Planting and processing method of low-GI rice

Abstract

The invention relates to the technical field of functional agricultural product production and grain processing, in particular to a planting and processing method of low-GI rice. Indica rice varieties with specific genetic backgrounds are systematically integrated on the basis of physiological metabolism regulation and control of humic acid substances, precise agronomic time point control and an innovative physical field post-processing technology, so that the glycemic index (GI) of the rice is reduced in a full-chain and targeted manner. According to the low-GI rice produced through the method, the GI value can be stably controlled to be 50 or below, meanwhile, the nutritional ingredients, the taste quality and the aroma characteristics of natural rice are completely reserved, and the unification of the blood glucose reducing function and the excellent eating quality is achieved.

Description

Technical Field

[0001] This invention relates to the field of functional agricultural product production and grain processing technology, specifically to a method for planting and processing low-GI rice. Background Technology

[0002] The glycemic index (GI) is a key indicator for assessing the impact of carbohydrate foods on postprandial blood glucose. Low-GI staple foods are crucial for dietary management in individuals with metabolic syndromes such as diabetes and obesity. Rice, as a major carbohydrate source, has a high GI, limiting its consumption by these populations. Existing technologies for reducing the GI of rice mainly focus on physical, chemical, or biological modifications to finished rice or raw materials. For example, Chinese patent CN114586925A, "A Method for Preparing Low-GI Rice," employs a multi-step processing technique involving ultrasonic treatment, cooking, ultra-high pressure, and cold refrigeration of coarse paddy rice to reduce the GI by promoting the formation of resistant starch. While effective, this method is complex, energy-intensive, and the intense hot and humid treatment severely damages the natural texture and flavor of the rice. Another patent, CN114081125A, entitled "A method for producing zero-fat, low-sugar, and low-GI grain powder," uses multi-step enzymatic hydrolysis and extraction to almost completely remove starch and fat, thus obtaining low-GI grain powder. However, this completely deviates from the natural form and consumption habits of "rice" as a whole grain, making it difficult to meet the market's demand for natural staple foods.

[0003] The aforementioned existing technologies share a common limitation: they all attempt to achieve a low GI by externally forcibly "correcting" or "depriving" the inherent characteristics of rice after its life activities have ceased, belonging to the "back-end remediation" or "deep modification" model. This method often comes at the cost of sacrificing the product's naturalness, complete nutrition, and excellent taste. Therefore, there is an urgent need in the field for a new method that can shape the low GI characteristics of rice from the source, maintain and enhance them during processing, and preserve its natural quality to the maximum extent. Based on this need, this invention innovatively proposes a "GI-directed regulation" production concept, integrating GI reduction intervention throughout the entire process of rice growth, harvesting, and post-harvest processing, aiming to produce truly "natural, low-glycemic, and delicious" rice. Summary of the Invention

[0004] The purpose of this invention is to provide a method for cultivating and processing low-GI rice. This method aims to solve the problem that existing technologies, which require drastic processing or deep modification to reduce the GI value, severely damage the natural morphology, nutrition, flavor, and eating quality of rice. By innovatively integrating and synergistically managing the entire chain from varietal genetic selection, growth and metabolic regulation, precise harvesting time to post-harvest physical field treatment, this invention aims to shape and stabilize the low-GI characteristics of rice from the source with minimal processing intervention. Ultimately, it produces truly "natural, low-glycemic, and delicious" rice with a GI value not exceeding 50, while perfectly preserving its natural nutrients, excellent sensory qualities, and characteristic aroma.

[0005] To achieve the above objectives, this invention provides a method for cultivating and processing low-GI rice, which is achieved through the synergistic effects of variety selection, metabolic intervention during the growth period, harvest timing control, and post-harvest physical field stabilization treatment. Specifically, it includes the following steps: (1) Establishing the variety and metabolic basis: Select indica rice varieties with an amylose content of 18-19% and a resistant starch content of >5% (dry basis); (2) Regulation of GI potential during the growth period: During the peak tillering stage to the booting stage of rice, an aqueous solution of humic acid was sprayed on the leaves, with the concentration of the aqueous solution of humic acid being 0.0001%-0.01%; (3) Optimal material composition locking: Harvest when the milk line of rice disappears and the grains enter the late waxy ripening stage, at which time the grain maturity is 75%-85%; (4) Stabilization of starch structure physical field: The hulled rice after step (3) is placed in a low temperature environment of -15℃ to -5℃ for 1 hour and microwaved using high-energy pulsed microwave; the energy flux density of the pulsed microwave is 0.5-4.2 kJ / kg, the pulse repetition frequency is 5-14 Hz, and the processing time is 5-15 minutes. (5) Quality preservation drying and post-ripening: The rice treated in step (4) is dried at 45-50℃ with a gradient heating method until the moisture content is 13%-15%. Then, it is stored at 15-25℃ and relative humidity <65% for 1-3 months, and then dehulled to obtain the low-GI rice.

