Preparation method of instant polygonatum that can improve polysaccharide content

Abstract

This invention relates to the field of food processing technology, specifically to a method for preparing instant-dissolving Polygonatum sibiricum that can increase polysaccharide content. Fresh Polygonatum sibiricum is cleaned, sliced, microwave-dried, and then pulverized. The pulverized material is fed into a twin-screw high-temperature shear mill with three temperature zones: Zone I (60-75℃) for low-temperature preheating to soften fibers and decompose mucilage; Zone II (85-95℃) for medium-temperature cell wall disruption to promote the precipitation of polysaccharides and saponins; and Zone III (110-120℃) for high-temperature modification to degrade proteins and fibers and induce Maillard reactions. After discharge, the material is cooled, infrared-dried, and subjected to low-temperature ultrafine pulverization, then sieved for sterilization and nitrogen-filled packaging. This invention, through the synergistic effect of high temperature, high pressure, and high shear force, completes the de-irritation, aroma enhancement, cell wall disruption, and modification of Polygonatum sibiricum in a short time. The resulting product has no numbing sensation on the tongue, possesses a rich nutty aroma, significantly increases the total polysaccharide content, does not clump when dissolved in hot water, has a solubility more than three times that of the untreated group, and leaves no chemical residue throughout the process, making it suitable for various health food applications.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a method for preparing quick-dissolving Polygonatum sibiricum that can increase polysaccharide content. Background Technology

[0002] Polygonatum rhizome, the dried rhizome of a plant in the genus Polygonatum of the Liliaceae family, is a traditional Chinese medicine that is both food and medicine. Rich in polysaccharides, saponins, flavonoids, and various amino acids, it possesses the effects of tonifying qi and nourishing yin, strengthening the spleen and moistening the lungs, and benefiting the kidneys. Modern research shows that Polygonatum polysaccharides exhibit significant physiological activities in enhancing immunity, anti-oxidation, and regulating blood sugar. With the development of the health food market, Polygonatum has been widely used in instant products such as meal replacement powders, solid beverages, health snacks, and baking ingredients. Its processing method directly affects the nutritional value and consumer acceptance of these products.

[0003] Currently, common processing methods for Polygonatum sibiricum include baking and grinding, air jet milling, steaming, chemical extraction, and enzymatic hydrolysis. The traditional "nine steaming and nine sun-drying" process is also used. On the one hand, raw Polygonatum sibiricum contains a large amount of mucilage and calcium oxalate needle crystals; direct consumption after grinding can easily cause numbness of the mouth and tongue, sore throat, and gastrointestinal discomfort, and the product has a strong medicinal odor. On the other hand, Polygonatum sibiricum powder obtained through ordinary grinding has poor solubility, easily clumps and precipitates when mixed with water, and the effective components (such as polysaccharides and saponins) are not easily extracted, resulting in low bioavailability. Furthermore, chemical extraction and enzymatic hydrolysis methods have problems such as solvent residue risks, long processing times, and high costs, making it difficult to meet the requirements of modern food industry for clean labeling and efficient production.

[0004] Therefore, there is an urgent need to develop a method for preparing Polygonatum sibiricum that can effectively remove the irritating components, improve flavor and taste, significantly increase the content and dissolution rate of active ingredients such as polysaccharides, and simultaneously possess good reconstitution properties and instant solubility. Based on this, this invention provides a high-temperature shear modification-based process for preparing instant Polygonatum sibiricum powder, aiming to solve the technical problems of poor taste, unpleasant aroma, significant loss of active ingredients, poor reconstitution properties, and low processing efficiency in traditional methods, thereby achieving high-quality, high-efficiency, and safe production of Polygonatum sibiricum products. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing quick-dissolving Polygonatum that can increase the polysaccharide content, so as to solve the problems of a bitter and astringent taste, strong Chinese medicine flavor, low dissolution rate of effective ingredients, and easy clumping when mixed with water in existing Polygonatum processing methods.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing Polygonatum sibiricum powder, wherein Polygonatum sibiricum is subjected to high-temperature and high-pressure shearing modification using a twin-screw high-temperature shearing machine. The twin-screw high-temperature shearing machine is sequentially configured with zones I, II, and III along the material conveying direction, wherein the temperature of zone I is 60~75℃, the temperature of zone II is 85~95℃, and the temperature of zone III is 110~120℃; the pressure inside the twin-screw high-temperature shearing machine is 1.5~3.0MPa; and the shear strength is 800~3000s. -1 .

