Aflatoxin b1 high-efficiency degradation and bamboo source functional dietary fiber integrated preparation method

Abstract

The application discloses an aflatoxin B1 high-efficiency degradation and bamboo source functional dietary fiber integrated preparation method and belongs to the technical field of biomass resource development and utilization. The application takes the crushed and screened bamboo shoot shell powder as raw material, mixes the bamboo shoot shell powder with a chlorine dioxide solution, carries out ultrasonic treatment, adds an alkaline solution, and continues secondary ultrasonic reaction; the reaction liquid is filtered to obtain filter residue and filtrate, the filter residue is washed with water and dried to prepare bamboo source insoluble dietary fiber; the filtrate is mixed with an organic solvent to precipitate a precipitate, the precipitate is washed with the organic solvent and dried to prepare bamboo source soluble dietary fiber. The application controls the ultrasonic intensity of the bamboo shoot shell fiber and the chlorine dioxide concentration and the like parameters, the prepared dietary fiber has good stability, oil and water absorption and slow release; the dietary fiber has good dispersibility and good normal-temperature storage stability, can be added into fluid, semi-fluid and solid, and has a wide application range.

Description

Technical Field

[0001] This invention belongs to the field of biomass resource development and utilization technology, specifically relating to an integrated preparation method of aflatoxin B1 efficient degradation and bamboo-derived functional dietary fiber. Background Technology

[0002] Bamboo shoots, as a traditional non-timber forest product, have long been a popular food source. In recent years, the deep processing of bamboo shoots, as a sustainable and nutrient-rich food resource, has attracted great attention from the scientific and industrial communities. Bamboo shoots are a nutrient-dense food, rich in protein, dietary fiber, essential minerals (such as potassium and calcium), and vitamins (such as B vitamins and vitamin C), while being low in natural fat. Furthermore, bamboo shoots contain various active compounds (such as phenols and phytosterols) with significant health-promoting properties, including antioxidant, anti-inflammatory, and potential benefits in improving cardiovascular metabolism. Bamboo shoot shells are a major byproduct of the bamboo shoot processing industry. The large quantities of discarded bamboo shoot shells not only lead to serious resource waste but also cause severe environmental pollution. Most dietary fiber has a good adsorption capacity, including the adsorption of certain toxins such as aflatoxin B1. Aflatoxin B1 is a toxic substance produced by Aspergillus fungi and is commonly found in various foods and feeds. Due to its significant toxic effects on human and animal health, most countries have established maximum limits for aflatoxin B1 in common foods and feeds. Bamboo shoot husks are rich in dietary fiber. In the processing of bamboo shoot fiber into food and feed, the degradation technology of aflatoxin B1 is crucial, while ensuring its basic efficacy as much as possible. Scientists have explored various physical, chemical, and biological methods to remove aflatoxin B1. Some of these methods have shown promising degradation effects on aflatoxin B1, but also come with certain negative attributes. Currently, no single method meets the efficiency, safety, and regulatory standards required for aflatoxin removal in agriculture.

[0003] Chlorine dioxide (ClO2) is a highly efficient oxidizing disinfectant with broad-spectrum and stable bactericidal properties, widely used for disinfection of water, fruits, and vegetables. Compared to other common chlorine-based disinfectants, one of the core advantages of using chlorine dioxide is its ability to significantly reduce the formation of harmful trihalomethanes. Studies have shown that chlorine dioxide can effectively degrade aflatoxin B1 in corn and apricot kernels. After chlorine dioxide treatment, the carbon-8-carbon-9 double bond on the furan ring of aflatoxin B1 breaks, and the cyclopentanone and methoxy groups are modified, thus completely eliminating its biological activity at the structural level. However, current research shows that the degradation rate of aflatoxin B1 by chlorine dioxide is less than 90%, and complete safe purification is still difficult to achieve for materials with high aflatoxin content. Therefore, a synergistic pretreatment strategy is currently the most feasible solution for achieving efficient degradation and removal of aflatoxin B1. It is particularly important to fully consider the oxidative degradation of nutrients during the detoxification process. Single chemical treatment methods often need to be supplemented with physical treatments to optimize the detoxification effect. Among existing detoxification technologies, physical methods exhibit superior aflatoxin inactivation efficacy through rapid and irreversible structural modification of aflatoxin molecules. As an emerging sustainable technology, high-intensity ultrasound technology shows great potential in degrading aflatoxin in food matrices, offering significant advantages over traditional detoxification methods. The cavitation effect generated by ultrasound can break the covalent bonds of water molecules, generating reactive substances such as hydroxyl radicals (OH·), hydrogen radicals (H·), and hydrogen peroxide (H2O2). Furthermore, ultrasound can produce a synergistic effect, accelerating the generation of free radicals and enhancing sonochemical oxidation to achieve the degradation of aflatoxin B1. During the ultrasonic degradation of aflatoxin B1, hydroxyl radicals (OH·) likely play a dominant role, while hydrogen radicals (H·) also contribute to some auxiliary degradation. Research data shows that the application of ultrasound technology can significantly increase the degradation rate of aflatoxin B1 to 91.3%.

[0004] Therefore, existing technologies lack a complete set of green processes that can simultaneously complete the resource utilization of bamboo shoot shell waste, the efficient removal of aflatoxin, and the integrated extraction of functional soluble / insoluble dietary fiber. Using chlorine dioxide oxidation or ultrasonic treatment alone has drawbacks such as insufficient degradation efficiency, large loss of fiber function, cumbersome procedures, and difficulty in meeting domestic and international feed toxin limits for the product safety indicators. There is an urgent need to develop a new process for the integrated preparation of bamboo-derived functional dietary fiber by ultrasound and chlorine dioxide, and the simultaneous and efficient degradation of aflatoxin B1. Summary of the Invention

[0005] The technical problem solved by this invention is to provide an integrated preparation method for efficient degradation of aflatoxin B1 and bamboo-derived functional dietary fiber. The dietary fiber prepared by this method has good safety, adsorption and in vitro antioxidant and hypoglycemic activities, and the aflatoxin B1 meets the relevant toxin limit standards in my country.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for integrating the efficient degradation of aflatoxin B1 with the preparation of bamboo-derived functional dietary fiber involves using pulverized and sieved bamboo shoot shell powder as raw material. The bamboo shoot shell powder is mixed with chlorine dioxide solution and then subjected to ultrasonic treatment. An alkaline solution is then added for a second ultrasonic reaction. The reaction solution is filtered to obtain filter residue and filtrate. The filter residue is washed with water and dried to obtain bamboo-derived insoluble dietary fiber. The filtrate is mixed with an organic solvent to precipitate a precipitate. The precipitate is washed with an organic solvent and dried to obtain bamboo-derived soluble dietary fiber.

[0008] Furthermore, the preparation steps of the bamboo shoot shell powder are as follows: bamboo shoot shells with a moisture content of 5% to 15% are coarsely crushed, then finely crushed by ball milling, vibration milling or disc milling, and sieved to obtain bamboo shoot shell powder with a particle size of 0.1 to 100 μm.

[0009] Furthermore, the mass ratio of the bamboo shoot shell powder to the chlorine dioxide solution is 1:10~50.

[0010] Furthermore, the concentration of the chlorine dioxide solution is 50~250 μg / mL.

[0011] Furthermore, the chlorine dioxide solution is prepared by passing chlorine dioxide gas into a carbonate, bicarbonate, or percarbonate solution to dissolve it, thereby obtaining a chlorine dioxide stock solution; the carbonate, bicarbonate, and percarbonate are selected from one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium percarbonate, and sodium percarbonate.