[0006] Preferably, the humic acid is at least one of fulvic acid (FA), sodium humate (HA-Na), or potassium humate (HA-K), and the spraying operation is performed at least twice, once during the tillering stage and once during the heading stage.

[0007] In step (2), the humic acid substances function as plant growth stimulants to regulate the carbon and nitrogen metabolic flow of rice, promote the accumulation of amylose and resistant starch components during starch synthesis, and enhance the thermal stability and enzymatic resistance of the synthesized starch granules.

[0008] In step (3), the criteria for judging the late waxy ripening stage are: more than 90% of the grains on the rice ear turn yellow, the contents of the grains are waxy, and a mark can be left when pinched with a fingernail but it is not easy to break.

[0009] In step (4), the core of the high-energy pulsed microwave synergistic low-temperature treatment is to use the low-temperature environment to inhibit the activity of biological enzymes and starch gelatinization, and at the same time use the non-thermal effects generated by the pulsed microwave energy field (including the hysteresis effect of ion polarization relaxation and molecular dipole orientation) to directionally perturb and rearrange the hydrogen bond network and helical structure of starch molecules, especially amylose molecules, thereby strengthening its ordered crystalline structure at the molecular level and improving the steric hindrance of starch enzymatic hydrolysis.

[0010] In step (4), the energy flux density of the pulsed microwave is preferably 2.0-3.5 kJ / kg, and the pulse repetition frequency is preferably 8-12 Hz. This combination of parameters can most effectively induce the formation of micro-stress and structural densification in starch granules, which is conducive to delaying digestion.

[0011] Preferably, in step (4), the treatment must be carried out within 1-1.5 hours after harvesting to ensure that the physiological activity of rice has not decreased significantly and that the starch structure is in a state that can be effectively regulated by the physical field.

[0012] Preferably, in step (5), the gradient heating method is as follows: initially drying at 35-40℃ for 1-2 hours, and then heating at 0.5-2.0℃ / hour to 45-50℃ to the drying endpoint, in order to prevent the hardening of the rice skin from hindering the migration of internal moisture and causing the rice to burst.

[0013] The low-GI rice prepared by this invention has a glycemic index (GI) ≤ 50 and its resistant starch content is more than 15% higher than that of rice of the same variety, from the same place of origin, and harvested at the same time but without the treatment in step (4).

[0014] The low-GI rice prepared by this invention exhibits high elastic modulus and moderate hardness in texture analysis after cooking. Furthermore, the retention rate of characteristic aroma components (such as 2-acetyl-1-pyrrolline) is ≥95% by headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).

[0015] The mechanism of the effect of high-energy pulsed microwave synergistic low-temperature treatment on starch granule structure in this invention is explained as follows: The high-energy pulsed microwave synergistic low-temperature treatment technology employed in this invention inhibits starch gelatinization and enzyme activity through a low-temperature environment, while simultaneously utilizing the non-thermal effects generated by high-energy pulsed microwaves to directionally regulate the starch molecular structure. The high peak power of the pulsed microwaves induces intense dipole oscillations and ionic polarization relaxation in starch molecules (especially amylose). Under the synergistic effect of low temperature, this promotes orientation rearrangement and hydrogen bond network reconstruction of amylose molecular chains, forming a more dense and ordered crystalline structure. The outer branches of amylopectin may also undergo local rearrangement, further strengthening the granule surface structure. This change in microstructure significantly reduces the enzyme accessibility of starch granules, making it difficult for digestive enzymes to contact and decompose starch molecules, thereby slowing down the digestion rate and achieving low-GI characteristics. Simultaneously, this physical field treatment avoids the damage to flavor compounds caused by thermal effects, perfectly preserving the natural rice aroma.

