Method for preparing agaricus bisporus powder rich in vitamin D2

Abstract

The invention discloses a method for preparing agaricus bisporus powder rich in vitamins, which comprises the following steps: step 1, selecting fresh agaricus bisporus which is free from mechanical injury and plant diseases and insect pests and has complete sporocarp, cleaning, and soaking in a color protection solution for color protection; 2, slicing the agaricus bisporus subjected to color protection treatment, and freeze-drying the sliced agaricus bisporus to obtain a dry agaricus bisporus product; and step 3, irradiating the agaricus bisporus dry product under the UV-B wave band with the wavelength of 280-320 nm, so that ergosterol in the agaricus bisporus dry product is converted into vitamins, and the agaricus bisporus powder rich in the vitamins is obtained. According to the invention, color-protecting fresh-keeping pretreatment is combined with a freeze-drying technology, so that nutritional active ingredients and flavor substances of agaricus bisporus can be reserved to the maximum extent, and the content of vitamin D2 is remarkably increased; compared with UVA and UVC, UVB can significantly improve the content of vitamin D2, the whole process is completed by single UV radiation, the preparation process does not need a UV light source switching step, and the energy consumption is low.

Description

(I) TECHNICAL FIELD

[0001] The present application relates to the technical field of food processing, and relates to a method for preparing double-spore mushroom powder rich in vitamin D2. (II) BACKGROUND

[0002] Vitamin D2 is one of the essential substances for the human body, participates in the metabolism of calcium and phosphorus in the body, helps maintain neuromuscular and skeletal homeostasis, and prevents osteoporosis and osteomalacia. Double-spore mushroom is one of the non-animal foods rich in ergosterol, and the rich ergosterol is a precursor of vitamin D2. It is an important component of edible fungus cell membrane, and can generate vitamin D2 under ultraviolet light irradiation, so double-spore mushroom is a good source of dietary vitamin D2. However, due to the fact that cultivation is basically in a light-avoiding environment, the natural content of vitamin D2 in double-spore mushroom is very low. The process technology of converting ergosterol into vitamin D2 through ultraviolet (UV) irradiation has been gradually verified and applied in the research and patent literature in the fields of food processing, biological medicine, etc.

[0003] At present, there are still significant technical bottlenecks in the system of converting double-spore mushroom powder rich in ergosterol into vitamin D2 through light conversion in industrial applications, and it is difficult to break through the threshold of the content of vitamin D2. This technical defect directly leads to low utilization rate of raw materials in the preparation process of double-spore mushroom powder, and additional precursor substances need to be added, which increases the cost of the downstream purification process, thereby restricting the industrialization process of the functional food in the dietary supplement market.

[0004] Patent CN202410965570.8 discloses a method for improving the content of vitamin D2 in edible mushroom fruiting bodies. The method includes preservation and storage pretreatment, drying and slicing, alternating ultraviolet irradiation and heat treatment, etc., which improves the content of vitamin D2 in edible mushrooms. However, the alternating ultraviolet radiation requires complex equipment and process, and the process is complicated, and the content of vitamin D2 in edible mushroom powder is limited, which does not reach the international advanced level (150 μg / g, European Union regulation NF2019 / 1471).

[0005] Patents CN202411800647.2, CN202311694055.2 and CN202310937704.0 all disclose a method for preparing high-vitamin D2. Vitamin D2 is prepared by methods such as dissolution, light conversion, extraction and crystallization. However, the raw materials they use are high-purity ergosterol, and the operation process is relatively complex, which is not suitable for commercial production.

[0006] ​​Patent CN201810244359.1 discloses a process for preparing high-purity vitamin D2 extract from edible fungi. This process involves obtaining ergosterol extract through supercritical extraction, saponification, and molecular distillation pretreatment, followed by pulsed irradiation to convert ergosterol into vitamin D2. However, this method requires expensive equipment for supercritical extraction, molecular distillation, and pulsed irradiation, resulting in high maintenance costs. Furthermore, the pulsed irradiation requires precise control of light intensity and pulse frequency, and insufficient light penetration depth occurs when the material layer is thick, leading to a high cost barrier for industrialization.

