is collected and passed through a 40-45 mesh sieve; preferably, the milled product 5 is collected and passed through a 45 mesh sieve.

[0016] In some embodiments, the rice mill uses 40#-60# sand rollers.

[0017] In some embodiments, the rice mill uses a 60# sand roller; the current of the first mill is 10.5±0.2A; and / or, the current of the second mill is 10.3±0.2A: and / or, the current of the third mill is 10.2±0.2A: and / or, the current of the fourth mill is 10.1±0.2A; and / or, the current of the fifth mill is 10.1±0.2A.

[0018] The second aspect of the present invention is to provide Indica rice pearls prepared by the preparation method as described above.

[0019] The third aspect of the present invention is to provide the use of the above-mentioned Indica rice in the preparation of hypoglycemic biological agents.

[0020] The fourth aspect of the present invention is to provide the use of the above-mentioned indica rice extract in the preparation of antioxidant biological preparations.

[0021] In some embodiments, the biological agent is a drug, a health product or a food.

[0022] The fifth aspect of the present invention is to provide a hypoglycemic biological preparation comprising an active ingredient and an excipient, wherein the active ingredient includes the above-mentioned Indica Rice Treasure; and the excipient is a pharmaceutically acceptable carrier, a health product acceptable carrier, or a food acceptable carrier.

[0023] The sixth aspect of the present invention is to provide an antioxidant biological preparation comprising an active ingredient and an auxiliary material, wherein the active ingredient includes the above-mentioned Indica rice treasure; and the auxiliary material is a pharmaceutically acceptable carrier, a health product acceptable carrier or a food acceptable carrier.

[0024] The invention provides a kind of indica rice treasure. Through the layered milling process, the rice husk, pericarp, seed coat and no more than 25% of the aleurone layer of indica rice are removed in sequence by the first milling to the fourth milling, and then the fifth milling is performed to obtain the remaining aleurone layer, and the milled material of the fifth milling, or the fifth milling and the fourth milling, is collected and passed through a sieve with a suitable mesh number (30 to 45 meshes) to obtain the indica rice treasure. The indica rice treasure of the invention has significantly improved contents of biologically active substances, especially total phenols and oryzanol, can effectively remove ABTS free radicals, hydroxyl free radicals and superoxide anion free radicals, inhibit the activities of alpha-glucosidase and alpha-amylase, can reduce the blood sugar of a hyperglycemic zebrafish model to the level of a control group, and has very good hypoglycemic and anti-oxidation effects.

[0025] Based on the invention, the indica rice treasure has good hypoglycemic and anti-oxidant effects, and can be used to prepare hypoglycemic and / or anti-oxidant biological preparations, including medicines, foods and health products, thereby improving the utilization rate of rice resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 These are rice products obtained through four processing techniques.

[0027] Figure 2 The structure of rice and the cross-section observation after milling; A is the structure of rice; B is the cross-section observation result of rice after three, four and five millings.

[0028] Figure 3 Standard curve for determination of total phenolic content.

[0029] Figure 4 is the total phenol content of four rice products (n=3).

[0030] Figure 5 The oryzanol content of four rice products (n=3).

[0031] Figure 6 is the ABTS free radical scavenging rate of the rice extract products without enzymatic hydrolysis (n=3); wherein, lowercase letters indicate significant differences in different gradients of the same type of rice extract products.

[0032] Figure 7 It is the scavenging rate of ABTS free radicals of gastrointestinal simulated enzymatic hydrolysate (n=3); wherein, lowercase letters indicate significant differences in different gradients of similar rice treasure products.

[0033] Figure 8 is the hydroxyl radical scavenging rate of the rice extract products without enzymatic hydrolysis (n=3); wherein, lowercase letters indicate significant differences in different gradients of the same type of rice extract products.

[0034] Fig. 9is the hydroxyl radical scavenging rate of gastrointestinal simulated enzymatic hydrolysate (n=3); wherein, lowercase letters indicate significant differences in different gradients of similar rice treasure products.

[0035] Fig.10 is the superoxide anion radical scavenging rate of the rice extract products without enzymatic hydrolysis (n=3); wherein, lowercase letters indicate significant differences in different gradients of the same type of rice extract products.

[0036] Fig.11 It is the superoxide anion free radical scavenging rate of gastrointestinal simulated enzymatic hydrolysate (n=3); wherein, lowercase letters indicate significant differences in different gradients of similar rice treasure products.

[0037] Fig.12 is the inhibition rate of α-glucosidase by unhydrolyzed rice products (n=3); wherein lowercase letters indicate significant differences in different gradients of the same type of rice products.

