Processing method of low-glycemic plant-based food

Abstract

The invention discloses a low-glycemic plant-based food processing method and a low-glycemic plant-based food product. The method comprises the following steps: crushing bulk plant-derived edible agricultural products; the preparation method comprises the following steps: compounding starch, protein, non-starch polysaccharide and functional lipid according to a specific ratio, and adding water for conditioning; and extruding and recombining the mixture in a double-screw extruder at a specific partition temperature and a screw rotating speed to obtain the food. The preferable scheme also comprises the following steps: adding a natural plant extract rich in 3-deoxidized anthocyanin; carrying out enzymolysis fermentation and embedding treatment on the protein to form sustained-release protein particles; a prebiotic sweetening agent composed of xylitol and stevioside and a sugarcane polyphenol plant source composition are added; and carrying out superheated steam treatment on the extruded product. According to the invention, through scientific compounding and extrusion structured recombination cooperation of nutritional components, a compact matrix is constructed, multiple functional components are combined, stable low glycemic content is realized from multiple ways of physical barrier, digestion inhibition, slow release and the like, and the nutrition and palatability of the product are ensured at the same time.

Description

Technical Field

[0001] This application relates to the field of food processing technology, and specifically to a processing method for a low glycemic index plant-based food. Background Technology

[0002] With the continued rise in the global incidence of metabolic syndromes such as diabetes and obesity, and the increasing health awareness of consumers, the demand for low glycemic index (GI) foods is becoming increasingly urgent. Plant-based foods, rich in dietary fiber, protein, and bioactive substances, are considered an important vehicle for developing low-GI health foods. Currently, the technical approaches aimed at reducing the GI value of foods mainly focus on two aspects: one is through formulation adjustments, such as adding high-amylose, dietary fiber, protein, or plant polyphenols, to physically or chemically inhibit the enzymatic digestion of starch; the other is utilizing food processing technologies, such as extrusion puffing and hydrothermal treatment, to promote the formation of resistant starch or alter the physical structure of the food matrix. However, existing technologies still have significant limitations. At the formulation level, simply adding functional ingredients mechanically often fails to achieve efficient and stable effects in complex food systems, potentially leading to problems such as deterioration in taste, inactivation of components, or insufficient synergistic effects. At the processing level, conventional single-screw extrusion or cooking processes have limited ability to restructure materials, making it difficult to precisely control the degree of starch gelatinization, protein denaturation, and interactions between components. This results in a final product with a loose structure and still high digestibility, or an excessive sacrifice of texture and flavor in pursuit of low GI. Furthermore, existing methods often focus on single technical aspects, lacking a systematic solution encompassing the entire chain from raw material selection, component design, structured processing to functional enhancement. This makes it difficult to simultaneously meet the multiple demands for low glycemic index, high nutritional value, good taste, and processing adaptability. Therefore, developing a low-glycemic plant-based food processing method that can systematically integrate multiple glycemic mechanisms and construct a stable, dense matrix through controllable processing is of great significance for promoting the upgrading of the health food industry. Summary of the Invention

[0003] To overcome the above-mentioned technical deficiencies, the purpose of this invention is to provide a processing method for low-glycemic plant-based foods, comprising the following steps: (1) Raw material pretreatment: crush bulk plant-based edible agricultural products into 100-300 mesh; (2) Nutritional component compounding: By weight, mix 50-70 parts starch, 15-30 parts protein, 12-20 parts non-starch polysaccharide, and 5-10 parts functional lipids, and add 15-30 parts water for conditioning. (3) Extrusion and reorganization: The mixture obtained in step (2) is placed in a twin-screw extruder, the screw speed is set to 70-180 r / min, and the temperature of the material in the mixing zone, kneading zone and forming zone is controlled at 60-90℃, 100-130℃ and 90-110℃ respectively. The low glycemic plant-based food is obtained after extrusion and reorganization.

[0004] As a preferred embodiment of this application, the bulk plant-derived edible agricultural products mentioned in step (1) include one or more of the following: cereals, false cereals, and legumes; preferably, the cereals include one or more of the following: rice, millet, wheat, corn, oats, and sorghum; the false cereals include one or more of the following: quinoa, buckwheat, and amaranth; and the legumes include one or more of the following: soybeans, mung beans, black beans, peas, kidney beans, and chickpeas.

