Preparation method of starch compound with low glycemic index and application of starch compound in improving intestinal probiotics

Abstract

The invention relates to a preparation method of a low glycemic index starch compound and application of the low glycemic index starch compound in improving intestinal probiotics. The invention discloses a method for reducing the glycemic index of liquid starch and application of the method in improving intestinal probiotics. The preparation method comprises the following steps: preparing starch milk or whole powder milk with a certain mass fraction, adding marine-derived non-starch polysaccharide with a certain mass fraction, and uniformly mixing and stirring to obtain compound milk; adjusting the pH value of the compound milk to be within a certain range, performing pre-gelatinization, performing cold-temperature treatment, directly performing microwave treatment, drying, crushing and sieving to obtain the starch-non-starch polysaccharide compound with a relatively low glycemic index value. Compared with a starch-polysaccharide compound prepared only through gelatinization and direct microwave treatment, the starch-polysaccharide compound prepared through gelatinization, cooling and microwave treatment has the advantages that interaction of starch and polysaccharide can be remarkably promoted by matching gelatinization, cooling and microwave treatment and adjusting pH, the content of anti-digestion starch of the starch-polysaccharide compound is remarkably increased, and meanwhile, the GI value is reduced. Meanwhile, the prepared compound remarkably improves the F / B value of flora, the abundance of lactobacillus and the abundance of bifidobacteria in the intestinal fermentation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of food, and relates to a preparation method of a low glycemic index starch complex and its application in improving intestinal probiotics. In particular, it relates to a method for synergistically reducing the digestive performance of liquid starch by using marine-derived non-starch polysaccharides and microwaves, and the application of this method in improving intestinal probiotics. Background Art

[0002] Starch is an important nutrient component in the human diet. When it is digested and decomposed in the human body, it releases glucose, which serves as one of the main energy sources for the human body. According to the digestion rate of starch, it can be divided into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS). Among them, RDS refers to the starch that can be digested within 20 minutes and can quickly cause a blood glucose response in the human body. However, long-term consumption of high-RDS foods will induce disorders in the human metabolic system, leading to the occurrence of metabolic diseases such as diabetes, and at the same time increasing the probability of chronic diseases such as cardiovascular diseases; SDS can act as partially hydrolyzed starch and stay in the small intestine for a longer time, enabling continuous release of glucose while reducing the glucose peak; RS refers to a type of starch that cannot be absorbed by the small intestine and directly enters the large intestine for fermentation. Its physiological function is similar to that of dietary fiber, which can effectively prevent intestinal diseases such as colon cancer. At the same time, RS can interact with the microbiota, and the metabolites produced, such as short-chain fatty acids like butyric acid and acetic acid, can not only improve the intestinal environment, inhibit the growth of harmful bacteria, and promote the proliferation of beneficial bacteria, but also participate in human blood circulation and play probiotic effects such as regulating lipid metabolism (Qadir N, Wani I A. In-vitro digestibility of rice starch and factors regulating its digestion process: A review[J]. Carbohydrate polymers, 2022, 291: 119600). Therefore, how to effectively reduce the digestion rate of starch, reduce its blood glucose response, and endow it with intestinal probiotic effects has become an important topic in the research and development of healthy foods.

[0003] Starch mostly exists in a gelatinized state in processed foods, such as baked foods, meal replacement powders, cereals, etc. In addition, some yogurts and sauce foods also use gelatinized starch as a thickener. Because the granules of gelatinized starch are disintegrated and most starch molecules leak out of the granules, increasing the contact area with digestive enzymes, its RDS content is very high, up to 80-90%. Therefore, it is very necessary to control the digestibility of gelatinized starch in processed foods (Lal M K, Singh B, Sharma S, et al. Glycemic index of starchy crops and factors affecting its digestibility: A review[J]. Trends in Food Science & Technology, 2021, 111: 741-755). At present, the regulation of the digestibility of gelatinized starch mainly involves adding ligand substances such as fatty acids and polyphenols to bind to starch, or using physical methods such as high-pressure homogenization and hydrothermal treatment to promote the ordered arrangement and aggregation of molecular chains (Zhang Z, Kumar Sharma A, Chen L, et al. Enhancing optimal molecular interactions during food processing to design starch key structures for regulating quality and nutrition of starch-based foods: an overview from a synergistic regulatory perspective[J]. Critical Reviews in Food Science and Nutrition, 2024: 1-17). However, due to the high degree of freedom of the gelatinized starch chains, the physical methods have limited effects and there is also a possibility of promoting the breakage of starch molecular chains, thus improving the starch digestibility. In addition, although adding ligand substances such as fatty acids and polyphenols can complex with starch and reduce its digestibility, the food system is relatively complex, the processing steps are cumbersome, and changes in temperature and pH will affect the activity of these ligand substances, thereby affecting the digestibility of starch.

