Truffle dietary fiber low-GI recombinant rice

Abstract

The invention discloses truffle dietary fiber low-GI recombinant rice which is prepared from raw material powder and truffle emulsion, and the raw material powder comprises the following components in percentage by mass: 50-60% of rice flour, 20-25% of konjaku flour and 20-25% of oat bran; the addition amount of the truffle emulsion is 30-35% of the mass of the raw material powder; the truffle polysaccharide modified starch has the characteristics of high fluidity and low viscosity, so that the materials can be better fused in a high-temperature extrusion process, the recombinant rice is cooled after being extruded, the gel capacity of the truffle polysaccharide modified starch enables the extruded recombinant rice to be more compact in structure and better in rice grain integrity after being cooked, and meanwhile, the truffle polysaccharide modified starch has the characteristics of high truffle fragrance sensory score, good taste and the like. Meanwhile, the truffle polysaccharide has relatively good blood sugar reducing activity, so that a better way is provided for adjuvant therapy of diabetes mellitus after long-term eating.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to truffle dietary fiber low GI reconstituted rice. Background Art

[0002] Recombinant rice is made by adding a small amount of monoglyceride and other additives to broken rice flour, brown rice and other grain flours, such as konjac flour, oats, coix seed flour and taro head flour, and extruding it with a twin-screw extruder to produce a product with an appearance and taste similar to ordinary rice. The existing solution is to increase the content of slowly digestible starch in recombinant rice and reduce the glycemic index through a reasonable compounding of different grains and an extrusion granulation process with specific parameters, thereby improving the satiety of people who are losing weight and patients with high blood sugar, and effectively alleviating starch hydrolysis and blood sugar increase in the consumer.

[0003] However, in the existing scheme, the starch undergoes gelatinization and aging reactions during the extrusion process, and a series of reactions occur in the substances such as protein and fat, which will greatly affect the flavor and taste of the recombinant rice. Producers often add additives to improve this problem. In order to improve the nutritional effect of recombinant rice, the producer will add various grain powders. The addition of too much grain powder cannot guarantee the edible taste and actual consumer acceptance of the recombinant rice. In the market, similar edible fungi are extruded into recombinant rice. In order to improve the edible taste, the producer adopts the addition of edible fungi enzymolyte to increase the flavor. However, the edible fungi enzymolyte is used, the amount of addition is small, the flavor is not obvious, the loss of nutrients is serious, and the edible taste is not significantly improved; in the subsequent rehydration, starch denaturation will cause the recombinant rice to reheat for a long time, the viscosity is too large, and other problems will be affected, so that the quality of the product is affected, and then the market promotion of recombinant rice is hindered. At present, most of the instant self-heating rice on the market is a high GI product, without special flavor, easy to gelatinize and hydrolyze, and digest quickly and have a high absorption rate after entering the human gastrointestinal tract, which is not conducive to long-term consumption by hyperglycemic patients and weight loss people. The recombinant rice proposed in this application is rich in truffle dietary fiber and low GI. Summary of the invention

[0004] The invention provides a truffle dietary fiber low GI reconstituted rice, which is prepared from raw material powder and truffle emulsion, wherein the raw material powder composition and mass percentage are 50-60%, konjac flour 20-25%, and oat bran 20-25%; and the added amount of truffle emulsion is 30-35% of the mass of the raw material powder.