[0005] As a preferred embodiment of this application, the starch in step (2) contains more than 30% amylose; the protein includes one or more of glutenin, alkali-soluble glutenin, legume protein isolate, and zein; the non-starch polysaccharide includes one or more of pectin, β-glucan, arabinoxylan, cellulose, guar gum, psyllium husk, locust bean gum, konjac glucomannan, inulin, and chitosan; and the functional lipid contains more than 50% polyunsaturated fatty acids, including one or more of linoleic acid, linolenic acid, oleic acid, arachidonic acid, phytosterols, tocopherols, and higher alkanols.

[0006] As a preferred embodiment of this application, step (2) further includes adding 0.5%-3% of a natural plant extract by weight of the total mass of the nutrient components, wherein the 3-deoxyanthocyanin content in the natural plant extract is greater than 3 mg / 100g; preferably, the natural plant extract is prepared by crushing one or more of the flowers, leaves, and stems of sorghum, sugarcane, corn, camellia, gesneriad, grape, quinoa, highland barley, moss, and ferns, adding acetic acid solution with a concentration of 1-5 wt% at a weight ratio of 1:3-1:10, and then extracting in a water bath at 30-50℃ for 5-120 min and collecting the supernatant.

[0007] As a preferred embodiment of this application, the protein in step (2) is pre-treated by enzymatic hydrolysis and fermentation: pea protein powder and white kidney bean extract are mixed and dispersed in water at a mass ratio of 5-10:3-5. First, a primary complex protease composed of alkaline protease and papain at a mass ratio of 5-7:2 is used for enzymatic hydrolysis at 45-55℃ for 2-4 hours. After enzyme inactivation, a secondary complex protease composed of neutral protease and animal protease at a mass ratio of 3-5:1 is used for enzymatic hydrolysis at 40-60℃ for 1-3 hours. After enzyme inactivation, the enzymatically hydrolyzed protein peptide product is obtained. The seed culture of Lactobacillus plantarum, Saccharomyces cerevisiae, and Lactobacillus bulgaricus is inoculated into the enzymatically hydrolyzed protein peptide product. The product is fermented and cultured at 36-39℃ for 48-72 hours under micro-hypoxic conditions. After freeze-drying, the enzymatically hydrolyzed fermented protein peptide powder is obtained.

[0008] As a preferred embodiment of this application, the enzymatically hydrolyzed fermented protein peptide powder undergoes an encapsulation process: sodium carboxymethyl cellulose, sodium alginate, and water-soluble chitosan are dissolved in water at a mass ratio of 5-7:2-4:3-7. The enzymatically hydrolyzed fermented protein peptide powder, along with food-grade emulsifier and edible oil, are added. After rapid membrane emulsification, a 3-5 wt% calcium chloride solution is added dropwise and solidified at room temperature for 30-50 minutes. The mixture is then centrifuged, washed, and freeze-dried to obtain slow-release protein particles. Preferably, the mass ratio of sodium carboxymethyl cellulose, sodium alginate, water-soluble chitosan, enzymatically hydrolyzed fermented protein peptide powder, food-grade emulsifier, and edible oil is 5-7:2-4:3-7:10-12:1-2:30-50.

[0009] As a preferred embodiment of this application, the specific mechanical energy consumption of the twin-screw extruder in step (3) is 120-300 kJ / kg, and the screw length-to-diameter ratio is 20-100:1; preferably, after the extrusion and reorganization, it is further subjected to superheated steam treatment at a temperature of 260-320℃ for 2-4 minutes.

[0010] As a preferred embodiment of this application, step (2) further includes adding a prebiotic sweetener, which is composed of xylitol and steviol glycosides mixed in a mass ratio of 5-7:2-4.

