Dictyophora rubrovolvata beta-glucan low-calorie hydrophilic colloid as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of food additives, and particularly discloses dictyophora rubrovolvata beta-glucan low-calorie hydrophilic colloid and a preparation method and application thereof.The dictyophora rubrovolvata beta-glucan in dictyophora rubrovolvata is extracted through a water extraction and alcohol precipitation method, and the extract has good physiological activities such as blood sugar lowering activity and immunity. And compounding the dictyophora rubrovolvata beta-glucan and erythritol through a series of steps of sol dissolving, decocting and cooling, so as to prepare the dictyophora rubrovolvata beta-glucan low-calorie hydrophilic colloid. The prepared dictyophora rubrovolvata beta-glucan low-calorie hydrophilic colloid is applied to preparation of low-calorie soft sweets, the situation that traditional soft sweets with gelatin as a gelling agent are low in nutritional value and rich in saccharides, and the risk of chronic diseases such as obesity, decayed teeth, hyperglycemia and type II diabetes mellitus can be possibly increased is broken through, and the prepared dictyophora rubrovolvata beta-glucan low-calorie hydrophilic colloid has the advantages of being simple in preparation process, low in cost and the like. And a development direction is provided for researching and developing a novel functional gelling agent into soft sweets.

Description

Technical Field

[0001] This invention relates to the field of food additives technology, and in particular to a novel hydrophilic colloid of *Dictyophora indica* β-glucan / erythritol, its preparation method, and its application. Background Technology

[0002] Red-topped bamboo fungus β-glucan is a natural polysaccharide and a pseudoplastic fluid with high viscosity and a weak gel structure, possessing excellent heat resistance, strong gel stability, and gelling properties. It also exhibits various physiological activities such as immunomodulation, hypoglycemic effects, antioxidant activity, anti-inflammatory activity, anti-tumor activity, anti-fatigue activity, anti-aging, and protection against alcoholic liver damage. Erythritol is a tetracarbon polyol sweetener with a mild sweetness and low caloric value, approximately one-tenth that of sucrose, and is commonly used as a sweetener in food. By combining these two ingredients, the gel structure of the polysaccharide is enhanced, and it is then used as a gelling agent in low-calorie gummies to prepare functional low-calorie gummies.

[0003] A review of existing gummies reveals that the vast majority use gelatin as a gelling agent. However, for certain consumer groups, such as vegetarians, those with halal or kosher certifications, these properties are not entirely suitable. Traditional gummies may increase the risk of chronic diseases such as obesity, tooth decay, high blood sugar, and type 2 diabetes, which is detrimental to health. Furthermore, the application of the novel hydrophilic colloid of *Dictyophora indica* β-glucan / erythritol as a gelling agent in the food industry is limited. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, its preparation method, and its applications.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical solution: One of the technical solutions of this invention is a method for preparing a novel hydrophilic colloid of β-glucan / erythritol from *Dictyophora indica*, comprising the following steps: S1. Pretreatment of red-topped bamboo fungus fruiting bodies: Grind the red-topped bamboo fungus fruiting bodies into fine powder, and then soak them in ethanol for 24 hours; S2. Hot water extraction: Extract with distilled water at a constant temperature of 75°C for 2 hours with stirring. After centrifugation, concentrate the supernatant using a rotary evaporator. S3, alcohol precipitation: Add ethanol and leave at room temperature overnight to achieve a final ethanol concentration of 80%. After centrifugation and freeze-drying, take the supernatant and discard the precipitate. S4. After deproteinization, the purified red-topped bamboo fungus β-glucan was obtained by concentration and freeze-drying. The supernatant was deproteinized with Sevag reagent, dialyzed with distilled water for 48 h, concentrated and freeze-dried after dialysis to obtain purified red-topped bamboo fungus β-glucan. S5, Sol: Add 3% by mass of red-topped bamboo fungus β-glucan and 5% by mass of erythritol to distilled water, and stir continuously until the red-topped bamboo fungus β-glucan and erythritol are completely dissolved; S6. Cooking: Under 100℃ conditions, the uniformly dispersed β-glucan / erythritol solution system of *Dictyophora indicum* is transformed into a gel form by continuous stirring. S6. Incubation treatment: Incubate at 25℃ for 4 hours to obtain a novel hydrophilic colloid of red-topped bamboo fungus β-glucan / erythritol.