[0004] As a natural functional ingredient, marine-derived non-starch polysaccharides contain groups such as sulfated and phosphorylated groups, and have better thickening and gelation properties than polysaccharides from other sources. They can also bind to starch molecules and slow down the hydrolysis of amylase. In recent years, microwave technology has been increasingly used in food processing due to its high energy efficiency and uniform heating. By rapidly oscillating the electromagnetic field to heat substances, it can cause rapid polar movement inside molecules (Y1lmaz A, Tugrul N. Effect of ultrasound-microwave and microwave-ultrasound treatment on physicochemical properties of corn starch[J]. Ultrasonics Sonochemistry, 2023, 98:106516). For example, Jung et al. prepared mixtures of gelatinized starch and non-starch polysaccharides of different types and concentrations and measured their digestibility. The results showed that the addition of non-starch polysaccharides could increase the content of resistant starch by up to 10% (Jung, D.S., Bae, I.Y., Oh, I.K., Han, S.-I., Lee, S.-J., & Lee, H.G. Classification of hydrocolloids based on in vitro starch digestibility and rheological properties of Segoamigel[J]. International Journal of Biological Macromolecules, 2017, 104:442-448. doi:10.1016 / j.ijbiomac.2017.06.063). At the same time, microwave technology is widely used in food systems, such as the meal replacement powder and yogurt systems mentioned above. However, there is no report on using marine-derived non-starch polysaccharides in combination with microwave technology to reduce the digestibility of liquid starch. Summary of the Invention

[0005] In order to overcome the steps of the prior art, the present invention provides a method for preparing a low glycemic index starch complex and its application in enhancing intestinal probiotics. By combining marine-derived non-starch polysaccharides with microwave technology, the present invention can effectively improve the functionality of the polysaccharides, enhance the hydration of the polysaccharides, and at the same time break the hydrogen bonds or other weak interactions in the polysaccharides and starch, resulting in a certain degree of change in their three-dimensional spatial structure and enhanced non-covalent interactions, forming a shielding effect, which can reduce the digestibility of liquid starch, lower the glycemic index, and at the same time the formed starch-polysaccharide complex can enter the intestine synergistically to play a probiotic role.

[0006] The object of the present invention is achieved by the following technical solutions. A preparation method of a low glycemic index starch complex includes the following steps:

[0007] (1) Prepare a starch milk or whole powder milk with a concentration of 5-20 wt%, and add 2-20% of marine-derived non-starch polysaccharides based on the dry weight of the starch or whole powder. Mix evenly to form a compound milk.

[0008] (2) Adjust the pH of the compound milk to 4-8, then conduct a pre-gelatinization treatment at 50-80 °C, and then keep it in a water bath at 4-20 °C for heat preservation. Subsequently, perform microwave treatment. The microwave treatment power is set within the range of 200-800 W, and the microwave treatment time is controlled between 0.5-5 min. Dry, pulverize, and sieve the obtained product to obtain a low glycemic index starch complex.

[0009] The starch described in step (1) is commercially available starch, such as rice starch, waxy corn starch, wheat starch, etc., or cereal or bean whole powder, such as rice whole powder, corn whole powder, wheat whole powder, etc.

[0010] The mass fraction of the starch milk or whole powder milk described in step (1) is 5-20 wt%.

[0011] The marine-derived non-starch polysaccharides described in step (1) mainly refer to commercially available alginates, carrageenans, porphyra polysaccharides, etc. The addition method of the marine-derived non-starch polysaccharides can be direct addition or dissolution in a solution and then addition to the starch milk or whole powder milk.

[0012] The dry basis usage amount of the marine-derived non-starch polysaccharides described in step (1) is 2-20 wt% of the starch dry basis.

[0013] The pH of the compound milk described in step (2) is adjusted using acetic acid and sodium bicarbonate.

[0014] Preferably, the pre-gelatinization temperature of the compound milk described in step (2) is controlled at 65-70 °C, and the time is controlled at 30-60 min, preferably controlled at 45-50 min.