[0011] As a preferred embodiment of this application, step (2) further includes adding a sugarcane polyphenol plant-derived composition accounting for 1%-5% of the total mass of the nutritional components. The sugarcane polyphenol plant-derived composition is composed of sugarcane polyphenols, plant polypeptides, fruit and vegetable fiber powder, and soluble dietary fiber powder in a mass ratio of 0.05-0.2: 0.5-1: 3-5: 2-4.

[0012] This application provides a low glycemic index plant-based food prepared by the processing method described above. The food has a relative density greater than 1.2 g / cm3, a dietary fiber content greater than 6%, and a glycemic index (GI) less than 55. The food is in the form of rice grains, noodles, biscuits, or steamed buns.

[0013] Compared with the prior art, the main advantage of this invention is that it provides a systematic, efficient and customizable overall solution for low glycemic plant-based foods.

[0014] This invention creatively combines the core processes of "scientific compounding of nutritional components" with "extrusion-structured recombination". Starting from the source of food matrix design, it constructs a dense and stable structure that can effectively delay digestion through the synergistic effect of multiple macronutrients and molecular reconstruction under precise thermomechanical action. This lays a solid physical foundation for low glycemic properties and breaks through the bottleneck of limited effects of adding single functional ingredients or conventional processing methods.

[0015] This solution boasts a high degree of functional integration and scalability. Its process framework can effectively integrate and enhance natural active ingredients (such as plant polyphenols) and modified proteins, achieving a synergistic effect of multiple hypoglycemic mechanisms, including inhibiting enzyme activity, delaying gastric emptying, and promoting resistant starch formation, thereby achieving a stable and reliable hypoglycemic effect.

[0016] While achieving its core functions, this method integrates functional lipids, prebiotics, and other components, taking into account both the overall nutrition and flavor of the product. The resulting food products come in various forms, meeting the needs for low glycemic index while also possessing good palatability and practicality. Attached Figure Description

[0017] Figure 1 This is a flow chart of the boiling, sterilization, and spray drying process for a vitamin-type soy milk powder according to this application. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. To facilitate a clearer understanding of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0021] Example 1 This embodiment provides a processing method for a low glycemic index plant-based food (rice grain form).

[0022] (1) Raw material pretreatment: Northeast japonica rice, oats, quinoa, and mung beans were selected as major plant-based edible agricultural products and mixed in a mass ratio of 5:2:2:1. The mixed raw materials were then pulverized in an ultrafine pulverizer and passed through a 200-mesh sieve to obtain a uniform composite plant powder.

[0023] (2) Nutritional component compounding: Prepare the following ingredients by weight: Starch component: 60 parts. The starch is derived from the compound plant powder obtained in step (1), and its amylose content is 35%.

[0024] Protein component: 20 parts. Wheat gluten powder and pea protein isolate were mixed at a mass ratio of 3:1.

[0025] Non-starch polysaccharide component: 15 parts. Composed of oat β-glucan (purity ≥70%), apple pectin and microcrystalline cellulose in a mass ratio of 5:3:2.

[0026] Functional lipid components: 5 parts. It uses perilla seed oil rich in linolenic acid and linoleic acid, with a total polyunsaturated fatty acid content of approximately 75%, and contains natural tocopherols.

[0027] The starch, protein, non-starch polysaccharide, and functional lipids were premixed in a high-speed mixer for 5 minutes to ensure initial uniform dispersion. Then, 25 parts of purified water were added to the premix, and the mixture was stirred and conditioned in a conditioning tank at 50°C for 15 minutes to allow the water to penetrate evenly, resulting in a material moisture content of approximately 28%, forming a wet mixture with good plasticity.

[0028] (3) Extrusion and reorganization: The wet mixture obtained in step (2) is uniformly fed into a co-rotating twin-screw extruder (screw length-to-diameter ratio L / D = 40:1) via a feeder. The screw speed is set to 120 r / min. The temperature of each zone of the extruder is precisely controlled: the temperature of zone I (mixing zone) is set to 80℃, the temperature of zone II (kneading zone) is set to 120℃, and the temperature of zone III (forming zone) is set to 100℃. Under the action of conveying, shearing, mixing and heating by the screw, the material undergoes physicochemical changes such as gelatinization, protein denaturation and intermolecular cross-linking, realizing the extrusion and recombination of nutritional components. After being extruded through the die (imitating the shape of rice grains), it is cut into rice grain-shaped wet preforms of about 5mm in length by a cutter. The specific mechanical energy consumption (SME) under this process condition is calculated to be about 180 kJ / kg.