[0006] Furthermore, in step S1, the volume concentration of ethanol is 75%.

[0007] Furthermore, in step S2, the centrifugation speed is 5000 r / min and the time is 10 min.

[0008] Furthermore, in step S4, the dialysis bag used for dialysis has a molecular weight cutoff of 8000-14000 Da.

[0009] Furthermore, in step S5, the continuous stirring speed is 1500 rpm and the stirring time is 3 min.

[0010] Furthermore, in step S6, the continuous stirring speed is 1500 rpm and the stirring time is 30 min.

[0011] The second technical solution of the present invention is a novel hydrophilic colloid of β-glucan / erythritol from *Dictyophora indica* prepared by the above method.

[0012] The third technical solution of the present invention is the application of a novel hydrophilic colloid of red-topped bamboo fungus β-glucan / erythritol in the preparation of low-calorie gummies.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention relates to a novel hydrophilic colloid, prepared by compounding β-glucan extracted from the fruiting body of *Dictyophora indicum* with erythritol. This invention can provide insights into the application of novel gelling agents, satisfying the needs of certain dietary types while achieving both health benefits and sensory pleasure.

[0014] The novel hydrophilic colloid of red-topped bamboo fungus β-glucan / erythritol prepared by this invention is applied to the preparation of low-calorie gummies. This breaks the traditional situation where gummies using gelatin as a gelling agent have low nutritional value, are rich in sugars, and may increase the risk of chronic diseases such as obesity, tooth decay, hyperglycemia, and type II diabetes. It also provides a direction for the research and development of novel functional gelling agents for gummies. Attached Figure Description

[0015] Figure 1 The image shows the preparation of low-calorie gummies; Figure 2 The hardness of compound gels with different erythritol concentrations; Figure 3 The textural properties of compound gels with different erythritol concentrations; Figure 4 Rheological properties of compound gels with different erythritol concentrations; Figure 5 The water-holding capacity of compound gels with different erythritol concentrations; Figure 6 Freeze-thaw stability of compound gels with different erythritol concentrations; Figure 7 Thermogravimetric analysis of DRP and EDM-5 prepared with 5% erythritol addition; Figure 8 The antioxidant capacity of DRP, ERY, and EDM-5; Figure 9 To assess the simulated digestion stability of DRP and EDM-5 in artificial saliva; Figure 10 To assess the simulated digestion stability of DRP and EDM-5 in artificial gastric fluid; Figure 11 To assess the simulated digestion stability of DRP and EDM-5 in an artificial gastrointestinal mixture; Figure 12 The moisture content and water activity of low-calorie gummies; Figure 13 A comparison chart of the reducing sugar content of low-calorie gummies and the national standard content; Figure 14 This is a comparison of the α-amylase inhibition rates between low-calorie gummies and acarbose. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0017] Example 1: Preparation of a novel hydrophilic colloid of β-glucan / erythritol from *Dictyophora indicum* This embodiment exemplifies the preparation process of a novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, as detailed below: S1. Pretreatment of red-topped bamboo fungus fruiting bodies: Grind the red-topped bamboo fungus fruiting bodies into fine powder, and soak 1000g of fine powder in 8000g of 75% ethanol for 24h. S2. Hot water extraction: Take 1000g of the mixed solution in S1, extract it with 31000g of distilled water at 75℃ with constant stirring for 2h, centrifuge (centrifugation speed 5000r / min, time 10min), and concentrate the supernatant using a rotary evaporator. S3, alcohol precipitation: Add ethanol and leave at room temperature overnight to achieve a final ethanol concentration of 80%. After centrifugation and freeze-drying, take the supernatant and discard the precipitate. S4. After deproteinization, the purified red-topped bamboo fungus β-glucan was obtained by concentration and freeze-drying. The supernatant was deproteinized with Sevag reagent and dialyzed with distilled water (the dialysis bag used for dialysis had a molecular weight cutoff of 8000-14000 Da) for 48 h. After dialysis, the purified red-topped bamboo fungus β-glucan (DRP) was obtained by concentration and freeze-drying. S5, Sol: Add 3g of red-topped bamboo fungus β-glucan and 5g of erythritol (ERY) to 1000g of distilled water, and stir continuously (stirring speed is 1500rpm, stirring time is 3min) until red-topped bamboo fungus β-glucan and erythritol are completely dissolved; S6. Cooking: Under 100℃ conditions, the uniformly dispersed β-glucan / erythritol solution system of red bamboo fungus is transformed into a gel form by continuous stirring (continuous stirring speed is 1500 rpm, stirring time is 30 min). S6. Incubation treatment: Incubate at 25℃ for 4 hours to obtain colloidal sample 1, denoted as EDM-5.

