Preparation method of high-activity defatted torreya grandis powder

Abstract

This invention discloses a method for preparing highly active defatted Torreya grandis powder. Using cold-pressed or low-temperature hot-pressed (≤60℃) Torreya grandis cake as raw material, the cake is screened to remove impurities, and then conditioned at 40-50℃ to a moisture content of 6%-8%. Following this, a coupled low-temperature spiral pressing pre-defatting process and supercritical CO2 deep defatting are employed, achieving a defatting rate of ≥95% and fat residue of ≤3% at ≤50℃. The cake is then coarsely pulverized and micro-pulverized at ≤35℃ to 5-50μm, followed by high-speed homogenization at 8000-12000r / min to eliminate agglomeration. Subsequently, it is vacuum-dried at 30-40℃ to a moisture content of ≤5%. A composite antioxidant of vitamin C and rosemary extract is added, and the product is finally graded, sieved, and vacuum-packed with nitrogen. This invention utilizes low-temperature physical processing throughout, leaving no solvent residue. The retention rate of active ingredients such as vitamin E and phytosterols is ≥80%, and the product solubility is ≥90%. This method achieves high-value conversion of Torreya grandis by-products, is green and industrially applicable, and is suitable for various processing needs in the health food industry.

Description

Technical Field

[0001] This invention belongs to the technical field of agricultural and forestry by-products, and particularly relates to a method for preparing highly active defatted Torreya grandis powder. Background Technology

[0002] Torreya grandis is a rare and precious dried fruit unique to China. Its kernels contain over 50% oil and are rich in unsaturated fatty acids, phytosterols, vitamin E, minerals, and active ingredients such as tau phenol derivatives, offering both nutritional and health benefits. With the large-scale production of Torreya grandis oil, the annual output of Torreya grandis cake (defatted Torreya grandis powder raw material) produced after oil extraction exceeds 10,000 tons. Currently, most of this is used as low-value animal feed or directly discarded, causing serious resource waste and environmental pressure.

[0003] In traditional processing techniques, torreya nut cake and meal are mostly produced by hot pressing and high-temperature drying. This process causes heat-sensitive substances such as vitamin E, phytosterols, and tau phenol derivatives to degrade by more than 40%, while also denaturing proteins and damaging dietary fiber structure, resulting in a significant reduction in product activity and nutritional value. Furthermore, traditional pressing and defatting leaves 8%-15% residual fat, which is prone to oxidation and rancidity. Solvent defatting carries the risk of solvent residue and damages the structure of proteins and active ingredients. In addition, current processing methods mostly employ coarse grinding, resulting in products with large particle sizes (>200μm), poor solubility, and a rough texture, making them difficult to use directly in food processing and limiting their application scenarios. Summary of the Invention

[0004] To address the problems in the prior art, the present invention proposes the following technical solution: A method for preparing highly active defatted Torreya grandis powder includes the following steps: S1. Raw material pretreatment: Select fresh cakes and pie from cold-pressed or low-temperature hot-pressed Torreya grandis (≤60℃), and remove impurities by screening and low-temperature conditioning to a moisture content of 6%-8%; S2, Low-temperature physical coupling degreasing: First, pre-degrease through low-temperature spiral pressing, then deep degrease through supercritical CO2 to obtain secondary degreased cake with ≤3% fat residue; S3, graded micro-pulverization and homogenization: sequentially coarsely pulverized and then micro-pulverized at low temperature to 5-50μm, and then homogenized at high speed to eliminate agglomeration; S4. Active Freshness Locking and Drying: Vacuum low-temperature drying is used until the moisture content is ≤5%, and natural antioxidants are added and mixed evenly; S5. Sieving and Packaging: After grading and sieving, vacuum nitrogen-filled packaging is used to obtain highly active defatted torreya powder.

[0005] As a preferred embodiment of the above technical solution, in step S1, the raw material screening is carried out by removing impurities through a 10-mesh vibrating screen, and the initial moisture content of the raw material is 8%-12%, crude fat is 45%-55%, crude protein is 20%-28%, and crude fiber is 15%-22%; the low-temperature conditioning is carried out at 40-50℃ and relative humidity of 50%-60% for 2-4 hours, and the material is turned over once every 30 minutes.