[0007] Therefore, both the preparation method of mushroom powder rich in vitamin D2 and its efficient photoconversion need further in-depth research. (III) Summary of the Invention

[0008] To address the above problems, this invention provides a method for preparing vitamin-rich... Methods for processing button mushroom powder to increase the vitamin content of button mushroom powder. content.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A method for preparing vitamin-rich The method for preparing button mushroom powder includes the following steps:

[0011] Step 1: Select fresh button mushrooms that are free from mechanical damage, pests, and diseases, and whose fruiting bodies are intact. After washing, soak them in a color-protecting solution for 20-40 minutes at room temperature. The color-protecting solution consists of: ascorbic acid concentration of 0.03-0.05 g / 100 mL, citric acid concentration of 0.2-0.4 g / 100 mL, sodium chloride concentration of 0.2-0.4 g / 100 mL, and water as the solvent.

[0012] Step 2: After color protection treatment, the button mushrooms are sliced ​​and freeze-dried to obtain dried button mushrooms;

[0013] Step 3: Irradiate the dried button mushrooms obtained in Step 2 under UV-B wavelengths of 280-320 nm to convert ergosterol into vitamin C. Obtain vitamin-rich Button mushroom powder.

[0014] In the color-protecting solution of the present invention, the concentration of ascorbic acid is 0.03-0.05 g / 100 mL, for example 0.03, 0.035, 0.04, 0.045, 0.05 g / 100 mL, preferably 0.035-0.045 g / 100 mL, more preferably 0.04 g / 100 mL; the concentration of citric acid is 0.2-0.4 g / 100 mL, for example 0.2, 0.25, 0.3, 0.35, 0.4 g / 100 mL, preferably 0.25-0.35 g / 100 mL, more preferably 0.3 g / 100 mL; the concentration of sodium chloride is 0.2-0.4 g / 100 mL, for example 0.2, 0.25, 0.3, 0.35, 0.4 g / 100 mL, preferably 0.25-0.35 g / 100 mL, more preferably 0.3 g / 100 mL.

[0015] In step one of this invention, the mass ratio of fresh button mushrooms to color-protecting liquid can be 1:2-4, such as 1:2, 1:3, 1:4, etc., and the soaking time at room temperature is 20-40 min, preferably 30 min.

[0016] In step two of this invention, the color-protecting mushrooms are longitudinally cut (from the stipe to the cap) into slices, and the slice thickness is generally maintained within the range of 3±0.5 mm.

[0017] In step two of this invention, the freeze-drying operation temperature is between -80 ℃ and 60 ℃; for example, pre-freezing: the obtained mushroom slices are laid flat in a single layer on a freeze-drying tray with a spacing of ≥5 mm, and placed in an ultra-low temperature freezer at -80 ℃ for 12 hours; sublimation drying: the pre-frozen mushroom slices are placed in a vacuum freeze dryer, and during drying, the cold trap is maintained at -50 ℃, the material temperature is maintained at -30 ℃, the vacuum degree is maintained at 10 Pa, and the drying time is 40 hours; desorption drying: the temperature is increased by 5 ℃ per hour, eventually reaching 60 ℃, and maintained at 60 ℃ for 4 hours, during which the vacuum degree is maintained at 10 Pa.

[0018] In step three of this invention, the dried button mushroom product obtained in step two is irradiated under a UV-B band with a wavelength of 280-320 nm, causing the ergosterol in it to be converted into vitamin C. The preferred irradiation distance is 20 cm-50 cm, the photoconversion dose is 1.0-4.0 J / cm², the mixture is stirred once periodically, the irradiation time is 60-90 min, and the conversion temperature is room temperature.

[0019] Preferably, the method further includes the following step A:

[0020] The dried button mushrooms obtained in step two are crushed and sieved to obtain button mushroom powder with a particle size between 20 and 200 mesh. This button mushroom powder is then used as the raw material for step three.

[0021] As a further preferred option, in step A, the particle size of the button mushroom powder is set to 80-150 mesh.

[0022] Preferably, the method further includes the following step B:

[0023] The button mushroom powder obtained in step 3 should be placed at a constant temperature of 20-40 ℃ in the dark for at least 8 hours.

[0024] As a further preferred option, in step B, the placement temperature is 20-30℃, with 30℃ being the most preferred; the placement time in the dark is 8-50 hours, such as 8 hours, 16 hours, 24 hours, 32 hours, 40 hours, 48 ​​hours, etc. The longer the placement time, the more vitamins in the button mushrooms will be released. The higher the content, the lower the vitamin content, but the lower the vitamin content in the later parts of the formula. The rate of increase in content has slowed down.

