A method for preparing a high-activity cabbage fruit and vegetable powder

Abstract

The application discloses a preparation method of high-activity cabbage fruit and vegetable powder, and comprises the following steps: low-temperature cell wall breaking of raw materials, directional enzymatic conversion, pulse flash enzyme inactivation, ultrasonic-assisted extraction, subcritical water extraction, combination and concentration, and grading drying and powdering process. The application can realize efficient directional conversion of glucosinolates, reduce the loss of heat-sensitive active ingredients, comprehensively separate various active components, and control the production cost while ensuring the retention of activity.

Description

Technical Field

[0001] This invention belongs to the field of deep processing of fruits and vegetables and preparation of functional foods, specifically relating to a method for preparing highly active cabbage fruit and vegetable powder. Background Technology

[0002] Cabbage is an annual or biennial herbaceous plant belonging to the Brassicaceae family and the Brassica genus. It includes several cultivated varieties such as head cabbage, purple cabbage, and collard cabbage, and is rich in various nutrients and functional components, including glucosinolates, vitamin C, polyphenols, and dietary fiber. Among these, sulforaphane and isothiocyanates, produced by the hydrolysis of glucosinolates with myrosinase, possess various physiological activities such as antioxidant, anti-inflammatory, and metabolic regulation, and are the core functional active ingredients of cabbage. In recent years, with the rapid growth of the functional food ingredient market, the demand for highly active cabbage fruit and vegetable powder as a natural functional ingredient has been increasing.

[0003] Currently, the conventional preparation processes for cabbage and vegetable powder mainly fall into two categories:

[0004] One type is the direct drying and powdering process, in which fresh cabbage is pre-treated by washing, cutting, and blanching, and then directly pulverized into powder using hot air drying, spray drying, or freeze drying. However, the high-temperature treatment of hot air and spray drying rapidly deactivates endogenous myrosinase, resulting in insufficient conversion of sulforaphane and severe degradation of heat-sensitive components such as vitamin C and polyphenols. While freeze drying can retain some enzyme activity, it lacks the conditions for targeted enzymatic hydrolysis, resulting in limited sulforaphane production. Furthermore, it requires significant equipment investment and has a long production cycle, making large-scale mass production difficult.

[0005] Another type is the extraction and enrichment process, which involves juicing or solvent extraction, concentration, and then drying. This process can only dissolve free active ingredients with a single solvent, and the extraction efficiency of bound phenols and glucosinolate derivatives is low; high-temperature concentration and drying still cause significant degradation of heat-sensitive components; and the extraction residue is mostly discarded directly, resulting in low raw material utilization and high environmental costs.

[0006] CN108094950A discloses a method for preparing purple cabbage powder, which involves blanching purple cabbage shreds in hot water at 96-100℃, followed by vacuum freeze-hot air drying. However, blanching in hot water completely deactivates endogenous myrosinase, preventing the enzymatic conversion of glucosinolates to sulforaphane. As a result, the product is difficult to enrich with sulforaphane active substances. Furthermore, this process only directly dries and pulverizes the material, lacking an active ingredient extraction and enrichment step. Processing residues are directly discarded, leading to low comprehensive utilization of raw materials.

[0007] CN118985915A discloses an industrial preparation method for broccoli powder, which uses countercurrent extraction of broccoli particles with hot water at 95-100℃. The high-temperature extraction conditions rapidly denature and inactivate endogenous myrosinase, retaining only high levels of sulforaphane precursors. It cannot achieve the enzymatic conversion of glucosinolates to sulforaphane, and cannot directly obtain products with high sulforaphane content. Furthermore, the single-step hot water extraction method has limited ability to dissolve bound active substances, and the solid residue after extraction is directly discarded, resulting in low comprehensive utilization of raw materials. Summary of the Invention

[0008] To address the problems existing in the prior art, the present invention aims to provide a method for preparing highly active cabbage fruit and vegetable powder. This method utilizes endogenous myrosinase to achieve efficient and directional conversion of glucosinolates to sulforaphane, uses pulse flash evaporation to inactivate the enzyme to maximize the protection of heat-sensitive active ingredients, and employs ultrasonic and subcritical water stepwise extraction to achieve comprehensive separation of multiple active ingredients, while simultaneously realizing high-value utilization of all components.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for preparing a highly active cabbage fruit and vegetable powder includes the following steps:

[0011] S1. Low-temperature cell wall breaking of raw materials: Fresh cabbage is subjected to low-temperature wet ultrafine grinding in a protective solution containing ascorbic acid to obtain cabbage pulp with a particle size of 20~80μm.