[0038] Fig.13 It is the inhibition rate of gastrointestinal simulated enzymatic hydrolysate on α-glucosidase (n=3); wherein, lowercase letters indicate significant differences in different gradients of the same type of rice treasure products.

[0039] Fig.14 It is the inhibition rate of α-amylase of the rice extract products without enzymatic hydrolysis (n=3); wherein, the lowercase letters indicate that the differences of different gradients of the same type of rice extract products are significant.

[0040] Fig.15 It is the inhibition rate of gastrointestinal simulated enzymatic hydrolysate on α-amylase (n=3); wherein, lowercase letters indicate significant differences in different gradients of similar rice treasure products.

[0041] Fig.16 The hypoglycemic effect of five-milled and four-sieved rice extract on hyperglycemic zebrafish (n=30); *** indicates significant difference (P<0.001). DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0043] The experimental methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0044] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0045] In addition, as used in the present invention, the term "or" is an inclusive "or" symbol and is equivalent to the term "and / or", unless the context clearly dictates otherwise. The term "based on" is not exclusive and allows for being based on other factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meanings of "a", "an", and "the" include plural referents. The meaning of "in..." includes "in..." and "on...".

[0046] In the present invention, the aleurone layer includes an aleurone layer and a subaleurone layer.

[0047] In the following embodiments, the indica rice glutinous rice described in the present invention is referred to as glutinous rice glutinous rice.

[0048] The present invention is further described in detail below with reference to specific embodiments.

[0049] Example 1

[0050] This embodiment provides a rice extract and studies its hypoglycemic and anti-oxidant effects.

[0051] 1 Experimental materials

[0052] (1) Materials and reagents

[0053] Table 1 Experimental reagents

[0054]

[0055]

[0056] (2) Instruments and equipment

[0057] Table 2 Experimental instruments and equipment

[0058]

[0059] 2 Experimental methods

[0060] A vertical independent rice mill (SATAKE, NDB15A-C) was used to extract rice extract from indica rice (yellow flower sticky variety grown in Nanzhou Town, Nan County, Hunan):

[0061] Process: remove impurities - hulling - brown rice husk separation - length machine (remove unripe grains) - enter rice mill (sand roller 60#), the weight of each cycle is 350KG, all current values ​​are adjusted according to the slice results (seed coat and endosperm thickness). The products of the fourth and fifth millings are extracted as rice treasures.

[0062] First grinding, the current is determined according to the slicing results, breaking the cortex and grinding out the rice husk (current setting 10.5A);

[0063] Second grinding: continue slicing and grinding out the peel (current setting 10.3A);

[0064] The third grinding is to grind out the seed coat (current setting is 10.2A);

[0065] The fourth grinding is to grind out no more than 25% of the aleurone layer (current value 10.1A) and extract the aleurone layer;

[0066] The fifth grinding is to grind out the remaining endosperm (current value 10.1A) and extract the endosperm.

[0067] Take the product from the fourth grinding and pass it through sieves of 30 mesh (rice pearls from four grindings and three sieves) and 45 mesh (rice pearls from four grindings and four sieves) respectively.

[0068] Take the product from the fifth mill and pass it through sieves of 30 mesh (five mills and three sieves for rice pearls) and 45 mesh (five mills and four sieves for rice pearls) respectively.

[0069] The types and names of rice pearls are shown in Table 3 below.

[0070] Table 3 Types and names of Mizhen

[0071]

[0072] 2.1 Observation of cross-section during rice processing

[0073] In the production process of rice pearls, in order to ensure the quality of rice pearls, the rice after milling is observed under a microscope. The milled rice is washed with deionized water and then soaked in fuchsin carbonate dye for 30 seconds for dyeing, washed with deionized water three times, and observed under an optical microscope.

[0074] 2.2 Determination of total phenol content in rice

[0075] Determine with reference to the Folin-Ciocaulten method (Li Wang, Timin Shan, Bing Xie, et al. Glycine betaine reduces chilling injury in peach fruit by enhancing phenolic and sugar metabolisms [J]. Food Chemistry, 2018, 272 (JAN. 30): 530-538). Weigh 0.3 g of sample (accurate to 0.0001 g) and add 10 mL of 60% ethanol. After ultrasonic extraction for 20 min, centrifuge at 6000 r / min for 10 min to obtain the supernatant. Prepare 0 mg / L, 4 mg / L, 12 mg / L, 20 mg / L, and 30 mg / L gallic acid solutions (60% ethanol) for the preparation of the standard curve. After adding the reagents according to Table 4, place in a water bath at 40°C for 1 hour, cool to room temperature, and measure the OD 778 .

