A low-glycemic food processing technology fusing white kidney bean extract
By microencapsulating white kidney bean extract and using a low-temperature molding and ripening process, the problems of easy inactivation of white kidney bean extract at high temperatures and uneven mixing were solved, achieving efficient preparation of low-GI foods and ensuring the taste and texture of the products.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YUZHOU XIANGPINJIAN PLANTING PROFESSIONAL COOP
- Filing Date
- 2026-04-29
- Publication Date
- 2026-06-05
AI Technical Summary
In existing technologies, white kidney bean extract is easily deactivated under high-temperature treatment, and uneven mixing leads to a rough product texture, and low-GI foods have poor taste.
By pre-treating white kidney bean extract with microencapsulation, combined with conditioning, gelatinization, and modification of starchy raw materials, and employing a low-temperature molding and ripening process, the white kidney bean extract is ensured to be evenly dispersed in food and maintain its activity, avoiding loss at high temperatures.
This technology enables the efficient preparation of low-GI foods, with high activity retention of white kidney bean extract, reduced starch digestion rate, and excellent product taste and texture. It also solves the problems of high-temperature inactivation of white kidney bean extract and uneven mixing in existing technologies.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of food processing technology, specifically to a low-glycemic food processing technology incorporating white kidney bean extract. Background Technology
[0002] With the continued growth of the population suffering from diabetes, obesity, and metabolic syndrome, the market demand for low glycemic index (GI) foods is increasingly strong. Grains / tube foods are the main source of starch in people's diets and are also the core category for low-GI food development. Currently, the industry mainly achieves low-GI modification of foods through two pathways: one is to modify the starch in raw materials through physical, chemical, or biological means to increase the content of resistant starch and reduce the rate of starch digestion; the other is to add white kidney bean extract, utilizing its α-amylase inhibitors to block the breakdown and absorption of starch, thereby reducing the rate of postprandial blood glucose rise.
[0003] However, existing technologies generally face the following technical problems when implementing the synergistic application of the two pathways mentioned above: To achieve a better low-GI effect, existing solutions need to simultaneously consider the effects of starch structure adjustment and bioactive components. However, starch structure adjustment processes (such as gelatinization and modification) often require high-temperature treatment, while bioactive components (such as α-amylase inhibitors) are temperature-sensitive, and high temperatures can easily lead to their loss of activity, preventing them from effectively blocking starch decomposition. Furthermore, rapid cooling of the material after structure adjustment can easily cause it to age and harden, affecting not only the uniformity of subsequent mixing of active components but also leading to unstable starch structure retrogradation, further weakening the low-GI effect. Additionally, low-GI foods generally suffer from a rough texture, primarily due to improper addition processes of white kidney bean extract. Subsequent addition results in the extract being distributed in a free state within the product, leading to uneven mixing and damaging the original texture of the food.
[0004] Therefore, it is necessary to propose a low-glycemic food processing technology that incorporates white kidney bean extract to solve the above problems. Summary of the Invention
[0005] (a) Technical problems to be solved
[0006] The purpose of this invention is to provide a low glycemic index food processing technology that incorporates white kidney bean extract, in order to solve the problems of high-temperature inactivation of white kidney bean extract, uneven mixing, and rough product taste in the prior art.
[0007] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a low-glycemic food processing technology incorporating white kidney bean extract, comprising the following steps: S1. Raw material pretreatment: The starchy raw material is crushed to obtain starchy powder. The starchy powder is then subjected to conditioning, gelatinization and modification treatments in sequence to obtain modified starchy base material. The modification treatment is used to increase the resistant starch content and reduce the rapidly digestible starch content in the starchy powder. S2. Adding white kidney bean extract: Pre-treat white kidney bean extract by microencapsulation to obtain encapsulated white kidney bean extract; add the encapsulated white kidney bean extract to the modified starch base and mix evenly to obtain a mixed base; S3. Molding and maturation: The mixed base material is shaped and matured; S4. Drying and Cooling: The cooked material is dried and cooled under controlled temperature to obtain low-GI food products.
[0008] Furthermore, in step S1, the starchy raw material is a cereal and / or tuber raw material; preferably, it is one or a combination of brown rice, oats, wheat, corn, buckwheat, sweet potato, and potato; the pulverization process is to pulverize the starchy raw material to pass through a 60-120 mesh sieve to ensure the fineness of the starchy base material, provide a basis for subsequent gelatinization modification, and at the same time avoid the rough texture of the finished product.
