Method for improving gel strength of gracilaria powder

Abstract

The invention discloses a method for improving the gel strength of gracilaria powder. The method comprises the following steps: carrying out enzymolysis treatment on gracilaria; carrying out yeast fermentation treatment on the gracilaria after enzymolysis; and filtering the fermented bacterial liquid, washing and cleaning the fermented gracilaria, drying to constant weight, carrying out superfine grinding until the particle size is less than 10 microns, and carrying out screw extrusion, crushing and sieving to obtain the gracilaria powder. In this way, the gracilaria powder is modified, the modified gracilaria powder can form strong gel after being heated and cooled at the temperature of 50 DEG C, the gel strength of the gracilaria powder can be greatly improved, meanwhile, the temperature needed by gelling of the gracilaria powder is reduced, more possibilities are provided for application of the gelling property of the gracilaria powder, and meanwhile the economic cost of the gracilaria powder is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for improving the gel strength of Gracilaria powder. Background Art

[0002] Gracilaria powder is a powdered product derived from Gracilaria seaweed. It is also a natural high-quality health food raw material that is high in dietary fiber, high in protein, low in fat, low in calories, and rich in minerals, trace elements and vitamins. Because its algae contain rich agar components, Gracilaria powder can form an irreversible gel after heating and cooling.

[0003] The gelling property of Gracilaria powder has a wide range of applications in the food industry, medicine and cosmetics. Taking the food industry as an example, Gracilaria powder is often used as a thickener, stabilizer and gelling agent to improve the texture and taste of food. For example: in meat products, the gelling property of Gracilaria powder can simulate the physical properties and sensory properties of fat, and improve the elasticity and taste of the product; in pastry food, it can improve the texture of pastries, making the product softer and more elastic; in beverages, it can prevent stratification and precipitation between different ingredients, maintain the uniformity and stability of food, etc. In addition, the gelling property of Gracilaria powder also has certain health functions. For example, it can combine with harmful heavy metal elements in the human body to generate water-insoluble heavy metal salt precipitation, which is excreted from the body with feces, thereby playing a detoxifying role. At the same time, Gracilaria powder can also promote intestinal peristalsis, increase fecal volume, and help prevent constipation and intestinal diseases.

[0004] However, the untreated Gracilaria powder has low gel strength and high gel temperature, which limits its application range. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a method for improving the gel strength of Gracilaria powder. The method modifies the Gracilaria powder so that the Gracilaria powder can form a gel at a relatively low temperature, thereby saving economic costs.

[0006] To achieve the above object, the present invention proposes a method for improving the gel strength of Gracilaria powder, which comprises the following steps:

[0007] The Gracilaria was subjected to enzymatic hydrolysis;

[0008] The enzymatically hydrolyzed Gracilaria is subjected to yeast fermentation treatment;

[0009] The fermented bacterial liquid is filtered, the fermented Gracilaria is rinsed clean, dried to constant weight, ultrafinely ground to a particle size of less than 10 μm, screw extruded, ground and sieved to obtain Gracilaria powder.

[0010] According to an embodiment of the present invention, a method for improving the gel strength of Gracilaria powder is provided. The method first prepares Gracilaria powder by enzymolysis-fermentation, and then performs ultrafine grinding and screw extrusion treatment on the Gracilaria powder, so that the Gracilaria powder is modified. The modified Gracilaria powder can form a strong gel after being heated and cooled at 50°C, which can greatly improve the gel strength of the Gracilaria powder and also reduce the temperature required for the gel of the Gracilaria powder, thereby providing more possibilities for the application of the gel properties of the Gracilaria powder and reducing its economic cost.

[0011] Optionally, the Gracilariae are enzymatically treated with α-amylase and saccharifying enzyme.

[0012] Optionally, enzymatic hydrolysis of Gracilaria is performed by washing Gracilaria, adding 5-15 times volume of 0.5%-20% sodium chloride solution, adjusting the pH value to 5.0-6.0, and then adding α-amylase and saccharifying enzyme to perform enzymatic hydrolysis at 50°C-60°C.

[0013] Furthermore, 200U-400U of α-amylase and 4000U-6000U of saccharifying enzyme are added per gram of Gracilaria; and the enzymolysis time is 1h-4h.

[0014] Optionally, the hydrolyzed Gracilaria is subjected to yeast fermentation treatment by: washing the hydrolyzed Gracilaria clean and draining the water, mixing with 10-30 times volume of yeast solution, and fermenting at 20° C.-30° C. for 4 h-8 h.