[0012] S2. Targeted enzymatic hydrolysis conversion: Add a citric acid buffer system to the cabbage pulp to adjust the pH value, and enzymatically hydrolyze at 35~45℃ for 30~90min to obtain the enzymatic hydrolysis conversion solution;

[0013] S3. Pulse flash evaporation to inactivate enzymes: The enzymatic hydrolysis conversion solution is subjected to pulse steam flash evaporation treatment, and then rapidly cooled to below 40°C to obtain an enzyme-inactivated solution.

[0014] S4. Ultrasonic-assisted extraction: Add water to the enzyme-inactivating solution at a ratio of 1:10 to 1:20 and mix well. Extract with ultrasound at an ultrasonic power of 150 to 300 W and a temperature of 35 to 50 °C for 20 to 40 minutes. Centrifuge to separate the first supernatant and the extraction residue.

[0015] S5. Subcritical water extraction: Add water to the extraction residue at a material-to-liquid ratio of 1:15 to 1:30 and mix well. Extract for 10 to 30 minutes at a temperature of 100 to 160°C and a pressure of 0.5 to 2.0 MPa. Separate the second supernatant and the final residue.

[0016] S6. Combining and concentrating: Combining the first supernatant and the second supernatant, and concentrating them under vacuum until the solid content is 20%~35% to obtain a concentrated extract;

[0017] S7. Grading and drying to produce powder: The concentrated extract is dried using a foam belt to obtain highly active cabbage fruit and vegetable powder; the final residue is dried under low temperature vacuum to obtain cabbage dietary fiber powder.

[0018] Furthermore, in step S1, the cabbage is any one of head cabbage, purple cabbage, kale, or small cabbage.

[0019] Furthermore, in step S1, the temperature of the low-temperature wet ultrafine pulverization is -5~5℃, the mass fraction of ascorbic acid in the protective solution is 0.5%~2.0%, and the particle size D50 of the pulverized slurry is 30~60μm.

[0020] Furthermore, in step S2, ascorbic acid is added to the cabbage pulp at a concentration of 0.1% to 0.5% of the pulp mass; the concentration of the citric acid buffer system is 0.05 to 0.2 mol / L, and the pH value is 5.5 to 6.0.

[0021] Furthermore, in step S3, the steam temperature is 110~130℃, the cycle is 3~8s for steam to be introduced and 5~15s for steam to be stopped, and the total processing time is 3~8min.

[0022] Furthermore, in step S4, the ultrasonic extraction adopts an intermittent ultrasonic mode, accounting for 50% to 80% of the work, and the ultrasonic frequency is 20 to 40 kHz; the centrifugation speed is 4000 to 8000 rpm, and the duration is 10 to 20 min.

[0023] Furthermore, in step S5, the subcritical water extraction pressure is 0.8~1.5MPa, the temperature is 120~150℃, and the extraction time is 15~25min.

[0024] Furthermore, step S6 also includes a refining process, specifically: the combined supernatant is first pre-concentrated to a solid content of 10%~15%, ethanol is added to a final volume fraction of 60%~75% for alcohol precipitation, the supernatant is centrifuged and the ethanol is recovered, food-grade β-cyclodextrin is added for encapsulation, and then vacuum concentration is continued to a solid content of 20%~35% to obtain a refined concentrate for subsequent drying.

[0025] Furthermore, in step S7, the foam carrier for drying the foam belt is a mixed aqueous solution containing 0.5%~2.0% methylcellulose and 1%~5% maltodextrin, with a foam expansion rate of 1.5~2.5 times, a drying temperature of 60~80℃, and a drying time of 2~4 hours.

[0026] Furthermore, the highly active cabbage fruit and vegetable powder prepared by the method has a sulforaphane content of not less than 2.0 mg / g, a vitamin C retention rate of not less than 80%, and a total polyphenol retention rate of not less than 75% on a dry basis.

[0027] Beneficial effects:

[0028] (1) Directed conversion by endogenous enzymes, with no exogenous residues: The conversion of sulforaphane into sulforaphane relies on the endogenous black mustard enzymes in cabbage, with a conversion rate of 70%~80%. No external enzyme preparations are required and there are no exogenous residues. Water is the main medium throughout the process, and ethanol can be recovered for purification. It is green, safe, and low-cost.

