LU600206B1 - A process for modifying insoluble fiber using subcritical water in combination with alkaline hydrogen peroxide - Google Patents

Abstract

The present invention relates to the technical field of dietary fiber preparation, particularly to a method for modifying insoluble dietary fiber by subcritical water in combination with alkaline hydrogen peroxide, which comprises the following steps: pretreatment of the raw material; defatting treatment by refluxing ethanol; enzymatic deproteinization; SW modification treatment; AHP modification treatment; and evaluation of the modification effect. The advantageous effect is that the method for modifying insoluble dietary fiber by subcritical water in combination with alkaline hydrogen peroxide proposed in the present invention achieves integrated and efficient modification of IDF through the combination of SW and AHP modification technology. This innovative strategy not only simplifies the modification process but also improves the modification efficiency of IDF, resulting in higher-value IDF products in a short time.

Description

A process for modifying insoluble fiber by subcritical LU600206

Water in combination with alkaline hydrogen peroxide

Technical area

The present invention relates to the technical field of the preparation of

Dietary fibers, in particular to a process for modifying insoluble dietary fibers using subcritical water in combination with alkaline hydrogen peroxide.

Technology in the background

Dietary fiber plays a crucial role in the structure of the human diet.

They not only contribute to intestinal health, but also prevent a number of chronic

Diseases such as obesity, diabetes, and cardiovascular diseases occur. However, in its natural state, insoluble fiber (IDF) is compact and difficult to digest and absorb directly by the body. This structural property limits the

Use of IDF in food, food supplements and pharmaceuticals, and the modification of IDF aims to change their structural properties by physical, chemical or biological methods in order to improve their functional properties such as

To improve solubility, water retention capacity, oil retention capacity and swelling capacity.

Improving these functional properties not only contributes to a better use of IDF in food, but also increases its benefits for human health, such as promoting intestinal peristalsis, preventing constipation and colon cancer, etc. Another important reason for changing IDF is improving its

taste and texture. Natural IDF added to food can produce a harsh taste that impairs the overall quality of the food.

Modification can make IDF have a more delicate taste and be more suitable for adding to various foods, thus expanding its application range.

Currently, there are three main categories of modification methods for IDF: physical

Modification, chemical modification and biological modification. First, physical modification technology is mainly based on mechanical comminution,

Heat treatment and high pressure homogenization to adjust the microstructure of IDF.

The advantages of this technology are that it is intuitive and easy to use, and the original nutrient composition of the IDF can be largely maintained, thus avoiding excessive chemical or biological interventions. However, the modification effect is relatively limited and focuses on optimizing the physical

Properties of IDF, such as refinement of particle size and improvement of

Dispersibility, while the profound changes in the chemical properties of

IDF are rather limited. In addition, the physical modification process is often associated with high energy consumption, which undoubtedly increases the cost burden of the

production process. The chemical modification technology focuses on the

Use of acid-base solutions, oxidants and other chemical agents to profoundly alter the chemical structure of IDF and thereby impair its functional

properties significantly. The great advantage of this approach is that the

Modification acts directly and specifically to improve the specific functional

properties of IDF. However, this process can involve the introduction of hazardous chemical residues, which are not only relevant for product safety, but can also impair the organoleptic properties (e.g., taste) of the IDF. At the same time, the chemical treatment process can impair the nutritional composition of the IDF to a certain extent, reducing its value as a healthy food ingredient. In bio-modification technology, on the other hand, the structure and properties of the IDF are gently adjusted through biological processes such as enzymatic action and microbial fermentation. The special feature of this

Technology is that the modification process affects the nutritional composition of the IDF less and has the potential to generate new components beneficial to human health during the modification process.

However, biomodification technology is relatively slow and requires extremely strict

Control of operating conditions (e.g. temperature, humidity, pH, etc.), which

Complexity of technology implementation is increased. In addition, the high costs for cultivating and extracting bioenzymes or specific microorganisms are driving the

Total production costs continue to rise, limiting the economic viability of the technology in certain application scenarios.

