Low-GI rhizoma polygonati black rice and preparation method thereof

Abstract

The invention relates to low-GI polygonatum sibiricum black rice and a preparation method thereof, and belongs to the technical field of food processing. The low-GI polygonatum sibiricum black rice is recombinant rice based on polygonatum sibiricum and black rice as raw materials, and comprises polygonatum sibiricum, black rice, coarse cereals, konjaku flour and vital gluten. Polygonatum sibiricum, black rice, tartary buckwheat and other coarse cereals, taro powder and vital wheat gluten are compounded according to a specific proportion, and structural recombination is performed to obtain the polygonatum sibiricum health-care food. According to the recombinant rice, through the synergistic effect of rhizoma polygonati and black rice, postprandial blood sugar response can be reduced, the symptom of hyperglycemia can be remarkably improved, the protective effect on the liver and pancreas is achieved, on the basis, the eating quality of the recombinant rice is improved, the pain point of poor taste of coarse cereals is solved, and the recombinant rice is particularly suitable for being used as staple food of diabetics or obese people.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, and particularly relates to a low-GI polygonatum black rice and a preparation method thereof. Background Art

[0002] With the acceleration of people's living rhythm, the change of dietary composition and lifestyle, the proportion of metabolic syndromes related to insulin resistance such as diabetes has been continuously increasing. The metabolic syndrome is closely related to the blood glucose-raising reaction caused by the long-term intake of refined rice and flour products with a high content of rapidly digestible starch. By extruding and recombining to prepare low-GI (glycemic index) recombined rice, the daily staple food structure can be improved without changing people's eating habits, effectively preventing the occurrence of the above-mentioned metabolic syndromes, and even having a therapeutic function for early-stage patients. However, it is difficult for various anti-digestive components to maintain low digestive activity after extrusion, high temperature and shearing. How to achieve a low GI is the key problem restricting the recombined rice for diabetes.

[0003] Extruded recombined rice, also known as nutrient-enriched rice, engineered rice, and artificial rice, is a rice product similar in shape to natural rice, which is prepared by using starchy materials as the main raw material, micro-pulverizing broken rice and mixing it with fortifiers, and through processes such as extrusion cooking, cutting and forming, and drying. Extruded recombined rice can make up for the deficiencies of natural rice in nutrients such as vitamins, proteins, and minerals, and at the same time increase the diversity of products.

[0004] Extruded recombined rice has the advantages of rich nutrition, easy storage, and fast cooking, but it generally has the problem of high digestibility. Here, "high digestibility" mainly means that its digestion speed is relatively fast, which easily leads to a rapid increase in postprandial blood glucose.

[0005] At present, domestic and foreign scholars mainly conduct in-depth research on aspects such as process optimization, nutritional fortification, and quality improvement of extruded recombined rice, and there are few reports on the digestibility of extruded recombined rice. In the existing related research, regarding reducing the digestibility of extruded recombined rice, there are methods such as adding resistant starch, lipids, and proteins, changing the starch structure, and increasing its anti-digestibility. For example, compounding rice with medium- and low-GI whole grains and miscellaneous grains cannot meet the requirements of low-GI whole grain rice. There have also been attempts to reduce the GI of miscellaneous grain rice by increasing the proportion of low-GI miscellaneous grains. However, when the proportion of a single miscellaneous grain exceeds a certain level, the taste and flavor of the miscellaneous grain rice will decline significantly, and the consumer acceptance is low. Summary of the Invention

[0006] The present invention provides a low-GI polygonatum black rice, which uses black rice as the base material and innovatively adds the medicinal and edible resource polygonatum into black rice, miscellaneous grains, wheat gluten powder, and konjac powder to obtain a recombined rice with a low GI, high quality, and good taste.

[0007] The present invention provides a low-GI polygonatum black rice, comprising polygonatum, black rice, miscellaneous grains, konjac flour and wheat gluten; by weight, the content of the black rice is 25%-35%, and the content of the miscellaneous grains is 65%-75%; the content of the polygonatum is 1%-5% of the total weight of the black rice and the miscellaneous grains.