[0029] (2) Step-by-step extraction with high activity retention: Ultrasonic-subcritical water step-by-step extraction can significantly increase the extraction rate of active ingredients by 30%~50%. Combined with pulse flash evaporation to inactivate enzymes, it reduces the loss of heat-sensitive ingredients by 40%~60%, effectively preserving the active substances in the product.

[0030] (3) Low temperature quality improvement, suitable for industrialization: Low temperature foam drying can control the temperature at 40~55℃, effectively retaining vitamin C, polyphenols and sulforaphane. The product quality is close to that of freeze drying, and the energy consumption is lower, making it suitable for large-scale production.

[0031] (4) Full value utilization of raw materials, zero waste and environmental protection: High-activity fruit and vegetable powder and high-purity dietary fiber powder can be prepared simultaneously, making full use of processing residues to achieve high value utilization of all components of raw materials, with no waste discharge. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to embodiments. These embodiments are merely illustrative and are intended to limit the scope of the invention.

[0033] Example 1: A method for preparing a highly active cabbage fruit and vegetable powder, comprising the following steps:

[0034] S1. Low-temperature cell wall breaking of raw materials: Fresh head cabbage is used as raw material. The outer leaves and core are removed, and the cabbage is cut into pieces and put into a cryoprotectant containing 1.0% (w / v) ascorbic acid. Wet ultrafine grinding is carried out at -2℃ to obtain cabbage pulp with a D50 of 45μm. The temperature is maintained at -2~2℃ throughout the grinding process, and the mixture is transferred to S2 within 10 minutes.

[0035] S2. Targeted enzymatic hydrolysis: Add 0.2% (w / v) ascorbic acid and 0.1 mol / L citrate buffer (pH 5.8) to the slurry and hydrolyze at 40℃ for 60 min. The conversion rate of glucosinolates was measured to be 76.8%, yielding the enzymatic hydrolysis solution.

[0036] S3, Enzyme Inactivation by Pulse Flash Evaporation: Steam temperature 120℃, pulse cycle of 5s steam on and 10s off, total treatment time 5min, followed by cooling to 35℃ with cold air. The residual activity of black myrosinase was measured to be ≤2%, and the residual activity of polyphenol oxidase was measured to be ≤3%.

[0037] S4. Ultrasonic-assisted extraction: Add water to the enzyme-inactivated solution at a ratio of 1:15, use ultrasonic power of 200W, 28kHz, duty cycle of 70%, extract at 40℃ for 30min, and centrifuge (6000rpm, 15min) to obtain the first supernatant and extraction residue.

[0038] S5. Subcritical water extraction: Add water to the extraction residue at a material-to-liquid ratio of 1:20, extract at 135℃ and 1.2MPa for 20 minutes, and separate by pressure filtration to obtain the second supernatant and the final residue.

[0039] S6. Combining and Concentrating: Combine the first supernatant and the second supernatant, pre-concentrate at 50℃ and -0.08MPa to a solid content of 12%, add ethanol to a final volume fraction of 65% for alcohol precipitation, centrifuge to collect the supernatant and recover the ethanol, add 3% (by weight of the supernatant) of food-grade β-cyclodextrin and stir for 30 min for encapsulation, then continue vacuum concentration at 50℃ and -0.08MPa to a solid content of 28% to obtain the purified concentrate.

[0040] S7. Grading and Drying: Add 1.5% methylcellulose and 3% maltodextrin as a foam carrier to the refined concentrate, stir to form a 2.0 times expanded foam, dry at 70℃ for 3 hours, and pulverize through a 100-mesh sieve to obtain approximately 180g of highly active cabbage fruit and vegetable powder. Finally, vacuum dry the residue at 50℃ until the moisture content is ≤8%, pulverize through an 80-mesh sieve to obtain approximately 120g of cabbage dietary fiber powder.

[0041] Example 2, a method for preparing a highly active cabbage fruit and vegetable powder, comprising the following steps:

[0042] S1. Low-temperature cell wall breaking of raw materials: Fresh purple cabbage is used as raw material. The outer leaves and the heart of the cabbage are removed, and the pieces are cut into pieces and put into a cryoprotective solution containing 0.5% (w / v) ascorbic acid. The cabbage is wet-processed and ultra-finely pulverized at 0℃ to obtain cabbage pulp with a D50 of 55μm. The temperature is maintained at 0~3℃ throughout the pulverization process, and the mixture is transferred to S2 within 10 minutes.