[0029] The resulting rice-grain-shaped wet pre-fat is dried with hot air at 50°C until the moisture content is below 12%, yielding the final low-glycemic plant-based food. This product has a firm texture and a natural grain aroma.

[0030] Example 2 Based on Example 1, this embodiment adds a natural plant extract to provide a processing method for a low-glycemic plant-based food (noodle form) with enhanced resistant starch formation.

[0031] (1) Raw material pretreatment: Same as Example 1.

[0032] (2) Preparation of natural plant extracts: The outer husks of black glutinous sorghum were selected and crushed through a 40-mesh sieve. 100g of sorghum husk powder was weighed and added to 500g of a 2 wt% food-grade acetic acid solution (solid-to-liquid ratio 1:5). The mixture was then placed in a 45℃ constant temperature water bath for 60 minutes, with intermittent stirring during extraction. After extraction, the mixture was centrifuged at 5000 rpm for 10 minutes, and the supernatant was collected and filtered through a 0.45μm membrane to obtain a clear natural plant extract. High-performance liquid chromatography (HPLC) analysis showed that the extract contained approximately 5.2 mg / 100g of 3-deoxyanthocyanins (such as apigenin-7-O-glucoside).

[0033] (3) Nutritional component compounding: Prepare the following ingredients by weight: 55 parts starch (a blend of corn starch with 38% amylose and high amylose), 22 parts protein (alkali-soluble rice protein), 18 parts non-starch polysaccharides (a mixture of konjac glucomannan and arabinoxylan at a mass ratio of 2:1), and 5 parts functional lipids (rice bran oil rich in oleic acid and phytosterols).

[0034] The above-mentioned dry base raw materials were mixed evenly in a mixer. Then, the natural plant extract obtained in step (2) (addition amount accounting for 1.5% of the total mass of the dry base nutrient components) was mixed with a total of 28 parts of conditioning water. This mixture was slowly added to the dry base raw materials and conditioned in a conditioning tank at 55°C for 20 minutes. Phenolic substances such as 3-deoxyanthocyanins in the natural plant extract can interact with starch and protein, and play a role in inhibiting excessive starch gelatinization and promoting the formation of resistant starch during subsequent extrusion.

[0035] (4) Extrusion, reorganization and post-processing: The conditioned material is fed into a twin-screw extruder (L / D=60:1). The screw speed is set to 150 r / min. Temperature control: Zone I 70℃, Zone II 110℃, Zone III 95℃. The material is extruded through a noodle die to obtain noodle-shaped wet preforms. The wet preforms are then immediately fed into a superheated steam treatment unit and treated in superheated steam at 280℃ for 3 minutes. This high-temperature, short-time treatment further promotes the formation of starch-lipid complexes and starch-polyphenol complexes, and produces Maillard reaction flavor compounds, while also causing slight gelation of the product surface, increasing its resistance to overcooking. The treated noodles are then cooled, cut, dried (moisture content <10%), and packaged.

[0036] Example 3 This embodiment integrates several preferred methods, including protein enzymatic hydrolysis and fermentation, encapsulation treatment, prebiotic sweeteners, and sugarcane polyphenol compositions, to provide a processing method for a multifunctional slow-release low glycemic plant-based food (biscuit-like).

[0037] (1) Preparation of enzymatically hydrolyzed fermented protein peptide powder: a. Enzymatic hydrolysis: Pea protein powder and white kidney bean extract (a source of α-amylase inhibitor) were mixed at a mass ratio of 8:4 and dispersed in 10 times their weight of water. The pH was adjusted to 9.0 with NaOH solution, and a primary complex protease (alkaline protease:papain = 6:2, based on 3% of the total substrate protein mass) was added. Enzymatic hydrolysis was carried out in a water bath at 50°C for 3 hours. The temperature was then raised to 90°C and maintained for 10 minutes to inactivate the enzyme. After cooling, the pH was adjusted to 7.0 with HCl solution, and a secondary complex protease (neutral protease:animal protease = 4:1, based on 2.5% of the remaining protein substrate) was added. Enzymatic hydrolysis was continued at 50°C for 2 hours, followed by enzyme inactivation at 90°C for 10 minutes. After cooling, the enzymatically hydrolyzed protein peptide solution was obtained.