[0005] The specific preparation method of the truffle dietary fiber low GI reconstituted rice of the present invention is as follows: 1. Grind one or more of rice, brown rice and germinated brown rice to a particle size of 1 to 2 mm; bake at 180 to 200° C. for 45 to 60 min; grind again and pass through an 80 to 100 mesh sieve to obtain rice flour; 2. Wash the oats, dry them at 75-85°C for 1-3 hours, bake them at 90-135°C for 40-50 minutes, cool them at room temperature, and grind them through a 80-100 mesh sieve to obtain oat bran; 3. Wash the konjac, dry it at 75-85° C. for 1-3 h, bake it at 90-135° C. for 40-50 min, cool it at room temperature, and pulverize it through a 80-100 mesh sieve to obtain konjac flour; 4. Use black truffle as raw material, dry and crush it, add ultrapure water, and perform ultrasonic extraction for 20 to 30 minutes, then bathe it in a constant temperature water bath at 60 to 90°C for 1.5 to 2 hours, collect the supernatant by centrifugation, extract the solid again for 1 to 2 times, collect and combine the supernatant, concentrate it, add anhydrous ethanol, stir it thoroughly, let it stand for solid-liquid separation, and dry the solid to obtain truffle polysaccharide; 5. The truffle emulsion is prepared by slicing truffles, vacuum drying them to a water content of 8% to 10%, and crushing them into truffle ultrafine powder at 20°C. The truffle ultrafine powder is extracted with CO2 supercritical fluid to obtain truffle essential oil. The truffle essential oil is mixed with pure water in equal volumes, 15% of the mass of truffle polysaccharide is added to the mixture, and high-speed shearing treatment is performed at 8000 to 12000 r / min for 0.5 to 2 min to obtain the truffle emulsion. The CO2 flow rate is 20-25 kg / h, the extraction temperature is 40-50°C, the extraction time is 1-3 hours, and the extraction pressure is 10-15 MPa; 6. Mix 50-60% rice flour, 20-25% konjac flour, and 20-25% oat bran to obtain raw powder, add truffle emulsion to the raw powder for conditioning to obtain a mixed slurry, wherein the amount of truffle emulsion added is 30-35% of the mass of the raw powder; extrude the mixed slurry into rice grains using an extruder, cool at room temperature for 45-60 minutes, and dry at 55-65° C. for 45-60 minutes to obtain truffle dietary fiber low GI reconstituted rice.

[0006] The rice grains were extruded using a twin-screw extruder with the following extrusion parameters: screw speed of 43 r / min, and zone heating during extrusion, which were 65°C in zone one, 90°C in zone two, 120°C in zone three, 100°C in zone four, and 80°C in zone five.

[0007] Advantages and technical effects of the present invention: (1) The recombinant rice of the present invention is rich in dietary fiber and has a low GI, is rich in nutrition, and has a strong truffle flavor. By rationally compounding rice flour, konjac flour, and oat bran, and undergoing a specific extrusion granulation process, a recombinant rice with a low glycemic index is obtained. Compared with other existing recombinant rice, the recombinant rice has a low degree of gelatinization, better sensory quality, a texture property closer to natural rice, a lower cooking loss rate, and a flavor and taste that are more in line with consumers' expectations of natural rice. No additional rice improver is required. The in vitro starch digestion test and the in vivo blood sugar response test have verified that the recombinant rice can significantly delay starch hydrolysis and blood sugar increase, and has a low glycemic index, making it suitable for consumption by the Chinese population. It helps reduce the problems of obesity, hypertension, hyperlipidemia, and hyperglycemia among urban and rural residents in my country, while providing a new choice for consumers. (2) The truffle essential oil in the present invention is prepared by supercritical extraction. It contains rich protein, 18 kinds of amino acids (including 8 essential amino acids that cannot be synthesized by the human body), unsaturated fatty acids, multiple vitamins, zinc, manganese, iron, calcium, phosphorus, selenium and other essential trace elements, as well as sphingolipids, cerebrosides, ceramides, triterpenes, androstenone, adenosine, truffle acid, sterols, truffle polypeptides and other large amounts of metabolites, and other nutrients are more easily absorbed by the human body, and its bioavailability is significantly improved; the use of supercritical extraction technology can effectively retain the utilization rate of the nutrients in truffles; the polypeptides in truffles are easily destroyed at high temperatures, and the use of mild extraction conditions can retain the maximum aroma and effectively improve the absorption and utilization rate of the nutrients by the human body. In addition, the main components of supercritically extracted truffle essential oil are olefin compounds, alcohol compounds, ketone compounds and ester compounds, which have multiple biologically active functions for the human body; (3) The truffle polysaccharide in the present invention is prepared by ultrasonic-assisted water extraction and alcohol precipitation. The polysaccharide is a biologically active macromolecule and is also one of the important components of truffles. It has no toxic side effects on biological cells and has multiple biological activities. The present invention utilizes the high fluidity and low viscosity characteristics of truffle polysaccharide-modified starch to enable the mixed materials to be better fused during low-temperature extrusion. After the recombinant rice is extruded and cooled, the gelling ability of the truffle polysaccharide-modified starch makes the extruded recombinant rice structure more compact, the rice grain integrity is better after steaming, the sensory score is high, the rice elasticity and chewiness are enhanced, and there is no need to add additional rice improvers (monoglyceride, calcium stearoyl lactylate or sucrose fatty acid ester). At the same time, truffle polysaccharide has good hypoglycemic activity. The hypoglycemic mechanism of truffle polysaccharide is to increase the SOD activity in serum and enhance the level of scavenging free oxygen radicals caused by alloxan, thereby repairing pancreatic islet tissue; (4) The truffle dietary fiber low GI recombinant rice of the present application can significantly delay starch hydrolysis and blood sugar increase, has a low glycemic index, and is suitable for long-term consumption by type II diabetic patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1It is a schematic diagram of the in vitro glycemic index results of truffle dietary fiber low GI recombinant rice, recombinant rice one, recombinant rice two, and commercially available natural rice; Figure 2 The blood glucose response curves of glucose, recombinant rice 1, recombinant rice 2, truffle dietary fiber low GI recombinant rice, and commercially available natural rice; Figure 3 This is a schematic diagram of the starch hydrolysis rate results of truffle dietary fiber low GI recombinant rice, recombinant rice one, recombinant rice two, and commercially available natural rice. DETAILED DESCRIPTION