[0016] The following are the core innovative points of this invention: First, this invention proposes a production concept of "GI-directed regulation," achieving a paradigm shift from "passive modification" to "active shaping." The core innovation of this invention lies in no longer viewing rice as a static raw material awaiting processing, but rather as a dynamic trait whose GI value can be systematically intervened and shaped from the growth stage. By selecting varieties with a specific genetic background in starch composition, we have established the "genetic potential" for low GI. Based on this, humic acid-like substances are applied exogenously during the critical periods of rice carbon and nitrogen metabolism and starch synthesis (from the tillering stage to the booting stage). These natural bioactive substances can regulate plant physiological metabolism, acting like a "metabolic switch," directionally guiding photosynthetic products to synthesize more amylose and resistant starch, while potentially influencing the assembly of starch granules, thus "actively shaping" the low-GI material basis of rice endosperm from the source.

[0017] Secondly, a spatiotemporal synergistic technology of "physiological state locking" and "physical field structure stabilization" is employed. This invention astutely recognizes that the maturity of rice (late waxy ripening stage) is a crucial window for the responsiveness of its internal chemical composition and physiological structure to subsequent treatment. Harvesting at this stage ensures sufficient starch synthesis but the cell walls are not yet excessively lignified, placing the grains in an optimal, "controllable" physiological state. Subsequently, we introduce a unique "high-energy pulsed microwave synergistic low-temperature treatment." The low-temperature environment "freezes" the biochemical reactions, protecting heat-sensitive components; while pulsed microwaves with specific parameters, inputting energy at intermittent high peak power, generate strong non-thermal biophysical effects in the material. This effect may induce intense dipole oscillations and localized stress in water and starch molecular chains, promoting orientation rearrangement of amylose molecular chains without causing gelatinization (dominated by thermal effects), forming a more dense and stable microcrystalline structure, and "solidifying" this "low-GI-friendly" starch structure at the molecular level. This represents a perfect spatiotemporal synergy between "optimal physiological timing" and "precise physical intervention."

[0018] Third, a "quality preservation" processing path is established to achieve a symbiotic win-win situation for function and flavor. Unlike the harsh processing commonly found in existing technologies, the subsequent steps of this invention (low-temperature tempering drying and moderate post-ripening) are all based on the principle of "minimum damage and maximum retention." The gradient temperature drying method prevents rice grains from bursting, protecting the integrity of the grain structure. The 1-3 month post-ripening period is not only a process of slow starch aging (which helps further form resistant starch), but also a process of balanced moisture within the rice grain, stress release, and flavor compound synthesis. This not only does not damage the quality, but also synergistically improves the final product's edible quality (such as taste and aroma) and functional attributes (GI value). The entire technology chain is interconnected, ultimately achieving a substantial unity and synergistic improvement of low-GI functionality and high edible quality in the same product.

[0019] Beneficial technical effects of the present invention: The GI reduction effect is significant, stable, and the mechanism is well-defined. Through systematic intervention at the genetic, physiological, and physical levels, this invention can stably control the GI value of rice to a low glycemic level below 50. In vitro digestion experiments show that the content of resistant starch in the product is significantly increased, and the in vitro digestion rate of starch is significantly slowed down. This is attributed to the metabolic regulation of humic acid increasing the biosynthesis of slowly digestible starch components, and the pulsed microwave treatment physically strengthening the starch's anti-enzymatic structure. Multiple safeguards ensure that the batch-to-batch GI value stability of the product far exceeds that of a single processing technology.

[0020] 2. Perfectly preserves the full nutritional value and core sensory qualities of natural rice. The entire production process involves no exogenous chemical additives and avoids harsh hydrolysis, extraction, or high-temperature, high-pressure treatments. The natural nutrients in the rice, such as protein, vitamins, minerals, and lipids, are fully preserved. The unique pulsed microwave low-temperature processing technology effectively stabilizes the starch structure while maximally protecting heat-sensitive volatile aroma compounds. The final product, after cooking, has a rich aroma, intact grains, good luster, and a perfectly balanced texture—soft yet firm, with excellent elasticity. Its sensory quality is indistinguishable from premium commercial rice, resulting in extremely high consumer acceptance.

