White tea and konjak vermicelli suitable for diabetics and preparation method of white tea and konjak vermicelli

Abstract

The invention relates to a preparation method of white tea and konjak vermicelli suitable for diabetics, which comprises the following steps: 1) taking aged white tea, crushing to obtain white tea superfine powder, adding purified water into the white tea superfine powder, uniformly stirring, and adding polyphenol oxidase for enzymolysis to obtain white tea flavor powder; (2) pulping fresh konjak tubers to obtain fresh konjak pulp; 3) uniformly stirring the fresh konjak pulp, the white tea flavor powder, the oat beta-glucan, the potassium alginate and the water to obtain a mixed colloid, and then preparing the mixed colloid into strips; and 4) curing, shaping, drying and packaging the strips to obtain the white tea and konjak vermicelli. The prepared white tea and konjak vermicelli is extremely low in glycemic index (GI) value, and is suitable for being used as a staple food substitute for diabetics; meanwhile, various active ingredients such as dietary fibers and tea polyphenols are rich, so that oxidation resistance and intestinal health regulation are facilitated. The white tea and konjak vermicelli prepared by the method perfectly combines the mellow fragrance of white tea and the taste of konjak, and is smooth and chewy in taste and free of bad fishy and alkaline taste.

Description

Technical Field

[0001] This invention relates to the field of functional food processing technology, specifically to a white tea konjac noodle suitable for diabetics, made primarily from konjac and aged white tea, and its preparation method. Background Technology

[0002] Konjac, rich in glucomannan, is an excellent low-calorie, high-fiber raw material, widely used in the development of meal replacements, staple foods, and other health foods. However, current konjac products on the market suffer from the following drawbacks: First, the flavors are monotonous, with konjac itself having a strong fishy and alkaline taste, resulting in poor palatability; second, most products rely solely on the physical feeling of fullness from konjac, lacking active health functions such as anti-oxidation and regulation of glucose and lipid metabolism; third, to improve taste, starch or other carbohydrates are often added, leading to an overall increase in the glycemic index (GI value), which is unfriendly to diabetic patients.

[0003] White tea, especially aged Shoumei, is rich in active ingredients such as tea polyphenols (e.g., catechins) and tea polysaccharides, possessing potential for antioxidant, anti-inflammatory, and blood sugar-lowering effects. However, effectively integrating it into food systems while maintaining its bioactivity remains a significant challenge. Directly adding tea powder often results in a bitter taste, and the coarse texture can negatively impact product quality.

[0004] Therefore, developing a konjac food that can precisely control the glycemic index (GI) while also having good flavor and added health benefits has significant market value and practical significance. Summary of the Invention

[0005] Therefore, the present invention provides white tea konjac noodles suitable for diabetic patients, which have a good taste, low glycemic index (GI) value, and also have the health benefits of white tea, as well as a method for preparing the same.

[0006] Unlike existing technologies, the above technical solution provides a method for preparing white tea konjac noodles suitable for diabetic patients, which includes the following steps: 1) Preparation of white tea flavor powder: Take aged white tea and pulverize it to a particle size D90≤15μm to obtain white tea ultrafine powder; add 20%-40% of its mass of purified water to the white tea ultrafine powder, stir evenly, add polyphenol oxidase, and enzymatically hydrolyze it for 10-30 minutes at 30℃-40℃ and pH 5.5-6.5, and then inactivate the enzyme at 90℃-100℃ for 5-10 minutes to obtain white tea flavor powder; 2) Preparation of fresh konjac pulp: Take fresh konjac tubers, wash and peel them, and immediately place them in an aqueous solution containing 0.1%-0.3% vitamin C to make pulp, thus obtaining fresh konjac pulp; 3) Mixing and shaping: By weight, place 50-70 parts fresh konjac paste, 5-15 parts white tea flavor powder prepared in step 1), 3-8 parts oat β-glucan, 0.5-2 parts potassium alginate and 10-30 parts water into a mixer and vacuum mix at 40℃-60℃ for 20-40 minutes to obtain a uniform mixed colloid; then shape it into strips by extrusion or injection molding. 4) Cooking and shaping: Place the strips in hot water at 85℃-95℃ and cook for 15-30 minutes to obtain vermicelli; 5) Drying and packaging: The cooked vermicelli is dried in stages. First, it is dried with hot air at 50℃-60℃ until the moisture content is 40%-50%, then dried with cold air at 25℃-35℃ until the moisture content is ≤15%, and finally packaged.