[0009] The present invention is further described in detail below by way of examples, but the protection scope of the present invention is not limited to the contents described above. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared according to conventional methods unless otherwise specified; Example 1: Preparation of Truffle Dietary Fiber Low GI Recombinant Rice 1. Grind rice and brown rice to a particle size of 1 to 2 mm; bake at 180°C for 60 min; grind again and pass through a 100-mesh sieve to obtain rice flour; 2. Wash the oats, dry them at 80°C for 2 hours, bake them at 100°C for 45 minutes, cool them at room temperature, and grind them through a 100-mesh sieve to obtain oat bran; 3. Wash the konjac, dry it at 80°C for 2h, bake it at 100°C for 40min, cool it at room temperature, and grind it through a 100-mesh sieve to obtain konjac flour; 4. Take black truffle as raw material, dry and crush at 50℃, add ultrapure water (g:mL=1:50), ultrasonically extract for 20min, then place in a 90℃ constant temperature water bath for 2h, centrifuge at 6500r / min for 20min, collect the supernatant, add water to the solid for extraction once, collect and combine the supernatant, vacuum concentrate, add anhydrous ethanol 3 times the volume of the concentrate to the concentrate, stir well to produce precipitate or floccules, let stand at 4℃ for 24h, centrifuge at 4000r / min for 15min, collect the precipitate, add ultrapure water to the precipitate and freeze-dry to obtain truffle polysaccharide; 5. The truffle emulsion is prepared by slicing the truffle, vacuum drying it to a water content of 8%, and crushing it into truffle ultrafine powder (particle size <100 μm) at 20°C. The truffle ultrafine powder is put into a reactor, the valve is closed, and the refrigeration cycle is turned on. After the value is constant, the CO2 flow rate is adjusted to 21 kg / h, the extraction temperature is 40-50°C, the extraction time is 2 hours, and the extraction pressure is 15 MPa. The truffle essential oil is extracted, the truffle essential oil is mixed with pure water (1:1), 15% of the mass of the mixed liquid is added with truffle polysaccharide, and a high-speed shear treatment is performed at 10,000 r / min for 1 minute to obtain the truffle emulsion; 6. Mix 60% rice flour, 20% konjac flour and 20% oat bran to obtain raw powder, add truffle emulsion to the raw powder for conditioning to obtain a mixed slurry, and the amount of truffle emulsion added is 35% of the mass of the raw powder; use a twin-screw extruder to extrude the mixed slurry into rice grains, and the screw speed is 43 r / min for extrusion. During extrusion, it is set to zone heating, which is 65℃ in zone one, 90℃ in zone two, 120℃ in zone three, 100℃ in zone four, and 80℃ in zone five. The rice grains are cooled at room temperature for 45 minutes and dried at 60℃ for 50 minutes to obtain truffle dietary fiber low GI recombinant rice.

[0010] Comparative Example 1: (1) The preparation of rice flour, konjac flour and oat bran is the same as in Example 1; (2) 60% of rice flour, 20% of konjac flour and 20% of oat bran are mixed to obtain raw powder, and a rice improver is added to the raw powder, wherein the amount of the rice improver added is 1.0% of the weight of the raw powder, and the rice improver is mono- and di-glycerides; after mixing, 35% of the weight of the raw powder of purified water is added for conditioning, and the mixed slurry is put into a twin-screw extruder for granulation. The extruder parameters are as follows: screw speed of 43 r / min; different temperature zones are used for extrusion, and the extrusion order is 65°C for zone 1, 90°C for zone 2, 120°C for zone 3, 100°C for zone 4 and 80°C for zone 5; and recombinant rice 1 is obtained after cooling.