[0006] As a preferred embodiment of the above technical solution, in step S2, the low-temperature spiral pressing adopts a double-spiral low-temperature oil press with a pressing chamber temperature ≤50℃, a spiral speed of 15-25r / min, a pressing pressure of 20-30MPa, a pressure gradient of 20MPa in the feeding section → 25MPa in the pressing section → 30MPa in the discharging section, a feeding speed of 50-80kg / h, and 8%-12% fat residue in the cake after pre-degreasing.

[0007] As a preferred embodiment of the above technical solution, in step S2, the conditions for supercritical CO2 deep degreasing are as follows: extraction vessel pressure 25-35 MPa, temperature 40-45℃, CO2 flow rate 10-15 L / h, extraction time 1.5-2.5 h; primary separation vessel pressure 5-8 MPa, temperature 35-40℃, secondary separation vessel pressure 3-5 MPa, temperature 30-35℃; CO2 purity ≥99.9%, and cake filling amount 60%-70% of the extraction vessel volume.

[0008] As a preferred embodiment of the above technical solution, in step S3, the coarse crushing adopts a hammer mill with a screen aperture of 4mm, and the crushed material passes through a 40-mesh sieve; the low-temperature micro-crushing adopts an airflow ultra-micro mill with a crushing chamber temperature ≤35℃, an airflow pressure of 0.8-1.2MPa, a classifying wheel speed of 8000-12000r / min, and a feeding speed of 20-30kg / h.

[0009] As a preferred embodiment of the above technical solution, in step S3, the rotation speed of the high-speed homogenizer is 8000-12000 r / min, the homogenization time is 10-15 min, 5% of the powder mass of deionized water is added during homogenization, and the machine is stopped and stirred once every 3 min. After homogenization, the proportion of the target particle size range is ≥90%.

[0010] As a preferred embodiment of the above technical solution, in step S4, the vacuum degree of the vacuum low-temperature drying is -0.08~-0.09MPa, the temperature is 30-40℃, the drying time is 3-5h, and water vapor is released once every 1h, each time ≤10s; the natural antioxidant is a mixture of vitamin C and rosemary extract at a mass ratio of 1:1, the amount added is 0.02%-0.05% of the powder mass, the mixing speed is 30r / min, and the mixing time is 5-10min.

[0011] As a preferred embodiment of the above technical solution, in step S5, the grading and sieving uses a 100-200 mesh vibrating screen, a 200 mesh screen for 5-10μm powder, a 150 mesh screen for 10-20μm powder, and a 100 mesh screen for 20-50μm powder; the vacuum degree of the vacuum nitrogen-filled packaging is ≤-0.09MPa, the oxygen content after nitrogen filling is ≤1%, the heat sealing temperature is 180-200℃, and the heat sealing time is 3s.

[0012] As a preferred embodiment of the above technical solution, the double-screw low-temperature oil press is equipped with a circulating water cooling system with a temperature control accuracy of ±1℃. After pressing, the crude oil and cake are separated by a 3000r / min centrifugal separator. If the residual fat in the cake exceeds the standard, it is returned to be pressed again once.

[0013] As a preferred embodiment of the above technical solution, before the supercritical CO2 deep degreasing, the first-degreased cake is crushed into particles ≤5mm; after the extraction is completed, the pressure relief rate is ≤5MPa / h; if the fat residue in the second-degreased cake is >3%, the extraction time is extended by 0.5h and the extraction is repeated.

[0014] The beneficial effects of this invention are as follows: 1. This invention employs a coupled process of low-temperature spiral pressing pre-degreasing and supercritical CO2 deep degreasing, with temperature controlled at ≤50℃ throughout the process. This process utilizes mechanical gradient pressure to rapidly separate most of the oil and supercritical CO2 to selectively extract residual oil, achieving a degreasing rate of ≥95% and fat residue of ≤3%. It also avoids the degradation of heat-sensitive components, resulting in a vitamin E retention rate of ≥90%, phytosterols of ≥85%, and tau phenol derivatives of ≥80%. At the same time, it fully preserves the protein and dietary fiber structure, achieving a dual optimization of thorough degreasing and nutritional activity.