[0015] Furthermore, the yeast culture liquid is prepared by inoculating brewer's yeast in sterile sugar water with a sugar concentration of 2%-7% at an inoculation amount of 0.2%-0.4%, activating it at 20℃-30℃ for 6h-12h, and then diluting the culture liquid 3-5 times with sterile water.

[0016] Optionally, the drying temperature is 60°C-100°C.

[0017] Optionally, the moisture content of the material during screw extrusion is 35%-55%, the temperature of the front zone of extrusion is 60°C-80°C, the temperature of the middle zone is 80°C-110°C, and the temperature of the rear zone is 110°C-130°C.

[0018] Optionally, crush through a 100 mesh sieve.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The gel strength of Gracilaria powder in Examples and Comparative Examples. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0022] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0023] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0024] The raw materials of Gracilaria gracilis were purchased from Lvxin (Fujian) Food Co., Ltd.

[0025] The yeast used is Angel active dry yeast.

[0026] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0027] Example 1

[0028] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0029] Preparation of yeast solution: Take 5L of sterile water, add 5% (w / v) white sugar, stir to dissolve, inoculate 0.2% (v / v) brewer's yeast and activate at 25°C for 8h (until the yeast concentration reaches 2×10 8 CFU / mL or more), and dilute the bacterial solution 4 times with sterile water to obtain yeast solution.

[0030] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0031] Ultrafine grinding: Filter out the fermented bacterial liquid, wash the fermented Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0032] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0033] Example 2

[0034] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0035] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0036] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0037] Ultrafine grinding: Filter out the fermented bacterial liquid, wash the fermented Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0038] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0039] Example 3

[0040] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0041] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.4% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0042] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0043] Ultrafine grinding: Filter out the fermented bacterial liquid, wash the fermented Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0044] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0045] Comparative Example 1

[0046] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0047] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0048] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0049] Ultrafine grinding: Filter out the fermented bacterial liquid, wash the fermented Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0050] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0051] Comparative Example 2

[0052] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0053] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0054] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0055] Ultrafine grinding: Filter out the fermented bacterial liquid, wash the fermented Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0056] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0057] Comparative Example 3

[0058] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0059] Ultrafine grinding: Wash the enzymatically hydrolyzed Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in an oven at 60°C to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0060] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0061] Comparative Example 4

[0062] Cleaning Gracilaria: Accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water and drain.

[0063] Ultrafine grinding: Dry the washed Gracilaria in a 60℃ oven to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0064] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0065] Comparative Example 5

[0066] Cleaning Gracilaria: Accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water and drain.

[0067] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0068] Gracilaria fermentation: Mix the cleaned Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0069] Enzymatic hydrolysis of Gracilaria: add 10L of 0.9% sodium chloride solution to the fermented Gracilaria, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2h. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0070] Ultrafine grinding: Wash the enzymatically hydrolyzed Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in an oven at 60°C to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10μm.

[0071] Screw extrusion: The ultrafinely crushed Gracilaria powder is screw extruded, and the parameters of the screw extrusion are: the moisture content of the material is 45%, the temperature of the front zone of the extrusion is 70°C, the temperature of the middle zone is 100°C, and the temperature of the back zone is 120°C. After screw extrusion, the powder is pulverized with an ordinary pulverizer and passed through a 100-mesh sieve to obtain Gracilaria powder.

[0072] Comparative Example 6

[0073] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0074] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0075] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0076] Ultrafine grinding: Wash the enzymatically hydrolyzed Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in an oven at 60°C to constant weight. After the sample is dried, use an ultrafine grinder to grind it to less than 10 μm to obtain Gracilaria powder.

[0077] Comparative Example 7

[0078] Enzymatic hydrolysis of Gracilaria: accurately weigh 1 kg of dry Gracilaria, remove impurities and wash with sufficient water; add 10L 0.9% sodium chloride solution, adjust the pH to 5 with hydrochloric acid or sodium hydroxide, then add 300000U α-amylase (200U-400U α-amylase per gram of Gracilaria) and 5000000U saccharifying enzyme (4000U-6000U saccharifying enzyme per gram of Gracilaria), and place in a 55°C constant temperature water bath for enzymatic hydrolysis for 2 hours. Rinse the enzymatically hydrolyzed Gracilaria with 2-3 times of water and drain the water to obtain the enzymatically hydrolyzed Gracilaria.

[0079] Preparation of yeast solution: Take 5L of sterile water, add 5% white sugar, stir to dissolve, inoculate 0.3% brewer's yeast and activate it at 25°C for 8h, then dilute the solution 4 times with sterile water to obtain yeast solution.

[0080] Gracilaria fermentation: Mix the enzymatically hydrolyzed Gracilaria with 20 times the volume of yeast solution and ferment at 25°C for 5 hours.