[0011] Comparative Example 2: The method is the same as that of Comparative Example 1, except that no mono- and di-glycerides are added to obtain recombinant rice 2.

[0012] Example 2: Performance test of recombinant rice of Example 1 and Comparative Example 1-2 1. Determination of in vitro glycemic index of different recombinant rice Take 100 mg of recombinant rice and 10 glass beads in a 50 mL centrifuge tube, add 1 mL of grade 3 water, treat in a boiling water bath for 10 min, cool to room temperature with running water, add 4 mL of pH=5.2 sodium acetate buffer, mix well and add the mixture to a mixed enzyme solution (10 mL, containing 30 U / mL porcine pancreatic α-amylase and 20 U / mL amyloglucosidase), then hydrolyze the mixture in a shaking water bath at 37 °C, take 0.2 mL of digestion solution at 0 min, 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, and 180 min, and quickly inactivate the enzyme in 0.8 mL of anhydrous ethanol, centrifuge at 14500 rcf for 3 min; take 0.5 mL of supernatant and measure reducing sugar by DNS method to calculate starch hydrolysis rate;

[0013] The starch hydrolysis curve was plotted with the starch hydrolysis rate as the ordinate and the time as the abscissa, and the area under the curve (AUC) was calculated to obtain the starch hydrolysis index (HI) of the sample, and then the prediceted GI (pGI) of the recombinant rice was obtained according to the calculation formula.

[0014] HI (%) = AUC sample / AUC white bread × 100; pGI = 0.862HI + 8.192.

[0015] Results Figure 1 As can be seen from the figure, the in vitro glycemic index of the recombinant rice of Comparative Examples 1-2 and the truffle dietary fiber low GI recombinant rice of Example 1 is lower than that of commercially available natural rice, while the in vitro glycemic index of the truffle dietary fiber low GI recombinant rice is lower than 55. The additional addition of truffle emulsion has a more obvious effect on blood sugar regulation. Therefore, the truffle dietary fiber recombinant rice of the present invention is a low glycemic index food.

[0016] 2. Determination of glycemic index of different recombinant rice Following the requirements of WS / T 652-2019, an in vivo test was used to further verify the glycemic index of recombinant rice. Ten healthy young students were selected as test subjects, and then the average values ​​of the data measured by the test subjects were compared. The test subjects were aged 22 to 25 years old, with a body mass index of 18.5 to 23.9 kg / m 2 , none of them had metabolic diseases, family history of diabetes and other metabolic diseases.

[0017] (1) Oral glucose tolerance test The subjects had their fasting blood glucose values ​​measured after fasting for 10 hours. Pure glucose powder (50 g per person) was used as a reference, dissolved in 200 mL of warm water and drunk within 5 minutes. The blood glucose values ​​were then measured at 15, 30, 45, 60, 90, and 120 minutes after eating. The subjects were judged to have qualified glucose tolerance based on the test results. Those with qualified glucose tolerance could participate in the food blood glucose tolerance test. (2) Food blood sugar tolerance test After the fasting blood glucose values ​​were measured, the subjects ate 50 g of cooked commercial natural rice, the recombinant rice of Comparative Examples 1-2, and the truffle dietary fiber low GI recombinant rice of Example 1, with 3 people in each group, and finished the consumption within 5 minutes. Then, the blood glucose values ​​were measured at 15, 30, 45, 60, 90, and 120 minutes after the meal, respectively. At the same time, edible glucose (50 g) was set as a control. With time (min) as the horizontal axis and blood glucose value (mmol / L) at each time point as the vertical axis, a blood glucose response curve is made, and the area under the blood glucose response curve (AUG) is calculated. Then the glycemic index of the food is calculated. The glycemic index formula is:

[0018] Results Figure 2 It can be seen from the figure that the average glycemic index of commercially available natural rice is 83.18, which is a high glycemic index food; while the in vivo glycemic index of the truffle dietary fiber low GI reconstituted rice of the present invention is 39.75.