[0076] Table 4 Total phenol content determination reagent addition amount

[0077]

[0078] The content of total polyphenols was calculated as follows:

[0079] X=c×10×n (2-1)

[0080] Where:

[0081] n——sample dilution multiple.

[0082] 2.3 Determination of oryzanol content in rice

[0083] The determination was carried out in accordance with LS / T 6121.1-2017 (LS / T 6121.1-2017, Grain and Oil Inspection, Determination of Oryzanol Content in Vegetable Oils, Spectrophotometric Method [S]. State Administration of Grain and Material Reserves, 2017). Weigh 0.02 g (accurate to 0.0001 g) of rice sample, add 15 mL of n-heptane, ultrasonicate for 20 min, centrifuge at 6000 r / min for 10 min, and take the supernatant. Adjust the absorbance to zero with n-heptane as reference and measure at 315 nm. The oryzanol content was calculated according to the following formula:

[0084]

[0085] Where:

[0086] X——oryzanol content in the sample, %;

[0087] A——OD 315 ;

[0088] V——volume of the liquid to be tested, mL;

[0089] N——sample dilution multiple;

[0090] m——sample mass, g;

[0091] 359——Extinction coefficient (E 1％ 1cm ), indicating that the UV absorbance is measured at a concentration of 1 g / 100 mL (1%), with a wavelength of 315 nm in a 10 mm cuvette.

[0092] 2.4 Simulated gastrointestinal enzymatic hydrolysis of rice pearls

[0093] The method of Ma Sitong et al. (Ma Sitong, Liu Jingbo, Zhang Ting, et al. Differences in antioxidant activity of egg white peptides after in vitro simulated gastrointestinal digestion and alkaline protease treatment and peptide sequence analysis [J]. Food Science, 2020, 41 (21): 113-120) was slightly modified. Weigh 1.5g of rice sample and add 30mL of deionized water. Add appropriate amount of pepsin and use 1mol / L HCl to hydrolyze the system at pH 2 and temperature 37°C for 2h; then adjust the pH value to 7.5 with 1mol / L NaOH solution, add trypsin, keep the system at pH 2 and temperature 37°C for 2h, inactivate the enzyme in a boiling water bath for 10min, cool to room temperature, centrifuge at 6000r / min for 10min, collect the supernatant, and store at -20°C for later use.

[0094] 2.5 Analysis of the antioxidant activity of rice

[0095] 2.5.1 ABTS free radical scavenging ability

[0096] Slightly modified according to GB / T 39100-2020 (GB / T 39100-2020, Determination of Antioxidant Activity of Peptides by DPPH and ABTS Method [S]. Beijing: China Standards Press, 2020). Weigh 40 mg of ABTS solid and 86.9 mg of K2S2O, dissolve in water and dilute to 10 mL, react in the dark for 24 hours, and use as ABTS mother solution. Mix the mother solution with 95% ethanol to make its absorbance 0.7±0.02, and use as ABTS determination solution (prepare and use immediately).

[0097] This experiment uses reduced glutathione (GSH) as a positive control. Weigh a certain amount of rice sample to prepare a suitable gradient test solution, and ultrasonicate for 20 minutes for use. Add the reagents according to Table 5 below and place the system in a dark place to avoid light for 5 minutes. Use deionized water as a reference to adjust the zero, and use a UV spectrophotometer to measure the absorbance at a wavelength of 734nm.

[0098] Table 5 Amount of reagent added for ABTS free radical scavenging ability determination

[0099]

[0100] The calculation formula is as follows:

[0101]

[0102] 2.5.2 Hydroxyl radical scavenging ability

[0103] In this experiment, reduced glutathione (GSH) was used as a positive control. The method of Li Shaojie et al. (Li Yujie, Liu Shaokang, Zhou Tao, et al. Effects of salt stress on active ingredients, antioxidant properties and antioxidant enzyme activities during sesame germination [J / OL]. Food Industry Science and Technology, https: / / doi.org / 10.13386 / j.issn1002-0306.2023110056, 2024-03-12) was slightly modified. Weigh a certain amount of rice sample to prepare a test solution with a suitable concentration gradient and ultrasonicate for 20 minutes. Take 1 mL of the above test solution, add 1 mL 4.5 mmol / L FeSO4, 1 mL 4.5 mmol / L salicylic acid-ethanol in turn, mix well, and finally add 1 mL 4.4 mmol / L H2O2 solution. React at 37°C for 15 minutes and measure the OD 510 The calculation formula is as follows:

[0104]