[0043] S2. Targeted enzymatic hydrolysis: Add 0.3% (w / v) ascorbic acid and 0.08 mol / L citrate buffer (pH 5.5) to the slurry and hydrolyze at 42℃ for 75 min. The conversion rate of glucosinolates was measured to be 73.2%, yielding the enzymatic hydrolysis solution.

[0044] S3, Pulse flash evaporation for enzyme inactivation: Steam temperature 115℃, pulse cycle 4s steam on, 12s steam off, total treatment time 6min, followed by cooling to 38℃ with cold air. The residual activity of black myrosinase was measured to be ≤3%, and the residual activity of polyphenol oxidase was measured to be ≤4%.

[0045] S4. Ultrasonic-assisted extraction: Add water to the enzyme-inactivated solution at a ratio of 1:12, use ultrasonic power of 250W, 25kHz, and duty cycle of 60%, extract at 42℃ for 35min, and centrifuge (5000rpm, 15min) to obtain the first supernatant and extraction residue.

[0046] S5. Subcritical water extraction: Add water to the extraction residue at a material-to-liquid ratio of 1:25, extract at 125℃ and 1.0MPa for 25 minutes, and separate by pressure filtration to obtain the second supernatant and the final residue.

[0047] S6. Combining and Concentrating: Combine the first supernatant and the second supernatant, pre-concentrate at 50℃ and -0.08MPa to a solid content of 10%, add ethanol to a final volume fraction of 70% for alcohol precipitation, centrifuge to collect the supernatant and recover the ethanol, add 2.5% (by weight of the supernatant) of food-grade β-cyclodextrin and stir for 30 min to embed, then continue vacuum concentration at 50℃ and -0.08MPa to a solid content of 25% to obtain the purified concentrate.

[0048] S7. Grading and Drying: 1.0% methylcellulose and 4% maltodextrin are added to the refined concentrate as a foam carrier. After stirring to form a foam that expands to 1.8 times its original size, the mixture is dried at 75°C for 3.5 hours and then pulverized through a 100-mesh sieve to obtain approximately 160g of highly active cabbage fruit and vegetable powder. The final residue is vacuum dried at 50°C until the moisture content is ≤8%, and then pulverized through an 80-mesh sieve to obtain approximately 100g of cabbage dietary fiber powder.

[0049] Example 3, a method for preparing a highly active cabbage fruit and vegetable powder, comprising the following steps:

[0050] S1. Low-temperature cell wall breaking of raw materials: Fresh kale is used as raw material. The coarse stems are removed, and the kale is cut into sections and placed in a cryoprotectant containing 2.0% (w / v) ascorbic acid. The kale is then wet-processed and ultra-finely pulverized at -5℃ to obtain kale pulp with a D50 of 30μm. The temperature is maintained at -5~-1℃ throughout the pulverization process, and the kale is transferred to S2 within 10 minutes.

[0051] S2. Targeted enzymatic hydrolysis: Add 0.15% (w / v) ascorbic acid and 0.15 mol / L citrate buffer (pH 6.0) to the slurry and hydrolyze at 38℃ for 50 min. The conversion rate of glucosinolates was measured to be 79.5%, yielding the enzymatic hydrolysis solution.

[0052] S3, Pulse flash evaporation for enzyme inactivation: Steam temperature 125℃, pulse cycle of 3s steam on and 8s off, total treatment time 4min, followed by cooling to 36℃ with cold air. The residual activity of black myrosinase was ≤1%, and the residual activity of polyphenol oxidase was ≤2%.

[0053] S4. Ultrasonic-assisted extraction: Add water to the enzyme-inactivated solution at a ratio of 1:18, use ultrasonic power of 300W, 35kHz, duty cycle of 80%, extract at 38℃ for 25min, and centrifuge (7000rpm, 12min) to obtain the first supernatant and extraction residue.

[0054] S5. Subcritical water extraction: Add water to the extraction residue at a material-to-liquid ratio of 1:15, extract at 150℃ and 1.8MPa for 15 minutes, and separate by pressure filtration to obtain the second supernatant and the final residue.