[0021] 3. The technology is green, efficient, and highly compatible with various industries. The humic acid used in the planting process is an environmentally friendly biostimulant. The core pulsed microwave treatment has a short processing time (5-15 minutes), high energy utilization efficiency, and lower overall processing energy consumption than processes requiring long cooking times, high pressure, or refrigeration. The process flow is clear, with well-defined operating standards for each step, making it easy to integrate with existing large-scale rice processing production lines. It has excellent prospects for industrial application and can provide a stable supply of high-quality, low-GI staple food products to the market. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the technical route and synergistic principle of the low-GI rice planting and processing method described in this invention.

[0023] Figure 2 This is a schematic diagram illustrating the mechanism of the effect of high-energy pulsed microwave synergistic low-temperature treatment on starch particle structure in this invention.

[0024] The names of the components shown in the diagram are as follows: Figure 2 In the middle, Figure A on the left shows the structure of starch granules before treatment. The structure is relatively loose, with crystalline and amorphous regions interspersed, and the hydrogen bond network is relatively loose, resulting in high enzyme accessibility. Figure 2 B on the right shows the structure of starch granules after treatment. The structure is more compact, the crystalline region is expanded and ordered, the hydrogen bond network is strengthened, and the enzyme accessibility is significantly reduced. Among them, 201 represents the hydrogen bond connection point, 202 represents the amylose molecular chain, 203 represents the crystalline region, 204 represents the amorphous region, and 205 represents the branch of amylopectin. Detailed Implementation

[0025] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0026] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by those skilled in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of those skilled in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or identical to those described in the embodiments of this invention may be used to implement this invention.

[0027] Unless otherwise stated, the test methods, detection methods and preparation methods disclosed in this invention all adopt conventional techniques in this technical field.

[0028] Example 1 A method for cultivating and processing low-GI rice, comprising the following steps: (1) Variety: "Low GI Indica No. 1" was selected, with an amylose content of 18.2% and a resistant starch content of 5.5% (dry basis); (2) Physiological regulation: During the peak tillering period (35 days after transplanting) and the early booting stage (early spikelet differentiation stage III), foliar spray with a concentration of 0.005% humic acid (FA) aqueous solution, with a spray volume of 50L per mu each time; (3) Timing: 32 days after heading, when about 85% of the grains in the field are in the late waxy ripening stage (more than 90% of the grains on the rice panicle turn yellow, the contents of the grains are waxy, and a mark can be left when pinched with a fingernail but it is not easy to break), mechanical harvesting is carried out. (4) Stabilization of physical field: Within 45 minutes after harvesting, the rice is sent into the processing chamber; the temperature inside the chamber is maintained at -10±2℃, the pulse microwave system is started, the energy flux density is set to 3.0kJ / kg, the pulse repetition frequency is 10Hz, and the processing is continued for 10 minutes. (5) Quality maintenance and post-ripening: The treated rice is first dried with hot air at 38℃ for 2 hours, and then dried to 48℃ at 1℃ / hour until the moisture content is 14.2%; the dried rice is stored in a warehouse at 22℃ and 60% humidity for 2 months. (6) Processing: After the storage period is over, the rice is hulled, milled, polished and color sorted to produce the finished low-GI rice M1.

[0029] Example 2 (1) Variety: "Wentangxian No. 2" was selected, with an amylose content of 19.0% and a resistant starch content of 6.0%; (2) Physiological regulation: Spray a 0.008% potassium humate (HA-K) solution only once during the booting stage; (3) Timing: Harvest at the late waxy maturity stage (approximately 80% maturity); (4) Physical field stabilization: processing temperature -8℃, energy flux density 2.5kJ / kg, pulse frequency 12Hz, processing time 12 minutes; (5) Quality maintenance and post-ripening: After drying at 40℃ for 1.5 hours, the temperature is increased to 50℃ at 1℃ / hour and dried to a moisture content of 13.8%. Store at 20℃ and 55% humidity for 3 months. (6) Processed to obtain finished rice M2.

[0030] Example 3 (1) Variety: Same as in Example 1; (2) Physiological regulation: Same as in Example 1; (3) Time point locking: Same as in Example 1; (4) Physical field stabilization: processing temperature -5℃, energy flux density 4.0kJ / kg, pulse frequency 8Hz, processing time 8 minutes; (5) Quality maintenance and post-ripening: After drying at 35℃ for 2.5 hours, the temperature is increased to 46℃ and dried to 14.5% moisture content. Store at 18℃ and 50% humidity for 1 month. (6) Processed to obtain finished rice M3.