[0007] Furthermore, it also includes a pretreatment step, which is to clean, slice, microwave dry and then pulverize the fresh Polygonatum sibiricum to obtain Polygonatum sibiricum granules, which are then conveyed to a twin-screw high-temperature shearing machine.

[0008] Furthermore, the thickness of the slices is 2-4 mm; the microwave drying conditions are: temperature 50-70℃, time 10-20 min, and the moisture content of the dried material is controlled at 30%-40%; the Polygonatum granules are wet granules with a particle size of 1-3 mm.

[0009] Furthermore, the residence time of the material in the twin-screw high-temperature shear is 10~30s, the residence time in Zone I is 2~8s, the residence time in Zone II is 3~10s, and the residence time in Zone III is 5~12s.

[0010] Furthermore, it also includes a post-processing step, which is to cool, infrared dry, and low-temperature ultrafine pulverize the material after high-temperature and high-pressure shearing modification, sieve, sterilize and package it with nitrogen to obtain Polygonatum powder.

[0011] Furthermore, the cooling is cooling to 40~60℃; infrared drying is drying to a moisture content of 8%~12%; and low-temperature ultrafine pulverization is pulverizing to 100~200 mesh at a temperature below 40℃.

[0012] Furthermore, the Solomon's seal is the rhizome of plants in the genus Solomon's seal of the Liliaceae family, including Solomon's seal multiflora, Solomon's seal yunnanensis, and / or Solomon's seal chicken head.

[0013] A kind of Polygonatum powder is prepared by the above method.

[0014] Furthermore, the total polysaccharide content in the Polygonatum powder is ≥36g / 100g, and its solubility in hot water at 80℃ is ≥16g / 100mL.

[0015] The application of the Polygonatum sibiricum powder in the preparation of meal replacement powders, solid beverages, health snacks, baking ingredients or candies.

[0016] The beneficial effects of this invention are:

[0017] 1. This invention effectively decomposes mucilage and calcium oxalate needle crystals through high-temperature and high-pressure shear modification, completely eliminating the numbness of the tongue and throat irritation. At the same time, the Maillard reaction gives the product a rich nutty roasted aroma, without any unpleasant Chinese medicine taste, and significantly improves the taste and flavor.

[0018] 2. The water solubility of the Polygonatum powder of this invention is more than 3 times higher than that of the untreated group. The powder has good flowability, does not clump or precipitate when mixed with hot water, has excellent dispersion stability, and its mixing performance is greatly improved.

[0019] 3. The total polysaccharide and total saponin content of the Polygonatum powder of this invention is significantly higher than that of the traditional "nine-steaming and nine-drying" process. The large molecular proteins and fibers are degraded into small molecular active substances, the content of effective ingredients is increased, and they are more easily absorbed by the human body. The digestion and absorption rate is improved, and irritating components are removed, reducing the burden on the stomach and intestines. In addition, the high-temperature treatment kills microorganisms, making it highly safe for consumption.

[0020] 4. The process of this invention is a completely physical process with no chemical reagent residue. The high-temperature shearing process of the twin-screw extruder only takes 10-30 seconds. The process is green and efficient, with low energy consumption, strong continuous production capability, and obvious cost advantages. The resulting Polygonatum powder has a wide range of applications and can be directly used in various products such as meal replacement powder, solid beverages, health snacks, baking ingredients, and candies. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0022] The preparation method of Huangjing powder of the present invention includes, in sequence, raw material pretreatment, high temperature and high pressure shearing modification, cooling and dehumidification, ultra-fine grinding and sieving and packaging.

[0023] In the pretreatment stage, the fresh Solomon's seal rhizomes are cleaned and sliced ​​(2-4 mm thick), then microwave-dried (50-70℃, 10-20 min) to control the moisture content to 30%-40%, and then coarsely crushed to make wet granules with a particle size of 1-3 mm and a solid content of 60%-70%, which is beneficial for subsequent continuous feeding and energy transfer.

[0024] High-temperature and high-pressure shear modification utilizes a twin-screw high-temperature shear mill (twin-screw extruder). The material sequentially passes through three temperature zones: Zone I (60-75℃, 2-8s) – low-temperature preheating softens fibers and loosens the structure, facilitating the full release of active ingredients such as polysaccharides and saponins, as well as aiding in the decomposition of mucilage and the destruction of calcium oxalate needle crystal structures, thereby promoting the elimination of tongue numbness and gastrointestinal irritation; Zone II (85-95℃, 3-10s) – medium-temperature cell disruption, where active ingredients such as polysaccharides and saponins are fully released under the synergistic effect of high temperature, high pressure, and shear; Zone III (110-120℃, 5-12s) – high-temperature modification promotes the degradation of protein and fiber macromolecules, completely destroys the calcium oxalate needle crystal structure, and induces the Maillard reaction to produce a roasted nut aroma. During the process, the pressure is controlled at 1.5-3.0 MPa, the screw speed at 150-300 r / min, and the shear strength at 800-3000 s⁻¹. -1 The material residence time is 10~30s.