[0015] Preferably, the preservation temperature of the cold and warm water bath described in step (2) is 4-10 °C, and the heat preservation time is 5-10 min, more preferably 5-7 min.

[0016] Preferably, the microwave power described in step (2) is set within the range of 400 W to 700 W. Preferably, the microwave treatment time described in step (2) is controlled between 3-4 min.

[0017] Preferably, the drying temperature described in step (2) is 30-60 °C, and the drying time is 8-24 h. Preferably, the drying temperature and time are 45 °C and 20 h respectively. The mesh number of sieving is 120-150 meshes.

[0018] The present invention also provides a low glycemic index starch complex prepared by the aforementioned method. No toxic or harmful substances are added or generated during the preparation of this starch complex, and it has a high content of resistant starch, which can significantly reduce the glycemic index (GI) value.

[0019] The present invention further provides the application of the low glycemic index starch complex in the preparation of foods or drugs for enhancing intestinal probiotics.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] (1) The method of the present invention is easy to implement, with simple equipment, low cost, capable of large-scale production, high production efficiency, and no high-energy-consuming treatment process. The method used is green, environmentally friendly, mild, and no toxic or harmful substances are generated during the process. At the same time, it overcomes the limitations of single technologies, and can increase the RS content of starch or whole powder from 11.5% to 71.5%, and reduce the PGI (Predicted Glycemic Index) from 85.56 to 48.8.

[0022] (2) Compared with polysaccharides from common sources, the addition of marine-derived non-starch polysaccharides can i) increase the dietary fiber content of the system, and ii) due to the presence of groups such as sulfated and phosphorylated groups, have more excellent thickening and gelation properties. Under the action of microwaves, the chain segments are more fully extended, and they are complexed with starch through non-covalent bonds, which can reduce the contact sites between starch and digestive enzymes and significantly reduce the glycemic index of starch.

[0023] (3) Marine polysaccharides have pH-dependent solubility. By controlling the pH of the system, the gel state, solubility of marine polysaccharides can be freely switched, and the promotion of the extension of starch chains can promote the non-covalent interaction and re-aggregation behavior between polysaccharides and starch during pre-gelatinization, cold and microwave processes, further regulating the digestive properties of starch. Detailed implementation manners

[0024] The following non-limiting examples can enable those of ordinary skill in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.

[0025] In the following examples, unless otherwise specified, the test methods are all conventional methods; unless otherwise specified, the materials can all be obtained commercially. The mesh numbers of sieving in the examples and comparative examples of this application are all 120 meshes; the RDS, SDS, RS, and PGI are rapidly digestible starch, slowly digestible starch, resistant starch, and predicted glycemic index respectively; the Hz, Jc, and Zc are alginate, carrageenan, and porphyra polysaccharide respectively, and Gj and Gd are pectin and guar gum; the parts are all by mass; unless otherwise specified, the emulsion and solution are both aqueous solutions, and the percentage concentrations in the emulsion and solution both refer to mass percentage concentrations, and the pH is adjusted with acetic acid or sodium bicarbonate.

[0026] Digestibility test method:

[0027] Add 6.0 g of porcine pancreatic enzyme to 80 mL of deionized water, stir magnetically for 20 min, then centrifuge at a speed of 4000 r / min for 20 min, and collect the supernatant. Add 3.15 mL of glucosidase to 3.6 mL of deionized water, mix well, take 6 mL and mix it with the supernatant of porcine pancreatic enzyme, and store the resulting mixed enzyme refrigerated. Take 5.75 mL of glacial acetic acid and mix it with an appropriate amount of deionized water, and make up the volume to 1000 mL. Weigh 13.61 g of sodium acetate trihydrate and dissolve it in deionized water, and make up the volume to 1000 mL. Mix the two solutions in a volume ratio of 1:4, and add 4 mL of calcium chloride solution (1 mol / L) to obtain a sodium acetate buffer solution (pH 5.2).

[0028] Accurately weigh 1 g (dry basis) of the sample into a 150 mL conical flask, place 7 glass beads in each flask and add 20 mL of sodium acetate buffer solution, and vortex to mix evenly. Add 5 mL of the mixed enzyme solution, hydrolyze by shaking at 37 °C and 160 rpm, take 1 mL of the supernatant into 20 mL of 70% ethanol solution at 20 min and 120 min respectively, centrifuge at 4000 r / min for 5 min, then take 0.1 mL of the supernatant into a centrifuge tube containing 3 mL of GOPOD solution, keep it in a water bath at 45 °C for 20 min, and then measure the absorbance value at 510 nm. Take 0.1 mL of 1 mg / mL glucose standard solution and repeat the above operation as a standard, and take 0.1 mL of deionized water and repeat the operation as a blank group.