[0012] Furthermore, the conditions for the two-stage ultrasonic treatment are: ultrasonic frequency 20~100kHz, power density 0.2~20W / cm². 2 The ultrasonic temperature is 30~60℃; the duration of the first ultrasonic segment is 15~75min, and the duration of the second ultrasonic segment is 15~60min after adding alkaline solution.

[0013] Furthermore, the duration of the first ultrasound segment is 60 minutes.

[0014] Furthermore, the alkaline solution is selected from any one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, and the mass fraction concentration of the alkaline solution is 0.1% to 2%.

[0015] Furthermore, the organic solvent is selected from one or a mixture of ethanol, isopropanol, and ethyl acetate, and the mass ratio of the filtrate to the organic solvent is 1:2 to 20.

[0016] Furthermore, bamboo-derived functional dietary fiber can be used alone or added as an additive to solid, semi-fluid, and liquid foods as well as livestock and poultry feed.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) This invention utilizes bamboo shoot shell fiber, which is abundant and inexpensive, as raw material. The production process is simple and easy to implement, which is conducive to the high-value utilization of agricultural and forestry biomass resources. The preparation method of this invention is simple and environmentally friendly, and the process has good stability. By controlling parameters such as the ultrasonic strength and chlorine dioxide concentration of bamboo shoot shell fiber, the prepared dietary fiber has good stability, oil and water absorption and slow release properties.

[0019] (2) The dietary fiber of the present invention has good dispersibility and good storage stability at room temperature. It can be added to fluids, semi-fluids and solids, and has a wide range of applications.

[0020] (3) The main raw materials used in this invention meet the requirements for food, feed raw materials and additives. This invention has good application prospects in the fields of agricultural and forestry biomass resource development and utilization, food and feed processing industry. Attached Figure Description

[0021] Figure 1 The graph shows the effect of ultrasound and ClO2 treatment on the degradation of aflatoxin B1 in bamboo shoot shell fiber. (A) ClO2 concentration; (B) treatment time; (C) initial concentration of aflatoxin B1 on the degradation performance of ultrasound-assisted ClO2 treatment. There are significant differences between the values ​​with different letters in the same graph (p < 0.05).

[0022] Figure 2 This diagram illustrates the synergistic effect of ultrasound-assisted ClO2 oxidation treatment in generating free radicals according to this application. (A) Degradation of aflatoxin B1 under different scavenging agents; (B) Generation of 7-hydroxycoumarin (coumarin-·OH adduct) under different treatment methods; (C) NBT (nitroblue tetrazolium)-mediated formation of formazan (NBT-O2·) under different treatment methods. - The generation of derivatives showed significant differences between values ​​with different letters in the same figure (p < 0.05). <0.05, <0.01;

[0023] Figure 3 The infrared spectrum of bamboo shoot shell fiber in this application is shown; wherein, (A) soluble dietary fiber (SDF); (B) insoluble dietary fiber (IDF); and (C) bamboo shoot shell powder (BSSP).

[0024] Figure 4The images shown are transmission electron micrographs of bamboo shoot shell fibers from this application; wherein, (A) bamboo shoot shell powder: 1000x; (B) untreated insoluble dietary fiber (IDF-N): 1000x; (C) ultrasonically assisted ClO2-treated insoluble dietary fiber (IDF-UO): 1000x; (D) ultrasonically assisted ClO2-treated soluble dietary fiber (SDF-UO): 1000x; (E) untreated soluble dietary fiber (SDF-N): 1000x; (F) ultrasonically assisted ClO2-treated soluble dietary fiber (SDF-UO): 10000x; (G) untreated soluble dietary fiber (SDF-N): 10000x.

[0025] Figure 5 The graphs show the water-holding capacity, water absorption and swelling capacity, and oil-holding capacity of bamboo shoot shell fiber under different treatment methods in this application; where (A) water-holding capacity (WHC); (B) water absorption and swelling capacity (WSC); and (C) oil-holding capacity (OHC), there are significant differences between the values ​​with different letters in the same graph (p < 0.05).

[0026] Figure 6 The graphs show the in vitro antioxidant capacity of bamboo-derived soluble dietary fiber under different processing methods in this application; (A) DPPH free radical scavenging experiment; (B) hydroxyl free radical scavenging experiment; (C) superoxide anion free radical scavenging experiment.

[0027] Figure 7 The graph shows the in vitro hypoglycemic capacity of bamboo-derived soluble dietary fiber under different treatment methods in this application; where (A) glucose adsorption capacity; (B) glucose diffusion capacity; (C) glucose dialysis delay index (GDRI); (D) α-amylase inhibition rate; (E) α-glucosidase inhibition rate. There are significant differences between the values ​​with different letters in the same graph (p < 0.05). Detailed Implementation

[0028] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0029] Example 1

[0030] 50g of bamboo shoot husks with a moisture content of 8% were crushed and sieved to obtain bamboo shoot husk powder with a particle size of 0.5~50μm. This powder was then thoroughly mixed with 500mL of a diluted chlorine dioxide solution with a concentration of 200μg / mL (approximately 0.1g of chlorine dioxide gas was passed through 50mL of 0.1% sodium percarbonate solution diluted 10 times with water). The mixture was then placed in an ultrasonic device for ultrasonic treatment for 60min at a sound frequency of 40kHz and a power density of 8W / cm³. 2The ultrasonic temperature was 40℃, and then 100mL of 1.5% sodium hydroxide solution was added and ultrasonic treatment was continued for 30min. After filtration, the filter residue was washed with water until the pH was 7, and dried at 60℃ for 12h to obtain 24.55g of bamboo-derived insoluble dietary fiber. The filtrate was thoroughly mixed with 8 times its mass of ethanol to produce a precipitate, which was then filtered. The filter residue was washed with 98% ethanol solvent until the pH was 7, and dried at 60℃ for 12h to obtain 5.45g of bamboo-derived soluble dietary fiber.

[0031] Example 2

[0032] 100g of bamboo shoot husks with a moisture content of 15% were crushed and sieved to obtain bamboo shoot husk powder with a particle size of 50-200μm. This powder was then thoroughly mixed with 5000mL of a diluted chlorine dioxide solution with a concentration of 50μg / mL (approximately 0.25g of chlorine dioxide gas was passed into 500mL of 0.2% sodium carbonate solution and diluted 10 times with water). The mixture was then placed in an ultrasonic device for ultrasonic treatment for 75 minutes at a sound frequency of 100kHz and a power density of 0.2W / cm³. 2 The ultrasonic temperature was 30℃, and then 200mL of 2% potassium hydroxide solution was added for further ultrasonic treatment for 60min. After filtration, the filter residue was washed with water until the pH was 7, and dried at 50℃ for 24h to obtain 47.7g of bamboo-derived insoluble dietary fiber. The filtrate was thoroughly mixed with 20 times its mass of ethanol to produce a precipitate, which was then filtered. The filter residue was washed with 100% isopropanol solvent until the pH was 7, and dried at 50℃ for 24h to obtain 11.8g of bamboo-derived soluble dietary fiber.

