Canna edulis ker starch resistant dextrin as well as preparation method and application thereof

Abstract

The invention discloses canna edulis ker starch resistant dextrin as well as a preparation method and application thereof. The method comprises the following specific steps: crushing canna edulis ker starch, and mixing the crushed canna edulis ker starch with water to form homogeneous slurry; pyrodextrin is generated through acid catalysis coking pyrolysis; carrying out enzymolysis purification by using alpha-amylase, carrying out branched chain re-synthesis by using starch branching enzyme, and removing residual reducing sugar by combining with saccharomyces cerevisiae fermentation; and carrying out graded purification by adopting an ultrafiltration membrane, and finally drying to obtain a resistant dextrin finished product. The embodiment verifies that the obtained resistant dextrin has excellent freeze-thaw stability (the transmittance is greater than or equal to 80% after freeze-thaw for five times) and digestion resistance (the proportion of anti-digestion components reaches 92.4%), and the product is light in color and excellent in sensory quality. The method disclosed by the invention is simple and convenient in process operation and high in efficiency, solves the problems of high energy consumption and low yield of a traditional method, provides technical support for developing functional foods and auxiliary therapeutic preparations for metabolic syndromes, and promotes high-valued utilization of canna edulis ker resources at the same time.

Description

Technical Field

[0001] This invention belongs to the field of carbohydrates, and specifically relates to a resistant dextrin from banana starch, its preparation method, and its application. Background Technology

[0002] Canna edulis Ker is a plant used for both medicinal and edible purposes. It belongs to the genus Canna in the family Cannaceae. Common names include banana taro and edible canna. It is mainly distributed in tropical and subtropical regions. In my country, it is commonly found in Yunnan, Guizhou and Guangxi. Its tubers are rich in starch and functional components, making it an important economic crop and medicinal resource.

[0003] The banana taro is neutral in nature and sweet in taste, and it enters the spleen and stomach meridians. It has the effects of strengthening the spleen and stomach, moistening the intestines and promoting bowel movements, and regulating metabolism. Modern research shows that banana taro contains active ingredients such as resistant dextrin, dietary fiber, polyphenols, and flavonoids. Among them, resistant dextrin, as a typical representative of water-soluble dietary fiber, shows unique advantages in regulating intestinal flora, controlling blood sugar and lipids, and enhancing satiety. Nathaniel D. Fastinger et al. confirmed through a randomized double-blind trial that resistant dextrin increases the abundance of Bifidobacteria in feces. Hu Fan et al. found that resistant dextrin improves insulin resistance in mice by enhancing insulin signal transduction. Yuka Kishimoto et al.'s research showed that resistant dextrin reduces triglyceride and cholesterol levels by delaying lipid absorption.

[0004] Based on existing research, resistant dextrin from plantain shows great promise in dietary intervention for metabolic syndrome. However, the industrialization of this component currently faces bottlenecks such as high energy consumption in extraction processes, insufficient analysis of its functional structure, and low efficiency in large-scale production. Future research should focus on multidisciplinary approaches to elucidate its structure-activity relationship and optimize preparation techniques, providing a scientific basis for the development of functional foods and adjunctive therapies for chronic diseases. Summary of the Invention

[0005] To overcome the problems of complex production process, low yield and insufficient functional structure analysis of resistant dextrin from plantain in the existing technology, the primary objective of this invention is to provide a method for preparing resistant dextrin from plantain starch. This method is an efficient process for preparing resistant dextrin from plantain based on the synergistic preparation of resistant dextrin from plantain using acid-heat method, enzymatic method and fermentation method.

[0006] Another objective of this invention is to provide a resistant dextrin of banana taro starch prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned resistant dextrin from banana starch.