[0031] Comparative Example 1 (No physiological regulation, conventional harvesting and processing) The variety is the same as in Example 1; no humic acid is sprayed during the planting process; the rice is harvested when it is fully mature (yellow ripening stage, more than 95% maturity); after harvesting, it is dried directly at 55℃ to 14% moisture content without any special treatment, and then processed into ordinary rice C1 after being stored for half a month.

[0032] Comparative Example 2 (with physiological regulation, but without physical field treatment) The variety, planting (including FA spraying) and harvesting time are the same as in Example 1; after harvesting, skip step (4) and directly dry, store and process according to the conditions of Example 1 to obtain rice C2.

[0033] Comparative Example 3 (with physiological regulation, but treated with high-temperature continuous microwave). The first three steps are the same as in Example 1; step (4) is changed to: at room temperature (25°C), use continuous microwave (non-pulse) with similar total input energy for 10 minutes; the subsequent steps are the same as in Example 1, and rice C3 is obtained.

[0034] Comparative Example 4 (with physiological regulation, but delayed physical field processing) The first two steps are the same as in Example 1; after the rice is harvested, it is piled up at room temperature for 24 hours, and then the same steps (4) (pulse microwave low temperature treatment) and subsequent steps are performed as in Example 1 to obtain rice C4.

[0035] Comparative Example 5 (Imitating Existing Patented Technology) Take rice from the same batch and harvested at the same time as in Example 1; instead of the treatment of this invention, process it according to the complete process of Example 1 in CN114586925A (soaking, ultrasonication, boiling, ultra-high pressure, refrigeration, drying) to obtain rice C5.

[0036] Comparative Example 6 (Premature Harvesting) The variety and planting method are the same as in Example 1; the rice is harvested early at the end of the milk stage (about 70% maturity), and the subsequent treatment is the same as in Example 1 to obtain rice C6.

[0037] Performance testing Test Standards Viscosity and elasticity determination: The textural properties of cooked rice were determined using a TA-XT2i material property analyzer (SMS, UK). Rice preparation followed the national standard GB / T15682-2008. 20g of rice prepared in Examples 1-3 and Comparative Examples 1-6 of this invention was washed three times, with a rice-to-water ratio of 1:1.3. The rice and water were mixed and placed in an aluminum box (90mm in diameter, 50mm in height), which was then placed in a steamer for cooking. During testing, 10 grains of rice were randomly selected from different positions within the aluminum box and symmetrically placed on the stage of the material property analyzer for measurement, maintaining a certain interval between the grains. Each sample was tested in parallel five times.

[0038] The GI value testing method, sensory evaluation and scoring method are consistent with Chinese invention patent CN114586925A.

[0039] Resistant starch content (%) determination: The resistant starch content was determined according to the AOAC official method 2002.02. Retention rate analysis of characteristic aroma components: The headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used for analysis (the peak area (or concentration) of the characteristic aroma components in the product of this invention was compared with the corresponding peak area of ​​the control rice of the same variety, origin and harvested at the same time but not subjected to the physical field treatment in step (4), and the retention rate percentage was calculated).

[0040] Table 1 shows the test results for each embodiment. Table 2 shows the results of the comparative tests for each item. Based on the data in Tables 1 and 2, it can be concluded that the low-GI rice produced by the method described in this invention (Examples 1-3) has a stable GI value below 50, a significantly increased resistant starch content of 6.8%-7.4%, and high sensory scores (83-85 points) with a characteristic aroma retention rate ≥95%. In contrast, except for Comparative Example 5 (GI 51), which imitates the existing patent, the GI values ​​of the other comparative products are all above 60, with Comparative Example 1, which was not subject to any regulation, reaching as high as 78. Moreover, its resistant starch content is generally low, and its aroma retention rate and eating quality are inconsistent. This indicates that this invention, through the synergistic effect of the entire chain of variety, physiology, harvesting, and physical field treatment, significantly reduces the GI while fully preserving the nutrition and flavor of natural rice, achieving a unity of blood sugar reduction function and eating quality.