[0033] Example 3

[0034] 10g of bamboo shoot husks with a moisture content of 5% were crushed and sieved to obtain bamboo shoot husk powder with a particle size of 0.1~50μm. This powder was then thoroughly mixed with 200mL of a diluted chlorine dioxide solution with a concentration of 100μg / mL (approximately 0.02g of chlorine dioxide gas was passed into 50mL of 0.05% potassium percarbonate solution and diluted 4 times with water). The mixture was then placed in an ultrasonic device for ultrasonic treatment for 15min at a sound frequency of 20kHz and a power density of 10W / cm³. 2 The ultrasonic temperature was 40℃, followed by the addition of 20mL of 0.1% potassium carbonate solution and ultrasonic treatment for another 15min. After filtration, the filter residue was washed with water until the pH reached 7.5 and dried at 45℃ for 24h to obtain 5.15g of bamboo-derived insoluble dietary fiber. The filtrate was thoroughly mixed with 2 times its mass of isopropanol to produce a precipitate. After filtration, the filter residue was washed with 90% isopropanol solvent until the pH reached 7.5 and dried at 45℃ for 24h to obtain 0.98g of bamboo-derived soluble dietary fiber.

[0035] Example 4

[0036] 1000g of bamboo shoot husks with a moisture content of 10% were crushed and sieved to obtain bamboo shoot husk powder with a particle size of 1~100μm. This powder was then thoroughly mixed with 40000mL of a diluted chlorine dioxide solution with a concentration of 150μg / mL (approximately 6g of chlorine dioxide gas was passed into 2000mL of 0.5% potassium bicarbonate solution diluted 20 times with water). Simultaneously, the mixture was placed in an ultrasonic device for ultrasonic treatment for 30min at a sound frequency of 50kHz and a power density of 5W / cm³. 2 The ultrasonic temperature was 50℃, and then 2000 mL of 1% potassium carbonate solution was added for further ultrasonic treatment for 45 min. After filtration, the filter residue was washed with water until the pH was 7, and dried at 70℃ for 12 h to obtain 495 g of bamboo-derived insoluble dietary fiber. The filtrate was thoroughly mixed with 10 times its mass of ethyl acetate to produce a precipitate, which was then filtered. The filter residue was washed with 95% ethanol solvent until the pH was 7, and dried at 70℃ for 12 h to obtain 108 g of bamboo-derived soluble dietary fiber.

[0037] Example 5

[0038] 500g of bamboo shoot husks with a moisture content of 10% were crushed and sieved to obtain bamboo shoot husk powder with a particle size of 0.1~100μm. This powder was then thoroughly mixed with 10000mL of a diluted chlorine dioxide solution with a concentration of 250μg / mL (approximately 2.5g of chlorine dioxide gas was passed into 500mL of 1% sodium bicarbonate solution diluted 20 times with water). The mixture was then placed in an ultrasonic device for ultrasonic treatment for 75min at a sound frequency of 30kHz and a power density of 20W / cm³. 2 The ultrasonic temperature was 45℃, and then 5000mL of 0.5% sodium carbonate solution was added and ultrasonic treatment was continued for 30min. After filtration, the filter residue was washed with water until the pH was 7.5, and dried at 45℃ for 24h to obtain 255.1g of bamboo-derived insoluble dietary fiber. The filtrate was thoroughly mixed with 2 times its mass of isopropanol to produce a precipitate. After filtration, the filter residue was washed with 90% isopropanol solvent until the pH was 7.5, and dried at 45℃ for 24h to obtain 53.8g of bamboo-derived soluble dietary fiber.

[0039] Example 6

[0040] To investigate the synergistic effect of ultrasound-assisted ClO2 oxidation, a series of comparative experiments were conducted. These experiments included ClO2 treatment alone (ClO2-T), ultrasound treatment alone (UT), and ultrasound-assisted ClO2 treatment (ClO2-UT) in bamboo shoot shell powder samples containing different initial concentrations of aflatoxin B1. The results are shown below. Figure 1 .

[0041] ClO2 treatment alone (ClO2-T) method: A 1.00 mg / mL aflatoxin B1 standard stock solution was diluted with methanol to prepare working solutions of different concentrations. Then, 10.0 g of bamboo shoot husk powder was accurately weighed into a 100 mL volumetric flask and brought to the mark with methanol. 2 mL of the prepared aflatoxin B1 working solution was added to the bamboo shoot husk powder sample. Referring to the Chinese national standard (GB 2761-2017) (limit of aflatoxin B1 in corn and its products: 20 μg / kg), the initial concentration of aflatoxin B1 was set to twice the limit value, i.e., 40 µg / kg. Methanol was used as a blank control group. The methanol solution in each volumetric flask was evaporated using an appropriate method until the solvent content was less than 5% of the dry weight. The volumetric flasks were then sealed with rubber stoppers, placed in a light-protected environment, and treated with ClO2 solutions of different concentrations. To minimize oxidative damage to other components in the sample, the treatment was maintained at 60 ± 5℃. To ensure the reliability of the experimental results, each experiment was repeated three times.

[0042] Sonication alone (UT) and sonication-assisted ClO2 treatment (ClO2-UT) methods: Bamboo shoot husk powder was thoroughly mixed with a certain concentration of chlorine dioxide solution (this step is not included in sonication alone), and then sonicated in an ultrasonic device. Approximately 25 mL of 70% methanol was then added to the flask to extract the toxin from a 5 g bamboo shoot husk powder sample containing aflatoxin B1. The mixed sample was placed on a shaker and shaken at 300 rpm for 5 min. After shaking, it was transferred to a centrifuge tube and centrifuged at 3500 × g for 5 min. The sample was then filtered through filter paper and a 0.22 μm organic membrane filter. Finally, 200 μL of the extract was transferred to a 1.5 mL centrifuge tube for storage. The aflatoxin B1 content was detected using an ELISA kit (Zoonbio Biotechnology Co., Ltd., Nanjing, China), and the experiment was performed according to the kit instructions.

[0043] Depend on Figure 1 As shown in Figure A, the degradation efficiency of aflatoxin B1 increased with increasing ClO2 concentration. When the ClO2 concentration was 200 μg / mL, the degradation rates of aflatoxin B1 by ClO2-T and ClO2-UT were 52.48% and 94.42%, respectively. When the ClO2 concentration was 250 μg / mL, there was no significant difference in the degradation rate of aflatoxin B1 treated with ClO2-T or ClO2-UT compared to 200 μg / mL ClO2 (p > 0.05). Therefore, a ClO2 treatment concentration of 200 μg / mL was selected as the condition for subsequent studies. Furthermore, after 60 min of treatment, the degradation rates of aflatoxin B1 by ClO2-T, UT, and ClO2-UT were 33.49%, 48.66%, and 91.90%, respectively. Figure 1B). When the treatment time was 75 min, there was no significant difference in the degradation rate of aflatoxin B1 after treatment with UT, ClO2-T, or ClO2-UT compared to 60 min (p > 0.05). Therefore, a treatment time of 60 min was selected as the condition for subsequent studies.