[0009] Furthermore, in step S1, the conditioning process involves adding purified water to the starch powder to adjust the moisture content of the material to 15%-35%, and conditioning at a constant temperature of 40-70℃ for 10-30 minutes to allow the moisture to fully penetrate into the starch granules, thereby achieving uniform swelling of the starch granules and creating homogenization conditions for subsequent gelatinization and modification.
[0010] Furthermore, in step S1, the gelatinization process involves steam gelatinizing the conditioned material at 90-120°C for 5-20 minutes to completely destroy the crystalline structure of the starch, allowing the starch granules to fully swell and gelatinize, thus providing a prerequisite for the formation of resistant starch in the subsequent modification process.
[0011] Furthermore, in step S1, the modification treatment involves one or more combinations of aging and retrogradation, physical extrusion modification, or enzymatic modification of the gelatinized material. Through targeted modification, the resistant starch content is effectively increased and the proportion of rapidly digestible starch is reduced, achieving a stable low glycemic index from the starch structure level. After modification, the modified starch matrix is cooled to a suitable temperature to prevent the material from aging and hardening rapidly, ensuring the uniformity of subsequent mixing.
[0012] Furthermore, in step S2, the α-amylase inhibitor activity in the white kidney bean extract is ≥20000 U / g; the microcapsule encapsulation pretreatment adopts fluidized bed bottom spray coating technology, and the wall material is one or more combinations of maltodextrin, β-cyclodextrin, hydroxypropyl methylcellulose, and resistant dextrin. The mass ratio of the wall material to the white kidney bean extract is (0.5-1.5):1. Through the fluidized bed bottom spray coating process, a dense and uniform protective layer is formed on the surface of the white kidney bean extract, which not only ensures the encapsulation rate and improves thermal stability, but also avoids the problem of dilution of effective ingredients and decrease in formability caused by excessive wall material, ensuring that the active ingredients are not lost during subsequent processing.
[0013] Furthermore, in step S2, the total amount of the coated white kidney bean extract added is 0.5%-5% of the dry weight of the modified starch matrix, which can be flexibly adjusted according to the target GI value of the product, so as to ensure the low GI effect without affecting the taste and texture of the product. The mixing temperature of the coated white kidney bean extract is 45-50℃.
[0014] Furthermore, in step S3, the molding and ripening process can be performed using either of the following two processes to suit different product form requirements, while strictly controlling the temperature and duration to avoid high temperatures damaging the activity of the white kidney bean extract: Process 1: Low-temperature extrusion molding and curing integrated process, controlling the extrusion die temperature ≤70℃, screw speed 120-200rpm, completing the molding and curing of materials in one step, controlling the material heating temperature throughout the process, without secondary high-temperature process, balancing molding efficiency and activity retention; Process 2: Cold forming followed by low-temperature curing. Cold forming is completed by room temperature roller pressing and calendering, followed by low-temperature baking or steaming for curing. The low-temperature baking temperature is ≤70℃ and the duration is ≤15min. The steaming for curing controls the center temperature of the material to ≤70℃ and the duration to ≤10min. The temperature and duration of the high-temperature section are strictly limited to ensure the stability of active ingredients and ensure the degree of product curing, avoiding a raw or astringent taste.
[0015] The two molding processes can adapt to the processing needs of different types of food.
[0016] Furthermore, in step S4, the drying temperature of the temperature-controlled drying process is ≤60℃, and the material is dried to a moisture content of 8%-14%, which ensures the product's shelf life while avoiding the loss of active ingredients and deterioration of texture caused by high-temperature drying.
[0017] This invention also protects a low glycemic index food, which is prepared by the above-mentioned method. The low glycemic index food has a dual low glycemic index mechanism of starch structure modification and α-amylase inhibition. The GI value meets the low GI standard. The α-amylase inhibitor activity in the white kidney bean extract is highly retained. The content of resistant starch in the finished product is stable and the content of rapidly digestible starch is significantly reduced.
[0018] (III) Beneficial Effects Compared with existing technologies, this invention provides a low-glycemic food processing technology that incorporates white kidney bean extract, which has the following beneficial effects: 1. This low-glycemic food processing technology, which incorporates white kidney bean extract, pre-treats the white kidney bean extract by coating it, replacing the traditional post-mixing method. This avoids the extract being distributed in a free state, ensuring that it is evenly dispersed in the mixed base material. This not only preserves the original taste of the food, but also avoids the problems of rough taste and reduced formability caused by excessive wall material by optimizing the wall material ratio. At the same time, it further enhances the thermal stability of α-amylase inhibitors, achieving the dual effect of activity preservation and taste improvement.