[0055] S6. Combining and Concentrating: Combine the first supernatant and the second supernatant, pre-concentrate at 50℃ and -0.08MPa to a solid content of 15%, add ethanol to a final volume fraction of 60% for alcohol precipitation, centrifuge to collect the supernatant and recover the ethanol, add 3.5% (by weight of the supernatant) of food-grade β-cyclodextrin and stir for 30 min to embed, then continue vacuum concentration at 50℃ and -0.08MPa to a solid content of 32% to obtain the purified concentrate.

[0056] S7. Grading and Drying: 2.0% methylcellulose and 2% maltodextrin are added to the refined concentrate as a foam carrier. After stirring to form a 2.2 times expanded foam, the mixture is dried at 65℃ for 2.5 hours and then pulverized through a 100-mesh sieve to obtain approximately 210g of highly active cabbage fruit and vegetable powder. The final residue is vacuum dried at 50℃ until the moisture content is ≤8%, and then pulverized through an 80-mesh sieve to obtain approximately 90g of cabbage dietary fiber powder.

[0057] Example 4, a method for preparing a highly active cabbage fruit and vegetable powder, comprising the following steps:

[0058] S1. Low-temperature cell wall breaking of raw materials: Fresh small cabbage is used as raw material. The outer leaves and roots are removed, and the pieces are cut into pieces and put into a cryoprotectant containing 1.2% ascorbic acid. The cabbage is wet-processed and ultra-finely pulverized at -3℃ to obtain cabbage pulp with a D50 of 40μm. The temperature is maintained at -3~1℃ throughout the pulverization process, and the mixture is transferred to S2 within 10 minutes.

[0059] S2. Targeted enzymatic hydrolysis: Add 0.25% (w / v) ascorbic acid and 0.12 mol / L citrate buffer (pH 5.7) to the slurry and hydrolyze at 41℃ for 55 min. The conversion rate of glucosinolates was measured to be 74.5%, yielding the enzymatic hydrolysis solution.

[0060] S3, Enzyme Inactivation by Pulse Flash Evaporation: Steam temperature 118℃, pulse cycle 5s steam on, 10s steam off, total treatment time 5min, followed by cooling to 37℃ with cold air. The residual activity of black myrosinase was ≤2%, and the residual activity of polyphenol oxidase was ≤3%.

[0061] S4. Ultrasonic-assisted extraction: Add water to the enzyme-inactivated solution at a ratio of 1:14, use ultrasonic power of 220W, 28kHz, duty cycle of 65%, extract at 42℃ for 30min, and centrifuge (5500rpm, 15min) to obtain the first supernatant and extraction residue.

[0062] S5. Subcritical water extraction: Add water to the extraction residue at a material-to-liquid ratio of 1:18, extract at 130℃ and 1.0MPa for 22 minutes, and separate by pressure filtration to obtain the second supernatant and the final residue.

[0063] S6. Combining and Concentrating: Combine the first supernatant and the second supernatant, pre-concentrate at 50℃ and -0.08MPa to a solid content of 11%, add ethanol to a final volume fraction of 68% for alcohol precipitation, centrifuge to collect the supernatant and recover the ethanol, add 2.8% (by weight of the supernatant) of food-grade β-cyclodextrin and stir for 30 min to embed, then continue vacuum concentration at 50℃ and -0.08MPa to a solid content of 26% to obtain the purified concentrate.

[0064] S7. Grading and Drying: 1.2% methylcellulose and 3.5% maltodextrin are added to the refined concentrate as a foam carrier. After stirring to form a 2.0 times expanded foam, it is dried at 72℃ for 3 hours and then pulverized through a 100-mesh sieve to obtain approximately 170g of highly active cabbage fruit and vegetable powder. The final residue is vacuum dried at 50℃ until the moisture content is ≤8%, and then pulverized through an 80-mesh sieve to obtain approximately 110g of cabbage dietary fiber powder.

[0065] Comparative Example 1: Traditional heat blanching and spray drying method, including the following steps:

[0066] Using the same batch of head cabbage as in Example 1 as raw material, the cabbage was cut into pieces, blanched in 95°C hot water for 8 minutes to inactivate enzymes, dried with hot air (70°C, 6 hours), and then pulverized through an 80-mesh sieve. It was extracted twice with 10 times the amount of 70% ethanol under reflux at 60°C (2 hours each time), the extracts were combined, concentrated, and then spray-dried (inlet air 180°C, outlet air 85°C) to obtain cabbage powder product.