[0044] exist Figure 1 Description C investigated the effect of initial aflatoxin B1 concentration on the degradation efficiency of bamboo shoot husk powder (BSSP) treated with ClO2. After ultrasonic-assisted ClO2 treatment, the degradation efficiencies of aflatoxin B1 at corresponding concentrations were 87.00%, 91.30%, 90.37%, 90.67%, and 91.97%, respectively. The results showed that when the initial aflatoxin B1 concentration in bamboo shoot husk powder (BSSP) was >15 μg / kg, there was no significant difference in degradation rate (p > 0.05). According to the Chinese national standard GB 2761-2017 (Limit of aflatoxin B1 in corn and its products: 20 μg / kg), ultrasonic-assisted ClO2 treatment, regardless of the initial concentration, could reduce the aflatoxin B1 residue in BSSP to an acceptable level, i.e., the aflatoxin B1 residues were 1.95, 2.61, 4.33, 5.60, and 6.02 μg / kg, respectively. Figure 1 As shown in C, even according to the stricter EU limit for aflatoxin B1 (2 μg / kg; European Commission Regulation (EU) No 165 / 2010), when the initial concentration is <15 μg / kg, ultrasonic-assisted ClO2 treatment can effectively reduce aflatoxin B1 (<1.95 μg / kg) in BSSP to below the EU limit.

[0045] Example 7

[0046] Free radical capture experimental method: tert-butanol (t-BuOH, 50 mM) and 1,4-benzoquinone (BQ, 50 mM) were used as hydroxyl radicals (OH·) and superoxide anion radicals (O2·), respectively. - A selective scavenger of aflatoxin B1 was used. 2 mL of aflatoxin B1 solution (50 μg / L) was added to a 25 mL beaker. The scavenger was added alone (t-BuOH or BQ) or simultaneously (50 mM each of t-BuOH and BQ). Subsequently, each sample preparation was subjected to ultrasonication and ClO2 oxidation treatment. The sample treatment method was the same as in Example 1, with the following conditions: 20 μg / mL ClO2 treatment for 60 min, ultrasonic treatment for 60 min, acoustic frequency of 40 kHz, and power density of 8 W / cm². 2 The ultrasonic temperature was 40℃. Results are shown below. Figure 2 A.

[0047] Figure 2A shows the effects of different free radical scavengers on the degradation of aflatoxin B1 by UT, ClO2-T, and ClO2-UT. The addition of t-BuOH and BQ significantly reduced the degradation rate of aflatoxin B1 to varying degrees, indicating that the hydroxyl radicals generated by ultrasonic treatment do indeed have a significant impact on the degradation of aflatoxin B1 (p < 0.05), while the superoxide anion radicals generated by ClO2 oxidation play a key role in the degradation process (p < 0.05). Compared with t-BuOH or BQ alone, the degradation rate of aflatoxin B1 by ClO2-UT was significantly lower than that under the combined action of t-BuOH and BQ, indicating that the hydroxyl radicals and superoxide anion radicals generated by ultrasonic-assisted ClO2 treatment jointly dominate the degradation of aflatoxin B1 (p < 0.05). Figure 2 Even under the combined action of t-BuOH+BQ, UT, ClO2-T, and ClO2-UT in A still showed slight degradation of aflatoxin B1, indicating that ultrasound and ClO2 treatment involve other factors that affect the degradation of aflatoxin B1.

[0048] like Figure 2 In the control group (shown in Figure A) without free radical scavengers, the degradation rate of aflatoxin B1 by ClO2-UT was 63.56% and 47.05% higher than that of UT and ClO2-T, respectively (p < 0.05). However, in the groups with t-BuOH alone, BQ alone, and BQ+t-BuOH, the degradation rates decreased by 18.71%, 35.19%, and 86.64%, respectively (p < 0.05), significantly lower than the degradation rate of ClO2-UT in the control group. These results indicate that free radical scavengers, by jointly inhibiting the effects of ultrasound and ClO2 treatment, limited the degradation of aflatoxin B1, thereby reducing the efficiency gain of ultrasound-assisted ClO2 treatment in the absence of these two free radical degradation pathways. This also confirms that hydroxyl radicals and superoxide anion radicals generated by ultrasound and ClO2 treatment are the common major factors driving the degradation of aflatoxin B1.

[0049] Quantitative experimental method for hydroxyl radicals: The hydroxylated product 7-hydroxycoumarin was quantified by fluorescence spectroscopy. After excitation at 332 nm, fluorescence emission at 456 nm was recorded. Results are shown below. Figure 2 B.

[0050] Quantitative experimental method for superoxide anion radicals: Nitroblue tetrazolium (NBT) was used to oxidize the superoxide anion to blue formazan, and the results were measured spectrophotometrically at 560 nm using a spectrophotometer. See [link to results]. Figure 2 C.

[0051] Quantitative analysis of hydroxyl radicals and superoxide anion radicals: Comparison of hydroxyl radicals (OH·) or superoxide anion radicals (O2·) in solution under three treatment methods- The study aimed to elucidate the contribution of different types of free radicals generated in the synergistic system to the degradation of aflatoxin B1. Polynomial fitting analysis was used to analyze the degradation kinetics of aflatoxin B1, and the kinetic parameters are listed in Tables 1 and 2. The synergistic effect was determined by calculating the synergistic index (SI), using the following formula:

[0052]

[0053] Depend on Figure 2 As shown in B, ultrasonic treatment resulted in a significantly higher production of hydroxyl radicals compared to ClO2 treatment (p < 0.05 within 30 min of treatment, and p < 0.01 after 45 min of treatment). Figure 2 Further analysis revealed that ClO2-UT generated 1.90 times and 2.97 times more hydroxyl radicals than UT and ClO2-T respectively within a 90-minute reaction time (p < 0.01). This indicates that ClO2-UT possesses the strongest ability to generate OH· among the three treatment methods. The kinetic parameter of the 7-hydroxycoumarin generation rate constant (k) of ClO2-UT was significantly higher than that of k. （U-T） 2.75 times higher than k （ClO2-T） The efficiency was 5.55 times higher. The SI value calculated in Table 1 was approximately 1.84, which is greater than 1, indicating that ultrasound-assisted ClO2 treatment has a higher degradation efficiency for aflatoxin B1, mainly based on the synergistic effect of hydroxyl radicals.

[0054] Table 1. Kinetic parameters of hydroxyl radicals generated under UT, ClO2-T, and ClO2-UT treatments.

[0055]

[0056] Depend on Figure 2 As shown in Figure C, ClO2 treatment significantly outperformed ultrasonic treatment in generating superoxide anion radicals, with a significantly higher radical yield (p < 0.01). During the 90-min experiment, the O2· treated with ClO2-UT significantly increased the superoxide anion radical production. - The yield was significantly higher than that of UT (9.58-fold increase) and ClO2-T (1.52-fold increase) (p < 0.01). This indicates that among the three treatments, ClO2-UT has the strongest O2· - Production capacity. The kinetic parameters of formazan derivatives mediated by NBT, namely the production rate constant (k) of ClO2-UT, are 37.11 times and 1.89 times higher than those of UT and ClO2-T, respectively, with an SI value of 1.80 (>1, Table 2). This indicates that ultrasound-assisted ClO2 treatment has a higher degradation efficiency for aflatoxin B1, which is also reflected in the synergistic effect of superoxide anion radicals.

[0057] Table 2 Kinetic parameters of superoxide anion radicals generated under UT, ClO2-T and ClO2-UT treatments

[0058]

[0059] The results above show that, compared with UT and ClO2-T, the hydroxyl radicals and superoxide anion radicals generated by ultrasound-assisted ClO2 treatment have a significant synergistic effect. This indicates that the main reason for the efficient degradation of aflatoxin B1 is the synergistic effect of the hydroxyl radicals and superoxide anion radicals generated by ultrasound-assisted ClO2 treatment.