[0038] b. Fermentation: Activated seed cultures of *Lactobacillus plantarum*, *Saccharomyces cerevisiae*, and *Lactobacillus bulgaricus* were inoculated into the above enzymatically hydrolyzed protein peptide solution at a volume ratio of 2:1:1, with a total inoculum of 5%. Fermentation was carried out under micro-anaerobic conditions (partial air replacement with nitrogen) at 37°C for 60 hours. After fermentation, the fermentation broth was rapidly frozen at -40°C, then dried to constant weight in a freeze dryer, and pulverized through a 100-mesh sieve to obtain enzymatically hydrolyzed fermented protein peptide powder. This process further degrades large peptide molecules, produces bioactive small peptides and beneficial metabolites, and reduces potential allergenicity.

[0039] (2) Preparation of sustained-release protein particles: Preparation of the aqueous phase: Dissolve sodium carboxymethyl cellulose, sodium alginate, and water-soluble chitosan in an appropriate amount of deionized water at a mass ratio of 6:3:5, and stir until completely dissolved to prepare a 3% total colloidal solution.

[0040] Preparation of the oil phase: Mix food-grade monoglyceride (emulsifier) ​​with soybean oil at a mass ratio of 1:40, heat to 60℃ and stir to dissolve.

[0041] The enzymatically hydrolyzed fermented protein peptide powder (10 parts) obtained in step (1) was slowly added to the aqueous phase and dispersed evenly under high-speed shear. Then, the oil phase (40 parts, based on the total mass of the aqueous phase + protein powder) was preheated to 60°C, and the aqueous phase was slowly added to the oil phase under high-speed shear to form a proemulsion. The proemulsion was homogenized three times under 60 MPa pressure using a microfluidic high-pressure homogenizer to obtain a stable microemulsion.

[0042] Under gentle stirring, the microemulsion was added dropwise to a 4 wt% calcium chloride solution using a dropper. Calcium ions crosslinked with sodium alginate, forming a gel film on the droplet surface. After curing at room temperature for 40 minutes, the microspheres were collected by filtration, washed three times with deionized water to remove surface oil and residual calcium ions, and finally freeze-dried to obtain dried sustained-release protein particles.

[0043] (3) Nutritional component compounding: Prepare the following core ingredients by weight: 65 parts starch (a blend of tapioca starch and mung bean starch, with an amylose content of 32%), 15 parts non-starch polysaccharides (a mixture of inulin and fructooligosaccharides in a 2:1 ratio, which has both dietary fiber and prebiotic effects), and 8 parts functional lipids (peanut oil rich in linoleic acid and arachidonic acid).

[0044] Mix the above ingredients thoroughly. Then, add the following in sequence: The sustained-release protein particles obtained in step (2) are 12 parts (based on the protein peptide powder contained therein, the protein contribution is approximately 20 parts).

[0045] Prebiotic sweetener: It is a mixture of xylitol and steviol glycosides in a mass ratio of 6:3, and the amount added accounts for 2% of the total mass of the nutritional components.

[0046] Sugarcane polyphenol plant-derived composition: Its composition is sugarcane polyphenol extract: plant polypeptide (soybean peptide): fruit and vegetable fiber powder (apple fiber): soluble dietary fiber powder (resistant dextrin) = 0.1:0.8:4:3, and the amount added accounts for 3% of the total mass of the nutritional components.

[0047] Mix all solid materials in a three-dimensional mixer for 20 minutes until highly homogeneous. Then add 22 parts of purified water for conditioning at 45°C for 10 minutes.

