A waxy corn starch-guar gum complex, and a method of making and using the same

Abstract

The present application belongs to the technical field of grain deep processing and functional carbohydrate material, and relates to a waxy corn starch-guar gum compound as well as a preparation method and application thereof. The present application adopts high-pressure homogenization assisted pullulanase debranching to prepare RS3, and then mixes and embeds the RS3 with guar gum in a dry state according to a dry basis mass ratio of 6% to 24% to construct a physical barrier, and finally performs autoclaving treatment on the RS3 to strengthen the structure under a water content of 20% to 40%, so as to obtain a waxy corn starch-guar gum compound with high resistance and heat resistance. The compound presents ABV type XRD characteristic peaks, the crystallinity is greater than or equal to 65%, the resistant starch (RS) content can reach more than 50%, and the gelatinization peak temperature is significantly improved, thereby solving the problem that the existing RS3 is prone to uncoiling and the anti-digestion performance is reduced during high-temperature processing, and expanding the application of waxy corn starch in healthy functional food.

Description

Technical Field

[0001] This invention belongs to the technical field of deep processing of grains and functional carbohydrate materials, specifically relating to a waxy corn starch-guar gum composite, its preparation method and application. Background Technology

[0002] Resistant starch (RS) is difficult to digest and absorb in the human small intestine, but it can be fermented by microorganisms in the colon to produce beneficial metabolites such as short-chain fatty acids. It plays an important role in regulating postprandial blood glucose response, improving gut microbiota, and preventing metabolic diseases such as obesity and type II diabetes, making it a current hot topic in functional starch research. Waxy corn starch, due to its high amylopectin content (>95%), possesses excellent processing characteristics such as low gelatinization temperature, high transparency, and good freeze-thaw stability, and is widely used in the food industry. However, in its natural state, its amylose content is extremely low, and the starch molecules are mainly composed of easily digestible branched structures, resulting in low resistant starch content and a high glycemic index, which severely limits its application in low-GI health foods. Resistant starch is classified into five categories based on its source and structure: physically encapsulated starch (RS1), resistant starch granules (RS2), retrograded starch (RS3), chemically modified starch (RS4), and starch-lipid complex starch (RS5). Physical methods (such as heat treatment, high-pressure homogenization, and radiation) affect the digestibility of starch by altering its granule structure or molecular arrangement. They have advantages such as being environmentally friendly and easy to operate, but also have limitations such as high equipment requirements, high energy consumption, and unstable results. Chemical methods (such as cross-linking and etherification) can process large volumes and thoroughly modify starch, but they involve chemical reagents and pose safety and environmental risks.

[0003] Enzymatically modified RS3 has attracted much attention in recent years due to its high efficiency, greenness, high specificity, and high safety. However, its crystal structure lacks thermal stability, making it prone to unwinding or destruction during subsequent high-temperature processing (such as baking and extrusion), leading to decreased digestibility and difficulty in meeting the industrial production requirements of resistant, low-GI staple foods. To simultaneously address the processing stability issue of RS3, existing research has explored strategies such as physical encapsulation, chemical cross-linking, or a combination of multiple technologies. Enzymatic modification combined with physical methods has become an important direction for developing high-performance RS, which can reduce the cost of enzyme use and is an important way to develop high-performance, multifunctional RS and promote its green industrialization. This patent aims to prepare a new type of starch material with low cost, high resistance, and high temperature resistance by using a high-pressure homogenization-assisted enzymatic debranching method to prepare RS3, guar gum physical encapsulation to construct RS1, and pressure heat treatment to strengthen the RS3+RS1 structure, thereby expanding the application of waxy corn starch in the field of health functional foods. Summary of the Invention

[0004] This invention aims to address the problem of insufficient heat resistance and resistance of RS3 obtained from waxy corn starch. It proposes a composite modification route involving high-pressure homogenization to assist debranching, guar gum encapsulation to construct a physical barrier, and pressurization to enhance the physical barrier. The goal is to create a starch with both high resistance and heat resistance for use in foods such as biscuits.