[0060] Example 8

[0061] Table 3 shows the extraction rates and particle sizes of soluble dietary fiber (SDF), insoluble dietary fiber (IDF), and total dietary fiber (TDF) under different treatment methods. Ultrasound-assisted ClO2 treatment (SDF-UO) showed the highest SDF extraction rate (10.95±0.15%), followed by ultrasound treatment (SDF-U) (9.04±0.17%), ClO2 treatment (SDF-O) (6.26±0.12%), and the untreated blank control (SDF-N) (5.78±0.11%) (p < 0.05). The cavitation bubbles and shear forces generated by ultrasound treatment enhanced cell wall rupture, thereby improving the extraction rate and dissolution rate. Compared with ClO2 treatment, ultrasound treatment contributed more to promoting SDF extraction. Correspondingly, the IDF extraction rate was lowest with ultrasound-assisted ClO2 treatment (IDF-UO) (49.13±2.80%), followed by ultrasound treatment (IDF-U) (52.05±3.01%) and ClO2 treatment (IDF-O) (55.38±2.32%), which was approximately equal to the untreated blank control (IDF-N) (55.69±2.45%) (p < 0.05). The final TDF extraction rates were similar across groups with no significant difference (p > 0.05), and the results were consistent with material balance. The particle size distribution analysis shown in Table 3 indicates that SDF-U and SDF-UO had lower PDI (p < 0.05) compared to SDF-N and SDF-O, suggesting a more concentrated particle size distribution. Among all dietary fiber samples, SDF had a significantly smaller particle size than IDF and TDF. Among the SDF samples, SDF-UO had the smallest average particle size, at 2.72±0.06 µm. Among the IDF and TDF samples, IDF-UO had the smallest average particle size in the IDF sample (49.13±2.80µm) and TDF-UO had the smallest average particle size in the TDF sample (60.08±2.56µm).

[0062] Table 3 Extraction rates and particle sizes of SDF, IDF, and TDF

[0063]

[0064] Processing time: 60 min, ultrasonic power: 500 W, frequency: 40 kHz, temperature: 40 ± 5 ℃, ClO2 concentration: 200 µg / mL, ball mill speed: 300 r / min, ball diameter: 10-100 mm, grinding time: 240 min. Different letters in the same column indicate significant differences (p < 0.05).

[0065] Example 9

[0066] Table 4 shows the total carbohydrate content (TCC), total phenolic content (TPC), and molecular weight (Mw / Mn) of SDF-N, SDF-O, SDF-U, and SDF-UO. The TCC of SDF-UO and SDF-U were 29.97±0.35% and 29.78±0.24%, respectively, higher than those of SDF-N (22.00±0.29%) and SDF-O (22.94±0.31%). SDF-UO had the highest TPC at 3.48±0.08%, followed by SDF-U (2.94±0.11%), SDF-O (2.42±0.12%), and SDF-N (2.01±0.31%) (p < 0.05). The TPC result is complementary to the lignin content of IDF in Table 5. The lignin content, from lowest to highest, is IDF-UO (10.41±0.36%), IDF-U (11.32±0.37%), IDF-O (12.40±0.41%), IDF-N (13.35±0.35%), and BSSP (17.42±0.52%) (p < 0.05). The increase in TPC of SDF after ultrasonic and ClO2 treatment is related to the degree of lignin depolymerization, that is, the residual lignin in IDF decreases after ultrasonic and ClO2 treatment.

[0067] Among the SDF samples, SDF-UO had the lowest molecular weight (Mw) at 111.12 ± 0.54 kDa, followed by SDF-U (117.89 ± 0.69 kDa), SDF-N (132.66 ± 0.63 kDa), and SDF-O (131.45 ± 0.87 kDa). SDF-UO also had the lowest Mw / Mn ratio, reflecting the highest uniformity of its molecular weight, which is beneficial for the water dispersibility and quality uniformity of dietary fiber.

[0068] Table 4. Molecular weight, dispersion index, total carbohydrate content, and total phenolic content of SDF

[0069]

[0070] Processing time: 60 min, ultrasonic power: 500 W, frequency: 40 kHz, temperature: 40 ± 5 ℃, ClO2 concentration: 200 µg / mL. Different letters in the same column indicate significant differences (p < 0.05).

[0071] Table 5 Main Chemical Composition of IDF

[0072]

[0073] Processing time: 60 min, ultrasonic power: 500 W, frequency: 40 kHz, temperature: 40 ± 5 ℃, ClO2 concentration: 200 µg / mL. Different letters in the same column indicate significant differences (p < 0.05).

[0074] Example 10

[0075] As shown in Table 6, compared with BSSP, the essential amino acids (EAA) of ClO2 treatment (BSSP-O), ultrasound treatment (BSSP-U), and ultrasound-assisted ClO2 treatment (BSSP-UO) decreased by 1.80%, 2.25%, and 4.72%, respectively, with no significant difference (p > 0.05). Compared with BSSP, the non-essential amino acids (NEAA) of BSSP-O, BSSP-U, and BSSP-UO decreased by 2.83% (p > 0.05), 10.53% (p < 0.05), and 12.80% (p < 0.05), respectively. Compared with BSSP, the total amino acids (TAA) of BSSP-O, BSSP-U, and BSSP-UO decreased by 2.48% (p > 0.05), 7.76% (p < 0.05), and 10.09% (p < 0.05), respectively. The Essential Amino Acid Index (EAAI) is commonly used to calculate nutritional indices for a comprehensive and scientific assessment of protein nutritional value. In this experiment, EAAI was used to ultimately evaluate the impact of pretreatment methods on the nutritional value of protein and amino acids. The results showed that compared to BSSP, the EAAI of BSSP-O, BSSP-U, and BSSP-UO increased by 0.72% (p > 0.05), 5.97% (p < 0.05), and 5.97% (p < 0.05), respectively. Although BSSP-U and BSSP-UO showed significant differences (p < 0.05), the difference was only slightly greater than 5%, which is acceptable for this level of amino acid loss in bamboo fiber.

[0076] Table 6. Effects of different pretreatments on the content of hydrolyzed amino acids in bamboo fiber.

[0077]

[0078]

[0079] Processing time: 60 min, ultrasonic power: 500 W, frequency: 40 kHz, temperature: 40 ± 5 ℃, ClO2 concentration: 200 µg / mL. Different letters in the same row indicate significant differences (p < 0.05).

[0080] Example 11

[0081] Depend on Figure 3 As can be seen from the infrared spectra of the SDF samples (A), they all exhibit similar infrared spectral characteristics, differing only slightly in absorption intensity. (600-3200 cm⁻¹) -1 The broadband at this point corresponds to the OH stretching vibration. The characteristic peaks of SDF-U, SDF-O, and SDF-UO are broader and stronger than those of SDF-N, indicating that sonication and ClO2 treatment disrupted the cellulose structure, including breaking some glycosidic bonds, and promoted the formation of more hydrogen bonds in the SDF sample. Furthermore, the wavenumbers of SDF-O and SDF-UO are simultaneously lower than those of SDF-N and SDF-U, starting from 3269 cm⁻¹. -1 and 3261cm -1 Moved to 3281cm -1 and 3272cm -1 This indicates a redshift has occurred. All SDF samples were at 2924 cm⁻¹. -1 Weak absorption peaks were observed at all locations, attributed to the CH stretching of the methyl and methylene groups. (1642 cm⁻¹) -1 The absorption peak at 1430 cm⁻¹ is attributed to the characteristic absorption peaks of COO⁻ and C=O of uronic acid; simultaneously, the increase in peak width and intensity indicates that the uronic acid content is high in SDF-U, SDF-O, and SDF-UO, especially in the latter two samples. -1 The absorption peak at 1443 cm⁻¹ may be due to the CH mixing vibration in the infrared spectrum of the SDF-N sample, while the corresponding absorption peak in the infrared spectrum of the SDF-U sample has redshifted to 1443 cm⁻¹. -1 The absorption peaks in the infrared spectra of SDF-O and SDF-UO were blue-shifted to 1390 cm⁻¹. -1 and 1394cm -1 Furthermore, the absorption peak intensities of the latter two were significantly reduced. All SDF samples showed peak intensities at 1030 cm⁻¹. -1 and 899cm -1 The strong absorption peaks observed nearby can be attributed to the stretching vibrations of CO.