[0018] Comparative Example 1 The difference from Example 1 is that the amount of erythritol added in S5 is 0g, resulting in colloidal sample 2.

[0019] Comparative Example 2 The difference from Example 1 is that the amount of erythritol added in S5 is 1g, resulting in colloidal sample 3.

[0020] Comparative Example 3 The difference from Example 1 is that the amount of erythritol added in S5 is 3g, resulting in colloidal sample 4.

[0021] Comparative Example 4 The difference from Example 1 is that the amount of erythritol added in S5 is 7g, resulting in colloidal sample 5.

[0022] Comparative Example 5 The difference from Example 1 is that the amount of erythritol added in S5 is 9g, resulting in colloidal sample 6.

[0023] Application Examples: Application of novel hydrophilic colloids of red-topped bamboo fungus β-glucan / erythritol in the preparation of low-calorie gummies This embodiment exemplifies the preparation of low-calorie gummies using a novel hydrophilic colloid of red-topped bamboo fungus β-glucan / erythritol. The specific process is as follows: 1) Take equal amounts of colloidal sample 1 to colloidal sample 6 and add 25% liquid maltitol at 100℃ and keep at 100℃, stirring continuously for 30 min; 7) Cooling: After the gel system has become uniform and stable, cool it to about 40°C by natural cooling method; 8) Acid adjustment: Dissolve 1.2% citric acid in warm water and add it to the gel system at 40℃. Then add 20% prune juice and stir continuously to make the system stable and evenly distributed. 9) Pouring and Cooling: After obtaining a uniform fruit juice gummy gel system through stirring, it can be poured into gummy molds that meet food-grade standards. After standing and cooling, it will eventually form the desired shape of the gummy, such as... Figure 1 As shown.

[0024] The hardness of compound gels with different erythritol concentrations, such as Figure 2 As shown; the textural properties of the compound gel with different erythritol concentrations are as follows: Figure 3 As shown; the rheological properties of the compound gels with different erythritol concentrations are as follows: Figure 4 As shown; the water-holding capacity of compound gels with different erythritol concentrations is as follows: Figure 5 As shown; the freeze-thaw stability of compound gels with different erythritol concentrations is as follows: Figure 6 As shown; the thermogravimetric diagrams of DRP and EDM-5 are as follows. Figure 7 As shown.