[0067] Comparative Example 2: Freeze-drying + water extraction method, including the following steps:

[0068] Using the same batch of head cabbage as in Example 1 as raw material, the cabbage was cut into pieces, pre-frozen at -40°C, and then placed in a freeze dryer (cold trap -50°C, vacuum degree 20Pa) for 24 hours until the moisture content was ≤5%. The cabbage was then pulverized and passed through an 80-mesh sieve. The cabbage was extracted twice with 10 times the amount of deionized water at 40°C (1 hour each time). The extracts were combined and then freeze-dried to obtain cabbage powder product.

[0069] Comparative Example 3: Without targeted enzymatic hydrolysis, the following steps were performed:

[0070] Using the same batch of head cabbage as in Example 1 as raw material, after obtaining cabbage pulp by operating step S1 in Example 1, skipping the directional enzymatic hydrolysis conversion in step S2, and directly performing the pulse flash evaporation enzyme inactivation treatment in step S3 (at this time, only a small amount of glucosinolates in the pulp are naturally converted during the cell wall breaking process), and then operating step S3 to S7 in Example 1 to obtain cabbage powder product.

[0071] Comparative Example 4: Enzyme inactivation without pulse flash evaporation, including the following steps:

[0072] Using the same batch of head cabbage as in Example 1 as raw material, after obtaining the enzymatic conversion solution by following steps S1-S2 of Example 1, skipping the pulse flash evaporation enzyme inactivation treatment in step S3, and directly performing ultrasonic-assisted extraction in step S4 (at this time, the black mustard enzyme still maintains activity and continues to catalyze the reaction during the ultrasonic process), and then following steps S4-S7 of Example 1 to obtain the cabbage powder product.

[0073] The results are shown in Table 1 below:

[0074] Table 1

[0075] Sulforaphane (mg / g dry basis) 2.5 2.2 2.6 2.3 0.3 1.3 0.7 1.9 Vitamin C retention rate (%) 86.5 85.2 89.3 86.8 36.2 90.5 86.2 68.5 Total polyphenol retention rate (%) 79.8 77.5 82.8 78.6 40.5 86.2 80.8 62.3 Glucosinoside conversion rate (%) 76.8 73.2 79.5 74.5 11.8 25.6 16.5 72.5 Isothiocyanates (mg / g) 1.4 1.2 1.5 1.3 — — — — Dietary fiber content (%) 72.5 68.3 76.8 70.8 — — — —

[0076] As shown in Table 1, the sulforaphane content (2.2–2.6 mg / g dry basis) of Examples 1–4 of the present invention was significantly higher than that of Comparative Examples 1–4 (0.3–1.9 mg / g dry basis), the vitamin C retention rate (85.2–89.3%) was significantly higher than that of Comparative Example 1 (36.2%) using the conventional method and Comparative Example 4 (68.5%) without enzyme inactivation treatment, and the total polyphenol retention rate (77.5–82.8%) was significantly higher than that of Comparative Example 1 (40.5%) and Comparative Example 4 (62.3%). The glucosinolate conversion rate (73.2–79.5%) was much higher than that of all comparative examples (11.8–72.5%). Comparative Example 3 demonstrated the critical necessity of the directional enzymatic hydrolysis conversion step (sulforaphane only 0.7 mg / g, conversion rate 16.5%); Comparative Example 4 demonstrated the crucial role of the pulse flash evaporation enzyme inactivation step in protecting polyphenols and vitamin C (polyphenol retention rate only 62.3%, vitamin C retention rate only 68.5%). The results of the examples of four cabbage varieties demonstrate that the method of the present invention is well applicable to head cabbage, purple cabbage, collard kale, and baby cabbage. These results fully demonstrate the synergistic necessity of each step in the process of the present invention and the significant advantages of the overall solution.

[0077] The above are merely preferred embodiments of the present invention, intended to facilitate understanding and implementation by those skilled in the art. Those skilled in the art can make appropriate modifications to the embodiments without departing from the innovative spirit and scope of protection of the present invention, and can also transfer and apply the core technical principles of the present invention to other applicable scenarios. The present invention is not limited to the above embodiments, and its scope of protection should cover all equivalent technical solutions obtained based on the core principles and innovative technical features of the present invention.