[0015] 2. This invention relies on graded low-temperature micro-pulverization (≤35℃) and high-speed homogenization processes. By precisely controlling the speed of the grading wheel and the airflow pressure, the particle size of the product can be controlled within 5-50μm, the specific surface area is increased, the solubility is ≥90%, and the dispersibility is significantly improved, making it suitable for food processing in multiple scenarios. At the same time, the by-products of torreya nut oil extraction are transformed into high-value healthy raw materials, with a by-product utilization rate of ≥95%. It also has the advantages of green process with no solvent residue and industrial continuous production capability. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0017] The present invention provides a method for preparing highly active defatted torreya nut powder, which mainly includes raw material pretreatment, low-temperature physical coupling defatting, graded micro-pulverization and homogenization, activity locking and drying, as well as sieving and packaging.

[0018] (a) Raw material pretreatment: 1. Raw material screening: Fresh cakes and mortarspar after cold pressing / low-temperature hot pressing (≤60℃) are selected. Moldy particles, metal impurities, and hard lumps are removed by passing through a 10-mesh vibrating screen. The initial moisture content is measured to be 8%-12% using an infrared moisture analyzer. The crude fat content is measured to be 45%-55% using the Soxhlet extraction method (GB / T5009.6-2016), the crude protein content is measured to be 20%-28% using the Kjeldahl nitrogen determination method (GB / T5009.5-2016), and the crude fiber content is measured to be 15%-22% using the crude fiber determination method (GB / T5009.10-2003) to ensure that the raw materials meet the processing requirements.

[0019] 2. Low-temperature conditioning: Spread the screened cake evenly on a tray in a constant temperature and humidity chamber, controlling the thickness to 2-3 cm. Set the temperature to 40-50℃ and the relative humidity to 50%-60%, and condition for 2-4 hours, turning it over once every 30 minutes. Finally, use a moisture meter to check that the moisture content is uniform to 6%-8%. This step softens the fiber cell walls, reduces the viscosity of the oil, and avoids incomplete local degreasing caused by uneven moisture content of the raw materials during the subsequent degreasing process.

[0020] (ii) Low-temperature physical coupling degreasing The core of this process lies in the synergistic coupling of "low-temperature mechanical pressing pre-degreasing + supercritical CO2 fluid deep degreasing," which ensures degreasing efficiency while avoiding damage to active ingredients. The specific operation and parameter control are as follows: 1. Low-temperature spiral pressing for degreasing (pre-degreasing stage) Equipment selection: A double-screw low-temperature oil press is adopted.

[0021] Equipment debugging: Before starting the machine, preheat the pressing chamber to 35℃, start the cooling system, and ensure that the temperature of the pressing chamber is stable at ≤50℃; adjust the screw speed to 15-25r / min (the speed is negatively correlated with the degreasing rate, the lower the speed, the more thorough the degreasing, but the efficiency needs to be balanced), and adjust the pressing pressure to 20-30MPa through the hydraulic system (pressure gradient: 20MPa in the feeding section → 25MPa in the pressing section → 30MPa in the discharging section).

[0022] Feeding and Separation: The conditioned cake is fed evenly through a screw feeder. During the pressing process, the temperature of the pressing chamber is monitored in real time. If it exceeds 50℃, the feeding speed is immediately reduced or the cooling water flow rate is increased. After pressing, the crude torreya oil and the primary defatted cake are separated by a centrifugal separator. The cake is collected and the fat residue is tested (target 8%-12%). If the residue exceeds the standard, it is returned for re-pressing once.

[0023] The principle is as follows: low temperature environment (≤50℃) avoids protein thermal denaturation and degradation of heat-sensitive active ingredients, gradient pressure realizes physical extrusion separation of oil and fat, while preserving the integrity of the cake fiber structure.

[0024] 2. Supercritical CO2 deep degreasing (fine degreasing stage) Equipment preparation: A supercritical CO2 extraction device is used, with an extraction vessel volume of 50L, equipped with a CO2 storage tank, condenser, high-pressure pump, separation vessel, and flow meter. Check the equipment's airtightness in advance to ensure stable system pressure and no leaks; CO2 purity ≥ 99.9%, condenser temperature set at 5-10℃ (to ensure CO2 liquefaction).