[0008] On the other hand, the present invention provides a preparation method of the above-mentioned low-GI polygonatum black rice, comprising the following steps:

[0009] S1. Clean the black rice and miscellaneous grains and grind them with a pulverizer to obtain a composite miscellaneous grain powder for standby;

[0010] S2. Dry and pulverize the polygonatum to obtain polygonatum powder for standby;

[0011] S3. Add the konjac flour and wheat gluten to the composite miscellaneous grain powder in step S1 and the polygonatum powder in S2, and mix evenly;

[0012] S4. Extrude the mixed material in step S3, rotate and cut it, and granulate and form it;

[0013] S5. Cool and dry to obtain the low-GI polygonatum black rice.

[0014] The low-GI polygonatum black rice of the present invention solves the pain points of poor taste and coarseness of traditional miscellaneous grain rice, has both low-GI and nutritional value, and can be used as the staple food for people with diabetes, obesity, etc.

[0015] The present invention has the following beneficial effects:

[0016] 1. Extruded restructured rice has the advantages of rich nutrition, easy storage and fast cooking, etc., but it generally has the problem of high digestibility. Compared with refined white rice and noodles, miscellaneous grains contain higher slowly digestible starch (SDS) and resistant starch (RS), and long-term consumption helps to control blood sugar levels and reduce the risk of diabetes. However, miscellaneous grains have a poor taste and low consumer acceptance. For a long time, the proportion of miscellaneous grains in the grain consumption structure of Chinese residents has been relatively low. The present invention provides a low-GI polygonatum black rice, which overcomes the problems of poor edible quality and low consumer acceptance of existing restructured rice, and breaks through the limitations of miscellaneous grains.

[0017] 2. Using black rice as the base material, innovatively adding the medicinal and edible resource polygonatum into black rice, miscellaneous grains, wheat gluten and konjac flour to obtain a low-GI, high-quality and good-taste restructured rice. The low-GI polygonatum black rice of the present invention has both low-GI and high nutritional value at the same time. The restructured rice of the present invention improves the viscoelasticity while reducing the GI value, and solves the pain points of poor taste and coarseness of traditional miscellaneous grain rice.

[0018] 3. Polygonatum sibiricum, a traditional plant with dual roles as food and medicine, is rich in active ingredients such as polysaccharides, saponins, and flavonoids. It can not only regulate blood sugar, maintain the integrity of the islet structure to a certain extent, protect the pancreas and liver, and improve the symptoms of diabetic mice. In this invention, Polygonatum sibiricum, black rice, miscellaneous grains, taro powder, and wheat gluten are combined through a twin-screw extrusion technology, which improves the food quality and taste, increases the acceptance of consumers, and protects the pancreas and liver through daily consumption, thus improving the diabetic syndrome.

[0019] 4. The flavonoid components in Polygonatum sibiricum in this invention (α-glucosidase inhibition rate > 60%) and the slow-digesting characteristics of black rice may form a "dual pathway" for blood sugar and blood lipid regulation. People with diabetes and obesity need to control blood sugar for a long time, but commercially available low-GI staple foods lack the auxiliary conditioning function of food and medicine homologous ingredients. Incorporating Polygonatum sibiricum into the formula of this invention can meet the needs of patients with chronic diseases for "combining diet and nourishment". Brief Description of the Drawings

[0020] Figure 1 Shows the organ indices of the livers of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2.

[0021] Figure 2 Shows the organ indices of the pancreases of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2.

[0022] Figure 3 Shows the organ indices of the spleens of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2.

[0023] Figure 4 Shows the organ indices of the kidneys of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2.

[0024] Figure 5 Shows the morphological structures of the livers of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2.

[0025] Figure 6 Shows the morphological structures of the pancreases of mice fed with extruded and recombined rice of the blank group, control group, model group, experimental group 1, and experimental group 2. Detailed Description of the Embodiments

[0026] In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] The following is a further detailed description of the present invention with specific embodiments, but the present invention is not limited to the following specific embodiments.

[0028] Extruded recombinant rice can make up for the deficiencies of natural rice in nutritional components such as vitamins, proteins, and minerals, while increasing product diversity. At present, domestic and foreign scholars mainly conduct in-depth research on aspects such as process optimization, nutritional fortification, and quality improvement of extruded recombinant rice, and there are few reports on the digestibility of extruded recombinant rice.