Content of the invention

The aim of the present invention is to provide a process for modifying insoluble

Providing fiber by subcritical water in combination with alkaline hydrogen peroxide to solve the above-mentioned problems of the prior art.

To achieve the above object, the present invention provides the following technical

Solution ready: a process for modifying insoluble fiber by subcritical

Water in combination with alkaline hydrogen peroxide, the process comprising the following

Steps include: (1) Pretreatment of raw materials; (2) Defatting treatment by ethanol reflux process; (3) Enzymatic deproteinization treatment; (4) SW modification treatment; (5) AHP modification treatment; (6) Evaluation of the modification effect.

Preferably, the pretreatment of the raw material comprises in particular: washing,

Drying, crushing and sieving the corn cob to be processed with a mesh size of 60 to obtain corn cob powder with uniform particle size.

Preferably, the ethanol reflux process for defatting treatment comprises in particular the following steps: the corn cob powder obtained in step (1) is introduced into a

round-bottomed flask, a sufficient amount of anhydrous ethanol is added to

Powder, a reflux device is installed, the ethanol is heated until it boils slightly and produces a stable reflux, and this condition is maintained for a certain

period to achieve sufficient degreasing. After completion of the

After defatting, the powder is cooled, filtered, washed several times with deionized water and air-dried to obtain defatted corn kernel powder.

Preferably, the specific process of enzymatic

Deproteinization treatment: Mix the defatted corn kernel powder obtained in step (2) with distilled water at a material-liquid ratio of 1:10 m:V, adjust the pH to 9.0 with 1 mol/L NaOH solution, add 0.7% alkaline protease, and stir the reaction in a water bath at 45°C for 1 h. The reaction is then carried out by stirring with 1 mol/L HCl solution. Adjust the pH of the solution to 6.5 with 1 mol/L HCl.

Addition of 0.3% sucrase and 1.5% o-amylase, stirring the reaction at 45°C for 1 h,

Iodine solution did not turn blue, boiling water bath for 10 min to inactivate d&$/600206

Enzyme and stopping the reaction; cooling, filtration, washed with deionized water to neutral, the filter residue was dried in 45 °C electric constant temperature blower

Oven drying to obtain the original corn grain IDF, called OIDF.

Preferably, the specific operation of the SW modification treatment comprises: mixing the maize grain OIDF obtained from the treatment in step (3) with distilled water in

Material-liquid ratio of 1:10 (m:V), and then pouring the above reaction solution into a microreactor, and modifying the treatment for 30 minutes at 140°C, 160°C, and 180°C, respectively; Immediately after completion of the reaction, the reaction vessel was quickly cooled to room temperature with tap water, centrifuged, filtered, the filter residue collected, washed with distilled water until neutral, and dried in an electric jet drying oven at 45°C to constant weight to obtain the SW-modified MIDF, called SWr-

MIDF, where T is the reaction temperature.

Preferably, the specific process of AHP-modified treatment comprises: mixing the SWT-MIDF obtained from the treatment in step (4) with 0.5%, 1%, 1.5% (w/w)

Hydrogen peroxide reaction solution in accordance with the material-liquid

A ratio of 1:20 (w/v) was sufficient, and the pH of the solution was adjusted to 11 with 5 mol/L NaOH. The above reaction solution was placed in a digital thermostatic

The solution was placed in a water bath at 80 °C, after which the pH of the solution was adjusted to neutral with 1 mol/L HCl to terminate the reaction, centrifuged, filtered, and the filtrate collected. The filtrate was washed with distilled water until neutral and

constant weight in an electric forced air drying oven at 45 °C to obtain AHP-modified MIDF designated SWT-AHPw»;-MIDF, where T is the

reaction temperature and w% is the mass fraction of hydrogen peroxide.