[0025] The present invention particularly prefers the preparation of vitamin-rich products. The method for preparing button mushroom powder is carried out according to the following steps:

[0026] Step 1: Select fresh button mushrooms that are free from mechanical damage, pests, and diseases, and whose fruiting bodies are intact. After washing, soak them in a color-protecting solution for 20-40 minutes at room temperature. The color-protecting solution consists of: ascorbic acid concentration of 0.03-0.05 g / 100 mL, citric acid concentration of 0.2-0.4 g / 100 mL, sodium chloride concentration of 0.2-0.4 g / 100 mL, and water as the solvent.

[0027] Step 2: After color protection treatment, the button mushrooms are sliced ​​and freeze-dried to obtain dried button mushrooms;

[0028] Step A: Crush and sieve the dried button mushrooms obtained in Step 2 to obtain button mushroom powder with a particle size between 80-150 mesh;

[0029] Step 3: Irradiate the Agaricus bisporus powder obtained in Step A under UV-B wavelengths of 280-320 nm to convert ergosterol into vitamin A. ;

[0030] Step B: Place the button mushroom powder obtained in Step 3 at a constant temperature of 20-30 ℃ in the dark for 8-50 h to obtain a product rich in vitamins. Button mushroom powder.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention first employs a color-protecting and preservation pretreatment combined with freeze-drying technology, which maximizes the retention of the nutritional and active components and flavor substances of button mushrooms. Furthermore, due to the antioxidant properties of ascorbic acid, citric acid, and sodium chloride, the color-protecting pretreatment significantly increases the vitamin D2 content compared to untreated button mushrooms. Moreover, UVB, compared to UVA and UVC, significantly increases the vitamin D2 content. The entire process is completed by single UV radiation, eliminating the need to switch UV light sources and reducing energy consumption.

[0033] 2. This invention combines particle size screening and UV light modulation to increase the dissolution rate of vitamin D2 precursors and enhance the penetration depth of UV photons. Combined with selective conversion in the UVB band, it successfully achieves efficient photoconversion of vitamin D2 in button mushrooms, thereby increasing the vitamin D2 content in button mushroom powder.

[0034] 3. This invention combines light-heat conversion, which significantly increases the vitamin D2 content in button mushroom powder. The entire process is simple to operate and has low equipment cost.

[0035] Specifically, in the process of ergosterol being converted into vitamin D2, it is first converted by light to Pre-V. (An intermediate in the conversion of ergosterol to vitamin D2), this intermediate generates byproducts such as photosterol and tachysterol during the photoreaction phase. Based on Pre-V Due to its thermosensitive properties, the intermediate requires a slow isomerization process to form vitamin D2. Therefore, under constant temperature thermal conversion at 30°C, Pre-V... Internal hydrogen migration forms stable vitamin D2, while simultaneously inhibiting side reactions. After complete reaction at 30°C in the dark, the vitamin D2 content significantly increases. (iv) Description of the attached drawings

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Figure 1 This is a schematic diagram of the phototransformation of ergosterol into vitamin D2.

[0038] Figure 2a and 2b The changes in ergosterol and vitamin D2 content of Agaricus bisporus in Example 1 after hot air drying, freeze drying, and color protection treatments are respectively.

[0039] Figure 3 This is a histogram showing the distribution of different particle sizes in Example 2.

[0040] Figure 4a and 4bThe changes in ergosterol and vitamin D2 content of powders with different particle sizes in Example 2 after ultraviolet radiation.

[0041] Figure 5 The changes in vitamin D2 content under different wavelengths of irradiation in Example 3 are shown.

[0042] Figure 6 The change in vitamin D2 content before and after storage in Example 4 is shown.

[0043] Figure 7 This is a comparison between conventional technical routes and the preferred technical routes of this invention. (V) Detailed Implementation Methods

[0044] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0045] In this embodiment of the invention, HPLC was used to determine the contents of ergosterol and vitamin D2. The specific method is as follows: Accurately weigh 20.0 mg (HPLC, 98%) of vitamin D2 and ergosterol reference standards and place them in a 100 mL volumetric flask. Dilute to the mark with anhydrous ethanol. Then, accurately pipette 0.125, 0.25, 0.5, 1.0, 2.0, and 4.0 mL of this stock solution into 10 mL test tubes respectively. Add the mobile phase and dilute to the mark. Shake well to obtain the standard diluted solution. The HPLC conditions are as follows:

[0046] a) Column: YMC-Pack ODS-A-C18 (250 mm × 4.6 mm, 5 μm).