[0029] However, extruded recombinant rice generally has the problem of high digestibility. In existing related research, the amount of hypoglycemic functional excipients required to significantly reduce the digestibility of extruded recombinant rice by the mutual matching method is large, and increasing the amount of excipients will make it difficult to granulate extruded recombinant rice and deteriorate the eating quality.

[0030] The present invention provides a low-GI polygonatum black rice, which improves the viscoelasticity while reducing the GI value, and solves the pain points of poor taste and roughness of traditional coarse cereals.

[0031] Polygonatum, belonging to the Liliaceae plant, is the dried rhizome of Polygonatum kingianum Coll, et Hemsl., Polygonatum sibiricum Red., or Polygonatum cyrtonema Hua. Polygonatum contains various components such as polysaccharides, steroidal saponins, alkaloids, anthraquinones, lignans, flavonoids, and amino acids.

[0032] For a long time, in the grain consumption structure of residents, coarse cereals have a poor taste and a low proportion. Moreover, there are many types of coarse cereals, and there are differences in the GI values between different coarse cereals, and the tastes are also different.

[0033] The present invention provides a low-GI polygonatum black rice, using black rice as the base material, innovatively adding the medicinal and edible resource polygonatum into black rice, coarse cereals, wheat gluten powder, and konjac powder to obtain a recombinant rice with low GI, high quality, and good taste, overcoming the problems of poor eating quality and low consumer acceptance of existing recombinant rice, and breaking through the limitations of coarse cereals.

[0034] The present invention provides a low-GI polygonatum black rice, comprising polygonatum, black rice, coarse cereals, konjac powder, and wheat gluten powder; by weight, the content of black rice in the low-GI polygonatum black rice is 25%-35%, the content of coarse cereals is 65%-75%, and the content of polygonatum is 1%-5% of the total weight of black rice and coarse cereals.

[0035] In one embodiment, the content of the black rice can be 25 - 35%. For example, it can be 25%, 28%, 30%, 35%, etc. The content of the polygonatum sibiricum can be 1% - 5%, for example, it can be 1% - 3%. For example, it can be 1%, 1.5%, 2%, 3%, etc.

[0036] The higher content of polygonatum sibiricum is not necessarily better. Polygonatum sibiricum has a unique smell itself, and the taste of miscellaneous grains is poor. The application of polygonatum sibiricum as a medicine and food dual-purpose ingredient is rarely combined with miscellaneous grains, konjac flour, etc. in recombinant rice. In the present invention, the flavonoid components in polygonatum sibiricum and the slow digestion characteristics of miscellaneous grains may form a "dual pathway" for blood glucose and blood lipid regulation. Through the synergistic effect of polygonatum sibiricum and miscellaneous grains, not only the GI value in the body is significantly reduced, significantly improving the hyperglycemia symptoms of diabetic mice, but also it has a certain protective effect on the liver and pancreas, with balanced nutrition and coordinated taste.

[0037] In one embodiment, the particle size of the polygonatum sibiricum can be ≤ 0.25 mm. The particle size of the black rice can be ≤ 0.25 mm. The particle size of the miscellaneous grains can be ≤ 0.25 mm.

[0038] In one embodiment, the content of the konjac flour and wheat gluten is 3% - 15% of the total weight of the black rice and miscellaneous grains, and the content ratio of the konjac flour to the wheat gluten is (1 - 2):(1 - 2). For example, the content ratio of the konjac flour to the wheat gluten can be 1:1, 1:2, 2:1, etc.

[0039] In the present invention, the addition of konjac flour and wheat gluten neither affects the glycemic index nor improves the edible quality of the recombinant rice.

[0040] In one embodiment, the miscellaneous grains include one or more of rye, black beans, red rice, corn, millet, coix seed, oats, quinoa, barley, highland barley, red beans, mung beans, soybeans, white kidney beans, colored kidney beans, chickpeas, buckwheat. In the embodiments of the present invention, buckwheat includes common buckwheat and tartary buckwheat. The buckwheat can be black tartary buckwheat.