[0041] The differences between the test results of the examples and the comparative examples mainly stem from the synergistic effect of the systematic technical chain of this invention and the precise control of key links. The examples, by selecting varieties with specific starch compositions and spraying humic acid during the critical metabolic period to regulate starch synthesis, laid the physiological foundation for low GI. Subsequently, harvesting at the end of the waxy ripening stage ensured that the starch structure was in an optimally controllable state. Most importantly, low-temperature pulsed microwave treatment was performed within one hour after harvesting, utilizing non-thermal effects to promote the rearrangement of amylose molecules and the strengthening of hydrogen bond networks, forming a dense structure resistant to enzymatic hydrolysis, thereby slowing down the digestion rate. In contrast, the comparative examples, due to the lack of a certain link (e.g., no physical field treatment in Comparative Example 2), improper execution of links (e.g., delayed treatment in Comparative Example 4, premature harvesting in Comparative Example 6), or the use of alternative technologies (e.g., continuous microwave treatment in Comparative Example 3, complex moist heat treatment in Comparative Example 5), resulted in insufficient regulation of starch structure, unoptimized metabolic basis, or damaged quality. Therefore, the GI reduction effect was limited, often at the expense of natural quality. This verifies the dual advantages of the "whole-chain targeted regulation" of this invention in terms of both function and quality compared to "local or back-end modification."

[0042] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for cultivating and processing low-GI rice, characterized in that, The method is achieved through the synergistic effect of variety selection, metabolic intervention during the growth period, harvest timing control, and post-harvest physical field stabilization treatment, and specifically includes the following steps: (1) Select a suitable indica rice variety; (2) Spray an aqueous solution of humic acid on the leaves of rice plants; (3) Harvest when the milk line of the rice disappears and the grains enter the late waxy ripening stage; (4) Microwave the harvested rice grains after step (3); (5) The rice treated by microwave in step (4) is further dehulled by gradient heating to obtain the low-GI rice.

2. The planting and processing method according to claim 1, characterized in that: In step (1), the suitable indica rice variety has an amylose content of 18-19% and a resistant starch dry basis content of >5%.

3. The planting and processing method according to claim 1, characterized in that: In step (2), the humic acid substance is at least one of fulvic acid, sodium humate or potassium humate, and the spraying operation is performed at least twice, at the tillering stage and the heading stage respectively; the concentration of the aqueous solution of the humic acid substance is 0.0001%-0.01%.

4. The planting and processing method according to claim 1, characterized in that: In step (3), the rice is harvested when the milk line disappears and the grains enter the late waxy ripening stage. At this time, the maturity of the grains is 75%-85%. The criteria for judging the late waxy ripening stage are: more than 90% of the grains on the rice ear turn yellow, the contents of the grains are waxy, and a mark can be left when pinched with a fingernail but it is not easy to break.

5. The planting and processing method according to claim 1, characterized in that: In step (4), the microwave treatment involves placing the hulled rice harvested in step (3) in a low-temperature environment of -15°C to -5°C and performing microwave treatment using high-energy pulsed microwaves.

6. The planting and processing method according to claim 5, characterized in that: The pulsed microwave has an energy flux density of 0.5-4.2 kJ / kg, a pulse repetition frequency of 5-14 Hz, and a processing time of 5-15 minutes.

7. The planting and processing method according to claim 6, characterized in that: The energy flux density of the pulsed microwave is 2.0-3.5 kJ / kg, and the pulse repetition frequency is 8-12 Hz. This combination of parameters can most effectively induce the formation of micro-stress and structural densification in starch granules, which are conducive to delaying digestion.

8. The planting and processing method according to claim 5, characterized in that: In step (4), the microwave treatment must be carried out within 1-1.5 hours after harvesting to ensure that the physiological activity of rice does not decrease significantly and that the starch structure is in a state that can be effectively regulated by the physical field.

9. The planting and processing method according to claim 1, characterized in that: In step (5), the gradient heating method is as follows: initially dry at 35-40℃ for 1-2 hours, and then heat up to 45-50℃ to the drying endpoint, in order to prevent the hardening of the rice skin from hindering the migration of internal moisture and causing the rice to burst.

10. The planting and processing method according to claim 9, characterized in that: The heating rate is 0.5-2.0℃ / hour.

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