[0081] Crushing: Wash the enzymatically hydrolyzed Gracilaria with 5 times the amount of clean water for 3 times, drain, and dry in an oven at 60°C to constant weight. After the sample is dried, grind it with an ordinary grinder and pass it through a 100-mesh sieve to obtain Gracilaria powder.

[0082] Test example

[0083] The gel strength of the Gracilaria powder obtained in Examples 1-3 and Comparative Examples 1-7 was tested.

[0084] The gel strength determination method is as follows: referring to the method for preparing 1.5% agar (dry basis) gel sample in GB 1886.239-2016 "National Food Safety Standard Food Additive Agar", according to the measured moisture content of Gracilaria powder, the sample weight is calculated according to the following formula.

[0085]

[0086] Where: X is the weight of the sample, g; D is the mass fraction of moisture in the sample, %.

[0087] Accurately weigh 0.95g of the sample calculated by the above formula, place it in a 100mL conical flask, add 60mL of hot water at different temperatures, maintain it in a constant temperature water bath for 10 minutes, then pour the adhesive liquid into a culture dish, cool it until a colloid is formed, seal it with plastic wrap, and measure its gel strength with a texture analyzer after 12 hours. The parameters of the texture analyzer are: using a P / 0.5 probe, the speeds before, during, and after the test are 2, 1, and 2mm / s respectively, the trigger force is 5g, and the downward deformation is 50%.

[0088] The results are as follows Figure 1 As shown in Figure 2, the gel strength of the Gracilaria powder obtained in Example 2 at 60°C is 351.30 g / cm 2; The gel strength at 70°C is 365.46 g / cm 2 ; Gel strength at 80°C is 417.17 g / cm 2 ; The gel strength at 90°C is 449.95 g / cm 2 ; Gel strength at 100°C is 466.23 g / cm 2 The gel strengths of the comparative examples are much lower than those of the embodiments.

[0089] In summary, according to the embodiments of the present invention, the gel strength of the Gracilaria powder prepared in Example 2 is the best, and a good gel strength can be formed at a lower temperature. By adopting the method of the present application, the Gracilaria powder is first prepared by enzymatic hydrolysis-fermentation, and then the Gracilaria powder is ultrafinely ground and screw extruded. The obtained gel strength is much higher than that before modification, and the gel temperature is much lower than that before modification.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0091] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for improving the gel strength of Gracilaria powder, characterized in that: The following steps are involved: The Gracilaria was subjected to enzymatic hydrolysis; The enzymatically hydrolyzed Gracilaria is subjected to yeast fermentation treatment; The fermented bacterial liquid is filtered, the fermented Gracilaria is rinsed clean, dried to constant weight, ultrafinely ground to a particle size of less than 10 μm, screw extruded, ground and sieved to obtain Gracilaria powder.

2. The method according to claim 1, characterized in that The enzymatic hydrolysis of Gracilaria was carried out using α-amylase and saccharifying enzyme.

3. The method according to claim 1, characterized in that The enzymatic hydrolysis treatment of Gracilaria is as follows: after washing Gracilaria, 5-15 times volume of sodium chloride solution with a concentration of 0.5%-20% is added, the pH value is adjusted to 5.0-6.0, and alpha-amylase and saccharifying enzyme are added to perform enzymatic hydrolysis at 50-60°C.

4. The method according to claim 2 or 3, characterized in that Add 200U-400U of α-amylase and 4000U-6000U of saccharifying enzyme per gram of Gracilaria; the enzymolysis time is 1h-4h.

5. The method according to claim 1, characterized in that The enzymatically hydrolyzed Gracilaria is subjected to yeast fermentation treatment as follows: the enzymatically hydrolyzed Gracilaria is rinsed and drained, and then mixed with 10-30 times the volume of yeast solution, and fermented at 20° C.-30° C. for 4 h-8 h.

6. The method according to claim 5, characterized in that The yeast liquid is prepared by inoculating brewer's yeast in sterile sugar water with a sugar concentration of 2%-7% at an inoculation amount of 0.2%-0.4%, activating it at 20°C-30°C for 6h-12h, and then diluting the liquid by 3-5 times with sterile water.

7. The method according to claim 1, characterized in that The drying temperature is 60℃-100℃.

8. The method according to claim 1, characterized in that The moisture content of the material in screw extrusion is 35%-55%, the temperature in the front zone of extrusion is 60℃-80℃, the temperature in the middle zone is 80℃-110℃, and the temperature in the rear zone is 110℃-130℃.

9. The method according to claim 1, characterized in that Grind through 100 mesh sieve.

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