[0105] 2.5.3 Superoxide anion scavenging ability

[0106] In this experiment, L-ascorbic acid was used as a positive control. The superoxide anion scavenging ability was determined by pyrogallol auto-oxidation-spectrophotometry (Hu Zexiang, Tong Lei, Geng Yanmeng, et al. Study on the scavenging of superoxide anions by luteolin nanoemulsion [J]. Chemical Engineering Management, 2022, (23): 156-158). Weigh a certain amount of rice sample to prepare a test solution with a suitable concentration gradient, ultrasonicate for 20 minutes and take the supernatant. Add 0.2mL of the above test solution and 1mL50mmol / L Tris-HCl to a 2mL centrifuge tube and incubate at 25℃ for 10min. Finally, add 30μL 6mmol / L pyrogallol solution and react at room temperature for 30min before measuring the OD 320 The calculation formula is as follows:

[0107]

[0108] Where: A 空白 A is a blank group with distilled water, Tris-HCl and pyrogallol solution added; 背景 A is the background group with the added sample solution, Tris-HCl and deionized water; 样品This is the experimental group to which the sample solution, Tris-HCl and pyrogallol solution were added.

[0109] 2.6 Analysis of the inhibitory effects of Mizhen on the activities of enzymes related to glucose metabolism

[0110] 2.6.1 α-Glucosidase Inhibition Ability

[0111] Modified on the basis of Zhang Na et al. (Zhang Na, Liu Li, Li Lu, et al. Optimization of ultrasound-assisted extraction process of polyphenols from green glue dandelion root and its in vitro antioxidant and hypoglycemic activities [J / OL]. Food Industry Science and Technology, https: / / doi.orgg / 10.13386 / j.issn1002-0306.2023100144, 2024-02-01). Acarbose was used as a positive control. A certain amount of rice sample was weighed to prepare a test solution with a suitable concentration gradient and ultrasonicated for 20 minutes. 50 μL of the above test solution and 50 μL of 1U / mL α-glucosidase (prepared in 0.1 mol / L pH 6.9 PBS) were mixed in a 96-well plate and incubated at 37°C for 10 minutes. 40 μL of 5 mmol / L pNPG solution (prepared in 0.1 mol / L pH 6.9 PBS) was added and incubated at 37°C for another 15 minutes. Add 120 μL 1 mol / L Na2CO3 solution to terminate the reaction and measure the OD with an enzyme-labeled instrument. 405 The calculation formula is as follows:

[0112]

[0113] Wherein: A1-A4 are sample absorbance, background absorbance (PBS replaces enzyme solution), A negative control absorbance (PBS replaces sample solution), negative control background absorbance (PBS replaces sample solution and enzyme solution).

[0114] 2.2.6.2 α-Amylase Inhibition Ability Determination

[0115] Acarbose was used as a positive control. A certain amount of rice sample was weighed to prepare a test solution with a suitable concentration gradient, and ultrasonicated for 20 minutes. 45 μL of the above test solution and 15 μL of 0.02 mg / mL α-amylase (prepared in 0.1 mol / L pH 6.9 PBS) were mixed in a 96-well plate and incubated at 37°C for 10 minutes. 60 μL of 0.08% starch solution was added, reacted at 37°C for 15 minutes, 60 μL of 1.0 mol / L HCl solution was added to terminate the reaction, and finally 20 μL of 0.01 mol / L iodine solution was added for color development. OD was measured using an enzyme reader 630 The calculation formula is as follows:

[0116]

[0117] Wherein: A1-A4 are sample absorbance, background absorbance (PBS replaces enzyme solution), A negative control absorbance (PBS replaces sample solution), negative control background absorbance (PBS replaces sample solution and enzyme solution).

[0118] 2.7 Determination of the hypoglycemic ability of Mizhen based on the hyperglycemic zebrafish model

[0119] The method was slightly modified according to Long Ruiyang (Long Ruiyang. Study on the extraction, structure, preparation and biological activity of Auricularia auriculariae polysaccharide and its zinc complex [D]. Guangzhou University, 2023). The zebrafish used in the experiment were wild-type AB strain zebrafish at 5 days post-fertilization (dpf). The hyperglycemic zebrafish model was established by feeding egg yolk powder and glucose.

[0120] 2.7.1 Determination of the maximum detectable concentration (MTC) of migratoria

[0121] The normal control group, model control group and experimental group (30 fish in each group, volume 25 mL) were set up as shown in Table 6. Zebrafish were treated according to Table 6, cultured at 28°C for 48h, and the MTC of Mizhen on hyperglycemic zebrafish was determined.