[0005] The first aspect of the present invention provides a waxy corn starch-guar gum complex, characterized in that the complex is composed of resistant starch RS3 obtained by high-pressure homogenization and pullulanase debranching of waxy corn starch and guar gum by hot pressing.

[0006] Furthermore, the amount of guar gum added is 6% to 24% of the dry weight of the waxy corn starch.

[0007] Furthermore, the amount of guar gum added is 12% to 24% of the dry weight of the waxy corn starch.

[0008] Furthermore, the pressure heat treatment conditions are: moisture content of 20% to 40% (based on dry basis of starch and colloids), treatment at 121°C for 0.5 to 1.5 hours.

[0009] Furthermore, the resistant starch (RS) content of the complex is not less than 50%.

[0010] Furthermore, the composite exhibits ABV-type XRD characteristic peaks and has a crystallinity of not less than 65%.

[0011] The second aspect of this invention provides a method for preparing the waxy corn starch-guar gum complex described in the first aspect, characterized by comprising the following steps: (1) Prepare a starch milk with a mass concentration of 5-30% by waxy corn starch, adjust the pH to 3-5 by using an acetate-sodium acetate buffer system, heat to 110-130℃ and stir for 20-40 min to obtain solution I; (2) After cooling solution I to room temperature, it is subjected to high-pressure homogenization at 4-6℃, with a pressure of 100-170 MPa and a homogenization number of 1-10 times to obtain solution II; (3) First, cool solution II to 40-60℃, then add pullulanase, and stir the reaction at 40-60℃ for 12-22h to obtain solution III; the amount of pullulanase added is 10-80 U / g starch; (4) Cool solution III to 20~30℃ and age for 12~28h. After centrifugation, take the precipitate, wash, dry, crush and sieve to obtain waxy corn starch RS3. (5) Waxy corn starch RS3 and guar gum are mixed at a dry basis mass ratio, wherein the amount of guar gum added is 6~24% of the dry basis mass of starch. The mixture is stirred at 40~50℃ for 5~6h, then dried, pulverized and sieved to obtain waxy corn starch-guar gum complex.

[0012] (6) Prepare a starch milk with a moisture content of 20-40% by preparing a waxy corn starch-guar gum complex, seal and hydrate for 8-16 hours, press-heat at 110-130℃ for 20-180 minutes, cool at room temperature for 1-3 hours, and then dry at 40-60℃.

[0013] Furthermore, after the reaction in step (3) is completed, the temperature is raised to 100-120℃ and maintained for 30 minutes to inactivate the enzyme.

[0014] Furthermore, in step (2), the high-pressure homogenization pressure is 170 MPa.

[0015] Furthermore, in step (3), the amount of pullulanase added is 10 U / g starch.

[0016] Furthermore, in step (5), the amount of guar gum added is 12% of the dry weight of starch.

[0017] Further, the hot pressing treatment in step (6) involves hydrating the sample at room temperature for 12 hours, and then placing the hydrated sample in a high-pressure autoclave at 121°C for 1 hour.

[0018] A third aspect of the present invention provides the application of the waxy corn starch-guar gum complex described in the first aspect in the preparation of baked goods, characterized in that the complex accounts for 10% to 30% of the dry weight of flour in the baked goods.

[0019] Furthermore, the baked product is a biscuit.

[0020] A fourth aspect of the present invention provides a method for preparing the baked product described in the third aspect, preferably a biscuit, characterized by comprising the following steps: (1) Mix the oil, egg liquid, salt, sweetener and leavening agent evenly in proportion to make a premix; (2) The heat-treated waxy corn starch-guar gum complex obtained in the second aspect is mixed with flour in proportion, and water and the premix obtained in step (1) are added to form dough, which is then fermented. (3) Roll the fermented dough into shape and bake it to obtain the finished product.

[0021] Further, the premixed mixture in step (1) consists of the following components in parts by weight: 10-15 parts vegetable oil, 15-25 parts egg liquid, 0.5-1.5 parts salt, 0.01-0.03 parts sucralose, 0.5-1.5 parts yeast, and 0.5-1.5 parts baking soda.