[0048] (4) Extrusion and reorganization: The mixture is fed into a twin-screw extruder (L / D=45:1), with the screw speed set to 100 r / min. Temperature is controlled in zones: Zone I (conveyor mixing) 85℃, Zone II (high-temperature kneading) 125℃, and Zone III (melt forming) 105℃. The mixture is extruded through a wide, flat die to form a continuous sheet-like preform approximately 3 mm thick. The preform is then rolled, shaped, and die-cut into biscuit shapes.

[0049] (5) Superheated steam treatment: The shaped cookie dough is then placed in a superheated steam tunnel and treated at 300°C for 2.5 minutes. This process quickly sets and dries the product (reducing moisture content to below 5%), imparting a unique baked aroma and crisp texture. Simultaneously, the superheated steam treatment helps form a denser microstructure, slowing down digestion.

[0050] Comparative Example 1 Similar basic raw materials (japonica rice and oat flour) as in Example 1 were used, but without precise compounding and extrusion reorganization of nutritional components. Specifically, the pulverized mixed grain flour was directly mixed with water to form dough, and then extruded into rice grains using a conventional single-screw food extruder at a relatively low temperature (60°C in Zone I, 90°C in Zone II, and 80°C in Zone III), followed by drying. The screw speed was low (60 r / min), resulting in weaker shearing and thermomechanical effects.

[0051] Comparative Example 2 The raw material composition is similar to that of Example 3, but the enzymatic hydrolysis, fermentation, and encapsulation steps of the protein are omitted, and untreated pea protein isolate powder is used directly. At the same time, no sugarcane polyphenol plant-derived composition or prebiotic sweetener is added, water is used instead of natural plant extracts, and ordinary steam drying is used instead of superheated steam treatment.

[0052] Performance testing and effect verification The products obtained in Examples 1-3 and Comparative Examples 1-2 were subjected to relevant physicochemical indicators, textural properties and in vitro simulated digestion properties tests to evaluate their glycemic index (GI) related attributes.

[0053] 1. Basic physicochemical indicators: Determine the product's density, total dietary fiber content, and protein digestibility (in vitro pepsin-trypsin two-step method).

[0054] 2. Evaluation of in vitro starch digestibility: An in vitro simulated gastrointestinal digestion model was used. A sample containing 0.5g of available carbohydrates was accurately weighed, and digestive solutions including amylase, pepsin, and secretin were added. The mixture was then hydrolyzed with shaking at 37℃. Samples were taken at specific time points (0, 10, 20, 30, 60, 90, 120, 180 min) to determine the reducing sugar content in the hydrolysate and calculate the starch hydrolysis rate. Using white bread as a reference (with its hydrolysis index set at 100), the hydrolysis index (HI) of the sample was calculated, and the glycemic index (eGI) of the sample was estimated using the formula GI = 0.862 × HI + 8.198.

[0055] 3. Texture analysis: Use a texture analyzer to determine the product's hardness, chewiness, etc.

[0056] The test results are shown in the table below: Microscopic observation shows that the structure is relatively dense with small pores. The structure is very dense with many complexes. The embedded particles have a loose structure and a relatively dense porous structure, but the uniformity is slightly poor.

[0057] The protein digestibility of Example 3 is the cumulative release digestibility of the sustained-release protein particles after 2 hours of simulated digestion, and its digestion curve shows obvious sustained-release characteristics.

[0058] Results analysis: 1. Density and Structure: The density of the products in all embodiments of this invention is greater than 1.2 g / cm³. 3 The density of the product was significantly higher than that of Comparative Example 1. This is attributed to the precise formulation of nutrients, appropriate conditioning moisture, and the intense shearing, melting, and compaction during twin-screw extrusion, resulting in a dense and uniform microstructure. Comparative Example 1, lacking high-intensity thermomechanical treatment, had a puffed and porous product with low density.

[0059] 2. Dietary Fiber and Digestive Barrier: In Examples 2 and 3, the dietary fiber content was significantly increased by adding specific non-starch polysaccharides (such as pectin, konjac gum, inulin, etc.) and fiber from sugarcane polyphenol compositions. These dietary fibers can increase chyme viscosity, delay gastric emptying, and form a physical barrier around starch granules, hindering the contact of digestive enzymes. Example 3 had the highest dietary fiber content.