[0122] Table 6 Treatment schemes for each group of Mizhen MTC

[0123]

[0124] 2.7.2 Evaluation of Mizhen’s auxiliary hypoglycemic efficacy

[0125] The normal control group, model control group, positive control group (15.0 μg / mL pioglitazone) and experimental group (30 fish in each group, volume 25 mL) were set up as shown in Table 7. Zebrafish were treated according to Table 7, where the concentrations of Mizhen solution were 1 / 4 MTC, 1 / 2 MTC and 1 MTC, respectively, and cultured at 28°C for 48 h, and the glucose level of zebrafish was measured with a blood glucose meter.

[0126] Table 7 Treatment plans for each group in determining the blood sugar lowering effect of Mizhen

[0127]

[0128] 2.8 Data Processing

[0129] The experimental data were organized and analyzed using Excel, and significance analysis and graphing were performed using SPSS Statistics27 and Origin2024. The data in the figure are expressed as mean ± standard deviation, and the lowercase letters marked on each data point represent significant differences at the 0.05 level.

[0130] 3 Results and analysis

[0131] The experimental raw materials used in this study are rice products produced by different processing technologies, including four milling and three sieves, four milling and four sieves, five milling and three sieves, and five milling and four sieves. For the convenience of subsequent explanation, the above five products are named A, B, C, and D products in turn ( Figure 1 ).

[0132] The product studied in this experiment is a new type of nutritional food. In order to more clearly understand the impact of gastrointestinal digestion on the antioxidant and hypoglycemic activities of rice products, this study subjected the experimental raw materials to simulated gastrointestinal digestion, and analyzed the antioxidant and hypoglycemic activities of the products by measuring the in vitro indicators of the corresponding gastrointestinal simulated enzymatic hydrolysates.

[0133] 3.1 Section observation results

[0134] Rice structure Figure 2 As shown in Figure A, rice extract mainly comes from the aleurone layer and embryo of rice. Figure 2 As shown in B (from left to right, the cross-section of rice after three, four and five millings), after the rice is processed by three millings, part of the seed coat remains on its surface, and the aleurone content in the milled material is low, so the quality of the three-milling rice treasure product is low; the cross-section of the rice after four milling still contains a thick aleurone layer; and the rice after five millings contains almost no aleurone components. Therefore, this project selects the high-quality and aleurone-rich four-milling and five-milling rice treasure products as experimental raw materials.

[0135] 3.2 Comparative analysis of total phenol content

[0136] Under alkaline conditions, phenolic compounds undergo redox reactions with phosphotungstomolybdic acid to generate blue compounds with strong absorption at 778nm. Within a certain concentration range, the absorbance is proportional to the content of phenolic compounds ( Figure 3 ). As for the experimental results, the total phenol content of product D was the highest, reaching 23.21mg / g±1.61mg / g; followed by product B, with a total phenol content of 16.56mg / g±0.45mg / g; the total phenol content of the remaining two rice products produced by the processing technology was low, only about 10mg / g. Studies have shown that phenolic substances have certain antioxidant activity. Zhang Nigeng et al. found that plant polyphenols can reduce the oxidative deterioration of yak minced meat during cold storage, which further illustrates the antioxidant activity of plant polyphenols; therefore, the antioxidant biological activity of product D with a higher total phenol content may be correspondingly higher.

[0137] like Figure 4As shown in the figure, when the number of milling times is constant, the total phenol content of the four-screen product is generally higher than that of the three-screen product, indicating that the total phenol content is higher in smaller particles; the total phenol content of the rice treasure product produced by the five-milling process is much higher than that of the four-milling rice treasure, indicating that the closer to the inner side of the aleurone layer, the higher the total phenol content. The above results fully demonstrate that different milling and screening processes will affect the size of the product particles and the material composition of the rice treasure product.

[0138] 3.3 Comparative analysis of oryzanol content

[0139] Studies have shown that γ-oryzanol has antioxidant and hypoglycemic activity. Its hypoglycemic activity is mainly achieved by inhibiting cholesterol esterase, thereby reducing the cholesterol content in the body. In recent years, γ-oryzanol has been used as an auxiliary drug in combination with berberine to treat diabetes.

[0140] Oryzanol is a fat-soluble vitamin and is mainly found in the gelatinized layer of rice. Therefore, when the number of milling times increases, the source of the rice product is closer to the embryo, which leads to a decrease in the oryzanol it contains. In addition, the size of the sieve hole will also affect the oryzanol content in the rice product. The oryzanol content of the four-sieve product is generally higher than that of the three-sieve product. From the test results ( Figure 5 ), product B has the highest oryzanol content of 575.93mg / 100g±1.06mg / 100g; except product C, the oryzanol content of processed rice products is maintained at a relatively high level, which to a certain extent indicates that rice treasure has good hypoglycemic activity; it also provides data support for the production and processing of rice treasure in the future.