[0041] In another embodiment, the present invention provides a preparation method of any one of the above low - GI polygonatum sibiricum black rice, comprising the following steps:

[0042] S1. Crush the cleaned black rice and miscellaneous grains with a pulverizer and pass through a 60 - mesh sieve to obtain a composite miscellaneous grain powder for standby;

[0043] S2. Dry - crush the polygonatum sibiricum and pass through a 60 - mesh sieve to obtain a polygonatum sibiricum powder for standby;

[0044] S3. Add the konjac flour and wheat gluten to the composite miscellaneous grain powder in step S1 and the polygonatum sibiricum powder in S2, and mix evenly;

[0045] S4. Extrude the mixed material in step S3, rotate and cut, and granulate and form.

[0046] S5. Cool and dry to obtain the low-GI polygonatum odoratum and black rice.

[0047] In step S1, black rice, buckwheat and miscellaneous grains can be crushed to a particle size of ≤ 0.25 mm. After crushing, black rice and miscellaneous grains can be put into a self-sealing bag for standby.

[0048] In step S2, polygonatum odoratum can be crushed to a particle size of ≤ 0.25 mm. The polygonatum odoratum can be nine-processed polygonatum odoratum, which is processed by "nine steaming and nine sunning".

[0049] In step S4, the feeding speed of extruding the mixed material in step S3 is 1 - 10 kg / h, the water addition amount is 20 - 40%, the temperature of the mixed preheating zone of the extruded material is 70 - 80 °C, the temperature of the extrusion conveying zone is 80 - 110 °C, the temperature of the pre-gelatinization zone is 110 - 135 °C, the temperature of the gelatinization shearing zone is 110 - 135 °C, the temperature of the melting zone is 100 - 120 °C, and the temperature of the die head forming zone is 70 - 80 °C; the screw speed is 40 - 60 rpm, and then it is rotated and cut into pellets, and the cutter speed is 1100 - 1500 rpm.

[0050] In step S5, the material processed in step S4 is dried at 40 - 55 °C until the moisture content is 11 - 13%.

[0051] The present invention uses black rice and miscellaneous grains as the base materials, introduces polygonatum odoratum and compound it with black rice and miscellaneous grains in a specific ratio, reduces the GI through synergistic effects, protects the organ damage, and introduces konjac powder and wheat gluten powder to improve the taste of miscellaneous grains. The twin-screw extrusion recombination technology is used to realize the recombination of the molecular structure of the material, realize the cross-border combination of polygonatum odoratum and miscellaneous grains and the synergistic application of konjac powder + wheat gluten powder, and break through the technical bottleneck of the existing low-GI rice being "tasteless".

[0052] The following further elaborates the present invention in detail in combination with specific embodiments and drawings.

[0053] The required black rice, polygonatum odoratum, miscellaneous grains, konjac powder, wheat gluten powder, etc. are obtained by purchase.

[0054] Example 1

[0055] (1) The cleaned black rice and miscellaneous grains are crushed by a crusher and passed through a 60-mesh sieve for standby; the miscellaneous grains include high amylose corn starch, corn, quinoa, white kidney beans, and mung beans; the weight ratio of black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans is 30:30:15:5:10:10. The weight content of black rice is 30%.

[0056] (2) Dry and crush the polygonatum odoratum and pass through a 60-mesh sieve for standby.

[0057] (3) Mix the crushed black rice with high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly. Add 3% polygonatum, 10% vital wheat gluten, and 5% konjac powder of the above mixed materials and mix evenly.

[0058] (4) Pour the evenly mixed raw materials into the feeder of the extruder. The solid feeding amount is 5.0 kg / h, the screw speed is 50 rpm, the liquid feeding amount is 30%, and the feeding speed is 10 kg / h. Using the extrusion recombination technology, the temperatures of the mixing preheating zone, extrusion conveying zone, pregelatinization zone, shear gelatinization zone, melting zone, and die head zone are set at 70 °C, 100 °C, 130 °C, 130 °C, 110 °C, and 70 °C respectively, and the cutter speed is 1500 rpm.

[0059] (5) Dry the prepared sample at 45 °C until the moisture content is 11 - 13%, and then package it to obtain the product.