Preferably, the specific process of assessing the modification effect comprises:

Evaluation of the modification effect of the SWr-AHPy0-MIDF product obtained in step (5), including the determination of water holding capacity, swelling capacity,

Oil retention capacity, glucose adsorption capacity and antioxidant capacity.

The advantageous effects of the present invention compared to the prior art are:

By combining SW and AHP modification techniques, the present

Invention provides an integrated and efficient modification of IDF by the methods described in the present

Invention proposed subcritical water-coupled alkaline

Hydrogen peroxide modification of insoluble fiber. This innovative strategy not only simplifies the modification process but also improves the efficiency of

Modification of IDF, resulting in higher quality IDF products in a short time.

The expertise of AHP modification technology in regulating the chemical structure of IDF is fully utilized and enables precise

Adapting the chemical structure of IDF to the requirements of different applications.

This fine-tuning allows IDF products to achieve a wider range of applications and higher market value.

The alkaline hydrogen peroxide modified fibers coupled with subcritical water have excellent hydration properties, including good water retention and swelling capacity, which increases the nutritional value and health benefits of the

Product and expands its application in food and health products; The subcritical water-coupled, alkaline hydrogen peroxide-modified fibers have increased glucose adsorption capacity and antioxidant capacity, which contributes to the regulation of blood sugar levels, the prevention of

Diabetes and the defense against free radical damage, helping to protect cellular health and increasing the competitiveness and health benefits of the product.

By combining SW and AHP modification technology, the present invention effectively avoids the introduction of chemical residues and thus ensures the

Safety of IDF products. At the same time, the technology also improves the taste of the

IDF, so that they better meet the taste preferences of consumers. This double

Guarantee of safety and taste makes the IDF product more competitive in the market.

Description of the attached drawings

Figure 1 shows a flow diagram of the method of the present invention.

Detailed description

In order to more clearly understand the purpose of the present invention, the technical solutions for a clear and complete description, and the advantages, the following

Embodiments of the present invention in detail in conjunction with the attached

drawings. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, not all of the

Embodiments, only for the explanation of the embodiments of the present invention, and is not used to limit the embodiments of the present invention, all other embodiments obtained by the ordinary person skilled in the art, without any creative work under the premise of protecting the scope of the present

Invention.

Embodiment 1

With reference to the attached Figure 1, the present invention represents a technical

Solution: a process for modifying insoluble fiber by alkaline hydrogen peroxide coupled with subcritical water, the process comprising the following steps: (1) Pretreatment of raw materials: The corn cob to be processed is washed, dried, crushed, and sieved through a 60-mesh sieve to obtain corn cob powder with a uniform grain size. (2) Defatting treatment by ethanol reflux method: The product obtained in step (1)

Corn cob powder is placed in a round-bottom flask, mixed with sufficient anhydrous ethanol to flood the powder, and a reflux device is installed. Heat the

Ethanol to a gentle boil and create a stable reflux, keep this

condition for a certain period of time to completely degrease. During this time, the

Heating intensity is controlled to avoid violent boiling of the ethanol. After completion of the

After defatting, the powder was cooled, filtered, washed several times with deionized water, and air-dried to obtain defatted corn kernel powder. (3) Enzymatic deproteinization: The defatted corn kernel powder obtained in step (2) was mixed with distilled water at a material-to-liquid ratio of 1:10 (m:v), the pH of the solution was adjusted to 9.0 with 1 mol/L NaOH, 0.7% alkaline protease was added, and the reaction was stirred in a water bath at 45°C for 1 h. The pH of the solution was adjusted to 6.5 with 1 mol/L HCl, 0.3% sucrase and 1.5% α-amylase were added, and the reaction was stirred at 45°C for 1 h. The iodine solution did not change the blue color, ur 600206 the reaction was terminated by inactivating the enzyme in a boiling water bath for 10 min.