[0060] 3. Starch Digestion and eGI: The starch hydrolysis rate and eGI of all examples were significantly lower than those of the comparative examples. Example 1 achieved a low eGI (52.1) through high amylose content, protein network encapsulation, and extrusion-produced resistant starch. Example 2, with its added natural plant extract (rich in 3-deoxyanthocyanins), inhibited α-amylase and α-glucosidase activity, forming a complex with starch and further reducing the hydrolysis rate, resulting in an eGI of 46.3. Example 3 combined multiple strategies, including slow-release protein particles (physical encapsulation to slow enzyme contact), prebiotic fiber, sugarcane polyphenols (multi-pathway inhibition of digestive enzymes), and superheated steam treatment to promote resistant starch formation, exhibiting the slowest starch digestion rate and the lowest eGI (40.5), falling into the category of low glycemic index foods (GI < 55). Comparative Example 1, due to its loose structure and highly gelatinized starch, was easily digested, resulting in an eGI as high as 75.8. While Comparative Example 2 showed some improvement, its eGI remained close to the medium-high GI value due to the lack of key functional components and processing technology.

[0061] 4. Protein digestion: The protein in Example 3 has the highest digestibility, and because its protein undergoes enzymatic fermentation and microencapsulation, the digestion process is more gradual, which helps to provide a continuous supply of amino acids and enhance satiety.

[0062] 5. Texture characteristics: The high hardness is related to the dense structure, which gives the product a good chewy feel and a feeling of fullness, unlike the crispy and easily melted texture of traditional puffed foods.

[0063] In summary, this invention, through the scientific compounding of raw materials combined with a specific extrusion and recombination process (and optional functionalization treatments), effectively constructs a dense food matrix and integrates multiple mechanisms that reduce the rate of starch digestion (including physical barriers, enzyme inhibitors, resistant starch formation, starch-other component complexation, etc.), thereby successfully preparing plant-based foods with a low glycemic index and high satiety. Specific embodiments demonstrate that by adjusting the formulation and process parameters, products with different forms and functional focuses can be obtained to meet diverse healthy dietary needs.

[0064] The above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope defined by the claims of this application.

Claims

1. A processing method for a low glycemic index plant-based food, characterized in that, Includes the following steps: (1) Raw material pretreatment: crush bulk plant-based edible agricultural products into 100-300 mesh; (2) Nutritional component compounding: By weight, mix 50-70 parts starch, 15-30 parts protein, 12-20 parts non-starch polysaccharide, and 5-10 parts functional lipids, and add 15-30 parts water for conditioning. (3) Extrusion and reorganization: The mixture obtained in step (2) is placed in a twin-screw extruder, the screw speed is set to 70-180 r / min, and the temperature of the material in the mixing zone, kneading zone and forming zone is controlled at 60-90℃, 100-130℃ and 90-110℃ respectively. The low glycemic plant-based food is obtained after extrusion and reorganization.

2. The processing method of the low glycemic index plant-based food according to claim 1, characterized in that, The bulk plant-derived edible agricultural products mentioned in step (1) include one or more of the following: cereals, false cereals, and legumes; preferably, the cereals include one or more of rice, millet, wheat, corn, oats, and sorghum; the false cereals include one or more of quinoa, buckwheat, and amaranth; and the legumes include one or more of soybeans, mung beans, black beans, peas, kidney beans, and chickpeas.

3. The processing method of the low glycemic index plant-based food according to claim 1 or 2, characterized in that, The starch in step (2) contains more than 30% amylose; the protein includes one or more of glutenin, alkali-soluble glutenin, legume protein isolate, and zein; the non-starch polysaccharides include one or more of pectin, β-glucan, arabinoxylan, cellulose, guar gum, psyllium husk, locust bean gum, konjac glucomannan, inulin, and chitosan; the functional lipids contain more than 50% polyunsaturated fatty acids, including one or more of linoleic acid, linolenic acid, oleic acid, arachidonic acid, phytosterols, tocopherols, and higher alkanols.