[0082] Depend on Figure 3 As can be seen from the infrared spectrum of the IDF sample (B), it also shows similar infrared spectral characteristics, with slight differences in absorption wavelength and intensity. The absorption wavelength between 3680-3000 cm⁻¹ is clearly visible in the spectrum of all IDF samples. -1The broad absorption band at 2922 cm⁻¹ corresponds to the stretching vibration of -OH. -1 The weak absorption peak at 1639 cm⁻¹ is characteristic of the stretching of saturated CH₄ in the cellulose and hemicellulose components. -1 The peak at 1031 cm⁻¹ is attributed to the bending vibration of adsorbed water or carboxylate ions, while the peak at 1031 cm⁻¹ is attributed to the bending vibration of adsorbed water or carboxylate ions. -1 The peak at 1730 cm⁻¹ corresponds to the COC ether bond originating from lignin or hemicellulose. BSSP samples retain the characteristic infrared absorption peaks of hemicellulose and lignin structural units because the soluble dietary fiber portion is not separated, while IDF samples show peaks at 1730 cm⁻¹. -1 The infrared absorption peak at that location Figure 3 C is clearly missing, 1730cm -1 The peaks at that point are attributed to the stretching vibrations of acetyl and uronic acid ester groups in hemicellulose, as well as the carboxyl ester bonds derived from ferulic acid and p-coumaric acid in lignin and hemicellulose.

[0083] Depend on Figure 3 Figures D and 3E show the XRD patterns and crystallinity variation diagrams of SDF and IDF samples. All SDF samples exhibit broad peaks at 17-23° and weak peaks at 30° and 35°, indicating a predominantly amorphous structure with a small number of crystalline regions. SDF-O and SDF-UO show a significant peak shift at 2θ = 22°, while the peak intensity at 20° is weakened. Compared to SDF-N (27.20%), the crystallinity of SDF-U (21.06%), SDF-O (22.03%), and SDF-UO (22.53%) is significantly reduced. These differences indicate that both ultrasonication and ClO2 treatment altered the grain size and arrangement. Figure 3 E indicates that the strong peak at 22° and the weak peak at 16° confirm the cellulose I structure. The crystallinity of BSSP, SDF-N, SDF-U, SDF-O, and SDF-UO are 65.0%, 67.63%, 71.20%, 71.76%, and 71.29%, respectively. The significant increase in the crystallinity of the modified fibers is related to the destruction of amorphous regions and the removal of some lignin and hemicellulose during ultrasonic and ClO2 treatment.

[0084] Example 12

[0085] Transmission electron microscopy images of SDF and IDF samples show that they mainly exist as irregular powdery dispersions with similar morphological characteristics. BSSP ( Figure 4 A) exhibits a large-particle, aggregated structure with a dense, smooth surface and very few cracks; its surface network structure is not obvious. In contrast, IDF-N ( Figure 4 B) exhibits a larger specific surface area and a relatively obvious network and fragment structure. Compared with IDF-N, IDF-UO ( Figure 4 C) exhibits a richer network and fragment structure, with a porous structure and smaller particle size, accompanied by surface collapse, fracture, and shrinkage. Similar experimental phenomena were also observed in SDF samples, similar to SDF-N ( Figure 4 Compared to the structure of E), SDF-UO ( Figure 4 D) It has more cavities and cracks, and honeycomb-like holes appear on the surface, so the specific surface area will increase accordingly.

[0086] Example 13

[0087] Water-holding capacity (WHC) determination method: Weigh 1.0 g of sample and mix it evenly in 30 mL of distilled water. Stir the sample at room temperature for 24 h, then centrifuge at 4000 g for 15 min. Dry the resulting precipitate in an oven at 105 °C. The formula for calculating WHC is as follows:

[0088]

[0089] Where m2 represents the weight (g) of the water-containing sample residue after centrifugation, and m1 represents the weight (g) of the sample dried to constant weight.

[0090] Dietary fiber with high WHC is recognized as a high-quality functional food component. It improves the texture and viscoelasticity of food and plays a significant role in increasing satiety, promoting bowel movements, regulating gut microbiota, and lowering blood levels. Figure 5 As shown in Figure A, the water-holding capacity of SDF-UO (10.95±0.39 g / g) was significantly higher than that of SDF-U (8.56±0.44 g / g) and SDF-O (7.02±0.41 g / g). After ultrasonic-assisted ClO2 treatment, the water-holding capacity of BSSP significantly increased from 2.55±0.16 mL / g (BSSP) to 7.16±0.13 g / g (BSSP-UO).

[0091] Water Swelling Capacity (WSC) Determination Method: Accurately weighed sample (1.0 g) is placed in pre-weighed centrifuge tubes. Add excess distilled water (25 mL, of which 20 mL is added) to each centrifuge tube. Vortex the sample-water mixture thoroughly to ensure complete wetting and dispersion, then allow it to equilibrate at 25°C for a predetermined time (20 h) to reach maximum hydration. The formula for calculating WSC is as follows:

[0092]

[0093] Where v2 represents the volume of the sample after water absorption (mL), v1 represents the volume of the sample before water absorption (mL), and m0 represents the mass of the sample before water absorption (g).

[0094] Depend on Figure 5As shown in Figure B, the WSC after treatment significantly increased from 2.46±0.12 mL / g (BSSP) to 6.16±0.36 mL / g (BSSP-UO). Furthermore, the WSC of IDF-UO (10.05±0.55 mL / g) was significantly higher than that of IDF-U (8.97±0.54 mL / g) and IDF-O (6.68±0.43 mL / g). The higher WHC and WSC of SDF-UO and IDF-UO are attributed to the reduction in particle size and increase in specific surface area resulting from ultrasound-assisted ClO2 treatment, which exposed more hydrophilic groups and expanded the contact area between SDF and IDF and water.

[0095] Oil-holding capacity (OHC) determination method: 0.5 g of sample was thoroughly mixed with 30 mL of soybean oil in a centrifuge tube. The mixture was allowed to equilibrate at room temperature for 20 h. Subsequently, the centrifuge tube was centrifuged at 4000 g for 15 min to separate unbound oil. After centrifugation, the supernatant oil layer was poured off and discarded. The formula for OHC is as follows:

[0096] OHC / (g / g) =

[0097] Where m4 represents the mass (g) after oil absorption saturation, and m3 represents the mass (g) before oil absorption.