[0022] Further, in step (2), the complex is mixed with flour at a ratio of 10% to 30% (dry basis), and premixed with an appropriate amount of water is added to form a dough.

[0023] Furthermore, the fermentation conditions in (2) are: static fermentation for 20-40 min in a constant temperature and humidity environment with a temperature of 35-38℃ and a relative humidity of 75-85%.

[0024] Further, in step (3), the dough is rolled to a thickness of 1-3 mm and shaped using a mold.

[0025] Furthermore, the baking conditions are: baking at 150-160℃ for 15-25 minutes.

[0026] The beneficial effects of this invention include: High-pressure homogenization was used as a pretreatment method to effectively improve the debranching efficiency of pullulanase.

[0027] By encapsulating guar gum and using heat treatment to strengthen the physical barrier, the thermal stability of resistant starch is enhanced, expanding its application potential in high-temperature processed foods. Attached Figure Description

[0028] Figure 1 XRD patterns of samples from Examples 1-3

[0029] Figure 2 XRD patterns of samples from Examples 4-6; Figure 3 XRD patterns of samples from Examples 7-9; Figure 4 DSC chromatograms of samples from Examples 3-9. Detailed Implementation

[0030] The following detailed embodiments further illustrate the concept and technical effects of the present invention to fully understand its purpose, features, and effects. Unless otherwise specified, all methods described are conventional methods. Unless otherwise specified, all materials are available from publicly available commercial sources. The illustrative embodiments and descriptions of the present invention are used to explain the invention and do not constitute an undue limitation thereof. It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0031] Example 1

[0032] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0033] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 100 MPa to obtain homogenized solution II.

[0034] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0035] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0036] The RS value of the original waxy corn starch was determined to be 6.23±3.77 (as shown in Table 1), while the RS value of the gelatinized control was 7.34±2.95 (as shown in Table 1), exhibiting a type A characteristic peak (as shown in Table 1). Figure 1 As shown), the crystallinity is 58.5%, and it has obvious gelatinization characteristic peaks (such as...). Figure 4 The peak temperature was 78.7℃ (as shown in Table 2). The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 1 was 13.92±1.18, exhibiting an ABV-type characteristic peak (as shown in Table 2). Figure 1 As shown in the figure, the crystallinity is 65.7%.

[0037] Example 2

[0038] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0039] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 150 MPa to obtain homogenized solution II.

[0040] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0041] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0042] The RS value of the waxy corn starch prepared under high pressure homogenization in Example 2 was determined to be 13.84 ± 2.71 (as shown in Table 1), exhibiting ABV-type characteristic peaks (as shown in Table 1). Figure 1 As shown in the figure, the crystallinity is 67.8%.

[0043] Example 3

[0044] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0045] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0046] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0047] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0048] The RS value of the waxy corn starch prepared under high pressure homogenization in Example 3 was determined to be 16.75 ± 0.82 (as shown in Table 1), exhibiting ABV-type characteristic peaks (as shown in Table 1). Figure 1 As shown), the crystallinity is 66.7%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 93.8℃.

[0049] Example 4

[0050] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0051] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0052] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0053] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0054] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 6% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0055] The RS value of the waxy corn starch prepared under high pressure homogenization in Example 4 was determined to be 17.08 ± 1.02 (as shown in Table 1), exhibiting ABV-type characteristic peaks (as shown in Table 1). Figure 2 As shown), the crystallinity is 68.9%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 91.3℃.

[0056] Example 5

[0057] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0058] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0059] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0060] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0061] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0062] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 5 was determined to be 23.21 ± 1.97 (as shown in Table 1), exhibiting an ABV-type characteristic peak (as shown in Table 1). Figure 2 As shown), the crystallinity is 69.8%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 83.9℃.

[0063] Example 6

[0064] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0065] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0066] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0067] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0068] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 24% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0069] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 6 was determined to be 24.24 ± 2.20 (as shown in Table 1), exhibiting ABV-type characteristic peaks (as shown in Table 1). Figure 2 As shown), the crystallinity is 62.2%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 90.9℃.