[0060] Example 2

[0061] Same as Example 1. The difference is that the weight ratio of black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans is 25:30:15:10:10:10. The weight content of black rice is 25%.

[0062] Example 3

[0063] Same as Example 1. The difference is that the weight ratio of black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans is 35:30:15:5:5:10. The weight content of black rice is 35%.

[0064] Example 4

[0065] Same as Example 1. The difference is that the weight ratio of black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans is 35:30:15:5:5:10. The weight content of black rice is 35%.

[0066] Example 5

[0067] The difference from Example 1 is: the amount of polygonatum added is 1%, specifically adding 1% of polygonatum to the above mixed materials in step (3).

[0068] Others are the same as Example 1.

[0069] Example 6

[0070] The difference from Example 1 is: the amount of polygonatum added is 5%, specifically adding 5% of polygonatum to the above mixed materials in step (3).

[0071] Others are the same as Example 1.

[0072] Comparative Example 1

[0073] The difference from Example 1 is that black rice is replaced with ground rice flour. Specifically, step (3) is changed to "Mix ground rice flour, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly in a ratio of 30:30:15:5:10:10, and additionally add 3% of polygonatum sibiricum, 10% of wheat gluten, and 5% of konjac powder to the above mixed materials."

[0074] Other steps are the same as those in Example 1.

[0075] Comparative Example 2

[0076] The difference from Example 1 is that wheat gluten is not added. Specifically, step (3) is changed to "Mix black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly in a ratio of 30:30:15:5:10:10. Additionally add 3% of polygonatum sibiricum and 5% of konjac powder to the above mixed materials."

[0077] Other steps are the same as those in Example 1.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that konjac powder is not added. Specifically, step (3) is changed to "Mix black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly in a ratio of 30:30:15:5:10:10. Additionally add 3% of polygonatum sibiricum and 10% of wheat gluten to the above mixed materials."

[0080] Other steps are the same as those in Example 1.

[0081] Comparative Example 4

[0082] The difference from Example 1 is that neither konjac powder nor wheat gluten is added. Specifically, step (3) is changed to "Mix black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly in a ratio of 30:30:15:5:10:10. Additionally add 3% of polygonatum sibiricum to the above mixed materials."

[0083] Other steps are the same as those in Example 1.

[0084] Comparative Example 5

[0085] The difference from Example 1 is that polygonatum sibiricum is not added. Specifically, step (3) is changed to "Mix black rice, high amylose corn starch, corn, quinoa, white kidney beans, and mung beans evenly in a ratio of 30:30:15:5:10:10. Additionally add 10% of wheat gluten and 5% of konjac powder to the above mixed materials."

[0086] Other steps are the same as those in Example 1.

[0087] Test Results and Analysis

[0088] The in vivo GI values, cooking characteristics, and texture characteristics of the extruded recombinant rice prepared in Examples 1-6 and Comparative Examples 1-5 were tested, and the test methods are as follows:

[0089] 1. Determination of in vivo GI value:

[0090] Eighteen male Sprague-Dawley rats at 7 weeks of age with a body weight of about 200 g were adaptively fed in an environment with a temperature controlled at about 25 °C and a 12 / 12 h light / dark cycle. After 7 days of adaptive feeding, they were randomly divided into 3 groups, with 6 rats in each group, parallel to each other. Take 50 g of the sample, calculate the water addition amount according to the starch content after steaming (0.2 g / mL), put it into a blender and break it into rice paste, so that the amount of recombinant rice intubated into each rat is 0.4 g. After fasting the rats for 10 h, tail vein blood samples were collected early the next morning, and their fasting blood glucose was detected using a blood glucose meter, repeated once after an interval of 5 min, and then the sample paste was injected into the rats through a gastric intubation needle, and blood samples were collected at 15, 30, 45, 60, 90, and 120 min after gastric intubation. After the rat tails recovered for about one week, other samples were measured using the same method. All animal experiments were carried out in accordance with the experimental guidelines and procedures approved by the Animal Ethics Committee of Nanchang University. The calculation formula for the GI value is as follows:

[0091] GI value = Area under the blood glucose response curve of the test food / Area under the blood glucose response curve of glucose × 100

[0092] 2. Sensory scoring of odor and taste:

[0093] Ten sensory scoring personnel were selected. During the evaluation process, when changing samples, the sensory scoring personnel needed to rinse their mouths and were prohibited from communicating with each other. The average value was calculated based on the comprehensive scoring results of each sensory scoring personnel. For data with too large scoring errors, they should be excluded and the average value should be recalculated to ensure the objectivity and accuracy of the evaluation results. The sensory scoring criteria refer to Table 1.