[0098] The OHC (hydroxyethylhexylene) content of dietary fiber can prevent oil loss during cooking, making it easier for fat-soluble nutrients to be lost during food processing. It also facilitates the absorption of fatty acids and bile acids, making food more beneficial to human health. Figure 5 As shown in Figure C, the OHC of IDF-UO (9.31±0.55 g / g) was significantly higher than that of IDF-U (8.53±0.54 g / g) and IDF-O (6.51±0.43 g / g). The high OHC of SDF-UO and IDF-UO is attributed to the loose structure of SDF-UO and IDF-UO after ultrasonic-assisted ClO2 treatment. This structure exposes more lipophilic groups, thereby enhancing the lipophilicity of SDF and IDF. At the same time, their honeycomb structure also facilitates the penetration of oil molecules.

[0099] Example 14

[0100] DPPH (2,2-diphenyl-1-picric hydrazine) determination method: Dissolve samples of different masses in 1 mL of water, centrifuge, and filter to obtain sample solutions for later use. Weigh a certain amount of DPPH and prepare a 0.04 mg / mL DPPH solution with anhydrous ethanol. Blank group: 50 μL deionized water + 150 μL anhydrous ethanol. Control group (negative control): 50 μL deionized water + 150 μL DPPH ethanol solution (0.15 mmol / L). Sample blank group: 50 μL sample solution (different concentrations) + 150 μL anhydrous ethanol. Sample group: 50 μL sample solution (different concentrations) + 150 μL DPPH ethanol solution (0.15 mmol / L). 2,6-Di-tert-butyl-p-cresol (BHT) is used as a positive control. The sample solution was thoroughly mixed with DPPH ethanol solution under light-protected conditions, incubated at room temperature for 30 min, and then centrifuged at 5000 r / min for 10 min. The absorbance at 515 nm was measured using a spectrophotometer to determine the free radical scavenging rate. The DPPH free radical scavenging rate (DPPHRS) was calculated using the following formula:

[0101]

[0102] Where T3 represents the absorbance of the sample group, T2 represents the absorbance of the blank sample group, and T1 represents the absorbance of the control group (T0 is the absorbance of the blank group, used for instrument zeroing).

[0103] Compared to IDF, SDF has better water solubility, thus exhibiting superior antioxidant capacity in aqueous solutions. DPPH is a widely used free radical scavenging agent for evaluating the free radical scavenging capabilities of various antioxidants. The DPPH free radical scavenging capabilities of the four SDF samples are as follows: Figure 6 As shown in Figure A, the samples were arranged in descending order: SDF-UO > SDF-U > SDF-O > SDF-N, and the clearance rate increased with increasing sample concentration. At 8 mg / mL, SDF-UO exhibited the highest DPPH clearance rate (89.36 ± 3.32%), comparable to the positive control BHT at 0.16 mg / mL (90.21 ± 2.45%).

[0104] Hydroxyl radical scavenging assay: Dissolve samples of different masses in 1 mL of water, centrifuge, and filter to obtain sample solutions for later use. Add 1 mL of 1.865 mmol / L o-phenanthroline ethanol solution, followed by 2 mL of 0.2 M pH 7.4 phosphate buffer and 1 mL of samples of different concentrations, respectively. Mix thoroughly, then add 1 mL of 1.865 mmol / L FeSO4·7H2O solution, mix again, and then add 1 mL of 0.03% (v / v) hydrogen peroxide solution. Place the mixture tube in a constant temperature water bath and incubate at 37°C for 60 min to allow the sample to react with the working solution. After incubation, centrifuge the reaction mixture at 10,000 rpm for 10 min at room temperature to separate any small amount of particulate matter in the liquid phase. Collect the clear supernatant and measure its photometric value at 536 nm using a spectrophotometer. Vitamin C was used as a positive control. The hydroxyl radical scavenging rate (HDRS) was calculated using the following formula:

[0105]

[0106] Where T7 represents the absorbance of the sample group, T6 represents the absorbance of the blank sample group, and T5 represents the absorbance of the control group (T4 is the absorbance of the blank sample group, used for instrument zeroing).

[0107] The hydroxyl radical scavenging assay, used to determine antioxidant activity, can be considered a supplement to the DPPH assay. Accordingly, hydroxyl radical scavenging activity ( Figure 6 B) It showed a similar trend to the DPPH experiment. At 8 mg / mL, SDF-UO showed the highest hydroxyl radical scavenging ability, with a scavenging rate of 74.32±3.01%, followed by SDF-U (70.50±2.08%), SDF-O (63.36±2.43%) and a similar SDF-N (62.62±2.64%).

[0108] Superradical scavenging assay: Dissolve samples of different masses in 1 mL of water, centrifuge, and filter to obtain sample solutions. Mix 0.1 mL of the sample solution with 1 mL of Tris-HCl buffer (50 mM, pH 8.2) and incubate at 25°C for 20 min. Then add 0.1 mL of 10 mM pyrogallol solution to the mixture and incubate for another 5 min. After incubation, measure the absorbance of the reaction mixture at 325 nm using a spectrophotometer. Vitamin C was used as a positive control. Calculate the superradical scavenging rate (SORS) using the following formula:

[0109]

[0110] Among them, T 11 The absorbance of the sample group, T 10T8 represents the absorbance of the blank sample group, while T9 represents the absorbance of the control group (T8 is the absorbance of the blank sample group, used for instrument zeroing).

[0111] The superoxide anion scavenging assay is also considered a complementary method to the DPPH and hydroxyl radical scavenging assays for assessing antioxidant activity. Superoxide anion radical assay ( Figure 6 C) indicates that, within the concentration range of 1-5 mg / mL, the antioxidant capacity of SDF-UO (P < 0.05) is superior to that of SDF-U, SDF-O, and SDF-N. Within this concentration range, the antioxidant properties are positively correlated with concentration.

[0112] Example 15

[0113] Glucose adsorption capacity determination method: Accurately weigh 0.1 g of each sample (denoted as W) and mix it thoroughly with 10 mL of a glucose solution with a concentration varying from 1 to 100 mmol / L (denoted as V, initial glucose concentration denoted as G1). The resulting mixture is magnetically stirred and incubated in a 37°C constant temperature bath for 6 hours to simulate physiological conditions. After incubation, the mixture is centrifuged at 5000 × g for 10 min to separate the supernatant from the residue. The glucose concentration in 1 mL of the collected supernatant is quantitatively determined according to the instructions of the Abnova glucose assay kit (denoted as G2). All operations are performed in triplicate to ensure reproducibility. The glucose adsorption capacity (expressed in μmol / g) is calculated using the following formula: Glucose adsorption capacity (μmol / g) = (G1 - G2) × V / W.

[0114] Depend on Figure 7 As shown in Figure A, which illustrates the glucose adsorption capacity of the SDF samples, they exhibited highly efficient glucose adsorption capacity within a concentration range of 5-100 mmol / L, with the adsorption capacity increasing with increasing glucose concentration. At a high glucose concentration of 100 mmol / L, the glucose adsorption capacity of the four SDF samples was ranked as follows: SDF-UO (85.32±2.76 µmol / g) > SDF-U (78.95±2.75 µmol / g) > SDF-O (74.07±2.59 µmol / g) ≈ SDF-N (72.96±3.43 µmol / g). Furthermore, when the glucose concentration decreased to 5 mmol / L, all SDF samples retained glucose adsorption capacity (15.02±0.36-19.17±0.67 µmol / g), which helps maintain low glucose levels in the intestine to alleviate postprandial hyperglycemia.