[0070] Example 7

[0071] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0072] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0073] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0074] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0075] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0076] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 20% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0077] The RS value of the waxy corn starch prepared under high pressure homogenization in Example 7 was determined to be 57.52 ± 1.27 (as shown in Table 1), exhibiting an ABV-type characteristic peak (as shown in Table 1). Figure 3 As shown), the crystallinity is 74.5%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4As shown in Table 2), the peak temperature was 113.4℃.

[0078] Example 8

[0079] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0080] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0081] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0082] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0083] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0084] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 30% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0085] The RS value of the waxy corn starch prepared under high pressure homogenization in Example 8 was determined to be 58.75 ± 2.46 (as shown in Table 1), exhibiting an ABV-type characteristic peak (as shown in Table 1). Figure 3 As shown), the crystallinity is 73.6%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 112.3℃.

[0086] Example 9

[0087] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0088] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0089] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0090] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0091] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0092] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 40% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0093] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 9 was determined to be 51.85 ± 1.67 (as shown in Table 1), exhibiting an ABV-type characteristic peak (as shown in Table 1). Figure 3 As shown), the crystallinity is 73.8%. It exhibits distinct gelatinization characteristic peaks (such as...). Figure 4 As shown in Table 2), the peak temperature was 117.7℃.

[0094] Example 10

[0095] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0096] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0097] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0098] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0099] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0100] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 40% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0101] Step 7. Accurately weigh 12 g of vegetable oil, 20 g of whole egg liquid, 1 g of salt, 0.02 g of sucralose, 1 g of yeast and 1 g of baking soda, place them in a container, and stir thoroughly until well mixed to obtain a premix for later use.

[0102] Step 8. Weigh 10 g of RS and mix with 90 g of flour (dry basis). Add the premix prepared in Step 7 and an appropriate amount of water, and knead into a smooth dough. Place the dough in a fermentation box at a temperature of 35-38℃ and a relative humidity of 75-85%, and let it ferment for 30 minutes.

[0103] Step 9. Roll out the fermented dough to a thickness of about 2 mm, then cut it into shapes using a 5 cm diameter round mold. Place the shaped dough pieces in a preheated oven and bake at 150°C (300°F) for 15-20 minutes, or until golden brown.

[0104] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 10 was determined to be 50.93 ± 1.78 (as shown in Table 1).

[0105] Example 11

[0106] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0107] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0108] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0109] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0110] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0111] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 40% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0112] Step 7. Accurately weigh 12 g of vegetable oil, 20 g of whole egg liquid, 1 g of salt, 0.02 g of sucralose, 1 g of yeast and 1 g of baking soda, place them in a container, and stir thoroughly until well mixed to obtain a premix for later use.

[0113] Step 8. Weigh 20 g of RS and mix with 80 g of flour (dry basis). Add the premix prepared in Step 7 and an appropriate amount of water, and knead into a smooth dough. Place the dough in a fermentation box at a temperature of 35-38℃ and a relative humidity of 75-85%, and let it ferment for 30 minutes.

[0114] Step 9. Roll out the fermented dough to a thickness of about 2 mm, then cut it into shapes using a 5 cm diameter round mold. Place the shaped dough pieces in a preheated oven and bake at 150°C (300°F) for 15-20 minutes, or until golden brown.

[0115] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 11 was measured to be 52.04 ± 3.35 (as shown in Table 1).

[0116] Example 12

[0117] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0118] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0119] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0120] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0121] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis weight) obtained in Step 4, and weigh guar gum at a ratio of 12% of the starch dry basis weight. After initially mixing the two in a dry state, place them in a 50°C environment and continuously stir and mix for 6 hours to ensure uniform mixing. Then dry, pulverize and sieve the mixture to obtain the waxy corn starch-guar gum complex.

[0122] Step 6. Accurately weigh a certain amount of the waxy corn starch-guar gum complex obtained in Step 5, add an appropriate amount of water, and prepare a starch slurry with a moisture content of 40% (starch and colloids on a dry basis). Seal the starch slurry and hydrate it at room temperature for 12 hours. Then, place the hydrated sample in an autoclave at 121℃ for pressure heat treatment for 1 hour. After pressure heat treatment, cool the sample at room temperature for 2 hours, and then transfer it to a 45℃ oven for overnight drying to finally obtain the high-resistance, heat-resistant waxy corn starch-guar gum resistant starch complex after pressure heat treatment.