[0094] Table 1 Sensory scoring criteria

[0095]

[0096]

[0097] 3. Determination of the sensory properties of eating quality:

[0098] Ten sensory scoring personnel were selected. Referring to the national standard GB / T 15682-2008, the eating quality of the recombinant rice was evaluated from aspects such as elasticity, viscosity, and hardness. The sensory scoring criteria refer to Table 2.

[0099] Table 2 Results of sensory evaluation of eating quality

[0100]

[0101] Table 2 Recombinant rice performance test results

[0102]

[0103] As can be seen from the data in Table 2, polygonatum has the smell and taste of traditional Chinese medicine, and the addition amount of polygonatum is not the more the better. The taste score first increases and then decreases, probably because polygonatum is sweet in taste and neutral in nature, with a certain sweet taste. When the addition amount of polygonatum is 3%, the highest taste score of the recombinant rice is 17.6. From the results of Example 1 and the comparative examples, it can be seen that through the synergistic effect of polygonatum and black rice, the in vivo GI value can be reduced.

[0104] Table 3 Sensory test results of eating quality

[0105]

[0106] As shown in Table 3, when gluten and konjac flour are compounded, the recombinant rice has a better taste. The taste of softness and hardness is close to that of natural polished rice, rather than the hard and loose taste of coarse grains.

[0107] 4. Organ index and histopathological analysis of mice:

[0108] Thirty male C57BL / 6J mice (body weight: 18 ± 2 g, age: 5 weeks old) were purchased from Beijing Spey Foster Biotechnology Co., Ltd., with the license number: SCXK (Jing) 2019-0010. The mice were placed in an animal room with good air circulation (temperature: 25 ± 2 °C, relative humidity: 50 ± 10%), with a day-night cycle (12 h of light and 12 h of darkness every day). During the breeding period, the bedding, fresh drinking water and feed were changed twice a week. The mice were allowed to eat and drink freely, and the fasting blood glucose and body weight of the mice were measured and recorded every week. All animal experiments were carried out in accordance with the experimental guidelines and procedures approved by the Animal Ethics Committee of Nanchang University.

[0109] After all mice were adaptively fed with normal standard feed and normal drinking water for 1 week, they were randomly divided into 5 groups with 6 mice in each group. After comprehensively considering the in vivo GI value, eating quality, smell and taste of different formulations of recombinant rice, Example 1 with 3% polygonatum sibiricum added had the best effect, so it was used as the experimental group for key research. The specific grouping is as follows: blank group (normal feed), control group (polished white rice), model group, experimental group 1 (dietary intervention with low-GI recombinant rice in Comparative Example 5), experimental group 2 (dietary intervention with low-GI recombinant rice in Example 1). Among them, the construction of the diabetic mouse model referred to the "Modeling Method of Mouse Type II Diabetes Model" provided by the purchased mouse company and was appropriately modified: after the mice were fed with high-fat feed for 4 weeks, they were fasted for 12 h. The mice in the model group and the experimental groups were intraperitoneally injected with streptozotocin (STZ) at a dose of 40 mg / kg for 3 consecutive days. The fasting blood glucose was measured on the 3rd and 7th days after the last injection. A fasting blood glucose ≥ 11.1 mmol / L indicated successful modeling. The blank group and the control group were simultaneously intraperitoneally injected with sodium citrate buffer. The specific feeding plan is shown in Table 2 below.

[0110] Table 2 Feeding Plan

[0111]

[0112] Fast for 12 h at the same fixed time every week, weigh, take blood from the tail, measure blood glucose with a blood glucose meter, and record.