[0019] like Figure 3 The results of starch hydrolysis rate show that the starch hydrolysis rate of recombinant rice 1, recombinant rice 2 and commercial natural rice is significantly higher than that of truffle dietary fiber low GI recombinant rice. The in vitro glycemic index of recombinant rice 1, recombinant rice 2 and commercial natural rice is 57.8, 54.3 and 86.9 respectively after conversion. Recombinant rice 1 and recombinant rice 2 do not add truffle emulsion, truffle emulsion has a significant effect of delaying blood sugar rise, and commercial natural rice belongs to high glycemic index food. This result further illustrates that the truffle dietary fiber low GI recombinant rice prepared by the present invention has obvious advantages in delaying blood sugar rise. It is verified by in vitro starch digestion test and in vivo blood sugar response test that the truffle dietary fiber low GI recombinant rice of the present invention can significantly delay starch hydrolysis and blood sugar rise, and its low glycemic index is suitable for consumption by Chinese people, and it provides new choices for consumers while reducing obesity, hypertension, hyperlipidemia and hyperglycemia problems among urban and rural residents in my country. The recombinant rice can significantly delay starch hydrolysis and blood sugar rise, and its low glycemic index is suitable for long-term consumption by type II diabetic patients.

[0020] 3. Cooking characteristics (1) Ripening time Take 3.0g of truffle dietary fiber low GI recombinant rice, recombinant rice one, recombinant rice two, and commercially available natural rice respectively, add 50mL of water to each and cook. After a certain period of time, take out a certain rice grain sample and press the rice grains with two glass plates. When more than 90% of the rice grains have no obvious white core, stop cooking and record the time. To ensure that all the rice grains are cooked, continue to seal and simmer the sample for 2min after stopping steaming. The cooking time is the recorded cooking time plus 2min of simmering time.

[0021] (2) Solid loss rate When the sample reaches the cooking time, accurately pipette 2.0 mL of rice soup and dry it at 100 °C for 10 h to constant weight. The unit of solid mass weighed is mg, and the solid loss is the amount of solid residue contained in each milliliter of rice soup.

[0022] (3) Rehydration rate Accurately weigh 1.0g of sample and put it into a non-woven bag, tie the mouth, and weigh the total mass of the non-woven bag containing rice grains as M0. Add 10mL of boiling water, cover it, and rehydrate it for 3 minutes. Take it out and hang the bag to room temperature without dripping water. Use filter paper to gently absorb the water on the surface of the bag, and weigh the mass as M1; the rehydration rate is calculated according to the following formula: rehydration rate (%) = M1 / M0×100%, the results are shown in Table 1; Table 1 Comparison of cooking characteristics of truffle dietary fiber low GI recombinant rice, comparative recombinant rice, and commercially available natural rice

[0023] Note: The data in the table are expressed as mean ± standard deviation. Different letters in the same row indicate significant differences (p < 0.05) Rehydration rate and ripening time are the most important indicators for evaluating rehydration. A higher rehydration rate in a shorter ripening time indicates that the truffle dietary fiber low GI reconstituted rice of the present application has better sensory quality and convenience characteristics.

[0024] As can be seen from Table 1: In the same time, the rehydration rate of truffle dietary fiber low GI recombinant rice is higher than that of commercially available natural rice, and has good rehydration. The fiber water absorption in konjac flour and oat bran makes water molecules contact with other starch particles in the material, thereby affecting the gelatinization of starch particles, resulting in moderate gelatinization degree of extruded recombinant rice, compact structure, starch is not easy to dissolve after cooking, and rice grain integrity is good; the ripening time of truffle dietary fiber low GI recombinant rice and comparative recombinant rice is greatly reduced, and the high temperature during the extrusion process makes the raw materials fully gelatinized, shortening the ripening time of rice grains during the reheating process; the solid loss rate is closely related to the taste quality of rice. During the cooking process, truffle dietary fiber low GI recombinant rice and recombinant rice 1 maintain a solid loss rate similar to that of commercially available natural rice, but the solid loss rate of recombinant rice 2 is higher, because no rice improver is added, and the molding is unstable. The above results show that the truffle dietary fiber low GI recombinant rice prepared by the present invention can achieve a stable effect without the addition of an additional improver.

[0025] (IV) Sensory evaluation of truffle dietary fiber low GI recombinant rice, recombinant rice 1, recombinant rice 2 and commercially available natural rice 10 students majoring in food were selected to form a scoring panel, and a sensory evaluation was conducted on the truffle dietary fiber low GI recombinant rice in Example 1, the comparative recombinant rice one, the comparative recombinant rice two, and the commercially available natural rice. A comprehensive evaluation was conducted on the smell, appearance structure (color, gloss, integrity), palatability (viscosity, softness, elasticity), taste, and cold rice texture (clustering, viscoelasticity, hardness) of the rice, and the average value was taken. The scoring criteria are shown in Table 2 below: comprehensive score = smell + appearance structure + palatability + taste + cold rice texture.