[0019] 2. This low-glycemic food processing technology, which incorporates white kidney bean extract, results in a product with a low GI value, high retention of white kidney bean extract activity, significantly slowed starch digestion rate, and effectively increased resistant starch content. At the same time, it ensures that the product's taste, texture, and cooking resistance are not compromised, thus balancing functionality and edibility. Detailed Implementation
[0020] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] In the following embodiments and comparative examples of the present invention, the α-amylase inhibitor activity in the white kidney bean extract used was 25000 U / g; the starch raw material was a commercially available food-grade raw material, and other reagents were all conventional food-grade reagents; the microcapsule coating was carried out using fluidized bed bottom spray coating technology.
[0022] Example 1 This embodiment provides a method for preparing low-GI grain noodles, the specific steps of which are as follows: S1. Raw material pretreatment: Wheat flour, brown rice, and oats are mixed in a mass ratio of 7:2:1 to obtain grain raw materials. The grain raw materials are crushed to pass through an 80-mesh sieve to obtain grain powder. Purified water is added to the grain powder to adjust the moisture content of the material to 28%, and it is conditioned at a constant temperature of 55℃ for 20 minutes. The conditioned material is then steam-gelatinized at 105℃ for 10 minutes to fully gelatinize the starch. An aging and retrogradation modification treatment is adopted. The gelatinized material is first cooled to 4℃ and kept at a constant temperature for 12 hours to complete the aging and retrogradation. Then, it is heated to 45℃ to obtain modified starch matrix. The modified starch matrix contains 12.6% resistant starch and 35.8% rapidly digestible starch.
[0023] S2. Adding white kidney bean extract: Using β-cyclodextrin as the wall material, the white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 1:1 to the wall material to the white kidney bean extract to obtain coated white kidney bean extract; under the condition of 45℃, the coated white kidney bean extract was added to the modified starch matrix and mixed for 15 minutes in a mixer to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 2% of the dry weight of the modified starch matrix.
[0024] S3. Molding and Curing: The mixed base material is extruded and shaped at room temperature to form vermicelli blanks. The vermicelli blanks are then baked at 70℃ for 12 minutes to complete the curing process.
[0025] S4. Drying and cooling: Use cold air to dry the vermicelli until the moisture content is 12% to obtain the low-GI grain vermicelli product.
[0026] Example 2 This embodiment provides a method for preparing low-GI cereal flakes, the specific steps of which are as follows: S1. Raw material pretreatment: Oats, brown rice, quinoa, and corn are mixed in a mass ratio of 4:3:2:1 to obtain grain raw materials. The grain raw materials are pulverized to pass through a 100-mesh sieve to obtain grain powder. Purified water is added to the grain powder to adjust the moisture content to 32%, and the mixture is conditioned at 60℃ for 15 minutes. The conditioned material is then steam-gelatinized at 110℃ for 8 minutes to fully gelatinize the starch. Enzymatic modification is then performed by adding pullulanase to the gelatinized material at a rate of 0.1% of the mass of the gelatinized material. The mixture is enzymatically hydrolyzed at 58℃ for 12 hours. After enzyme inactivation, the temperature is lowered to 48℃ to obtain modified starch matrix. The modified starch matrix is found to contain 14.2% resistant starch and 32.1% rapidly digestible starch.
[0027] S2. Adding white kidney bean extract: Maltodextrin and hydroxypropyl methylcellulose were mixed at a mass ratio of 2:1 as wall material. The white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 0.8:1 to the wall material, to obtain coated white kidney bean extract. The coated white kidney bean extract was added to the modified starch matrix at 48℃ and mixed for 20 minutes to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 3% of the dry weight of the modified starch matrix.
[0028] S3. Molding and maturation: The mixed base material is rolled and pressed into sheets at room temperature to form grain flake blanks. The grain flake blanks are then baked at 70℃ for 10 minutes to complete the maturation.
[0029] S4. Drying and Cooling: Use 60℃ hot air to dry the material until the moisture content is 10%, and then let the dried grain flakes cool naturally to obtain the low-GI grain flake product.