[0008] The objective of this invention is achieved through the following solution:

[0009] A method for preparing resistant dextrin from plantain starch includes the following steps:

[0010] (1) Raw material pretreatment: The banana taro starch is crushed and sieved, then mixed with water and stirred to form a homogeneous slurry;

[0011] (2) Acid-thermal reaction: Add acid to the slurry obtained in step (1), coke and pyrolyze to generate pyrodextrin;

[0012] (3) Enzymatic hydrolysis and purification: Dissolve the pyrodextrin obtained in step (2) in water to obtain a pyrodextrin aqueous solution, add α-amylase for enzymatic hydrolysis; then add starch branching enzyme for branching resynthesis, inactivate the enzyme, centrifuge and take the supernatant;

[0013] (4) Fermentation to remove sugar: Add activated brewer's yeast to the supernatant obtained in step (3) for fermentation to remove sugar, and centrifuge to remove the cells and residual reducing sugar;

[0014] (5) Ultrafiltration fractionation: The reaction solution obtained after centrifugation in step (4) is purified stepwise using an ultrafiltration membrane to remove macromolecular impurities and small molecule sugars;

[0015] (6) Drying and shaping: The purified solution obtained in step (5) is concentrated and dried to obtain the banana taro starch resistant dextrin product.

[0016] Furthermore:

[0017] In step (1), the ratio of banana taro starch to water is 1:3-1:7 (w / v, g / mL), preferably 1:5 g / mL; the sieving refers to passing through a 100-mesh sieve.

[0018] In step (2), the amount of acid added (based on the dry weight of the acid) is 1.5-2.5 wt% of the dry weight of the slurry (i.e., the mass of starch), preferably 2 wt%; the temperature of the coking pyrolysis is 160-180℃, preferably 170℃; and the time of the coking pyrolysis is 2-4h, preferably 3h.

[0019] The acid includes one of hydrochloric acid, nitric acid, and citric acid.

[0020] In step (3), the enzyme activity of the α-amylase is 5000 U / g; the enzyme activity of the starch branching enzyme is 5000 U / g;

[0021] The concentration of the pyrodextrin aqueous solution is 20-40 wt% (w / v, g / mL), preferably 30%;

[0022] The amount of α-amylase added is 0.5-1.5 wt% of the dry weight of dextrin, preferably 1 wt%; the enzymatic hydrolysis time after adding α-amylase is 1-3 h, preferably 2 h, and the enzymatic hydrolysis temperature is 85-95℃, preferably 90℃.

[0023] The amount of starch branching enzyme added is 0.2-0.6 wt% of the dry weight of the caramelized dextrin, preferably 0.4 wt%; the enzymatic hydrolysis time after adding starch branching enzyme is 0.5-1.5 h, preferably 1 h, and the enzymatic hydrolysis temperature is 60-70℃, preferably 65℃.

[0024] In step (4), when activating the brewing yeast: the amount of yeast added is 0.5-1.5 wt%, preferably 1 wt%; the pH value is 6-8, preferably pH value is 7;

[0025] When adding brewing yeast for fermentation: the amount of brewing yeast added is 0.5-1.5wt%, preferably 1wt%; the fermentation temperature is 28-36℃, preferably 32℃; the fermentation time is 12-36h, preferably 24h.

[0026] In step (5), the ultrafiltration membrane combination is 10-15kDa (to remove macromolecular impurities) and 1-3kDa (to retain target resistant dextrin), preferably 10kDa and 1kDa.

[0027] In step (6), the purified solution is concentrated to a solid content of 20%; the drying is spray drying or freeze drying.

[0028] The banana taro starch resistant dextrin prepared by this invention has good digestibility and freeze-thaw stability, and can be used to prepare bread, pastries or beverages.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] This invention presents a highly efficient process for preparing resistant dextrin from plantain root using a synergistic acid-heat, enzymatic, and fermentation method. This process boasts high extraction efficiency and relatively simple operation, while simultaneously reducing the color of the charred dextrin and improving its sensory quality. It provides a scientific basis for the development of functional foods and adjuvant preparations for chronic diseases, and contributes to the high-value utilization of plantain root resources. Attached Figure Description

[0031] Figure 1 Scanning electron microscope image of the banana taro starch resistant dextrin prepared in Example 1;

[0032] Figure 2 The infrared spectrum of the banana taro starch resistant dextrin prepared in Example 1;

[0033] Figure 3 The image shows the X-ray diffraction pattern of the banana taro starch resistant dextrin prepared in Example 1. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available products. The α-amylase and amylase used in the embodiments were purchased from Shanghai Yuanye Biotechnology Co., Ltd. and Novozymes, respectively, and the brewing yeast was purchased from Angel Yeast Co., Ltd.