[0029] The digestibility of starch is characterized by calculating the contents of RDS, SDS, and RS. The calculation formula is as follows: where At: the absorbance value of the test sample (AU);

[0030]

[0031] V: the total volume of the test sample (mL);

[0032] C: the concentration of the standard glucose solution (mg / mL);

[0033] As: Absorbance value (AU) of the standard glucose solution;

[0034] Wt: Sample mass (g);

[0035] D: Dilution factor

[0036] In vitro fermentation method:

[0037] Accurately weigh 1 g (dry basis) of the sample into a 150 mL conical flask, place 7 glass beads in each flask, add 20 mL of sodium acetate buffer solution, and vortex to mix evenly. Adjust the pH of the sample to 1.2 with 5% hydrochloric acid solution and record the amount of hydrochloric acid used. After adding 1 mL of 2% pepsin solution, incubate in a water bath shaker at 37 °C for 30 min, and at the same time, prepare a blank group. Then, adjust the pH of the sample to 5.2 with 1 M and 0.1 M sodium hydroxide solutions, add 5 mL of mixed enzymes, and hydrolyze at 37 °C and 160 rpm for 120 min, and inactivate the enzymes in a boiling water bath for 10 min. After the sample is cooled to room temperature, centrifuge at 6000 r / min for 15 min, add 20 mL of distilled water again and centrifuge under the same conditions. The precipitate is dried in a vacuum drying oven at 35 °C and crushed and sieved for standby.

[0038] Place the accurately weighed above-mentioned sample in a conical bottom centrifuge tube and sterilize it under an ultraviolet lamp for 30 min. Then, add 8 mL of culture medium and 1 mL of fecal bacteria solution to it, and carry out a fermentation experiment in an incubator under anaerobic conditions at 37 °C. Set five time points of 0, 6, 12, 24, and 48 h, and set 3 parallels for each time point. Take out the centrifuge tube at each time node, centrifuge at 10000 r / min and 4 °C for 10 min, and store the supernatant and precipitate in a -80 °C refrigerator.

[0039] Method for determining the abundance of bacteria:

[0040] Extract the total DNA of bacteria in the sample from the precipitate sample of the in vitro fermentation product frozen at -80 °C. Use the following primers to amplify the V3-V4 region of the bacterial 16S rRNA gene by polymerase chain reaction (PCR): 338F 5’-ACCTACGGGAGGCAGCA-3’ and 806R 5’-GACTACHVGGGTWTCT AAT-3’, and sequence it on the GENEDENOVA platform. The F / B value and the abundance of bacteria are obtained through data analysis.

[0041] Example 1

[0042] Weigh the rice starch and determine its moisture content, then add distilled water to prepare a solution with a mass fraction of 10%. Weigh 12% of the dry starch weight of alginate and add it to the starch milk, adjust the system pH to 4.5, stir at 65 °C for 45 minutes for standby. After that, quickly transfer it to a 4 °C water bath and place it for 5 min. Then carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 3.5 min. Dry the obtained product at 45 °C for 20 h, crush it, and pass through a 120-mesh sieve to obtain the starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0043] Example 2

[0044] Weigh the rice starch and determine its moisture content, then add distilled water to prepare a solution with a mass fraction of 8%. Weigh 20% of the dry starch weight of alginate and add it to the starch milk, adjust the system pH to 4.5, stir at 65 °C for 45 minutes for standby. After that, quickly transfer it to a 4 °C water bath and place it for 7 min. Then carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 3.5 min. Dry the obtained product at 45 °C for 20 h, crush it, and pass through a 120-mesh sieve to obtain the starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0045] Example 3

[0046] Weigh the rice starch and determine its moisture content, then add distilled water to prepare a solution with a mass fraction of 20%. Weigh 2% of the dry starch weight of alginate and add it to the starch milk, adjust the system pH to 4, stir at 65 °C for 60 minutes for standby. After that, quickly transfer it to a 10 °C water bath and place it for 5 min. Then carry out microwave treatment, where the microwave power is set within the range of 800 W and the treatment time is controlled at 5 min. Dry the obtained product at 45 °C for 20 h, crush it, and pass through a 120-mesh sieve to obtain the starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0047] Example 4