[0047] b) Mobile phase: Mobile phase A: 75% acetonitrile, Mobile phase B: 25% methanol (vitamin D2)

[0048] Mobile phase A: 85% acetonitrile, Mobile phase B: 15% methanol (ergosterol)

[0049] c) Detection wavelengths: 265 nm (vitamin D2), 280 nm (ergosterol)

[0050] d) Column temperature: 30 ℃ (vitamin D2), 35 ℃ (ergosterol)

[0051] e) Flow rate: 1.0 mL / min.

[0052] HPLC standard curves for ergosterol and vitamin D2 were prepared using the above method, with the peak area as the ordinate and the corresponding concentration as the abscissa.

[0053] In the embodiments of the present invention, room temperature refers to 20-30 ℃.

[0054] Example 1

[0055] Step 1: Select fresh button mushrooms, wash them, and divide them into four groups: no soaking, blanching in boiling water, color-protecting solution, and blanching after color protection. The blanching temperature is 100℃, and the blanching time is 1 min. The color-protecting solution consists of ascorbic acid (0.04 g / 100 mL), citric acid (0.3 g / 100 mL), and sodium chloride (0.3 g / 100 mL). The color protection process involves soaking the mushrooms at room temperature for 30 min at a mass-to-liquid ratio of 1:3 (m / m).

[0056] Step 2: Cut the pre-treated button mushrooms longitudinally (from the stem to the cap), adjusting the diameter according to the size of the cap, and the slice thickness is 3±0.5 mm.

[0057] Step 3: The button mushroom slices from Step 2 were dried with hot air (60 ℃, 48 h) and freeze-dried until the moisture content was ≤10%. The freeze-drying process consisted of three stages: pre-freezing, sublimation drying, and desorption drying. Pre-freezing: The mushroom slices obtained in Step 2 were laid in a single layer on a freeze-drying tray with a spacing of ≥5 mm and placed in an ultra-low temperature freezer at -80 ℃ for 12 h. Sublimation drying: The pre-frozen button mushroom slices were placed in a vacuum freeze dryer. During drying, the cold trap was maintained at -50 ℃, the material temperature was maintained at -30 ℃, and the vacuum degree was maintained at 10 Pa for 40 h. Desorption drying: The temperature was increased by 5 ℃ per hour until it reached 60 ℃. The temperature was maintained at 60 ℃ for 4 h, and the vacuum degree was maintained at 10 Pa during the process to obtain dried button mushrooms. The samples obtained by hot air drying were named D (hot air drying), DB (hot air drying - blanching), D-CP (hot air drying - color protection), and D-BCP (hot air drying - blanching - color protection); the samples obtained by freeze drying were named FD (freeze drying), FD-B (freeze drying - blanching), FD-CP (freeze drying - color protection), and FD-BCP (freeze drying - blanching - color protection).

[0058] Step 4: Using ethanol as the extraction solvent, the mass-to-liquid ratio of the sample from Step 3 was 1:50 (m / v). The ultrasonic frequency was 40 kHz, the power was 300 W, the ultrasonic temperature was 50 ℃, and the ultrasonic time was 60 min. The extract was centrifuged at 10000 rpm for 10 min to separate the residue. The supernatant was collected to obtain the ergosterol extract. This extract was diluted 5 times with the above mobile phase. 1.0 mL of the diluted extract was filtered through a 0.22 μm microporous membrane to obtain the test solution. The ergosterol concentration was detected by HPLC under the conditions described above. The ergosterol mass was calculated based on the detected ergosterol concentration, and then the ergosterol content (Content (μg / g)) was calculated, i.e., the ergosterol mass (μg) contained in each gram of dried button mushrooms. The results are as follows. Figure 2a As shown.

[0059] Step 5: Irradiate the samples from Step 3 under ultraviolet light at a wavelength of 280-320 nm, a distance of 20 cm-50 cm, a photoconversion dose of 2.0 J / cm², stir and turn the samples every 15 min, irradiate for 60 min, and keep the conversion temperature at room temperature.