Claims

1. A method for preparing a highly active cabbage and vegetable powder, characterized in that, The process includes the following steps: S1. Low-temperature cell wall disruption of raw materials: Fresh cabbage is subjected to low-temperature wet ultrafine grinding using a protective solution containing ascorbic acid as a medium to obtain cabbage pulp with a particle size of 20-80 μm; S2. Targeted enzymatic hydrolysis: Citric acid buffer system is added to the cabbage pulp to adjust the pH value, and enzymatic hydrolysis is performed at 35-45℃ for 30-90 min to obtain an enzymatic hydrolysis solution; S3. Enzyme inactivation by pulsed flash evaporation: The enzymatic hydrolysis solution is subjected to pulsed steam flash evaporation treatment, and then rapidly cooled to below 40℃ to obtain an enzyme-inactivated solution; S4. Ultrasonic-assisted extraction: The enzyme-inactivated solution is mixed with water at a material-to-liquid ratio of 1:10-1:20, and extracted under ultrasonic power of 150-300W and temperature of 35-50℃. S5. Ultrasonic extraction for 20-40 min, followed by centrifugation to obtain the first supernatant and extraction residue; S6. Subcritical water extraction: The extraction residue is mixed with water at a material-to-liquid ratio of 1:15-1:30 and extracted for 10-30 min at a temperature of 100-160℃ and a pressure of 0.5-2.0 MPa, resulting in the separation of the second supernatant and final residue; S7. Combining and concentration: The first and second supernatants are combined and concentrated under vacuum to a solid content of 20%-35% to obtain a concentrated extract; S8. Grading and drying to obtain high-activity cabbage fruit and vegetable powder: The concentrated extract is dried using a foam belt; the final residue is dried under low-temperature vacuum to obtain cabbage dietary fiber powder.

2. The preparation method according to claim 1, characterized in that, In step S1, the cabbage is any one of head cabbage, purple cabbage, collard kale, or baby cabbage.

3. The preparation method according to claim 1, characterized in that, In step S1, the temperature of the low-temperature wet ultrafine pulverization is -5~5℃, the mass fraction of ascorbic acid in the protective solution is 0.5%~2.0%, and the particle size D50 of the pulverized slurry is 30~60μm.

4. The preparation method according to claim 1, characterized in that, In step S2, ascorbic acid is added to the cabbage pulp at a concentration of 0.1% to 0.5% of the pulp mass; the concentration of the citric acid buffer system is 0.05 to 0.2 mol / L, and the pH value is 5.5 to 6.

0.

5. The preparation method according to claim 1, characterized in that, In step S3, the steam temperature is 110~130℃, the cycle is 3~8s for steam to be introduced and 5~15s for steam to be stopped, and the total processing time is 3~8min.

6. The preparation method according to claim 1, characterized in that, In step S4, the ultrasonic extraction adopts intermittent ultrasonic mode, accounting for 50% to 80% of the work, and the ultrasonic frequency is 20 to 40 kHz; the centrifugation speed is 4000 to 8000 rpm, and the duration is 10 to 20 min.

7. The preparation method according to claim 1, characterized in that, In step S5, the subcritical water extraction pressure is 0.8~1.5MPa, the temperature is 120~150℃, and the extraction time is 15~25min.

8. The preparation method according to claim 1, characterized in that, Step S6 also includes a refining process, specifically: the combined supernatant is first pre-concentrated to a solid content of 10%~15%, ethanol is added to a final volume fraction of 60%~75% for alcohol precipitation, the supernatant is centrifuged and the ethanol is recovered, food-grade β-cyclodextrin is added for encapsulation, and then vacuum concentration is continued to a solid content of 20%~35% to obtain a refined concentrate for subsequent drying.

9. The preparation method according to claim 1, characterized in that, In step S7, the foam carrier for drying the foam belt is a mixed aqueous solution containing 0.5%~2.0% methylcellulose and 1%~5% maltodextrin, with a foam expansion rate of 1.5~2.5 times, a drying temperature of 60~80℃, and a drying time of 2~4 hours.

10. The highly active cabbage and vegetable powder prepared by the method according to any one of claims 1 to 9, characterized in that, On a dry basis, the sulforaphane content is not less than 2.0 mg / g, the vitamin C retention rate is not less than 80%, and the total polyphenol retention rate is not less than 75%.