[0141] 3.4 Comparative analysis of antioxidant activity

[0142] Many free radicals are produced in the normal aerobic metabolism of organisms, and the accumulation of free radicals in cells will induce oxidative stress, which will then destroy the original redox balance and cause aging and disease. Therefore, the antioxidant research of nutritional foods is very necessary for the functional evaluation of foods.

[0143] 3.4.1 ABTS free radical scavenging rate

[0144] After testing, the IC50 of product A, product B, product C, product D and GSH on ABTS free radical scavenging ability is shown in Table 8:

[0145] Table 8 IC50 of ABTS free radical scavenging ability

[0146]

[0147] ABTS free radical scavenging rate is currently a widely used method to evaluate the antioxidant activity of bioactive substances, and can be applied to the measurement of water-soluble and fat-soluble compounds. Figure 6 and Figure 7 It can be seen that the ABTS free radical scavenging ability of rice is strong, and the ABTS free radical scavenging rate can reach a high level at a lower concentration. However, whether it is rice treasure products or their enzymatic hydrolysates, their ability to scavenge ABTS free radicals is lower than that of GSH. This is because compared with GSH, in addition to antioxidant ingredients, rice treasure products also contain more insoluble impurities (such as cellulose, etc.), which leads to its IC50 being higher than GSH. Among them, the most significant scavenging ability is product D, and the ABTS scavenging rates of this product and its gastrointestinal simulated enzymatic hydrolysate can reach 60.41%±1.33% and 98.73%±0.10%, respectively. In addition, after gastrointestinal simulated enzymatic hydrolysis, the scavenging ability of the four rice treasure products on ABTS has been greatly improved, and their ABTS free radical scavenging rates have reached more than 90%.

[0148] 3.4.2 Hydroxyl radical scavenging rate

[0149] After testing, the IC50 of product A, product B, product C, product D and GSH for scavenging hydroxyl free radicals is shown in Table 9:

[0150] Table 9 IC50 of hydroxyl radical scavenging ability

[0151]

[0152] Hydroxyl radicals are the most active oxygen free radicals, which can damage adjacent biological molecules in cells, thus causing aging, cancer and other diseases. Figure 8 and Fig. 9 As shown, the hydroxyl radical scavenging ability of the four rice products increases with the increase of concentration. Among them, the most significant scavenging ability is product D, with an IC50 of 43.50 mg / mL and a hydroxyl radical scavenging rate of 27.13% ± 3.09%. The hydroxyl radical scavenging ability of the gastrointestinal simulated enzymatic hydrolysate of product D is also the most outstanding, with an IC50 of 21.15 mg / mL and a scavenging rate of 62.07% ± 0.89%. The IC50 of GSH, which is used as a positive control, is 3.67 mg / mL. In addition, after gastrointestinal simulated enzymatic hydrolysis, the hydroxyl radical scavenging rate of product B is significantly improved, from the original 20.04% ± 2.41% to 60.45% ± 1.77%.

[0153] 3.4.3 Superoxide anion free radical scavenging rate

[0154] After testing, the IC50 of product A, product B, product C, product D and VC for scavenging superoxide anion free radicals is shown in Table 10:

[0155] Table 10 IC50 of superoxide anion free radical scavenging ability

[0156]

[0157] Superoxide anion free radicals can oxidize lipids, DNA and proteins, leading to oxidative stress in cells, which in turn can lead to diseases such as cancer, acute stroke and atherosclerosis. Therefore, the superoxide anion free radical scavenging ability of bioactive substances is one of the important indicators for evaluating antioxidant activity in vitro. Fig.10 and Fig.11 It can be seen that with the increase of concentration, the superoxide anion free radical scavenging levels of the four rice products without enzymatic hydrolysis all increased, but the increase was slightly different; the product D had the strongest scavenging ability at low concentration (5mg / mL), with a scavenging rate of 13.86%±1.75%; but the product C had the strongest scavenging ability at high concentration (25mg / mL), with a scavenging rate of 34.55%±1.25%. After simulated enzymatic hydrolysis in the gastrointestinal tract, among the four rice products, the product D had the most significant scavenging ability, with a scavenging rate of 69.91%±2.47% and an IC50 of 2.57mg / mL; while the IC50 of the positive control VC was only 0.03mg / mL.