[0025] Depend on Figure 2 It can be seen that in the preparation of the novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, the gel hardness increases progressively as the erythritol concentration increases from 0% to 5%; however, the gel hardness decreases as the concentration increases from 5% to 9%. Figure 3 It can be seen that the addition of erythritol improved the elasticity of the *Dictyophora indica* β-glucan / erythritol composite microgel, with the optimal elasticity being 3.56 mm. Figure 4 It is known that a 5% erythritol concentration represents the optimal critical state for gel aggregation, with a cohesiveness of 0.25; the adhesiveness and chewiness are also optimal at a 5% erythritol concentration, at 2.27 and 0.08, respectively. The composite gel with a 5% erythritol content may also exhibit good stability and retention, maintaining its excellent textural properties during storage and transportation. Figure 5It was found that in the preparation of the novel hydrophilic colloid *Dictyophora indicum* β-glucan / erythritol, the water-holding capacity of the *Dictyophora indicum* β-glucan / erythritol microgel was directly proportional to the erythritol concentration. An inflection point in the water-holding capacity of the composite gel appeared at an erythritol concentration of 5%. Further increasing the erythritol concentration to 9% resulted in the highest water-holding capacity of the microgel, reaching 85.87%. Figure 6 It was found that in the preparation of the novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, the increase in erythritol concentration was positively correlated with the freeze-thaw stability of the microgel. When the erythritol concentration was 9%, the freeze-thaw stability of the composite gel reached its highest level, 76%. Based on cost considerations and the analysis of the above experimental results, a microgel with a 5% erythritol concentration (EDM-5) was selected as the optimal concentration for subsequent experiments.

[0026] Depend on Figure 7 It can be seen that in the preparation of the novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, the degradation temperature of EDM-5 gel is 62℃ higher than that of DRP gel. This proves that the addition of erythritol increases the thermal decomposition residue of the compound gel and promotes the formation of the three-dimensional network structure of the gel. Therefore, the thermal stability of EDM-5 gel is increased.

[0027] In the preparation of the novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, the microgel exhibited shear-thinning behavior, with viscosity increasing with increasing erythritol concentration. The highest gel viscosity (0.72 Pa·s) was observed at a 9% erythritol concentration. However, the apparent viscosities at 5%, 7%, and 9% erythritol concentrations were nearly identical. Based on texture analysis, the microgel with a 5% erythritol concentration (EDM-5) was selected as the optimal concentration.

[0028] The antioxidant capacity of DRP, ERY, and EDM-5 is as follows: Figure 8 As shown, by Figure 8 It was found that in the preparation of the novel hydrophilic colloid of *Dictyophora indica* β-glucan / erythritol, three antioxidant experiments were conducted on erythritol (ERY), DRP, and EDM-5, focusing on their DPPH radical scavenging ability, hydroxyl radical scavenging ability, and total reducing power. EDM-5 exhibited the most outstanding antioxidant performance. EDM-5 achieved a DPPH radical scavenging rate of 42.9% and a hydroxyl radical scavenging rate of 77.1%. Its total reducing power reached 0.43. These three sets of data demonstrate its powerful role in the antioxidant process. Furthermore, erythritol showed a high hydroxyl radical scavenging ability. These data indicate that the compound gel can significantly improve the antioxidant capacity of DRP.

[0029] The stability of DRP and EDM-5 in simulated digestion in artificial saliva is as follows: Figure 9As shown; the simulated digestion stability of DRP and EDM-5 in artificial gastric juice is as follows. Figure 10 As shown; the simulated digestion stability of DRP and EDM-5 in artificial gastrointestinal mixture is as follows. Figure 11 As shown. By Figures 9-11 It is known that in the preparation of the novel hydrophilic colloid of *Dictyophora indicum* β-glucan / erythritol, in vitro simulated digestion results showed that EDM-5 was hardly digested in the oral cavity and stomach, but was easily digested in the intestine.

[0030] The water content and water activity of low-calorie gummies are as follows: Figure 12 As shown in the figure; a comparison chart of the reducing sugar content of low-calorie gummies with the national standard content is shown below. Figure 13 As shown in the figure; a comparison of the α-amylase inhibition rates between low-calorie gummies and acarbose. Figure 14 As shown.

[0031] Depend on Figure 12 The moisture content of low-calorie gummies was determined using the direct drying method as specified in the national standard GB5009.3-2016. The results showed that the moisture content of the gummies was 13 g / 100 g < 18 g / 100 g, which meets the requirements for moisture content of plant-based gummies in SB-T10021-2017. The water activity of the low-calorie gummies was determined using a water activity meter. The experimental results showed that the water activity of the tested sample was 0.65, which meets the water activity requirements for gel gummies and can extend the product's shelf life.