[0030] Example 3 This embodiment provides a method for preparing low-GI cereal meal replacement pellets, the specific steps of which are as follows: S1. Raw material pretreatment: Brown rice, buckwheat, and corn are mixed in a mass ratio of 5:3:2 to obtain grain raw materials. The grain raw materials are crushed to pass through a 60-mesh sieve to obtain grain powder. Purified water is added to the grain powder to adjust the moisture content of the material to 22%, and it is conditioned at a constant temperature of 50℃ for 25 minutes. The conditioned material is then steam-gelatinized at 100℃ for 15 minutes to fully gelatinize the starch. Physical extrusion modification is performed, and the material is cooled to 50℃ after extrusion to obtain modified starch matrix. The modified starch matrix is tested to show that the resistant starch content is 11.8% and the rapid digestible starch content is 37.4%.
[0031] S2. Adding white kidney bean extract: Using resistant dextrin as the wall material, the white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 1.2:1 to the wall material to the white kidney bean extract to obtain coated white kidney bean extract; under 50℃, the coated white kidney bean extract was added to the modified starch matrix and mixed for 15 minutes in a mixer to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 1.5% of the dry weight of the modified starch matrix.
[0032] S3. Molding and maturation: The low-temperature extrusion molding and maturation integrated process is adopted. The mixed base material is fed into a twin-screw extruder, and the extrusion die temperature is controlled at 68℃ and the screw speed is 160rpm. The molding and maturation of the grain meal replacement pellets are completed in one step.
[0033] S4. Drying and Cooling: The material is dried with hot air at 58℃ until the moisture content is 13%. The dried grain meal replacement pellets are then naturally cooled to obtain the low-GI grain meal replacement pellet product.
[0034] Example 4 This embodiment provides a method for preparing low-GI sweet potato vermicelli, the specific steps of which are as follows: S1. Raw Material Pretreatment: Fresh sweet potatoes were selected, washed, peeled, and then crushed into a paste that passed through an 80-mesh sieve to obtain sweet potato starch slurry. The moisture content of the material was adjusted to 30%, and the mixture was conditioned at 50℃ for 25 minutes. The conditioned material was then steam-gelatinized at 100℃ for 12 minutes to ensure complete starch gelatinization. A combination of aging and enzymatic modification was used for further treatment: pullulanase (0.2% of the mass of the gelatinized material) was added to the gelatinized material, and the mixture was enzymatically hydrolyzed at 55℃ for 1 hour. After enzyme inactivation, the temperature was slowly lowered to 4℃ and allowed to stand at a constant temperature for 16 hours to complete aging. The temperature was then raised to 45℃ to obtain the modified starch-based material. Testing showed that the modified starch-based material contained 13.8% resistant starch and 34.2% rapidly digestible starch.
[0035] S2. Adding white kidney bean extract: β-cyclodextrin and resistant dextrin were mixed at a mass ratio of 1:1 as wall material. The white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 1:1 to the wall material to obtain coated white kidney bean extract. The coated white kidney bean extract was added to the modified starch matrix at 46℃ and mixed for 20 minutes to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 2.5% of the dry weight of the modified starch matrix.
[0036] S3. Molding and maturation: The mixed base material is extruded and shaped at room temperature to form sweet potato vermicelli blanks. The vermicelli blanks are then baked at 68℃ for 14 minutes to complete the maturation.
[0037] S4. Drying and cooling: Use cold air to dry the vermicelli until the moisture content is 12% to obtain the low-GI sweet potato vermicelli product.
[0038] Example 5 This embodiment provides a method for preparing low-GI potato flour, the specific steps of which are as follows: S1. Raw Material Pretreatment: Fresh potatoes were selected, washed, peeled, crushed, and pulped through an 80-mesh sieve to obtain potato starch slurry. The moisture content of the material was adjusted to 30%, and the mixture was conditioned at 50℃ for 25 minutes. The conditioned material was then steam-gelatinized at 100℃ for 12 minutes to ensure complete starch gelatinization. A combination of aging and enzymatic modification was used for further treatment: pullulanase (0.2% of the mass of the gelatinized material) was added to the gelatinized material, and enzymatic hydrolysis was performed at 55℃ for 1 hour. After enzyme inactivation, the temperature was slowly lowered to 4℃ and kept at a constant temperature for 16 hours to complete aging. The temperature was then raised to 45℃ to obtain the modified starch matrix. Testing showed that the modified starch matrix contained 14.0% resistant starch and 33.8% rapidly digestible starch.