[0123] Step 7. Accurately weigh 12 g of vegetable oil, 20 g of whole egg liquid, 1 g of salt, 0.02 g of sucralose, 1 g of yeast and 1 g of baking soda, place them in a container, and stir thoroughly until well mixed to obtain a premix for later use.

[0124] Step 8. Weigh 30 g of RS and mix with 70 g of flour (dry basis). Add the premix prepared in Step 7 and an appropriate amount of water, and knead into a smooth dough. Place the dough in a fermentation box at a temperature of 35-38℃ and a relative humidity of 75-85%, and let it ferment for 30 minutes.

[0125] Step 9. Roll out the fermented dough to a thickness of about 2 mm, then cut it into shapes using a 5 cm diameter round mold. Place the shaped dough pieces in a preheated oven and bake at 150°C (300°F) for 15-20 minutes, or until golden brown.

[0126] The RS value of the waxy corn starch prepared by high-pressure homogenization in Example 12 was determined to be 43.62 ± 0.26 (as shown in Table 1).

[0127] Table 1. In vitro digestibility of modified starch and its resistant biscuits

[0128] Table 2. Summary Table of DSC Data .

[0129] Example 13

[0130] As shown in Table 3, the substrate was fully hydrolyzed at a pullulanase dosage of 80 U / g. Subsequent high-pressure homogenization at 170 MPa did not significantly change the resistant starch content, indicating that under fully hydrolyzed conditions, high-pressure homogenization has limited effect in generating shorter linear chains. Furthermore, the resistant starch content decreased as the enzyme dosage decreased from 80 U / g to 10 U / g. Notably, using only 10 U / g of enzyme resulted in no significant difference in resistant starch content compared to the 80 U / g dosage, reaching the same level.

[0131] Table 3. Digestibility of modified starch .

[0132] Example 14

[0133] Step 1. Accurately weigh a certain amount of waxy corn starch (on a dry basis). Prepare a buffer solution using 33.6 mg of sodium acetate trihydrate and 98.7 μL of acetic acid (analytical grade). Disperse the starch in this buffer solution, adjust the pH of the system to 4.0, and prepare a starch slurry with a mass concentration of 6%. Then, place the starch slurry in a high-temperature reactor, heat it to 120°C, and stir vigorously at this temperature for 30 minutes to complete gelatinization, obtaining solution I.

[0134] Step 2. Cool solution I to room temperature, then place it in an environment of 4°C and homogenize it twice using a high-pressure homogenizer at a pressure of 170 MPa to obtain homogenized solution II.

[0135] Step 3. Cool solution II and maintain it at 50°C, then add pullulanase at a concentration of 10 U / g (based on dry starch). Stir and react at 50°C for 12 hours to debranch the enzyme. After the reaction is complete, raise the temperature to 121°C and maintain it for 30 minutes to inactivate the enzyme, yielding solution III.

[0136] Step 4. Cool Solution III to 25°C and allow it to age at this temperature for 24 hours. After aging, centrifuge and collect the lower precipitate. Wash the precipitate several times with deionized water, and finally dry it in a 45°C oven to constant weight. Crush the dried sample and sieve it through a 100-mesh sieve to obtain waxy corn starch RS3.

[0137] Step 5. Accurately weigh the waxy corn starch RS3 (dry basis mass) obtained in Step 4, and weigh chitosan at a ratio of 12% of the starch dry basis mass. After initial mixing of the two in a dry state, place them in a 50℃ environment and continuously stir for 6 hours to ensure uniform mixing. Then, dry, pulverize, and sieve the mixture to obtain the waxy corn starch-guar gum composite. The results are shown in the table. At the same concentration, replacing the colloid with chitosan shows that its resistance is lower than that of guar gum.

[0138] As can be seen from the data in Table 4, the effect of first performing wet heat treatment followed by guar gum compounding is lower in RS content than that of first compounding with guar gum followed by wet heat treatment.