[0048] Weigh the waxy corn starch and determine its moisture content, then add distilled water to prepare a solution with a mass fraction of 10%. Weigh 10% of the dry starch weight of alginate and add it to the starch milk, adjust the system pH to 8, stir at 80 °C for 30 minutes for standby. After that, quickly transfer it to a 20 °C water bath and place it for 5 min. Then carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 5 min. Dry the obtained product at 45 °C for 20 h, crush it, and pass through a 120-mesh sieve to obtain the starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0049] Example 5

[0050] Weigh rice starch and measure its moisture content, add distilled water to make a solution with a mass fraction of 5%, weigh carrageenan accounting for 20% of the dry weight of the starch and incorporate it into the starch milk, adjust the pH of the system to 4, stir at 80 °C for 60 minutes for standby, and quickly transfer it to a 20 °C water bath and place it for 10 min after completion; then perform microwave treatment, where the microwave power is set within the range of 200 W and the treatment time is controlled within 5 min. Dry the obtained product at 45 °C for 20 h, pulverize it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0051] Example 6

[0052] Weigh rice starch and measure its moisture content, add distilled water to make a solution with a mass fraction of 8%, weigh alginate accounting for 20% of the dry weight of the starch and incorporate it into the starch milk, adjust the pH of the system to 4, stir at 50 °C for 30 minutes for standby, and quickly transfer it to a 4 °C water bath and place it for 10 min after completion; then perform microwave treatment, where the microwave power is set within the range of 800 W and the treatment time is controlled within 30 s. Dry the obtained product at 45 °C for 20 h, pulverize it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0053] Example 7

[0054] Weigh rice starch and measure its moisture content, add distilled water to make a solution with a mass fraction of 20%, weigh alginate accounting for 10% of the dry weight of the starch and incorporate it into the starch milk, adjust the pH of the system to 7, stir at 50 °C for 60 minutes for standby, and quickly transfer it to a 4 °C water bath and place it for 5 min after completion; then perform microwave treatment, where the microwave power is set within the range of 200 W and the treatment time is controlled within 5 min. Dry the obtained product at 45 °C for 20 h, pulverize it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0055] Example 8

[0056] Weigh wheat starch and measure its moisture content, add distilled water to make a solution with a mass fraction of 10%, weigh alginate accounting for 12% of the dry weight of the starch and incorporate it into the starch milk, adjust the pH of the system to 7, stir at 50 °C for 60 minutes for standby, and quickly transfer it to a 15 °C water bath and place it for 5 min after completion; then perform microwave treatment, where the microwave power is set within the range of 800 W and the treatment time is controlled within 3.5 min. Dry the obtained product at 45 °C for 20 h, pulverize it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. Measure its digestion performance and in vitro glycemic index. The experimental results are shown in Table 1.

[0057] Example 9

[0058] Weigh rice flour and measure its moisture content, then add distilled water to prepare a 5% (by mass) solution; weigh 20% (by dry weight of starch) of porphyra polysaccharide and add it to the starch milk, adjust the pH of the system to 4, stir at 65 °C for 45 minutes and set aside. After that, quickly transfer it to a 4 °C water bath and place it for 5 minutes; then carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 3.5 minutes. Dry the obtained product at 45 °C for 20 h, crush it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. Measure its digestibility and in vitro glycemic index. The experimental results are shown in Table 1.

[0059] Comparative Example 1

[0060] Weigh rice starch and measure its moisture content, add distilled water to prepare a 10% (by mass) solution, do not adjust the pH of the starch milk, continuously stir at 65 °C for 45 minutes, and then quickly transfer it to a 4 °C water bath and place it for 5 minutes; then carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 3.5 minutes. After freeze-drying, crush it and sieve it through a 120-mesh sieve, and measure the digestibility and in vitro glycemic index. The sample is denoted as Ap. The experimental results are shown in Table 1.

[0061] Comparative Example 2

[0062] Weigh rice starch and measure its moisture content, add distilled water to prepare a 10% (by mass) solution; weigh 12% (by dry weight of starch) of alginate and add it to the starch milk, adjust the pH of the system to 4.5, stir at 65 °C for 45 minutes, and then quickly transfer it to a 4 °C water bath and place it for 5 minutes. Dry the obtained product at 45 °C for 20 h, crush it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. The experimental results are shown in Table 1.