[0007] This invention innovatively combines aged white tea ultrafine powder with fresh konjac pulp, supplemented with other specific dietary fiber components and processing techniques, to prepare a white tea konjac noodle product suitable for diabetic patients. The preparation method of the white tea konjac noodle product suitable for diabetic patients described in this invention has the following advantages: Raw Material Innovation and Flavor Synergy: This invention utilizes ultrafine pulverization technology to break down the cell walls of aged white tea, improving the dissolution rate and bioavailability of active ingredients. Simultaneously, polyphenol oxidase is used to moderately enzymatically hydrolyze the ultrafine white tea powder, mimicking the traditional withering process of white tea. This promotes the oxidation and polymerization of catechins in the tea leaves, generating more theaflavins, significantly enhancing the richness of the tea aroma and the fullness of the flavor, while effectively masking the fishy and alkaline taste of konjac.

[0008] Precise GI control and nutritional fortification: This invention uses fresh konjac pulp to replace part of the konjac flour, retaining more natural flavor and trace components. It also incorporates oat β-glucan and potassium alginate, which form a synergistic gel network with konjac glucomannan. This not only enhances the noodles' toughness and cooking resistance but also creates a viscous barrier in the intestines, significantly delaying glucose absorption, thus ensuring the final product's GI value is ≤30.

[0009] Technological innovation ensures product quality: Adding Vitamin C during the pulping of fresh konjac effectively prevents browning. Vacuum stirring removes air bubbles from the colloid, resulting in a denser and more transparent product structure. The segmented drying process (hot air followed by cold air) avoids surface hardening and internal hollowing caused by excessively rapid drying, ensuring uniform texture and good rehydration of the noodles.

[0010] Preferably, in step 1), the aged white tea is Shoumei white tea aged for 4-6 years, and its raw material is fresh leaves picked in the summer. This invention, by selecting Shoumei tea aged for about 5 years (summer raw material), partially converts its tea polyphenols into theaflavins and thearubigins, resulting in a more mellow flavor and reducing the bitterness of new tea.

[0011] Preferably, in step 1), the amount of polyphenol oxidase added is 0.5‰-2‰ of the mass of white tea ultrafine powder.

[0012] Preferably, in step 2), the mass ratio of the vitamin C-containing aqueous solution to the konjac tuber is 1-2:1.

[0013] Preferably, in step 3), the vacuum degree of the vacuum stirring is -0.05MPa to -0.08MPa.

[0014] Preferably, in step 3), the raw materials of the mixed colloid further include 1-3 parts by weight of L-arabinose. The L-arabinose can selectively inhibit the activity of sucrase in the small intestine, thereby further helping to stabilize postprandial blood glucose levels in the prepared white tea konjac noodles.

[0015] The present invention also provides a white tea konjac noodle suitable for diabetic patients, which is prepared by the above-described preparation method.

[0016] Preferably, the white tea konjac noodles of the present invention, suitable for diabetic patients, have a glycemic index (GI) value ≤ 30.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Low GI value and health benefits: The white tea konjac noodles prepared by this invention have an extremely low glycemic index (GI), making them ideal as a staple food substitute for diabetic patients. They are also rich in dietary fiber, tea polyphenols, and other active ingredients, which help with anti-oxidation and gut health regulation.

[0018] 2. Excellent flavor: The white tea konjac noodles prepared by this invention perfectly combine the mellow aroma of white tea with the texture of konjac, resulting in a smooth, chewy texture without any unpleasant fishy or alkaline taste.

[0019] 3. Stable process, suitable for industrial production: The preparation method provided by this invention has a clear process flow, is simple to operate, and is easy to achieve large-scale and standardized production. Detailed Implementation

[0020] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following detailed description is provided in conjunction with specific embodiments.

[0021] Example 1: A method for preparing white tea konjac noodles suitable for diabetic patients White tea flavoring powder: Take 1000g of Shoumei white tea aged for 5 years (summer raw material), and pulverize it to D90≈10μm using an ultrafine pulverizer. Take 100g of white tea ultrafine powder, add 30g of purified water and mix well, then add 0.1g of polyphenol oxidase (i.e., 1‰), and enzymatically hydrolyze it at 35℃ and pH 6.0 for 20 minutes. Then, quickly inactivate the enzyme at 95℃ for 8 minutes, and let it cool for later use.

[0022] Fresh konjac paste: Take 5000g of fresh konjac, wash and peel it, and immediately put it into 6000g of aqueous solution containing 0.2% vitamin C. Use a high-speed tissue homogenizer to make the paste for 2 minutes to obtain fresh konjac paste.