[0035] Example 1:

[0036] (1) Raw material pretreatment: After crushing the banana taro starch, pass it through a 100-mesh sieve, add water at a material-to-liquid ratio of 1:5 (w / v, g / mL), and stir to form a homogeneous slurry;

[0037] (2) Acid-thermal reaction: Add hydrochloric acid to the slurry obtained in step (1), and coke pyrolyze to generate pyrodextrin; wherein, the mass of hydrochloric acid added (based on the dry weight of hydrochloric acid) is 2wt% of the dry weight of the slurry; the coking temperature range is 170℃ and the time is 3h.

[0038] (3) Enzymatic hydrolysis and purification: The pyrodextrin obtained in step (2) was dissolved in water to obtain a pyrodextrin aqueous solution. α-amylase (enzyme activity 5000 U / g) was added for enzymatic hydrolysis, followed by the addition of starch branching enzyme (enzyme activity 5000 U / g) for branching resynthesis. After enzyme inactivation, the supernatant was collected by centrifugation. The concentration of the pyrodextrin aqueous solution was 30 wt% (w / v, g / mL). The amount of α-amylase added was 1 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding α-amylase was 2 h at a temperature of 90℃. The amount of starch branching enzyme added was 0.4 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding starch branching enzyme was 1 h at a temperature of 65℃.

[0039] (4) Fermentation to remove sugar: Activated brewer's yeast is added to the supernatant obtained in step (3) for fermentation to remove sugar, and the cells and residual reducing sugar are removed by centrifugation; wherein, the amount of yeast added is 1 wt%, the fermentation temperature is 32℃, and the fermentation time is 24 h. When the brewer's yeast is activated: the amount of yeast added is 1 wt%, and the pH value is 7.

[0040] (5) Ultrafiltration fractionation: The reaction solution obtained after centrifugation in step (4) is purified stepwise using ultrafiltration membranes to remove macromolecular impurities and small molecule sugars; wherein the ultrafiltration membrane combination is 10 kDa and 1 kDa respectively.

[0041] (6) Drying and Shaping: The purified solution obtained in step (5) is concentrated to a solid content of 20%, and spray-dried to obtain the banana taro starch resistant dextrin product. The scanning electron microscope image, infrared spectrum, and X-ray diffraction pattern of the banana taro starch resistant dextrin in Example 1 are shown below. Figure 1 , Figure 2 and Figure 3 .

[0042] Example 2:

[0043] (1) Raw material pretreatment: After crushing the banana taro starch, pass it through a 100-mesh sieve, add water at a material-to-liquid ratio of 1:3 (w / v, g / mL), and stir to form a homogeneous slurry;

[0044] (2) Acid-thermal reaction: Add hydrochloric acid to the slurry obtained in step (1), and coke pyrolyze to generate pyrodextrin; wherein, the mass of hydrochloric acid added (based on the dry weight of hydrochloric acid) is 1.5 wt% of the dry weight of the slurry; the coking temperature range is 160℃ and the time is 2h.

[0045] (3) Enzymatic hydrolysis and purification: The pyrodextrin obtained in step (2) was dissolved in water to obtain a pyrodextrin aqueous solution. α-amylase (enzyme activity 5000 U / g) was added for enzymatic hydrolysis, followed by the addition of starch branching enzyme (enzyme activity 5000 U / g) for branching resynthesis. After enzyme inactivation, the supernatant was collected by centrifugation. The concentration of the pyrodextrin aqueous solution was 20 wt% (w / v, g / mL). The amount of α-amylase added was 0.5 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding α-amylase was 1 h, and the temperature was 95℃. The amount of starch branching enzyme added was 0.2 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding starch branching enzyme was 0.5 h, and the temperature was 70℃.

[0046] (4) Fermentation to remove sugar: Activated brewer's yeast is added to the supernatant obtained in step (3) for fermentation to remove sugar, and the cells and residual reducing sugar are removed by centrifugation; wherein, the amount of yeast added is 0.5 wt%, the fermentation temperature is 28℃, and the fermentation time is 12 h. When the brewer's yeast is activated: the amount of yeast added is 0.5 wt%, and the pH value is 6.