[0039] S2. Adding white kidney bean extract: β-cyclodextrin and resistant dextrin were mixed at a mass ratio of 1:1 as wall material. The white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 1:1 to the wall material to obtain coated white kidney bean extract. The coated white kidney bean extract was added to the modified starch matrix at 46℃ and mixed for 15 minutes to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 2.5% of the dry weight of the modified starch matrix.
[0040] S3. Molding and maturation: The mixed base material is extruded and shaped at room temperature to form potato starch raw material. The raw material is then baked at 68℃ for 14 minutes to complete the maturation.
[0041] S4. Drying and cooling: Use cold air to dry the vermicelli until the moisture content is 12%, to obtain the low-GI potato vermicelli product.
[0042] Example 6 This embodiment provides a method for preparing low-GI rice flour, the specific steps of which are as follows: S1. Raw Material Pretreatment: Indica rice was selected, and after impurity removal, washing, and draining, it was pulverized through a 100-mesh sieve to obtain rice flour. Purified water was added to the rice flour to adjust the moisture content to 30%, and the mixture was conditioned at 52℃ for 20 minutes. The conditioned material was then steam-gelatinized at 105℃ for 12 minutes to ensure complete starch gelatinization. An aging and retrogradation modification treatment was then performed: the gelatinized material was rapidly cooled to room temperature, then placed in a 4℃ environment for constant temperature aging and retrogradation for 14 hours. The temperature was then slowly increased to 46℃ to obtain a modified starch-based material. Testing showed that the modified starch-based material contained 13.2% resistant starch and 33.6% rapidly digestible starch.
[0043] S2. Adding white kidney bean extract: β-cyclodextrin and maltodextrin were mixed at a mass ratio of 1:1 as wall material. The white kidney bean extract was pre-treated by fluidized bed bottom spray coating technology at a mass ratio of 1:1 to the wall material to obtain coated white kidney bean extract. Under the condition of 45℃, the coated white kidney bean extract was added to the modified starch matrix and mixed for 15 minutes in a mixer to obtain a mixed matrix. The total amount of coated white kidney bean extract added was 2% of the dry weight of the modified starch matrix.
[0044] S3. Molding and Curing: The process of first cold molding and then low-temperature curing is adopted. The mixed base material is extruded into round or flat rice noodle blanks at room temperature through a special rice noodle extruder. The rice noodle blanks are then baked at 68℃ for 13 minutes to complete the curing.
[0045] S4. Drying and Cooling: The rice noodles are dried with 60℃ hot air until the moisture content is 12.5%, and then the dried rice noodles are naturally cooled to obtain the low-GI rice noodle product.
[0046] Comparative Example 1 This comparative example uses conventional grain noodles, with the same raw material composition as Example 1. The difference from Example 1 is that no grain modification treatment was performed, no white kidney bean extract was added, and the remaining process parameters are completely consistent with Example 1.
[0047] Comparative Example 2 The difference between this comparative example and Example 1 is that no grain modification treatment was performed, the white kidney bean extract was not pre-treated with coating and was directly added to the material, the amount added was the same as in Example 1, and the other process parameters were completely consistent with those in Example 1.
[0048] Comparative Example 3 The difference between this comparative example and Example 1 is that no white kidney bean extract was added, and only grain aging and retrogradation modification treatment was performed. The remaining process parameters are completely consistent with those of Example 1.
[0049] Comparative Example 4 The difference between this comparative example and Example 3 is that the temperature of the extrusion die head is controlled at 90°C during molding and curing, while the other process parameters are completely consistent with those of Example 3.
[0050] Performance testing The products prepared in the above embodiments of the present invention and comparative examples 1-4 were subjected to performance tests. The test items included GI value, α-amylase inhibitor activity retention rate, resistant starch content, rapidly digestible starch content, textural index difference rate, shape retention rate after boiling for 10 minutes, and sensory taste score. The test results are shown in the table below.