[0023] Mixing and Shaping: In a vacuum mixer, add 600g fresh konjac paste, 80g white tea flavor powder, 50g oat beta-glucan, 10g potassium alginate, 20g L-arabinose, and 200g purified water. Mix at 50℃ and -0.06MPa vacuum for 30 minutes to obtain a uniform, translucent colloid. Extrude into noodles with a diameter of approximately 2mm through a circular perforated plate.

[0024] Maturation and shaping: The extruded noodles are dropped directly into 90℃ hot water and kept warm for 20 minutes to mature.

[0025] Drying and Packaging: The cooked vermicelli is first placed in a 55℃ hot air drying oven and dried to a moisture content of about 45%; then it is transferred to a 30℃ cold air drying room and slowly dried to a moisture content of 13%. Finally, it is vacuum-packed in food-grade packaging bags.

[0026] Example 2: A method for preparing white tea konjac noodles suitable for diabetic patients 1) Preparation of white tea flavor powder: Take 1000g of Shoumei white tea aged for 4 years (summer raw material), and pulverize it to D90≈15μm using an ultra-micro pulverizer to obtain white tea ultra-micro powder; take 100g of white tea ultra-micro powder, add 20g of purified water, stir evenly, then add 0.2g of polyphenol oxidase (i.e. 2‰), and enzymatically hydrolyze it for 30 minutes at 30℃ and pH 6.5, and then inactivate the enzyme at 100℃ for 5 minutes to obtain white tea flavor powder; 2) Preparation of fresh konjac pulp: Take 5000g of fresh konjac tubers, wash and peel them, and immediately place them in 10000g of aqueous solution containing 0.1% vitamin C to make pulp, thus obtaining fresh konjac pulp.

[0027] 3) Mixing and Shaping: In a vacuum mixer, add 700g fresh konjac paste, 150g white tea flavor powder, 30g oat β-glucan, 5g potassium alginate, 10g L-arabinose, and 300g purified water. Mix at 60℃ and -0.05MPa vacuum for 20 minutes to obtain a uniform and transparent mixed colloid; extrude into noodles with a diameter of approximately 2mm through a circular perforated plate. 4) Cooking and shaping: Place the strips in hot water at 85°C and cook for 30 minutes to obtain vermicelli; 5) Drying and Packaging: The cooked vermicelli is first placed in a 50°C hot air drying oven and dried to a moisture content of about 50%; then it is transferred to a 35°C cold air drying room and slowly dried to a moisture content of 13%. Finally, it is vacuum-packed in food-grade packaging bags.

[0028] Example 3: A method for preparing white tea konjac noodles suitable for diabetic patients 1) Preparation of white tea flavor powder: Take 1000g of Shoumei white tea (summer raw material) aged for 6 years, and pulverize it to D90≈15μm using an ultra-micro pulverizer to obtain white tea ultra-micro powder; take 100g of white tea ultra-micro powder, add 40g of purified water, stir evenly, then add 0.05g of polyphenol oxidase (i.e. 0.5‰), and enzymatically hydrolyze it for 10 minutes at 40℃ and pH 5.5, and then inactivate the enzyme at 90℃ for 10 minutes to obtain white tea flavor powder; 2) Preparation of fresh konjac pulp: Take 5000g of fresh konjac tubers, wash and peel them, and immediately place them in 8000g of aqueous solution containing 0.3% vitamin C to make pulp, thus obtaining fresh konjac pulp.

[0029] 3) Mixing and Shaping: In a vacuum mixer, add 500g fresh konjac paste, 50g white tea flavor powder, 80g oat β-glucan, 20g potassium alginate, 30g L-arabinose, and 100g purified water. Mix at 40℃ and -0.08MPa vacuum for 40 minutes to obtain a uniform and transparent colloid; extrude into noodles with a diameter of approximately 2mm through a circular perforated plate. 4) Cooking and shaping: Place the strips in hot water at 95°C and cook for 15 minutes to obtain vermicelli; 5) Drying and Packaging: The cooked vermicelli is first placed in a 60℃ hot air drying oven and dried to a moisture content of about 40%; then it is transferred to a 25℃ cold air drying room and slowly dried to a moisture content of 13%. Finally, it is vacuum-packed in food-grade packaging bags.