[0063] Comparative Example 3

[0064] Weigh rice starch and measure its moisture content, add distilled water to prepare a 10% (by mass) solution; weigh 12% (by dry weight of starch) of alginate and add it to the starch milk, adjust the pH of the system to 4.5. Carry out microwave treatment, where the microwave power is set within the range of 550 W and the treatment time is controlled at 3.5 minutes. Dry the obtained product at 45 °C for 20 h, crush it, and sieve it through a 120-mesh sieve to obtain a starch-non-starch polysaccharide complex. The experimental results are shown in Table 1.

[0065] Table 1 Effects of samples in examples and comparative examples on digestibility and F / B value, Bifidobacterium abundance, and Lactobacillus abundance during intestinal fermentation

[0066]

[0067]

[0068] Note: RDS represents rapidly digestible starch, SDS represents slowly digestible starch, RS represents resistant starch, and F / B represents the ratio of Bifidobacterium / Lactobacillus

[0069] The above results show that (by comparing the examples with the comparative examples), the combined action of marine - sourced non - starch polysaccharides and microwave treatment can significantly reduce the RDS content of starch or rice flour whole powder and increase the RS content, thus achieving a low - GI level. Among them, Example 1 shows the most significant change. The RS content of rice starch or whole powder has increased by 12 times respectively, and the GI value can reach as low as 45.8. At the same time, during the intestinal fermentation process of the obtained starch - polysaccharide complex, it shows that it can significantly increase the content of beneficial bacteria, such as the F / B value, the abundances of Bifidobacterium and Lactobacillus, which can be increased by up to 155%, 209% and 241% respectively compared with the starch - polysaccharide complexes obtained only by gelatinization or only by microwave treatment. This shows that the obtained complex with a lower GI value may have the potential nutritional function of improving the intestinal microenvironment and can endow the body with more nutritional effects. It can be seen that this effect is relatively significant and the operation is simple.

[0070] The above - described examples are the preferred implementation methods of the results of the present invention, but do not cover all the implementation methods of the present invention. Any changes, simplifications, combinations, substitutions, modifications, etc. made based on the principles of the present invention are within the protection scope of the present invention.

Claims

1. A preparation method of a low glycemic index starch complex, characterized in that, It includes the following steps: (1) Prepare a starch milk or whole powder milk with a concentration of 5 - 20 wt%, add 2 - 20% of marine - sourced non - starch polysaccharides based on the dry weight of the starch or whole powder, and mix evenly to form a compound milk; (2) Adjust the pH of the compound milk to 4 - 8, then conduct pre - gelatinization treatment at 50 - 80 °C, and then keep it warm in a water bath at 4 - 20 °C; subsequently, conduct microwave treatment, set the microwave treatment power within the range of 200 - 800 W, control the microwave treatment time between 0.5 - 5 min, dry, crush, and sieve the obtained product to obtain a starch complex with a low glycemic index.

2. The method according to claim 1, characterized in that: The starch is one or more of legume starch or pure legume starch; the whole powder is cereal whole powder; the marine - sourced non - starch polysaccharides used are one or more of alginate, carrageenan, or porphyra polysaccharide.

3. The method according to claim 1, characterized in that: In step (1), the concentration of the starch milk or whole powder milk is 8 - 12 wt%.

4. The method according to claim 1, characterized in that: In step (1), the addition amount of the marine - sourced non - starch polysaccharides is 10 - 14% of the dry weight of the starch or whole powder.

5. The preparation method according to claim 1, characterized in that, In step (2), the pre - gelatinization temperature range is 60 - 70 °C, and the pre - gelatinization time is 30 - 60 min.

6. The preparation method according to claim 1, wherein In step (2), the water - bath insulation temperature is within the range of 4 - 10 °C, and the treatment time is controlled between 5 - 10 min.

7. The preparation method according to claim 1, wherein In step (2), the microwave treatment power is set within the range of 400 - 700 W, and the microwave treatment time is controlled between 3 - 4 min.

8. The method according to claim 1, characterized in that, In step (2), the drying temperature is 30 - 60 °C, the drying time is 8 - 24 h, and the mesh number of sieving is 100 - 120 mesh.

9. A starch complex with a low glycemic index prepared by the preparation method according to any one of claims 1 - 8.

10. Use of the starch complex with a low glycemic index according to claim 9 in the preparation of foods or drugs for enhancing intestinal probiotics.

Images