Cooling, filtration, washing with deionized water to neutral, the filter residue was dried in a 45 °C electric constant temperature fan drying oven to obtain the original 5 IDF of corn kernels, called OIDF. (4) SW modification treatment: The resulting from the treatment in step (3)

Corn kernel OIDF is mixed with distilled water in a ratio of 1:10 (m:V), then the above reaction solution is poured into a microreactor and subsequently modified for 30 minutes at 140°C, 160°C, and 180°C, respectively. Immediately after the reaction, the reaction vessel was quickly cooled to room temperature with tap water, centrifuged, filtered, and the

Filter residue was collected, washed with distilled water until neutral and dried in an electric fan drying oven at 45 °C to a constant weight to

SW-modified MIDF, called SWT-MIDF (T stands for the reaction temperature). (5) AHP modification treatment: The SWT-MIDF obtained in step (4) was treated with 0.5%, 1%, 1.5% (w/w) hydrogen peroxide reaction solution according to the material-liquid

ratio of 1:20 (w/v), and the pH of the solution was adjusted to 11 with 5 mol/L NaOH. The above reaction solution was placed in a digital thermostatic

water bath at 80 °C. The pH of the solution was then adjusted to neutral with 1 mol/L HCl, the reaction was stopped, centrifuged, filtered, and the filtrate was collected.

The filtrate was washed with distilled water until neutral and evaporated in an electric

Forced air drying oven at 45 °C to obtain AHP-modified MIDF designated SWTt-AHPw%-MIDF (T stands for the reaction temperature, w% for the mass fraction of hydrogen peroxide). (6) Evaluation of the modification effect: The SWT-AHPw%-MIDF obtained in step (5)

MIDF product was evaluated for its modifying effect, including the

Determination of hydration properties (water retention and swelling capacity),

Oil retention capacity, glucose adsorption capacity and antioxidant capacity.

Embodiment 2

Based on Embodiment 1, the corn cob was first subjected to defatting and deproteinization according to the above technical scheme to obtain OIDF, and then subjected to SW modification treatment under the following conditions: temperature of 140 °C and time of 30 min. After modification, the pH

Value set to 11 and a 1.5% (w/w) hydrogen peroxide solution was added, and the

The reaction was carried out for 4 h under conditions of 80 °C. At the end of the reaction, the pH was adjusted to neutral to terminate the reaction, followed by centrifugation and washing. Finally, the filter residue was dried to obtain the modified product SW140°C-AHP1.5%-MIDF. The product had a

Water retention capacity of 4.14 g/g, swelling capacity of 2.82 mL/g, oil retention capacity of 3.03 g/g, and glucose adsorption capacity of 293.66 mg/g. The antioxidant capacity of the ABTS radical scavenger was 1.08 umol Trolox/g absolute dry mass (DM) and that of the

DPPH radical scavenger 0.03 pmol Trolox/g DM.

Embodiment 3

Based on Embodiment 2, a similar procedure was followed as in Example II, but the conditions for the SW modification were set to a temperature of 160 °C for 30 min; the conditions for the AHP modification were set to a pH of 11, and the amount of hydrogen peroxide was set to 1.0% (w/w), and the&600206

The reaction was carried out at 80 °C for 4 h. At the end of the reaction, the pH was adjusted to neutral, and the reaction was stopped and then subjected to centrifugal treatment and water washing. Finally, the filter residue was dried to obtain the modified SW160°C-AHP1.0%-MIDF product. The product exhibited a

Water retention capacity of 4.65 g/g, a swelling capacity of 3.37 ml/g, a

Oil retention capacity of 3.65 g/g, a glucose adsorption capacity of 397.06 mg/g and antioxidant capacities of 3.01 umol Trolox/g DM (ABTS radical scavenger) and 0.04 umol

Trolox/g DM (DPPH radical scavenger).