[0115] Glucose diffusion capacity assay and glucose dialysis delay index (GDRI) calculation method: 0.1 g of sample was added to 5 mL of 100 mM glucose solution and mixed thoroughly. The mixture was dialyzed against 100 mL of distilled water at 37 °C using a dialysis membrane with a molecular weight cutoff (MWCO) of 12000 Da. 1 mL of dialysate was collected at 15, 30, 45, 60, 75, 90, 105, 120, 150, and 180 min, and its glucose concentration was measured using an Abnova glucose assay kit (denoted as G3). A sample without dietary fiber was used as a blank control, and the glucose concentration of the dialysate at this time point was recorded as G4. All tests were performed in triplicate, and GDRI was calculated using the following formula: GDRI = 100 - [(G3 / G4) × 100].

[0116] Depend on Figure 7 Figure B shows the effect of SDF samples on glucose diffusion capacity. It indicates that the glucose content in the dialysate of SDF samples increased with time. The glucose content in the dialysate of SDF-UO and SDF-U was 17.32±0.21 µmol and 21.64±0.46 µmol at 15 min, respectively, and reached 328.45±6.54 µmol and 340.36±5.93 µmol at 180 min, respectively. From 45 min to 180 min, SDF-UO, SDF-U, and SDF-O showed a stronger inhibitory effect on glucose transport across the dialysis membrane into the external solution than the control group (p < 0.05). The GDRI of each SDF sample could be calculated based on relevant data on glucose diffusion delay, such as... Figure 7 As shown in C. The GDRI values ​​of the four samples were different: SDF-UO was 35.05% at 30 min, SDF-U was 22.60% at 45 min, SDF-O was 11.10% at 90 min, and SDF-N was 7.07% at 45 min.

[0117] Assay for α-amylase inhibition: 100 μL of sample (concentration range: 0.25-1.5 mg / mL) or acarbose (positive control) was mixed with 1 mL of a mixture containing 0.02 mol / L sodium phosphate buffer (pH 7.0) and α-amylase (0.83 mg / L). The mixture was incubated in a 37°C water bath for 15 min, followed by the addition of 200 μL of 1% potato starch solution and incubation at 37°C for another 15 min. Then, 2 mL of 3,5-dinitrosalicylic acid (DNS) reagent was added and the reaction was terminated by heating in a boiling water bath for 5 min. After cooling to room temperature, the mixture was diluted with 9 mL of distilled water, and its absorbance was measured at 540 nm (recorded as A1). The absorbance of the blank control (without sample) was measured under the same conditions and recorded as A2. The α-amylase inhibition rate is expressed as a percentage and calculated using the following formula: α-amylase inhibition rate (%) = (A2-A1) / A2 × 100.

[0118] Assay for α-glucosidase inhibition: 0.6 mL of 0.1 mol / L phosphate buffer, 0.2 mL of α-glucosidase (5 U / mL), and 0.2 mL of sample or acarbose (positive control) at a concentration range of 0.25–1.5 mg / mL were thoroughly mixed. The mixture was pre-incubated at 37 °C for 15 min, and then mixed with 0.4 mL of 20 mmol / L p-nitrophenyl-α-D-glucopyranoside (PNP-Gluc) solution. After further incubation at 37 °C for 30 min, the reaction was terminated by adding 2 mL of 0.1 mol / L sodium carbonate. For the blank control group, the sample was replaced with an equal volume of buffer. The amount of p-nitrophenol (p-NP) generated was quantified by measuring the absorbance at 405 nm. The absorbance values ​​of the test tube and control tube were recorded as A3 and A4, respectively. The inhibition percentage was calculated using the following formula: α-glucosidase inhibition rate (%) = (A4 – A3) / A4 × 100.

[0119] Depend on Figure 7 Figures D and 7E show the inhibitory activity of SDF samples against α-amylase and α-glucosidase. All SDF samples exhibited dose-dependent inhibitory activity against both enzymes in vitro. IC 50 The values ​​(defined as the sample concentration that inhibits 50% of enzyme activity) have been calculated and are listed in Table 7. For α-amylase inhibitory activity, IC50... 50 The values, arranged in ascending order, were: SDF-UO (0.773±0.010 mg / mL) < SDF-U (0.993±0.015 mg / mL) < SDF-O (1.148±0.018 mg / mL) ≈ SDF-N (1.195±0.020 mg / mL), while the IC50 of the positive control acarbose was... 50The value is 0.847±0.013 mg / mL. The results show that the inhibitory effect of SDF-UO on α-amylase is higher than that of acarbose. The α-glucosidase inhibitory activity shows the IC of all SDF samples 50 Values in ascending order of IC: SDF-UO (0.510±0.011 mg / mL) < SDF-U (0.643±0.014 mg / mL) < SDF-O (0.817±0.016 mg / mL) < SDF-N (0.881±0.016 mg / mL) 50 All values are higher than that of acarbose (< 0.25 mg / mL). Overall, the four SDF samples all have good inhibitory effects on α-amylase and α-glucosidase, especially SDF-UO.

[0120] Table 7 Inhibitory activities of SDF samples against α-amylase and α-glucosidase

[0121]

[0122] Polynomial Fit was used to calculate the IC of α-amylase and α-glucosidase 50 values. Different letters in the same column indicate significant differences (p < 0.05).

[0123] The above description is only the preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for the integrated preparation of aflatoxin B1-efficient degradation and bamboo-derived functional dietary fiber, characterized in that, Using crushed and sieved bamboo shoot shell powder as raw material, the bamboo shoot shell powder is mixed with chlorine dioxide solution and then subjected to ultrasonic treatment. An alkaline solution is then added for a second ultrasonic reaction. The reaction solution is filtered to obtain filter residue and filtrate. The filter residue is washed with water and dried to obtain bamboo-derived insoluble dietary fiber. The filtrate is mixed with an organic solvent to precipitate a precipitate. The precipitate is washed with an organic solvent and dried to obtain bamboo-derived soluble dietary fiber.

2. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The preparation steps of the bamboo shoot shell powder are as follows: bamboo shoot shells with a moisture content of 5% to 15% are coarsely crushed, then finely crushed by ball milling, vibration milling or disc milling, and sieved to obtain bamboo shoot shell powder with a particle size of 0.1 to 100 μm.

3. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The mass ratio of bamboo shoot shell powder to chlorine dioxide solution is 1:10~50.

4. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The concentration of the chlorine dioxide solution is 50~250 μg / mL.

5. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The chlorine dioxide solution is prepared by passing chlorine dioxide gas into a carbonate, bicarbonate, or percarbonate solution to dissolve it, thereby obtaining a chlorine dioxide stock solution; the carbonate, bicarbonate, and percarbonate are selected from one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium percarbonate, and sodium percarbonate.

6. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The conditions for the two-stage ultrasonic treatment are: ultrasonic frequency 20~100kHz, power density 0.2~20W / cm³. 2 The ultrasonic temperature is 30~60℃; the duration of the first ultrasonic segment is 15~75min, and the duration of the second ultrasonic segment is 15~60min after adding alkaline solution.

7. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The duration of the first ultrasound segment is 60 minutes.

8. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The alkaline solution is selected from any one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, and the mass fraction concentration of the alkaline solution is 0.1% to 2%.

9. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: The organic solvent is selected from one or a mixture of ethanol, isopropanol, and ethyl acetate, and the mass ratio of the filtrate to the organic solvent is 1:2 to 20.

10. The integrated preparation method of aflatoxin B1 high-efficiency degradation and bamboo-derived functional dietary fiber according to claim 1, characterized in that: Bamboo source functional dietary fiber can be used alone or added as an additive to solid, semi-fluid, and liquid foods and livestock and poultry feed.

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