[0026] Table 2 Sensory scoring standards for rice

[0027] The results of sensory evaluation of the truffle dietary fiber low GI recombinant rice in Example 1, the comparative recombinant rice and commercially available natural rice are shown in Table 3: Table 3 Comparison of sensory evaluation of truffle dietary fiber low GI recombinant rice, control recombinant rice and commercially available natural rice

[0028] As can be seen from Table 3, the texture characteristics of truffle dietary fiber low GI recombinant rice are closer to natural rice, with a lower cooking loss rate, and the flavor and taste are more in line with consumers' expectations of natural rice, while the scores for smell and cold rice texture are higher. This is because in addition to the appropriate amount of truffle emulsion, truffle dietary fiber low GI recombinant rice also adds dietary fiber (wheat bran dietary fiber, konjac flour). The polypeptides in truffles are easily destroyed at high temperatures. Supercritical extraction can maximize the retention of truffle aroma and effectively improve the absorption and utilization rate of this nutrient by the human body; truffle polysaccharide is used to modify starch The high fluidity and low viscosity of truffles can make the materials better integrated during the low-temperature extrusion process. The recombinant rice is cooled after extrusion. The gelling ability of truffle polysaccharide modified starch makes the extruded recombinant rice structure tighter, the rice grains have better integrity after cooking, the sensory score is high, and the elasticity and chewiness of the rice are enhanced without the need to add additional improvers. In addition, the water absorption of the fiber in konjac flour and oat bran allows water molecules to come into contact with other starch particles in the material, thereby affecting the gelatinization of the starch particles, resulting in the extruded recombinant rice having a moderate degree of gelatinization, a tight structure, starch not easily dissolved after cooking, and good rice grain integrity.

Claims

1. A truffle dietary fiber low GI reconstituted rice, characterized in that: The invention is prepared from raw material powder and truffle emulsion, wherein the raw material powder composition and mass percentage are 50-60% rice powder, 20-25% konjac powder and 20-25% oat bran; and the added amount of truffle emulsion is 30-35% of the mass of the raw material powder.

2. The truffle dietary fiber low GI reconstituted rice according to claim 1, characterized in that: The raw material powder and truffle emulsion are mixed and then squeezed into rice grains, cooled at room temperature for 45 minutes to 60 minutes, and dried at 55 to 65° C. for 45 minutes to 60 minutes to obtain truffle dietary fiber low GI reconstituted rice.

3. The truffle dietary fiber low GI reconstituted rice according to claim 1, characterized in that: The truffle emulsion is prepared by slicing truffles, vacuum drying them to a water content of 8% to 10%, and crushing them into ultrafine truffle powder at 20°C. The ultrafine truffle powder is extracted with CO2 supercritical extraction to obtain truffle essential oil. The truffle essential oil is mixed with equal volumes of pure water, 15% of truffle polysaccharide by mass of the mixed liquid is added, and the mixture is subjected to high-speed shear treatment at 8000 to 12000 r / min for 0.5 to 2 min to obtain the truffle emulsion.

4. The truffle dietary fiber low GI reconstituted rice according to claim 3, characterized in that: Truffle polysaccharide uses black truffle as raw material. After drying and crushing, ultrapure water is added, and ultrasonic extraction is carried out for 20 to 30 minutes. Then, the truffle is bathed in a constant temperature water bath at 60 to 90°C for 1.5 to 2 hours, and the supernatant is collected by centrifugation. The solid is extracted again for 1 to 2 times, and the supernatant is collected and combined, concentrated, anhydrous ethanol is added, the mixture is fully stirred, allowed to stand for solid-liquid separation, and the solid is dried to obtain the product.

5. The truffle dietary fiber low GI reconstituted rice according to claim 1, characterized in that: The rice grains were extruded using a twin-screw extruder with a screw speed of 43 r / min. The extrusion was set to zone heating, with the temperatures of 65°C in zone one, 90°C in zone two, 120°C in zone three, 100°C in zone four, and 80°C in zone five.

6. The truffle dietary fiber low GI reconstituted rice according to claim 1, characterized in that: One or more of rice, brown rice and germinated brown rice are crushed to a particle size of 1-2 mm; baked at 180-200° C. for 45-60 min; crushed again, and passed through an 80-100 mesh sieve to obtain rice flour.

7. The truffle dietary fiber low GI reconstituted rice according to claim 1, characterized in that: The oats or konjac are washed, dried at 75-85° C. for 1-3 hours, baked at 90-135° C. for 40-50 minutes, cooled at room temperature, and crushed through a 80-100 mesh sieve to obtain oat bran or konjac flour.

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