[0025] The material loses pressure and expands and becomes loose when discharged. It is cooled to 40~60℃ and dried with infrared to 8%~12% moisture content. Then it is pulverized at low temperature to 100~200 mesh, sieved, sterilized, and packaged with nitrogen to obtain the finished product.

[0026] The process of this invention utilizes the synergistic effect of high temperature, high pressure and high shear force to change the microfiber structure and cell wall integrity of Polygonatum in a very short time. On the one hand, it eliminates unpleasant flavors and irritating components, and on the other hand, it significantly improves the freeness and dissolution rate of effective components such as polysaccharides and saponins, while giving the product good water solubility, dispersibility and reconstitution stability.

[0027] Example 1 In this embodiment, the method of the present invention is used to prepare Polygonatum sibiricum powder.

[0028] Select fresh, disease-free Polygonatum rhizomes, remove fibrous roots and mud, wash them clean, and cut the washed Polygonatum into 3mm thick slices; use microwave drying equipment to dry at 60℃ to reduce the moisture content of the material to about 35%; put the dried Polygonatum slices into a coarse pulverizer and pulverize them into wet particles with a particle size of about 2mm, at which point the solid content of the material is about 65%.

[0029] The aforementioned wet granules were fed into a twin-screw extruder (length-to-diameter ratio 25:1) for modification treatment. Three temperature zones were set sequentially, with the following parameters for each zone: Zone I 70℃ (3s), Zone II 90℃ (8s), and Zone III 115℃ (9s). The barrel pressure was controlled at 2.2MPa, the screw speed at 220r / min, and the shear strength at 2000s. -1 The residence time of the material in the barrel is 20 seconds.

[0030] The material extruded from the twin-screw extruder die is in the form of expanded, loose strips, which are immediately cooled to 50°C using an air-cooled conveyor belt. The cooled material is then fed into an infrared dryer and dried at 80°C until the moisture content is 10%. The dried material is then fed into a low-temperature ultrafine pulverizer and pulverized at a temperature below 40°C and passed through a 150-mesh sieve. After sieving, the material undergoes short-term high-temperature instantaneous sterilization (110°C, 5s) and is then packaged with nitrogen to obtain the Polygonatum sibiricum powder of this invention.

[0031] Example 2 In this embodiment, the method of the present invention is used to prepare Polygonatum powder, and the basic steps are the same as in Example 1.

[0032] Fresh, disease-free rhizomes of Polygonatum yunnanense were selected, cleaned, and cut into 2mm thick slices. They were then microwave-dried at 50℃ to reduce the moisture content to about 30%. The dried Polygonatum slices were coarsely crushed into particles with a diameter of about 1mm and a solid content of about 70%.

[0033] The above-mentioned granular material was fed into a twin-screw extruder, with the three temperature zones set as follows: Zone I 60℃ (8s), Zone II 85℃ (10s), and Zone III 110℃ (12s). The barrel pressure was controlled at 1.5MPa, the screw speed at 150r / min, and the shear strength at 800s. -1 The material residence time is 30 seconds.

[0034] After discharge, the material is cooled to 40°C, then dried in an infrared dryer until the moisture content is 8%. The dried material is then ultra-finely pulverized under low temperature conditions, passed through a 200-mesh sieve, sterilized, and then packaged in nitrogen to obtain the finished product.

[0035] Example 3 In this embodiment, the method of the present invention is used to prepare Polygonatum powder, and the basic steps are the same as in Example 1.

[0036] Select fresh, disease-free Polygonatum rhizomes, clean them, and cut them into 4mm thick slices. Use microwave drying at 70℃ to reduce the moisture content to about 40%. Coarsely pulverize the dried Polygonatum slices into particles with a diameter of about 3mm and a solid content of about 60%.

[0037] The above-mentioned granular material was fed into a twin-screw extruder, with the three temperature zones set as follows: Zone I 75℃ (2s), Zone II 95℃ (3s), and Zone III 120℃ (5s). The barrel pressure was controlled at 3.0 MPa, the screw speed at 300 r / min, and the shear strength at 3000 s⁻¹. -1 The material residence time is 10 seconds.