[0158] The results of the above three in vitro antioxidant capacity tests all show that after simulated gastrointestinal enzymatic hydrolysis, the antioxidant properties of the simulated gastrointestinal hydrolysates at the same concentration are stronger than those of the rice treasure products without enzymatic hydrolysis. The essence is that after the enzymatic hydrolysis of the former, the concentration of small molecule peptides in its solution system increases, thereby significantly improving its antioxidant properties. Among the four types of rice treasures, the rice treasures produced by the five-milling and four-screening process and their gastrointestinal simulated enzymatic hydrolysates have the strongest free radical scavenging ability, among which the ABTS free radical has the most significant scavenging effect on the above three free radicals, reaching 60.41%±1.33% and 98.73%±0.10% respectively; in addition, both of them also have good scavenging effects on hydroxyl free radicals and superoxide anion free radicals, reaching 27.13%±3.09% and 62.07%±0.89%, 31.73%±1.39% and 69.91%±2.47% respectively; in summary, the antioxidant activity of rice treasures produced by the five-milling and four-screening process is relatively excellent, and it can exert antioxidant activity in the body after digestion and enzymatic hydrolysis by the human body.

[0159] 3.5 Comparative analysis of hypoglycemic activity

[0160] 3.5.1 α-Glucosidase Inhibition Rate

[0161] After testing, the half-inhibitory concentrations of product A, product B, product C, product D and their gastrointestinal simulated hydrolysates and acarbose on α-glucosidase are shown in Table 11:

[0162] Table 11 Half inhibition concentration of four rice products and their gastrointestinal simulated enzymatic hydrolysates on α-glucosidase

[0163]

[0164] α-glucosidase can hydrolyze α-glucosidic bonds and promote the conversion of carbohydrates into glucose. Clinically, the effect of lowering blood sugar is usually achieved by inhibiting α-glucosidase on the intestinal mucosa. Fig.12 and Fig.13 It can be seen that the four rice products have weak inhibitory ability against α-glucosidase at low concentrations, and the inhibitory ability gradually increases with the increase of concentration. Among them, the most significant inhibitory ability is product B, with an IC50 of 35.84 mg / mL and an inhibition rate of 62.65% ± 1.56%. The four gastrointestinal simulated hydrolysates have a strong inhibitory ability at a lower concentration (2.5 mg / mL), and compared with the unhydrolyzed products, the inhibitory ability of different rice hydrolysates on α-glucosidase is relatively small. The inhibition rate of the high concentration (30 mg / mL) hydrolysate solution exceeds 50%, among which the strongest inhibitory ability is the hydrolysate of product B, with an IC50 of 10.17 mg / mL and an inhibition rate of up to 73.06% ± 1.28%. Acarbose is used as a positive control, and the IC50 is only 0.34 mg / mL.

[0165] 3.5.2 α-Amylase Inhibition Rate

[0166] After testing, the half-inhibitory concentrations of product A, product B, product C, product D and their gastrointestinal simulated hydrolysates and acarbose on α-amylase are shown in Table 12:

[0167] Table 12 Half inhibition concentration of four rice products and their gastrointestinal simulated enzymatic hydrolysates on α-amylase

[0168]

[0169] α-Amylase is one of the important hydrolytic enzymes that catalyzes starch hydrolysis. Fig.14 and Fig.15 It can be seen that the inhibitory ability of product C on α-amylase is weak at low concentrations, and its inhibitory ability is concentration-dependent; the inhibitory ability of product B increases slightly with concentration, and the inhibition rate of high concentration (40 mg / mL) B solution is only 59.31%±2.03%. The most significant inhibitory ability is product D, and the inhibition rate of 20 mg / mL D solution on α-amylase is as high as 98.20%±0.57%. In addition, the four gastrointestinal simulated hydrolysates have strong inhibitory ability at low concentrations, and the inhibition rate of α-amylase by the hydrolysate solution with a concentration of 1.5 mg / mL is more than 50%, among which the strongest inhibitory ability is the hydrolysate of product D, with an IC50 of 0.55 mg / mL; at a concentration of 2.0 mg / mL, the inhibition rate is as high as 96.38%±1.72%. Acarbose is used as its positive control, and its IC50 is only 0.02 mg / mL.

[0170] In summary, the inhibitory ability of rice products on α-amylase is much better than that of α-glucosidase, and the most significant inhibitory abilities on the two enzymes are the products produced by the five-mill and four-screen and four-mill and four-screen processing techniques. Among them, the half-inhibitory concentrations of rice products produced by the five-mill and four-screen and its gastrointestinal hydrolysate for α-glucosidase are 40.12 mg / mL and 13.80 mg / mL, slightly higher than the rice products processed by the four-mill and four-screen process (35.84 mg / mL and 10.17 mg / mL, respectively); and its half-inhibitory concentration for α-amylase is 3.91 mg / mL and 0.55 mg / mL, which is much lower than the rice products processed by the four-mill and four-screen process (30.56 mg / mL and 1.48 mg / mL, respectively).