[0030] Example 4: A method for preparing white tea konjac noodles suitable for diabetic patients (without adding L-arabinose) White tea flavoring powder: Take 1000g of Shoumei white tea aged for 5 years (summer raw material), and pulverize it to D90≈12μm using an ultrafine pulverizer. Take 100g of white tea ultrafine powder, add 30g of purified water and mix well, then add 0.1g of polyphenol oxidase (i.e., 1‰), and enzymatically hydrolyze it at 35℃ and pH 6.0 for 20 minutes. Then, quickly inactivate the enzyme at 95℃ for 10 minutes, and let it cool for later use.

[0031] Fresh konjac paste: Take 5000g of fresh konjac, wash and peel it, and immediately put it into 7000g of aqueous solution containing 0.2% vitamin C. Use a high-speed tissue homogenizer to make paste for 4 minutes to obtain fresh konjac paste.

[0032] Mixing and Shaping: In a vacuum mixer, add 650g fresh konjac paste, 90g white tea flavor powder, 50g oat beta-glucan, 10g potassium alginate, and 200g purified water. Mix at 50℃ and -0.06MPa vacuum for 30 minutes to obtain a uniform and transparent colloid. Extrude into noodles with a diameter of approximately 2mm through a circular perforated plate.

[0033] Maturation and shaping: The extruded noodles are dropped directly into 90℃ hot water and kept warm for 20 minutes to mature.

[0034] Drying and Packaging: The cooked vermicelli is first placed in a 55℃ hot air drying oven and dried to a moisture content of about 45%; then it is transferred to a 30℃ cold air drying room and slowly dried to a moisture content of 12%. Finally, it is vacuum-packed in food-grade packaging bags.

[0035] The effects of the white tea konjac noodles prepared in Examples 1 to 4 above were verified.

[0036] Using commercially available konjac noodles as a reference, sensory evaluation, glycemic index (GI) determination, and antioxidant activity tests were conducted on the white tea konjac noodles prepared in Examples 1 to 4. The sensory evaluation method followed GB / T 23587-2024, "General Rules for the Quality of Starch Products." The GI value determination method involved an in vitro digestion simulation based on the national standard WS / T 652—2019, "Methods for Determination of Glycemic Index of Foods." The antioxidant activity test used a fluorescent probe method (AAPH free radical system).

[0037] The performance of commercially available ordinary konjac noodles and the white tea konjac noodles prepared in Examples 1 to 4 are shown in Table 1 below.

[0038] Table 1 Performance testing of ordinary konjac noodles and white tea konjac noodles prepared in Examples 1 to 4 Example Sensory evaluation GI value ORAC value Commercially available konjac noodles The color is light yellow, uniform, and glossy; the strips are regular in shape, uniform in thickness, and not sticky; they have a light konjac aroma and natural seasoning; the texture is smooth and chewy, not sticky, and relatively resistant to overcooking. 20 120μmol TE / 100g Example 1 It has a uniform texture, is light brown in color, has a distinct aroma of aged white tea, a refreshing and chewy taste, no fishy smell of konjac, and is very resistant to boiling. 13 3340 μmol TE / 100g Example 2 It has a uniform texture, is brownish-brown in color, has a very distinct aroma of aged white tea, a very refreshing and chewy taste, no fishy smell of konjac, and is very resistant to boiling. 11 4430 μmol TE / 100g Example 3 The tea has a uniform texture, is yellow in color, and has a slightly aged white tea aroma. It has a slightly refreshing and chewy taste, no fishy smell of konjac, and is relatively resistant to boiling. 14 2740 μmol TE / 100g Example 4 It has a uniform texture, is light brown in color, has a distinct aroma of aged white tea, a refreshing and chewy taste, no fishy smell of konjac, and is very resistant to boiling. 15 3400 μmol TE / 100g As shown in Table 1, the sensory evaluation of the white tea konjac noodles prepared using this invention is as follows: the texture is uniform, light brown in color, with a distinct aroma of aged white tea, a smooth and chewy texture, no fishy smell of konjac, and it is resistant to overcooking. In contrast, commercially available ordinary konjac noodles have a smooth and chewy texture and are less resistant to overcooking.

[0039] The GI value determination shows that the white tea konjac noodles prepared in Examples 1-3 of this invention have a GI value of less than 14. In Example 4, no L-arabinose was added, and the GI value of the white tea konjac noodles prepared was 15. This indicates that the white tea konjac noodles prepared in this invention are low-GI foods, and the addition of L-arabinose can further reduce the GI value of the food.