[0113] Weigh the organs such as the spleen, kidney, liver, and pancreas of the mice and calculate the organ index. The calculation formula is: organ index = organ weight (mg) / mouse weight (g).

[0114] Dehydrate, clear, and embed the fixed mouse liver and pancreas tissues in EP tubes in paraffin and cut them into 4-μm-thick sections. Then add hematoxylin staining solution and stain for 3-6 min, and wash off the excess staining solution with running water. Next, place the sections in 1% hydrochloric acid alcohol for differentiation for 1-3 s, rinse with running water for 2 s, soak in bluing solution, bluing for 10 s, rinse with running water for 20 s, stain with 0.5% eosin staining solution for 3 min, wash with distilled water for 2 s, and then immerse the sections in 80% ethanol for 30 s, 95% ethanol for 30 s, absolute ethanol for 2 s, xylene solution for 2 s in turn. Finally, mount with neutral gum and observe the pathological changes of the liver and pancreas under a microscope (magnification: 200 times).

[0115] Table 6 Changes in Blood Glucose of Mice during the Intervention Period

[0116]

[0117] After comprehensively considering the in vivo GI value, eating quality, smell and taste of different formulations of recombinant rice, Example 1 with 3% polygonatum sibiricum has the best effect, so it is used as the experimental group for key research. As can be seen from Table 6, after 3 weeks of dietary intervention, the fasting blood glucose levels of the control group and the model group mice were 5.03 mmol / L and 22.70 mmol / L respectively, indicating that eating polished white rice does not affect the fasting blood glucose of healthy mice, while eating polished white rice will significantly affect the fasting blood glucose of diabetic mice. After 3 weeks of dietary intervention, the fasting blood glucose levels of the mice in Experimental Group 1 and Experimental Group 2 decreased significantly (p < 0.05), indicating that eating low-GI recombinant rice added with polygonatum sibiricum can improve the hyperglycemia symptoms of diabetic mice, and long-term consumption helps to reduce the fasting blood glucose of diabetic mice. Comparing Experimental Group 2 with Experimental Group 1, the fasting blood glucose levels of the mice in Experimental Group 2 and Experimental Group 1 decreased by 52.82% and 20.61% respectively, indicating that low-GI recombinant rice added with polygonatum sibiricum and containing both polygonatum sibiricum and black rice has a more significant effect on improving the hyperglycemia symptoms of diabetic mice.

[0118] As Figure 1 shown, compared with the blank group, the liver indices of the mice in the control group and the model group both increased, indicating that whether it is healthy mice or diabetic mice, eating polished white rice will exacerbate liver enlargement in mice. Among them, the liver index of the mice in the model group increased significantly (p < 0.05), indicating that eating polished white rice has a greater impact on the liver of diabetic mice. The liver index of the mice in Experimental Group 2 decreased significantly (p < 0.05), indicating that eating low-GI recombinant rice added with polygonatum sibiricum can improve liver fat accumulation in diabetic mice and has a certain protective effect on the liver.

[0119] As Figure 2 shown, the pancreas index can reflect the oxidative damage of pancreatic tissue. Diabetes will cause oxidative stress damage to pancreatic tissue, reduce the number of islet β cells and cause damage, resulting in reduced insulin secretion. The pancreas index of the mice in Experimental Group 2 increased significantly (p < 0.05), indicating that eating the low-GI polygonatum sibiricum black rice of the embodiment of the present invention may reduce the damage of pancreatic tissue by increasing the pancreas index, thereby improving the effect of pancreatic atrophy in diabetic mice.

[0120] As Figure 3 and 4 shown, compared with the blank group, there were no significant differences in the spleen index and kidney index of the mice in the control group (p > 0.05). The spleen index and kidney index of the mice in Experimental Group 2 decreased significantly (p < 0.05). Eating the low-GI polygonatum sibiricum black rice of the embodiment of the present invention can relieve the symptoms of spleen and kidney enlargement in diabetic mice, may enhance the immune function of the body, and has a certain protective effect on organs to a certain extent.