Embodiment 4

Embodiment 3 was similar to embodiment 2, but the conditions for the

SW modification set to a temperature of 180°C for 30 min; the conditions for the

AHP modification were adjusted to a pH of 11, and the amount of

Hydrogen peroxide was adjusted to 0.5% (w/w), and the reaction was carried out at 80°C for 4 h. At the end of the reaction, the pH was adjusted to neutral, and the reaction was terminated. Centrifugation and washing were then performed. Finally, the filter residue was dried to obtain the modified SW180°C-AHP0.5%-MIDF product. The product exhibited a water holding capacity of 3.81 g/g, a swelling capacity of 2.55 mL/g, an oil holding capacity of 2.70 g/g, a glucose adsorption capacity of 191.48 mg/g, and antioxidant capacities of 4.25 pmol Trolox/g DM for ABTS radicals and 0.05 pmol

Trolox/g DM for DPPH radicals.

Comparison example 1

Based on Embodiment 1, corn cobs were first defatted, deproteinized, washed, and dried according to the technical scheme described above to obtain a corn cob OIDF product. The product was treated with a

Water retention capacity of 2.24 g/g, a swelling capacity of 1.97 ml/g, a

Oil holding capacity of 1.88 g/g, a glucose adsorption capacity of 57.25 mg/g and an antioxidant capacity of 2.35 umol Trolox/g DM (ABTS radical scavenger) and 0.04 umol

Trolox/g DM (DPPH radical scavenger). (OIDF from maize kernels was not tested with SW and

AHP modification and directly subjected to physicochemical properties and functional characterization).

Comparison example 2

Based on embodiment 1, the corn cob was first subjected to defatting and deproteinization and then to SW-

Modification treatment under the following conditions: temperature of 160°C and time of 30 min. After completion of the modification, the filtrate residue was subjected to

subjected to drying treatment, and the modified SW160° C.-IDF product was obtained.

The water holding capacity of the product was 4.12 g/g, the swelling capacity 2.74 mL/g, the oil holding capacity 2.70 g/g, the glucose adsorption capacity 119.66 mg/g and the antioxidant capacities of the ABTS radical scavenger 3.31 µmol Trolox/g DM and the DPPH-

radical scavenger with 0.05 μmol Trolox/g DM. (Maize kernel OIDF was not treated with AHP-coupled modification, and the physicochemical and functional properties were determined only after SW-modified treatment.)

Comparison example 3

Based on Embodiment 1, the corn cob was first subjected to defatting and deproteinization treatment according to the above technical scheme and to AHP modification treatment. The modification conditions were as follows: pH adjustment to 11, addition of 1.0% (w/w) hydrogen peroxide solution, and reaction at 80°C for 4 hours. At the end of the reaction, the pH was adjusted to neutral, the reaction was terminated, and then centrifugation and water washing were carried out. Finally, the filter residue was dried to obtain the modified AHP 1.0%.

IDF product. The product had a water retention capacity of 3.51 g/g, a

Swelling capacity of 2.43 mL/g, an oil retention capacity of 2.56 g/g, a

Glucose adsorption capacity of 154.91 mg/g and antioxidant capacity of 0.50 umol

Trolox/g DM for the ABTS radical scavenger and 0.03 umol Trolox/g DM for the DPPH

(Maize kernel OIDF was not modified with SW and only with AHP-

Modification for physicochemical and functional properties).

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that numerous changes, modifications,

Substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is limited by the appended claims and their equivalents.