[0032] Depend on Figure 13 The reducing sugar content of the low-calorie gummies was determined using the DNS method, and the result showed that it was 21.05 g / 100 g, which is greater than the requirement of 10 g / 100 g for reducing sugar content in jelly candies in the national standard SB / T 10021-2017. The results indicate that this batch of low-calorie gummies meets the national standard requirements for jelly candies.

[0033] Depend on Figure 14 The assay of the α-amylase inhibition rate of low-calorie gummies, which is also a measure of their hypoglycemic function, showed that gummies with added prune juice effectively enhanced the inhibition rate of α-amylase. Prune juice gummies at a concentration of 4 mg / ml exhibited an inhibition rate as high as 84.01% against α-amylase. In contrast, acarbose, used as a positive control at a concentration of 4 mg / ml, showed an inhibition rate of 78.36%. This indicates that prune juice gummies have excellent hypoglycemic effects and high inhibitory efficacy against α-amylase activity.

[0034] The above results indicate that the novel hydrophilic colloid of red bamboo fungus β-glucan / erythritol in low-calorie gummies possesses gelling properties, and the low-calorie gummies made from it can effectively enhance the inhibition rate of α-amylase, and meet the national standards for gel candies in terms of moisture content, water activity, and reducing sugar content.

[0035] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a low-calorie hydrophilic colloid of Dictyophora rubrovolvata β-glucan, characterized by, It comprises the following steps: S1, red pholiota fruit body pretreatment: red pholiota fruit body is ground into fine powder, and then soaked in ethanol for 24 h; S2, hot water extraction: distilled water is used to extract at 75℃ under constant stirring for 2 h, and after centrifugation, the supernatant is concentrated by a rotary evaporator; S3, alcohol precipitation: ethanol is added, and the final concentration of ethanol is 80% at room temperature overnight, and after centrifugation and freeze-drying, the supernatant is taken and the precipitate is discarded; S4, deproteinization, and after concentrated freeze-drying, refined red pholiota β-glucan is obtained, the supernatant is deproteinized by Sevag reagent, and distilled water is dialyzed for 48 h, and after dialysis, concentrated freeze-drying is carried out to obtain refined red pholiota β-glucan; S5, sol: 3% red pholiota β-glucan and 5% erythritol are added to distilled water, and continuous stirring is carried out until red pholiota β-glucan and erythritol are completely dissolved; S6, simmering: under the condition of 100℃, the red pholiota β-glucan / erythritol solution system in a dispersed uniform state is converted into a gel form by continuous stirring; S6, incubation treatment 25℃ incubation for 4h, to obtain red pholiota β-glucan / erythritol new type hydrophilic colloid.

2. The preparation method of Dictyophora rubrovolvata β-glucan / erythritol novel hydrocolloid according to claim 1, characterized in that: In the step S1, the volume concentration of ethanol is 75%.

3. The preparation method of Dictyophora rubrovolvata β-glucan / erythritol novel hydrocolloid according to claim 1, characterized in that: In the step S2, the centrifugal speed is 5000r / min, and the time is 10min.

4. The preparation method of Dictyophora rubrovolvata β-glucan / erythritol novel hydrocolloid according to claim 1, characterized in that: In the step S4, the molecular weight cut-off of the dialysis bag used for dialysis is 8000-14000Da.

5. The preparation method of Dictyophora rubrovolvata β-glucan / erythritol novel hydrocolloid according to claim 1, characterized in that: In the step S5, the continuous stirring speed is 1500rpm, and the stirring time is 3min.

6. The preparation method of Dictyophora rubrovolvata β-glucan / erythritol novel hydrocolloid according to claim 1, characterized in that, In the step S6, the continuous stirring speed is 1500rpm, and the stirring time is 30min.

7. A red pholiota β-glucan / erythritol new type hydrophilic colloid prepared by the method of any one of claims 1-6.

8. The use of the red pholiota β-glucan / erythritol new type hydrophilic colloid of claim 7 in the preparation of low-calorie soft candy.

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