[0047] (5) Ultrafiltration fractionation: The reaction solution obtained after centrifugation in step (4) is purified stepwise using ultrafiltration membranes to remove macromolecular impurities and small molecule sugars; wherein the ultrafiltration membrane combination is 12kda and 2kda respectively.

[0048] (6) Drying and shaping: The purified solution obtained in step (5) is concentrated to a solid content of 20%, and spray-dried to obtain the banana taro starch resistant dextrin product.

[0049] Example 3:

[0050] (1) Raw material pretreatment: After crushing the banana taro starch, pass it through a 100-mesh sieve, add water at a material-to-liquid ratio of 1:7 (w / v, g / mL), and stir to form a homogeneous slurry;

[0051] (2) Acid-thermal reaction: Add hydrochloric acid to the slurry obtained in step (1), and coke pyrolyze to generate pyrodextrin; wherein, the mass of hydrochloric acid added (based on the dry weight of hydrochloric acid) is 2.5 wt% of the dry weight of the slurry; the coking temperature range is 180℃ and the coking time is 4h.

[0052] (3) Enzymatic hydrolysis and purification: The pyrodextrin obtained in step (2) was dissolved in water to obtain a pyrodextrin aqueous solution. α-amylase (enzyme activity 5000 U / g) was added for enzymatic hydrolysis, followed by the addition of starch branching enzyme (enzyme activity 5000 U / g) for branching resynthesis. After enzyme inactivation, the supernatant was collected by centrifugation. The concentration of the pyrodextrin aqueous solution was 40 wt% (w / v, g / mL). The amount of α-amylase added was 1.5 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding α-amylase was 3 h, and the temperature was 85 ℃. The amount of starch branching enzyme added was 0.6 wt% of the dry weight of the pyrodextrin. The hydrolysis time after adding starch branching enzyme was 1.5 h, and the temperature was 60 ℃.

[0053] (4) Fermentation to remove sugar: Activated brewer's yeast is added to the supernatant obtained in step (3) for fermentation to remove sugar, and the cells and residual reducing sugar are removed by centrifugation; wherein, the amount of yeast added is 1.5 wt%, the fermentation temperature is 36℃, and the fermentation time is 36 h. When the brewer's yeast is activated: the amount of yeast added is 1.5 wt%, and the pH value is 8.

[0054] (5) Ultrafiltration fractionation: The reaction solution obtained after centrifugation in step (4) is purified stepwise using ultrafiltration membranes to remove macromolecular impurities and small molecule sugars; wherein the ultrafiltration membrane combination is 15kda and 3kda respectively.

[0055] (6) Drying and shaping: The purified solution obtained in step (5) is concentrated to a solid content of 20%, and spray-dried to obtain the banana taro starch resistant dextrin product.

[0056] Determination of freeze-thaw stability of resistant dextrin

[0057] The freeze-thaw stability of resistant dextrin is typically assessed by simulating multiple freeze-thaw cycles to evaluate its physical stability. The specific method involves freezing the resistant dextrin solution at -18°C for 24 hours, followed by thawing at room temperature until completely thawed; this constitutes one cycle. This process is repeated 3-5 times, and the changes in solution state are observed. Indicators include whether precipitation occurs, layering, or a decrease in viscosity. The precipitation rate is determined by centrifugation to evaluate freeze-thaw stability, and the transmittance is detected by Fourier transform infrared spectroscopy.

[0058] Table 1 Freeze-thaw stability of dextrins with different resistance

[0059]

[0060] Note: Different letters indicate significant differences (P < 0.05).

[0061] As shown in Table 1, all examples exhibited only slight changes in transparency after five repeated freeze-thaw cycles, indicating good freeze-thaw stability. Example 1 demonstrated the best freeze-thaw stability. This result further clarifies the applicability of plantain resistant dextrin in the frozen beverage industry.