[0038] After discharge, the material is cooled to 60°C, then dried using an infrared dryer until the moisture content is 12%. The dried material is then ultra-finely pulverized under low temperature conditions, passed through a 100-mesh sieve, sterilized, and then packaged with nitrogen to obtain the finished product.

[0039] Comparative Example 1 The difference between this comparative example and Example 1 is that after completing the pretreatment of the raw materials (washing, slicing, microwave drying to 35% moisture content, coarsely crushing to 2mm particles), the high temperature and high pressure shearing modification step is not performed. Instead, the wet particles of Polygonatum are directly dried with hot air at 60°C to a moisture content of 10%, then crushed normally (without low temperature control), passed through a 150-mesh sieve, sterilized and packaged, and used as a control sample.

[0040] Comparative Example 2 This comparison is based on traditional processing methods.

[0041] Fresh Polygonatum rhizome from the same batch as in Example 1 was selected, washed, sliced, and repeatedly steamed and dried. Specifically, the Polygonatum rhizome slices were placed in a steamer and steamed for 4 hours under normal pressure, then removed and dried at 60°C until dry. This process of "one steaming and one drying" was repeated nine times.

[0042] The Polygonatum slices, which had been steamed and sun-dried nine times, were dried at 60℃, pulverized normally, passed through a 150-mesh sieve, sterilized, and packaged as a control sample.

[0043] Comparative Example 3 The difference between this comparative example and Example 1 is that the temperature zones of the twin-screw extruder were adjusted, and the three temperature zones were set as follows: Zone I 50℃, Zone II 70℃, and Zone III 90℃. Other parameters (pressure 2.2MPa, speed 220r / min, residence time 20s) and subsequent cooling, drying, pulverizing, and packaging steps are the same as in Example 1.

[0044] The key performance indicators of the Polygonatum odoratum powders prepared in Examples 1-3 and Comparative Examples 1-3 were tested, and the results are shown in the table below: Table 1. Key performance indicators of Polygonatum odoratum powder prepared in Examples 1-3 and Comparative Examples 1-3

[0045] The results showed that the total polysaccharide content of Examples 1-3 (36.1~38.5g / 100g) was significantly higher than that of Comparative Example 1 (12.3g / 100g, unmodified) and Comparative Example 2 (18.6g / 100g, traditional nine-steaming and nine-drying process). This indicates that the high-temperature and high-pressure shear modification of the present invention can effectively promote the release and retention of polysaccharides, and its content is about twice that of the traditional process and more than three times that of ordinary pulverization.

[0046] The solubility of the samples was determined in hot water at 80°C. The solubility of Examples 1-3 (16.5~18.2 g / 100 mL) was more than 3 times that of Comparative Example 1 (5.1 g / 100 mL) and more than 2 times that of Comparative Example 2 (7.8 g / 100 mL), indicating that the present invention significantly improves the instant solubility of Polygonatum powder.

[0047] Furthermore, sensory evaluation (a double-blind evaluation conducted by 10 trained food professionals) showed that: Examples 1-3 had no numbing sensation on the tongue; Comparative Example 1 had a severe numbing sensation on the tongue; Comparative Example 2 still had a slight numbing sensation on the tongue; Comparative Example 3 (low-temperature shearing) also had a slight numbing sensation on the tongue; indicating that only at high temperatures (110~120℃) can the calcium oxalate needle crystals and mucus that cause the numbing sensation on the tongue be completely decomposed.

[0048] Meanwhile, Examples 1 and 3 produced a rich nutty roasted aroma, which is a sign of a complete Maillard reaction; Comparative Example 2 was mainly caramel-flavored and lacked nutty aroma; Comparative Example 3 had only a faint caramel aroma; indicating that the temperature in Zone III (110~120℃) is the key to achieving an ideal Maillard reaction and producing a pleasant nutty aroma.

[0049] Weigh 10g of sample, add 100mL of 80℃ hot water, stir for 30s and observe; the agglomeration rate of Examples 1-3 is extremely low (<2%), and the powder is evenly dispersed; while Comparative Example 1 has serious agglomeration (>30%), and Comparative Examples 2 and 3 still have a lot of agglomeration, indicating that the product of the present invention has excellent reconstitution performance.