4. The processing method of the low glycemic index plant-based food according to claim 3, characterized in that, Step (2) also includes adding 0.5%-3% of a natural plant extract by weight of the total nutrient components, wherein the 3-deoxyanthocyanin content in the natural plant extract is greater than 3 mg / 100g; preferably, the natural plant extract is prepared by crushing one or more of the following plants: sorghum, sugarcane, corn, camellia, gesneriad, grape, quinoa, highland barley, moss, and fern flowers, leaves, and stems, adding acetic acid solution with a concentration of 1-5 wt% at a weight ratio of 1:3-1:10, and extracting in a water bath at 30-50℃ for 5-120 min, and then collecting the supernatant.

5. The processing method of the low glycemic index plant-based food according to any one of claims 4, characterized in that, The protein in step (2) is pre-treated by enzymatic hydrolysis and fermentation: Pea protein powder and white kidney bean extract are mixed and dispersed in water at a mass ratio of 5-10:3-5. First, a primary complex protease composed of alkaline protease and papain at a mass ratio of 5-7:2 is used for enzymatic hydrolysis at 45-55℃ for 2-4 hours. After enzyme inactivation, a secondary complex protease composed of neutral protease and animal protease at a mass ratio of 3-5:1 is used for enzymatic hydrolysis at 40-60℃ for 1-3 hours. After enzyme inactivation, the enzymatically hydrolyzed protein peptide product is obtained. The seed culture of Lactobacillus plantarum, Saccharomyces cerevisiae, and Lactobacillus bulgaricus is inoculated into the enzymatically hydrolyzed protein peptide product. The product is fermented and cultured at 36-39℃ for 48-72 hours under micro-hypoxic conditions. After freeze-drying, the enzymatically hydrolyzed fermented protein peptide powder is obtained.

6. The processing method of the low glycemic index plant-based food according to claim 5, characterized in that, The enzymatically hydrolyzed fermented protein peptide powder undergoes an encapsulation process: sodium carboxymethyl cellulose, sodium alginate, and water-soluble chitosan are dissolved in water at a mass ratio of 5-7:2-4:3-7. The enzymatically hydrolyzed fermented protein peptide powder, along with food-grade emulsifier and edible oil, are added. After rapid membrane emulsification, a 3-5 wt% calcium chloride solution is added dropwise and solidified at room temperature for 30-50 minutes. The mixture is then centrifuged, washed, and freeze-dried to obtain slow-release protein particles. Preferably, the mass ratio of sodium carboxymethyl cellulose, sodium alginate, water-soluble chitosan, enzymatically hydrolyzed fermented protein peptide powder, food-grade emulsifier, and edible oil is 5-7:2-4:3-7:10-12:1-2:30-50.

7. The processing method of the low glycemic index plant-based food according to any one of claims 6, characterized in that, The specific mechanical energy consumption of the twin-screw extruder in step (3) is 120-300 kJ / kg, and the screw length-to-diameter ratio is 20-100:1; preferably, after the extrusion and reorganization, it is also subjected to superheated steam treatment at a temperature of 260-320℃ for 2-4 minutes.

8. The processing method of the low glycemic index plant-based food according to any one of claims 7, characterized in that, Step (2) also includes adding a prebiotic sweetener, which is composed of xylitol and steviol glycosides in a mass ratio of 5-7:2-4.

9. The processing method of the low glycemic index plant-based food according to any one of claims 8, characterized in that, Step (2) also includes adding a sugarcane polyphenol plant source composition accounting for 1%-5% of the total mass of the nutritional components. The sugarcane polyphenol plant source composition is composed of sugarcane polyphenols, plant polypeptides, fruit and vegetable fiber powder, and soluble dietary fiber powder in a mass ratio of 0.05-0.2: 0.5-1: 3-5: 2-4.

10. A low-glycemic plant-based food product prepared by the processing method of claim 9, characterized in that, The relative density of the food is greater than 1.2 g / cm³. 3 The dietary fiber content is greater than 6%, and the glycemic index (GI) is less than 55; the food is in the form of rice grains, noodles, biscuits, or steamed buns.

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