[0040] As shown in Table 1, the ORAC (Oxygen Radical Absorption Capacity) values ​​of the white tea konjac noodles prepared in Examples 1-4 of this invention are significantly higher than those of the commercially available ordinary konjac noodles in the comparative example, indicating that the antioxidant properties of the white tea konjac noodles prepared in this invention are significantly improved compared to ordinary konjac noodles.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.

[0042] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this invention, or any equivalent structural or procedural transformations made using the content of this specification, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of patent protection for this invention.

[0043] This invention relates to a method for preparing white tea konjac noodles suitable for diabetic patients, comprising the following steps: 1) pulverizing aged white tea to obtain white tea ultrafine powder, adding purified water to the white tea ultrafine powder and stirring evenly, then adding polyphenol oxidase for enzymatic hydrolysis to obtain white tea flavor powder; 2) pulping fresh konjac tubers to obtain fresh konjac pulp; 3) stirring the fresh konjac pulp, white tea flavor powder, oat β-glucan, potassium alginate, and water evenly to obtain a mixed colloid, and then forming it into strips; 4) cooking, shaping, drying, and packaging the strips to obtain white tea konjac noodles. The white tea konjac noodles prepared by this invention have an extremely low glycemic index (GI), making them suitable as a staple food substitute for diabetic patients; they are also rich in dietary fiber, tea polyphenols, and other active ingredients, which help with anti-oxidation and regulating intestinal health. The white tea konjac noodles prepared by this invention perfectly combine the mellow aroma of white tea with the texture of konjac, resulting in a smooth, chewy texture without any unpleasant fishy or alkaline taste.

Claims

1. A method for preparing white konjac vermicelli for diabetics, characterized in that, It comprises the following steps: 1) Preparation of white tea flavor powder: crush aged white tea to a particle size D90≤15 μm to obtain white tea ultrafine powder; add 20%-40% of the mass of the white tea ultrafine powder of purified water, stir uniformly, then add polyphenol oxidase, and enzymatically hydrolyze at 30-40 ℃, pH 5.5-6.5 for 10-30 minutes, and then inactivate the enzyme at 90-100 ℃ for 5-10 minutes to obtain white tea flavor powder; 2) Preparation of fresh konjac pulp: take fresh konjac tubers, wash and peel, then immediately beat into pulp in an aqueous solution containing 0.1%-0.3% vitamin C to obtain fresh konjac pulp; 3) Mixing and molding: place 50-70 parts of fresh konjac pulp, 5-15 parts of white tea flavor powder prepared in step 1), 3-8 parts of oat beta-glucan, 0.5-2 parts of potassium alginate, and 10-30 parts of water in a blender, and vacuum stir at 40-60 ℃ for 20-40 minutes to obtain a uniform mixed colloid; then mold into strips by extrusion or injection molding device; 4) Maturation and shaping: place the strips in hot water at 85-95 ℃ for 15-30 minutes of heat preservation and maturation to obtain vermicelli; 5) Drying and packaging: dry the matured vermicelli in sections, first dry at 50-60 ℃ with hot air to a water content of 40%-50%, then dry at 25-35 ℃ with cold air to a water content of ≤15%, and finally package.

2. The preparation method of white tea konjac noodles suitable for diabetic patients according to claim 1, characterized in that, In step 1), the aged white tea is Shoumei white tea aged for 4-6 years, and the raw material is fresh leaves picked in summer.

3. The preparation method of white tea konjac noodles suitable for diabetic patients according to claim 1, characterized in that, In step 1), the addition amount of polyphenol oxidase is 0.5‰-2‰ of the mass of white tea ultrafine powder.

4. The preparation method of white tea konjac noodles suitable for diabetic patients according to claim 1, characterized in that, In step 2), the mass ratio of the aqueous solution containing vitamin C to konjac tubers is 1-2:

1.

5. The preparation method of white tea konjac noodles suitable for diabetic patients according to claim 1, characterized in that, In step 3), the vacuum degree of the vacuum stirring is -0.05 MPa to -0.08 MPa.

6. The method of preparing white tea konjac vermicelli suitable for diabetics as claimed in claim 1, wherein, In step 3), the raw materials of the mixed colloid further include 1-3 parts by weight of L-arabinose.

7. A white tea konjac vermicelli suitable for diabetics, characterized in that, It is prepared by the preparation method of any one of claims 1-6.

8. The white tea konjac vermicelli for diabetics, according to claim 7, characterized in that, Its glycemic index GI value is ≤30.