[0060] Step Six: Add the sample from Step Five to the saponification solution (a mixture of anhydrous ethanol and 50% sodium hydroxide aqueous solution, with a volume ratio of 1:3) at a mass-to-liquid ratio of 1:50 (m / v). Add sodium ascorbate at a mass-to-liquid ratio of 1:4 (m / v). After saponification at 80 °C for approximately 60 min, allow to cool to room temperature. Extract three times with n-hexane, wash the solution with distilled water until neutral, evaporate the solution to dryness at 35 °C, and dissolve in 10 mL of methanol to obtain the vitamin D2 test sample. Dilute the sample three times with the above mobile phase. Filter 1.0 mL of the diluted extract through a 0.22 μm microporous membrane to obtain the test solution. Detect the vitamin D2 concentration using HPLC under the conditions described above. Calculate the vitamin D2 mass based on the detected ergosterol concentration, and then calculate the vitamin D2 content (Content (μg / g)), i.e., the vitamin D2 mass (μg) per gram of dried button mushrooms. The results are as follows. Figure 2b As shown.

[0061] Example 2

[0062] Step 1: Select fresh button mushrooms, wash them, and then soak them in a color-protecting solution to protect their color. The color-protecting solution consists of ascorbic acid (0.04 g / 100 mL), citric acid (0.3 g / 100 mL), and sodium chloride (0.3 g / 100 mL), with water as the solvent. The color-protecting process is carried out by soaking at room temperature for 30 minutes at a mass-to-liquid ratio of 1:3 (m / m).

[0063] Step 2: Cut the pre-treated button mushrooms longitudinally (from the stem to the cap), adjusting the diameter according to the size of the cap, and the slice thickness is 3±0.5 mm.

[0064] Step 3: Freeze-dry the button mushroom slices from Step 2 until the moisture content is ≤10%. The freeze-drying process consists of three stages: pre-freezing, sublimation drying, and desorption drying. Pre-freezing: Spread the mushroom slices obtained in Step 2 in a single layer on a freeze-drying tray with a spacing of ≥5 mm, and place it in an ultra-low temperature freezer at -80 ℃ for 12 h. Sublimation drying: Place the pre-frozen button mushroom slices in a vacuum freeze dryer. During drying, the cold trap is maintained at -50 ℃, the material temperature is maintained at -30 ℃, and the vacuum degree is maintained at 10 Pa for 40 h. Desorption drying: Increase the temperature by 5 ℃ per hour until it reaches 60 ℃, and maintain it at 60 ℃ for 4 h, during which the vacuum degree is maintained at 10 Pa to obtain dried button mushrooms.

[0065] Step 4: The obtained dried button mushrooms were pulverized and sieved using a layered sieve method. The mesh sizes of the sieves from top to bottom were 10, 20, 50, 80, 150, and 200, respectively, yielding powders with mesh sizes of 10-20, 20-50, 50-80, 80-150, and less than 200, which were named MS10-20, MS20-50, MS50-80, MS80-150, and MS200, respectively. The particle size distribution of different batches of sample powder was determined using a laser diffraction particle size analyzer. The ground powder was suspended in water in a measuring cell (small volume unit sample module). The sample material refractive index was 1.53, the sample material absorbance was 0.001, and the dispersion medium refractive index was 1.333. The suspension was analyzed when the masking rate was between 70% and 80%. The MS10-20 and MS20-50 particles had larger particle sizes, and their average particle size could be measured using a ruler. Average particle size as Figure 3 As shown in Table 1.

[0066] Table 1

[0067]

[0068] Step 5: Irradiate the samples from Step 4 under ultraviolet light at a wavelength of 280-320 nm, a distance of 20 cm-50 cm, a photoconversion dose of 2.0 J / cm², stir and turn the samples every 15 min, irradiate for 60 min, and keep the conversion temperature at room temperature.

[0069] Step Six: Ergosterol and Vitamin D2 were extracted from the sample obtained in Step Five according to the method in Example 1. The contents of ergosterol and Vitamin D2 in the resulting test solution were determined according to the method in Example 1. The results are as follows: Figure 4a and 4b As shown.