[0139] Table 4. Digestibility of Modified Starch .

Claims

1. A waxy corn starch-guar gum complex, characterized in that, The complex is composed of resistant starch RS3, obtained by high-pressure homogenization and pullulanase-assisted debranching of waxy corn starch, and guar gum, which are then compounded by hot pressing.

2. The complex according to claim 1, characterized in that, The amount of guar gum added is 6% to 24% of the dry weight of the waxy corn starch. The complex exhibits ABV-type XRD characteristic peaks and has a crystallinity of not less than 65%.

3. The method for preparing the waxy corn starch-guar gum complex according to claim 1 or 2, characterized in that, Includes the following steps: (1) Prepare a starch milk with a mass concentration of 5-30% by waxy corn starch, adjust the pH to 3-5 by using an acetate-sodium acetate buffer system, heat to 110-130℃ and stir for 20-40 min to obtain solution I; (2) After cooling solution I to room temperature, it is subjected to high-pressure homogenization at 4-6℃, with a pressure of 100-170 MPa and a homogenization number of 1-10 times to obtain solution II; (3) First, cool solution II to 40-60℃, then add pullulanase, and stir the reaction at 40-60℃ for 12-22h to obtain solution III; the amount of pullulanase added is 10-80 U / g starch; (4) Cool solution III to 20~30℃ and age for 12~28h. After centrifugation, take the precipitate, wash, dry, crush and sieve to obtain waxy corn starch RS3. (5) Waxy corn starch RS3 and guar gum are mixed at a dry basis mass ratio, wherein the amount of guar gum added is 6~24% of the dry basis mass of starch. The mixture is stirred at 40~50℃ for 5~6h, then dried, pulverized and sieved to obtain waxy corn starch-guar gum complex. (6) Prepare a starch milk with a moisture content of 20-40% by preparing a waxy corn starch-guar gum complex, seal and hydrate for 8-16 hours, press-heat at 110-130℃ for 20-180 minutes, cool at room temperature for 1-3 hours, and then dry at 40-60℃.

4. The method according to claim 3, characterized in that, After the reaction in step (3) is completed, the temperature is raised to 100-120℃ and maintained for 30 minutes to inactivate the enzyme.

5. The method according to claim 3, characterized in that, In step (2), the high-pressure homogenization pressure is 170 MPa; in step (3), the amount of pullulanase added is 10 U / g starch; and in step (5), the amount of guar gum added is 12% of the dry weight of starch.

6. The method according to claim 3, characterized in that, The hot pressing treatment in step (6) involves hydrating the sample at room temperature for 12 hours, then placing the hydrated sample in a high-pressure sterilizer at 121°C for 1 hour.

7. The application of the waxy corn starch-guar gum complex according to claim 1 or 2, or the preparation method according to any one of claims 3 to 6, in the preparation of baked goods, characterized in that, The complex in the baked product accounts for 10% to 30% of the dry weight of the flour.

8. The application according to claim 7, characterized in that, The baked product is a biscuit, and the method for preparing the biscuit includes: (1) Mix the oil, egg liquid, salt, sweetener and leavening agent evenly in proportion to make a premix; (2) The heat-treated waxy corn starch-guar gum complex obtained in the second aspect is mixed with flour in proportion, and water and the premix obtained in step (1) are added to form dough, which is then fermented. (3) Roll the fermented dough into shape and bake it to obtain the finished product.

9. The application according to claim 8, characterized in that, The premix described in step (1) consists of the following components in parts by weight: 10-15 parts vegetable oil, 15-25 parts egg liquid, 0.5-1.5 parts salt, 0.01-0.03 parts sucralose, 0.5-1.5 parts yeast, and 0.5-1.5 parts baking soda.

10. The application according to claim 9, characterized in that, In step (2), the complex is mixed with flour at a ratio of 10% to 30% (dry basis), and premixed with an appropriate amount of water is added to form a dough. The fermentation conditions in step (2) are: in a constant temperature and humidity environment of 35-38℃ and 75-85% for 20-40 min of static fermentation.

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