[0051]
[0052] The glycemic index (GI) was determined using an in vitro simulated digestion method. In an in vitro environment simulating the human gastrointestinal tract, α-amylase and saccharifying enzyme were used to sequentially hydrolyze the sample stepwise, with glucose release measured periodically. Starch hydrolysis kinetics curves were plotted, and the starch hydrolysis index (HI) was calculated. White bread was used as a reference standard to convert the sample's estimated glycemic index (pGI). The α-amylase inhibitor activity retention rate was determined using the DNS method, with the total activity of the initially added white kidney bean extract as a baseline to calculate the activity retention rate in the finished product. The content of resistant starch and rapidly digestible starch was determined using the Englyst method. The difference rate of textural indicators was calculated using the combined average of hardness, elasticity, and cohesiveness. Each example used a commercially available product of the same form that did not employ this process as a control. The shape retention rate was the percentage of intact product after boiling for 10 minutes. Sensory evaluation was conducted by a blind panel of 10 professionals, with a maximum score of 10 points. Higher scores indicated a smoother, more delicate texture without roughness or breaks.
[0053] The test results show that the GI values of the products prepared in the embodiments of this invention all meet the low GI standard and are significantly lower than those of the comparative examples, verifying the synergistic effect of the dual low glycemic mechanism of grain structure modification and α-amylase inhibition. The α-amylase inhibitor activity retention rates of the prepared products are all high, far exceeding those of uncoated, high-temperature processed comparative examples 2 and 4. The coating pretreatment and low-temperature molding and ripening process of this invention effectively solves the problem of inactivation of white kidney bean extract during high-temperature processing. The resistant starch content of the finished product is stable, the rapid digestible starch content is significantly reduced, the difference rate of texture indicators is low, the taste score is high, and the cooking resistance is good. The process of this invention effectively guarantees the edible quality of the product. Comparative example 2, due to the lack of coating treatment, has an extremely low activity retention rate; comparative example 4, due to the molding and ripening temperature exceeding the limits of the claims, has a significantly reduced activity retention rate, further proving the rationality and necessity of the process parameters in the claims of this invention.
[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A low-glycemic food processing technology incorporating white kidney bean extract, characterized in that, Includes the following steps: S1. Raw material pretreatment: The starchy raw material is crushed to obtain starchy powder. The starchy powder is then subjected to conditioning, gelatinization and modification treatments in sequence to obtain modified starchy base material. The modification treatment is used to increase the resistant starch content and reduce the rapidly digestible starch content in the starchy powder. S2. Adding white kidney bean extract: Pre-treat white kidney bean extract by microencapsulation to obtain encapsulated white kidney bean extract; add the encapsulated white kidney bean extract to the modified starch base and mix evenly to obtain a mixed base; S3. Molding and maturation: The mixed base material is shaped and matured; S4. Drying and Cooling: The matured material is dried and cooled under controlled temperature to obtain low-GI food products.
2. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S1, the starchy raw material is a cereal and / or tuber raw material; preferably, it is one or a combination of brown rice, oats, wheat, corn, buckwheat, sweet potato, and potato; the pulverizing process is to pulverize the starchy raw material to pass through a 60-120 mesh sieve.
3. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S1, the conditioning process involves adding purified water to the starch powder to adjust the moisture content of the material to 15%-35%, and conditioning at a constant temperature of 40-70℃ for 10-30 minutes; the gelatinization process involves steam gelatinizing the conditioned material at 90-120℃ for 5-20 minutes.
4. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S1, the modification treatment is one or more combinations of aging and regeneration, physical extrusion modification, or enzymatic modification of the gelatinized material.
5. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S2, the α-amylase inhibitor activity in the white kidney bean extract is ≥20000 U / g; the microcapsule coating pretreatment adopts fluidized bed bottom spray coating, and the wall material is one or more combinations of maltodextrin, β-cyclodextrin, hydroxypropyl methylcellulose, and resistant dextrin, with the mass ratio of wall material to white kidney bean extract being (0.5-1.5):
1.
6. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S2, the total amount of the coated white kidney bean extract added is 0.5%-5% of the dry weight of the modified starch matrix, and the mixing temperature of the coated white kidney bean extract is 45-50℃.
7. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S3, the molding and curing process adopts a low-temperature extrusion molding and curing integrated process, controlling the extrusion die temperature to ≤70℃ and the screw speed to 120-200rpm.
8. The low glycemic index food processing technology incorporating white kidney bean extract according to claim 1, characterized in that: In step S3, the molding and maturation process adopts a cold molding followed by low-temperature maturation process. The cold molding is completed by room temperature rolling and calendering, followed by low-temperature baking or steaming maturation. The low-temperature baking temperature is ≤70℃ and the duration is ≤15min. The steaming maturation process controls the material center temperature to be ≤70℃ and the duration to be ≤10min.
9. A low glycemic index food, characterized in that: It is prepared by the preparation method according to any one of claims 1-8.