[0070] Example 3

[0071] Step 1: Select fresh button mushrooms, wash them, and then soak them in a color-protecting solution to protect their color. The color-protecting solution consists of ascorbic acid (0.04 g / 100 mL), citric acid (0.3 g / 100 mL), and sodium chloride (0.3 g / 100 mL), with water as the solvent. The color-protecting process is carried out by soaking at room temperature for 30 minutes at a mass-to-liquid ratio of 1:3 (m / m).

[0072] Step 2: Cut the pre-treated button mushrooms longitudinally (from the stem to the cap), adjusting the diameter according to the size of the cap, and the slice thickness is 3±0.5 mm.

[0073] Step 3: Freeze-dry the button mushroom slices from Step 2 until the moisture content is ≤10%. The freeze-drying process consists of three stages: pre-freezing, sublimation drying, and desorption drying. Pre-freezing: Spread the mushroom slices obtained in Step 2 in a single layer on a freeze-drying tray with a spacing of ≥5 mm, and place it in an ultra-low temperature freezer at -80 ℃ for 12 h. Sublimation drying: Place the pre-frozen button mushroom slices in a vacuum freeze dryer. During drying, the cold trap is maintained at -50 ℃, the material temperature is maintained at -30 ℃, and the vacuum degree is maintained at 10 Pa for 40 h. Desorption drying: Increase the temperature by 5 ℃ per hour until it reaches 60 ℃, and maintain it at 60 ℃ for 4 h, during which the vacuum degree is maintained at 10 Pa to obtain dried button mushrooms.

[0074] Step 4: The obtained dried button mushroom product is crushed and sieved. A layered sieve method is used, with the mesh size of the sieves from top to bottom being 80 and 150 mesh, respectively, to obtain a powder with a mesh size of 80-150, named MS80-150 (corresponding to Example 2).

[0075] Step 5: Irradiate the Agaricus bisporus powder obtained in Step 4 under UV-C (200-280 nm), UV-B (280-320 nm), and UV-A (320-400 nm) wavelengths, respectively, at a distance of 20-50 cm, with a photoconversion dose of 2.0 J / cm². Stir the powder every 15 min for a total irradiation time of 60 min at room temperature. Extract vitamin D2 from the resulting sample according to the method in Example 1, and determine the vitamin D2 content according to the method in Example 1. The results are as follows: Figure 5 As shown.

[0076] Example 4

[0077] Step 1: Select fresh button mushrooms, wash them, and then soak them in a color-protecting solution to protect their color. The color-protecting solution consists of ascorbic acid (0.04 g / 100 mL), citric acid (0.3 g / 100 mL), and sodium chloride (0.3 g / 100 mL), with water as the solvent. The color-protecting process is carried out by soaking at room temperature for 30 minutes at a mass-to-liquid ratio of 1:3 (m / m).

[0078] Step 2: Cut the pre-treated button mushrooms longitudinally (from the stem to the cap), adjusting the diameter according to the size of the cap, and the slice thickness is 3±0.5 mm.

[0079] Step 3: Freeze-dry the button mushroom slices from Step 2 until the moisture content is ≤10%. The freeze-drying process consists of three stages: pre-freezing, sublimation drying, and desorption drying. Pre-freezing: Spread the mushroom slices obtained in Step 2 in a single layer on a freeze-drying tray with a spacing of ≥5 mm, and place it in an ultra-low temperature freezer at -80 ℃ for 12 h. Sublimation drying: Place the pre-frozen button mushroom slices in a vacuum freeze dryer. During drying, the cold trap is maintained at -50 ℃, the material temperature is maintained at -30 ℃, and the vacuum degree is maintained at 10 Pa for 40 h. Desorption drying: Increase the temperature by 5 ℃ per hour until it reaches 60 ℃, and maintain it at 60 ℃ for 4 h, during which the vacuum degree is maintained at 10 Pa to obtain dried button mushrooms.

[0080] Step 4: The obtained dried button mushrooms are crushed and sieved. A layered sieve method is used, with the mesh sizes of the sieves from top to bottom being 80 and 150 mesh, respectively, to obtain a powder with a mesh size of 80-150, which is named MS80-150.

[0081] Step 5: Irradiate the button mushroom powder obtained in Step 4 under UV-B (280-320 nm) band at a distance of 20 cm-50 cm, with a light conversion dose of 2.0 J / cm². Stir the powder every 15 min for 60 min, and keep the powder at room temperature.