[0062] In vitro digestion assay of resistant dextrin

[0063] The simulated in vitro digestion assay for resistant dextrin assesses its resistance to enzymatic digestion by simulating the human gastrointestinal environment (gastric stage: pH 2.0 containing pepsin, treated at 37°C for 1–2 hours; small intestinal stage: pH 6.8–7.0 containing pancreatin, reaction for 2–4 hours). After digestion, the reaction is terminated by high temperature or pH adjustment. Undigested residue is separated by centrifugation, washed with ethanol, dried, and weighed. The glucose release is determined using the DNS method or a GOPOD kit, and the proportion of resistant components is calculated.

[0064] Table 2. Proportions of different antidigestive components in resistant dextrin

[0065]

[0066] According to the results of simulated in vitro digestibility, the proportions of digestible components of resistant dextrin in different examples were 92.4%, 88.3%, and 90.7%, respectively, all showing good resistance to digestion. Among them, the proportion of resistance to digestion was the highest in Example 1.

[0067] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing resistant dextrin from banana and taro starch, characterized in that, Includes the following steps: (1) Crush the banana taro starch and sieve it. Mix it with water and stir to form a homogeneous slurry. (2) Add acid to the slurry obtained in step (1) and coke pyrolysis to generate pyrodextrin; (3) Dissolve the pyrodextrin obtained in step (2) in water to obtain a pyrodextrin aqueous solution, add α-amylase for enzymatic hydrolysis; then add starch branching enzyme for branching resynthesis, inactivate the enzyme, centrifuge and take the supernatant. (4) Add activated brewer's yeast to the supernatant obtained in step (3) for fermentation to remove sugar, and centrifuge to remove cells and residual reducing sugar; (5) Use ultrafiltration membrane to purify the reaction solution obtained after centrifugation in step (4) stepwise to remove macromolecular impurities and small molecule sugars; (6) The purified solution obtained in step (5) is concentrated and dried to obtain the banana taro starch resistant dextrin product.

2. The preparation method according to claim 1, characterized in that, In step (1), the ratio of banana taro starch to water is 1:3-1:7 g / mL, preferably 1:5 g / mL; the sieving refers to passing through a 100-mesh sieve.

3. The preparation method according to claim 1, characterized in that, In step (2), the amount of acid added is 1.5-2.5 wt% of the dry weight of the slurry, preferably 2 wt%; the temperature of the coking pyrolysis is 160-180℃, preferably 170℃; and the time of the coking pyrolysis is 2-4h, preferably 3h.

4. The preparation method according to claim 1, characterized in that, In step (3), The concentration of the pyrodextrin aqueous solution is 20-40 wt%, preferably 30%; The amount of α-amylase added is 0.5-1.5 wt% of the dry weight of dextrin, preferably 1 wt%; the enzymatic hydrolysis time after adding α-amylase is 1-3 h, preferably 2 h, and the enzymatic hydrolysis temperature is 85-95℃, preferably 90℃. The amount of starch branching enzyme added is 0.2-0.6 wt% of the dry weight of the caramelized dextrin, preferably 0.4 wt%; the enzymatic hydrolysis time after adding starch branching enzyme is 0.5-1.5 h, preferably 1 h, and the enzymatic hydrolysis temperature is 60-70℃, preferably 65℃.

5. The preparation method according to claim 1, characterized in that, In step (4), when adding brewing yeast for fermentation: the amount of brewing yeast added is 0.5-1.5wt%, preferably 1wt%; the fermentation temperature is 28-36℃, preferably 32℃; and the fermentation time is 12-36h, preferably 24h.

6. The preparation method according to claim 1, characterized in that, In step (3), the enzyme activity of the α-amylase is 5000 U / g; the enzyme activity of the starch branching enzyme is 5000 U / g; In step (4), when the brewing yeast is activated: the amount of yeast added is 0.5-1.5 wt%; the pH value is 6-8.

7. The preparation method according to claim 1, characterized in that, In step (5), the ultrafiltration membrane combination consists of 10-15 kDa and 1-3 kDa, respectively.

8. The preparation method according to claim 1, characterized in that, In step (6), the purified solution is concentrated to a solid content of 20%; the drying is spray drying or freeze drying.

9. A banana taro starch resistant dextrin prepared by the preparation method according to any one of claims 1-8.

10. The use of the banana taro starch resistant dextrin according to claim 9 in the preparation of bread, pastries or beverages.

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