Claims (7)

Claims LU600206 1. A process for modifying insoluble dietary fiber using subcritical water in combination with alkaline hydrogen peroxide, characterized in that the process comprises the following steps: (1) pretreatment of the raw materials; (2) defatting treatment by ethanol refluxing; (3) enzymatic deproteinization treatment; (4) SW modification treatment; (5) AHP treatment; (6) evaluation of the modification effect. 2. A process for modifying insoluble fiber by subcritical water in combination with alkaline hydrogen peroxide according to claim 1, characterized in that the pretreatment of the raw material comprises in particular: washing, drying, crushing and sieving the corn kernel to be processed with 60 mesh to obtain corn kernel powder with a uniform particle size. 3. A process for modifying insoluble dietary fiber using subcritical water in combination with alkaline hydrogen peroxide according to claim 2, characterized in that the defatting treatment by the ethanol reflux method specifically comprises: placing the corn kernel powder obtained in step (1) in a round-bottomed flask and adding a sufficient amount of anhydrous ethanol to flood the powder. Installing the reflux device, heating until the ethanol gently boils and creating a stable reflux, maintaining this state for a certain time to achieve complete defatting. During this period, the heating intensity must be controlled to avoid violent boiling of the ethanol. Defatting is completed, cooling, filtering and washing the powder with deionized water several times, and air drying to obtain defatted corn kernel powder. 4. A method for modifying insoluble dietary fiber by subcritical water in combination with alkaline hydrogen peroxide according to claim 1, characterized in that the specific process of the enzymatic deproteinization treatment comprises: mixing the defatted corn kernel powder obtained in step (2) with distilled water in a material-liquid ratio of 1:10 m:V, and adjusting the solution pH to 9.0 with 1 mol/L NaOH. Add 0.7% alkaline protease, 45°C water bath stirring reaction for 1 h, with 1 mol/L HCl is adjusted to 6.5 solution pH, add 0.3% sucrase and 1.5% α-amylase, 45°C water bath stirring reaction for 1 h, iodine detection does not produce blue, boiling water bath for 10 min inactivation of the enzyme, the end of the reaction; Cooling, filtration, washed with deionized water to neutral, the filter residue was dried in 45 °C electrothermal constant temperature blower drying oven to obtain the original IDF of corn cobs, called as OIDF. 5. A method for modifying insoluble fiber by subcritical water in combination with alkaline hydrogen peroxide according to claim 1, characterized in that the specific operation of the SW modification treatment comprises: mixing the corn grain OIDF obtained from the treatment in step (3) with distilled water in a material-liquid ratio of 1:10 m:V. Then, the above reaction solution was poured into a microreactor, and the modification treatment was carried out at 140°C, 160°C, and 180°C, respectively, for 30 minutes; Immediately after the reaction, the reaction vessel nk}600206 tap water was quickly cooled to room temperature, centrifuged, filtered, the filtrate residue was collected, washed with distilled water until neutral, and dried in an electric jet drying oven at 45 °C to constant weight to obtain the SW-modified MIDF, called SWt-MIDF, where T represents the reaction temperature. 6. A method for modifying insoluble dietary fiber using subcritical water in combination with alkaline hydrogen peroxide according to claim 1, characterized in that the specific procedure of the AHP modification treatment comprises: the SWT-MIDF obtained from the treatment in step (4) was thoroughly mixed with 0.5%, 1%, and 1.5% (w/w) hydrogen peroxide reaction solution according to the material-liquid ratio of 1:20 (w/v). The pH of the solution was adjusted to 11 with 5 mol/L NaOH, and the above reaction solution was placed in a digital thermostatic water bath at 80°C for 4 hours. Thereafter, the pH of the solution was adjusted to neutral with 1 mol/L HCl, and the reaction was terminated by centrifugation, filtration, collecting the filtrate residue, and washing with distilled water to neutrality. It was then dried to constant weight in an electric drying oven at 45°C to obtain AHP-modified MIDF, referred to as SWTt-AHPw%-MIDF, where T is the reaction temperature and w% is the mass fraction of hydrogen peroxide. 7. A method for modifying insoluble fiber by subcritical water in combination with alkaline hydrogen peroxide according to claim 1, characterized in that the specific process of evaluating the modification effect comprises: evaluating the modification effect of the SWT-AHPy0-MIDF product obtained in step (5), including determining the water holding capacity, swelling capacity, oil holding capacity, glucose adsorption capacity and antioxidant capacity.