[0171] 3.5.2 Analysis of Mizhen’s hypoglycemic ability based on a hyperglycemic zebrafish model

[0172] Through comparative analysis of the inhibitory ability of the four rice treasure products on the activity of enzymes related to sugar metabolism in experiments 3.5.1 and 3.5.2, it was found that the rice treasure products produced and processed by five mills and four sieves have a strong hypoglycemic ability. In order to further analyze the hypoglycemic activity of this product, a hyperglycemic zebrafish model was selected to evaluate its hypoglycemic activity in vivo. MTC refers to the maximum concentration that a drug can reach without affecting the health of the body. As shown in Table 13, when the concentration range of rice treasure is 0-2000μg / mL, the mortality rate of zebrafish is 0 and its phenotype is similar to that of the model control group; concentrations exceeding this range will cause the death of zebrafish. Therefore, this experiment selected 2000μg / mL as the MTC of five-mill and four-sieve rice treasure for subsequent experiments.

[0173] Table 13 MTC determination of five-mill four-sieve rice

[0174]

[0175]

[0176] Feeding zebrafish with egg yolk powder and glucose can rapidly increase the glucose content in the blood of zebrafish. In this experiment, the hyperglycemic zebrafish mentioned above were used as a model to analyze the in vivo blood sugar lowering ability of Mizhen. The experiment showed that ( Fig.16), Wumo Si Si Mi Zhen has a strong blood sugar lowering ability, and Mi Zhen's blood sugar lowering ability is concentration-dependent. The blood sugar lowering effect of 1000μg / mL Wumo Si Si Mi Zhen solution is equivalent to that of the positive control (15.0μg / mL pioglitazone); the blood sugar concentration of hyperglycemic zebrafish treated with 1000μg / mL Mi Zhen solution was reduced to 1.34±0.09mmol / mL, which is similar to the blood sugar concentration of zebrafish in the normal control group (0.99±0.03mmol / mL). This shows that Wumo Si Si Mi Zhen has a good blood sugar lowering effect, and the blood sugar lowering effect of 1 / 2MTC Wumo Si Si Mi Zhen solution is equivalent to that of 15.0μg / mL pioglitazone.

[0177] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing indica rice treasures, characterized in that: Extracting rice extract from indica rice using a rice mill includes the following steps: (1) First grinding: grinding out the rice husks; (2) Second grinding: grinding out the peel; (3) Third grinding: grinding out the seed coat; (4) Fourth grinding: grinding out no more than 25% of the aleurone layer to obtain grinding product 4; (5) Fifth grinding: grinding out the remaining aleurone layer to obtain grinding product 5; (6) collecting the milled product 5, or the milled product 5 and the milled product 4; (7) Pass through a 30-45 mesh sieve.

2. The preparation method according to claim 1, characterized in that Pass through 40-45 mesh sieve.

3. The preparation method according to claim 2, characterized in that: The milled product 5 is collected and passed through a 40-45 mesh sieve; preferably, the milled product 5 is collected and passed through a 45 mesh sieve.

4. The preparation method according to claim 1, characterized in that: The rice mill uses 40#-60# sand rollers: Preferably, the rice mill uses a 60# sand roller; the current of the first roller is 10.5±0.2A; and / or, the current of the second roller is 10.3±0.2A; and / or, the current of the third roller is 10.2±0.2A; and / or, the current of the fourth roller is 10.1±0.2A; and / or, the current of the fifth roller is 10.1±0.2A.

5. The preparation method according to claim 1, characterized in that: The indica rice is glutinous rice, preferably yellow flower glutinous rice.

6. Indica rice treasures prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the indica rice seed as claimed in claim 6 in the preparation of hypoglycemic biological preparations.

8. Use of the indica rice extract as claimed in claim 6 in the preparation of antioxidant biological preparations.

9. The use according to claim 7 or 8, characterized in that The biological preparation is a medicine, a health product or a food.

10. A hypoglycemic or antioxidant biological preparation, characterized in that: The invention comprises active ingredients and auxiliary materials, wherein the active ingredients include the indica rice treasure as claimed in claim 6; and the auxiliary materials are pharmaceutically acceptable carriers, health care product acceptable carriers or food acceptable carriers.

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