[0121] As Figure 5As shown, the liver cells of the mice in the blank group were evenly stained, with a complete structure, arranged orderly and tightly; obvious fatty degeneration occurred in the livers of the mice in the control group, there were more fat vacuoles in the cytoplasm, the arrangement between cells was relatively loose, and some cell nuclei were in a dissolved state; the livers of the mice in the model group were more severely damaged, the arrangement between cells was loose and irregular, there were more fat vacuoles and they were of different sizes, and there were more dissolved cell nuclei. It shows that whether it is healthy mice or diabetic mice, eating white polished rice will increase the liver fat of mice and cause lesions in the liver tissue, and the impact of eating white polished rice on the liver tissue of diabetic mice is greater.

[0122] Compared with the model group, the livers of the mice in experimental group 1 and experimental group 2 were significantly improved, and the fat vacuoles were significantly reduced. Compared with experimental group 1, the cell structure of the internal organs in experimental group 2 was clearer, the structure was more complete, and the degree of atrophy was smaller as shown in the figure. It shows that eating the low-GI polygonatum black rice of the embodiment of the present invention can significantly improve the liver fat accumulation of diabetic mice and has a certain protective effect on the liver.

[0123] As Figure 6 As shown, the islet structure of the mice in the blank group was clear, the edge boundary was neat, the cell distribution was uniform, and the islets were filled with evenly distributed insulin secretion granules; the cytoplasm in the center of the islets of the mice in the control group showed degenerative changes, and the islet outline was irregular; the pancreatic tissue of the mice in the model group showed obvious damage, the islet area was small, the acini in the exocrine part invaded the islets, and the islet cells degenerated and necrosed. It shows that whether it is healthy mice or diabetic mice, eating white polished rice will cause lesions in the pancreatic tissue, and the impact of eating white polished rice on the pancreatic tissue of diabetic mice is greater.

[0124] Compared with the model group, the islet structure of the mice in experimental group 1 and experimental group 2 was clear, there were insulin secretion granules in the islets, the islet area increased, and the degree of pancreatic tissue lesions also improved. It shows that eating the low-GI polygonatum black rice of the embodiment of the present invention can improve the islet structure of diabetic mice, can maintain the integrity of the islet structure to a certain extent, and has a protective effect on the pancreas.

Claims

1. A low GI Polygonatum odoratum black rice, characterized in that: The invention comprises polygonatum, black rice, miscellaneous grains, konjac flour and gluten powder; in terms of weight, the content of the black rice is 25-35%, the content of the miscellaneous grains is 65%-75%; the content of the polygonatum is 1%-5% of the total weight of the black rice and the miscellaneous grains.

2. The low GI polygonatum black rice according to claim 1, characterized in that By weight, the content of the konjac flour and the gluten powder is 3%-15% of the total weight of the black rice and the miscellaneous grains, wherein the content ratio of the konjac flour to the gluten powder is (1-2): (1-2).

3. The low GI polygonatum black rice according to claim 1, characterized in that The particle size of the polygonatum is ≤0.25 mm; the particle size of the miscellaneous cereals is ≤0.25 mm.

4. The low GI polygonatum black rice according to claim 1, characterized in that The miscellaneous grains include one or more of rye, black beans, red rice, corn, millet, coix seed, oats, quinoa, barley, highland barley, red beans, mung beans, soybeans, white kidney beans, spotted kidney beans, chickpeas, and buckwheat.

5. The low GI polygonatum black rice according to claim 1, characterized in that Used as a staple food for diabetics.

6. A method for preparing low GI polygonatum black rice according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, the cleaned black rice and coarse grains are crushed with a pulverizer to obtain composite coarse grain powder, for standby use; S2, drying polygonatum to obtain polygonatum powder, and setting aside; S3, adding konjac flour and gluten powder to the composite grain powder of step S1 and the polygonatum powder of S2, and mixing them uniformly; S4, extruding the mixed material of step S3, rotary cutting, and granulating and forming; S5, cooling and drying, to obtain the low GI polygonatum odoratum black rice.

7. The method according to claim 6, characterized in that In step S1, black rice and miscellaneous grains are crushed to a particle size of ≤0.25 mm; in step S2, polygonatum is crushed to a particle size of ≤0.25 mm.

8. The method according to claim 6, characterized in that In step S5, the material processed in step S4 is dried at 40-55°C until the moisture content is 11-13%.

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