[0082] Step Six: The *Agaricus bisporus* powder obtained in Step Five was stored at a constant temperature of 20℃, 30℃, and 40℃ in the dark for 0h, 8h, 16h, 24h, 32h, 40h, and 48h respectively, maintaining environmental stability during storage. Vitamin D2 was extracted from the resulting samples according to the method in Example 1, and its content was determined. The results are as follows... Figure 6 As shown.

Claims

1. A method for preparing vitamin-rich... The method for preparing button mushroom powder is characterized by: The method includes the following steps: Step 1: Select fresh button mushrooms that are free from mechanical damage, pests, and diseases, and whose fruiting bodies are intact. After washing, soak them in a color-protecting solution for 20-40 minutes at room temperature. The color-protecting solution consists of: ascorbic acid concentration of 0.03-0.05 g / 100 mL, citric acid concentration of 0.2-0.4 g / 100 mL, sodium chloride concentration of 0.2-0.4 g / 100 mL, and water as the solvent. Step 2: After color protection treatment, the button mushrooms are sliced ​​and freeze-dried to obtain dried button mushrooms; Step 3: Irradiate the dried button mushrooms obtained in Step 2 under UV-B wavelengths of 280-320 nm to convert ergosterol into vitamin C. Obtain vitamin-rich Button mushroom powder.

2. The method as described in claim 1, characterized in that: In the color-protecting solution, the concentration of ascorbic acid is 0.035-0.045 g / 100 mL, preferably 0.04 g / 100 mL; the concentration of citric acid is 0.25-0.35 g / 100 mL, preferably 0.3 g / 100 mL; and the concentration of sodium chloride is 0.25-0.35 g / 100 mL, preferably 0.3 g / 100 mL.

3. The method as described in claim 1, characterized in that: In step one, the mass ratio of fresh button mushrooms to color-protecting solution is 1:2-4, and the soaking time at room temperature is 20-40 minutes.

4. The method as described in claim 1, characterized in that: In step two, the freeze-drying operation temperature is between -80℃ and 60℃.

5. The method as described in claim 1, characterized in that: In step three, the irradiation distance is 20 cm-50 cm, the photoconversion dose is 1.0-4.0 J / cm², the mixture is stirred once periodically, the irradiation time is 60-90 min, and the conversion temperature is room temperature.

6. The method according to any one of claims 1-5, characterized in that: The method further includes the following step A: The dried button mushrooms obtained in step two are crushed and sieved to obtain button mushroom powder with a particle size between 20 and 200 mesh. This button mushroom powder is then used as the raw material for step three.

7. The method as described in claim 6, characterized in that: In step A, the particle size of the button mushroom powder is made to be 80-150 mesh.

8. The method according to any one of claims 1-5, characterized in that: The method further includes the following step B: The button mushroom powder obtained in step 3 should be placed at a constant temperature of 20-40 ℃ in the dark for at least 8 hours.

9. The method as described in claim 8, characterized in that: In step B, the placement temperature is 20-30 ℃, with 30 ℃ being the optimal temperature; the placement time in the dark is 8-50 h.

10. The method as described in claim 1, characterized in that: The preparation is rich in vitamins The method for preparing button mushroom powder is carried out according to the following steps: Step 1: Select fresh button mushrooms that are free from mechanical damage, pests, and diseases, and whose fruiting bodies are intact. After washing, soak them in a color-protecting solution for 20-40 minutes at room temperature. The color-protecting solution consists of: ascorbic acid concentration of 0.03-0.05 g / 100 mL, citric acid concentration of 0.2-0.4 g / 100 mL, sodium chloride concentration of 0.2-0.4 g / 100 mL, and water as the solvent. Step 2: After color protection treatment, the button mushrooms are sliced ​​and freeze-dried to obtain dried button mushrooms; Step A: Crush and sieve the dried button mushrooms obtained in Step 2 to obtain button mushroom powder with a particle size between 80-150 mesh; Step 3: Irradiate the Agaricus bisporus powder obtained in Step A under UV-B wavelengths of 280-320 nm to convert ergosterol into vitamin A. ; Step B: Place the button mushroom powder obtained in Step 3 at a constant temperature of 20-30 ℃ in the dark for 8-50 h to obtain a product rich in vitamins. Button mushroom powder.

Images