[0050] Furthermore, comparative experiments show that if a single temperature zone is set in the twin-screw high-temperature shear mill (e.g., maintaining a constant temperature of 90℃ or 115℃), the gradient synergistic effect cannot be achieved. The three functional stages—low-temperature preheating and softening, medium-temperature cell wall breaking and precipitation, and high-temperature modification and flavor enhancement—are all indispensable. At a single temperature, the rapid and intense reaction leads to rapid gelatinization and water loss, resulting in surface hardening, incomplete decomposition of mucilage and calcium oxalate needle crystals, a noticeable numbing sensation on the tongue, and a bitter taste. The total polysaccharide content only reaches 18-25 g / 100 g, and the hot water solubility is less than 10 g / 100 mL. In addition, if the pressure inside the barrel is controlled below 1.5 MPa (e.g., 1.0 MPa), instantaneous pressure loss and expansion cannot occur during discharge, hindering component dissolution. The agglomeration rate during mixing is as high as 15% or more, and both solubility and polysaccharide content decrease significantly. Therefore, the synergistic effect of the three temperature zones (60~75℃, 85~95℃, 110~120℃) and the high pressure conditions of 1.5~3.0MPa used in this invention is a necessary technical prerequisite for achieving the effects of de-irritation, cell wall breaking and modification, aroma enhancement and rapid dissolution.

[0051] The above results fully demonstrate that the present invention, through high-temperature and high-pressure shearing modification using a twin-screw high-temperature shearing machine and the setting of three temperature stages, can synergistically achieve de-irritation, efficient cell wall breaking, and aroma enhancement. The resulting Polygonatum powder is superior to the untreated group and the traditional process group in terms of polysaccharide content, solubility, flavor, and reconstitution properties, and has better application prospects.

[0052] This invention is not limited to the preferred embodiments described above. Anyone can derive other forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A method for preparing Polygonatum sibiricum powder, characterized in that: High-temperature and high-pressure shearing modification of Polygonatum sibiricum was carried out using a twin-screw high-temperature shearing machine. The twin-screw high-temperature shearing machine was divided into three zones (I, II, and III) along the material conveying direction. The temperature in zone I was 60–75℃, in zone II it was 85–95℃, and in zone III it was 110–120℃. The pressure inside the twin-screw high-temperature shearing machine was 1.5–3.0 MPa, and the shear strength was 800–3000 s⁻¹. -1 .

2. The method for preparing Polygonatum sibiricum powder according to claim 1, characterized in that: It also includes a pretreatment step, which is to clean, slice, microwave dry and then pulverize the fresh Polygonatum sibiricum to obtain Polygonatum sibiricum granules, which are then fed to a twin-screw high-temperature shearing machine.

3. The method for preparing Polygonatum sibiricum powder according to claim 2, characterized in that: The slice thickness is 2-4 mm; the microwave drying conditions are: temperature 50-70℃, time 10-20 min, and the moisture content of the material after drying is controlled at 30%-40%; the Polygonatum granules are wet granules with a particle size of 1-3 mm.

4. The method for preparing Polygonatum sibiricum powder according to claim 1, characterized in that: The residence time of the material in the twin-screw high-temperature shear is 10~30s, the residence time in Zone I is 2~8s, the residence time in Zone II is 3~10s, and the residence time in Zone III is 5~12s.

5. The method for preparing Polygonatum sibiricum powder according to claim 1, characterized in that: It also includes a post-processing step, which is to cool, infrared dry, and low-temperature ultrafine pulverize the material after high-temperature and high-pressure shearing modification, sieve, sterilize and package it with nitrogen to obtain Polygonatum powder.

6. The method for preparing Polygonatum sibiricum powder according to claim 5, characterized in that: The cooling process involves cooling to 40-60°C; infrared drying to a moisture content of 8%-12%; and low-temperature ultrafine pulverization to pulverize to 100-200 mesh at a temperature below 40°C.

7. The method for preparing Polygonatum odoratum powder according to any one of claims 1-6, characterized in that: The Solomon's seal is the rhizome of plants in the genus Solomon's seal of the Liliaceae family, including Solomon's seal multiflora, Solomon's seal yunnanensis, and / or Solomon's seal chicken head.

8. A kind of Polygonatum powder, characterized in that: It is prepared by the method described in any one of claims 1-7.

9. The Polygonatum powder according to claim 8, characterized in that: The total polysaccharide content of the Polygonatum powder is ≥36g / 100g, and its solubility in hot water at 80℃ is ≥16g / 100mL.

10. The use of the Polygonatum powder according to claim 8 or 9 in the preparation of meal replacement powder, solid beverage, health snack, baking ingredient or candy.

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