[0025] Raw material loading: Crush the defatted cake into particles ≤5mm (to increase the specific surface area), and evenly fill it into the extraction vessel. The filling amount is 60%-70% of the vessel volume (to avoid material compaction affecting CO2 flow). Close the vessel door and lock it.

[0026] Parameter settings and operation: Extraction stage: Start the high-pressure pump to inject liquefied CO2 into the extraction vessel, adjust the pressure to 25-35MPa and the temperature to 40-45℃, and control the CO2 flow rate to 10-15L / h through the flow meter (the flow rate is positively correlated with the extraction efficiency and needs to be matched with the loading volume); maintain these parameters for extraction for 1.5-2.5h, and record the temperature and pressure data every 30min during this period to ensure that the fluctuation range is ≤±0.5MPa and ±1℃.

[0027] Separation stage: The extracted CO2-oil mixture enters the primary separation vessel (pressure 5-8 MPa, temperature 35-40℃), where most of the oil is separated. The remaining mixture enters the secondary separation vessel (pressure 3-5 MPa, temperature 30-35℃) for further separation of residual oil, ensuring the pure recycling of CO2. The separated oil is collected in a storage tank, and residual oil on the inner wall of the separation vessel is cleaned periodically.

[0028] Discharge and testing: After extraction, slowly release the pressure of the extraction vessel (pressure release rate ≤5MPa / h, to avoid material splashing), open the vessel door and take out the secondary defatted cake, and use Soxhlet extraction to test for fat residue (target ≤3%). If the residue exceeds the standard, extend the extraction time by 0.5h and extract again.

[0029] Principle: Supercritical CO2 combines gas diffusion and liquid solubility. Under specific temperature and pressure conditions, it has a strong selective solubility for oils and fats, and does not react with proteins or active ingredients in the oilseed cake, leaving no solvent residue. The low-temperature (40-45℃) environment maximizes the retention of active ingredients such as vitamin E and phytosterols.

[0030] (III) Grading and Homogenization 1. Coarse grinding: A hammer mill with a 4mm screen is used to grind the secondary defatted cake and pass it through a 40-mesh standard sieve (425μm aperture). The material under the sieve (coarse powder) is collected, and the material over the sieve is returned for re-grinding to ensure that the coarse powder has a uniform particle size of 5μm, so as to avoid large particles affecting the efficiency of subsequent micro-grinding.

[0031] 2. Low-temperature micronization: Equipment selection: an airflow ultrafine pulverizer is adopted, equipped with a low-temperature refrigeration system (temperature control range -5-25℃) and a classifying wheel (adjustable speed).

[0032] Parameter adjustment: Set the classifier speed according to the target particle size: 5-10μm (12000r / min), 10-20μm (10000r / min), 20-50μm (8000r / min); start the cooling system to cool the grinding chamber temperature to ≤35℃, and adjust the airflow pressure to 0.8-1.2MPa (the higher the pressure, the finer the particle size).

[0033] Grinding operation: Coarse powder is fed evenly through a screw feeder (feeding speed 20-30 kg / h). Within the grinding chamber, the material is subjected to high-speed airflow (speed ≥ 300 m / s) for impact, collision, and shearing, achieving ultrafine grinding. Simultaneously, a classifying wheel separates unqualified coarse particles (which are returned to the grinding chamber for re-grinding), while qualified micro-powder enters the collector. The grinding chamber temperature is monitored in real time. If it exceeds 35℃, the feeding speed is reduced or the cooling power is increased to prevent oxidation of active ingredients due to excessive temperature.

[0034] 3. Homogenization and Dispersion: Transfer the finely pulverized powder to a high-speed homogenizer, add 5% (by weight of powder) of deionized water (to improve homogenization effect), set the speed to 8000-12000 r / min, and homogenize for 10-15 min, stopping and stirring every 3 min to prevent material sedimentation. After homogenization, use a laser particle size analyzer (model: Mastersizer3000) to detect the particle size distribution, ensuring that the target particle size range accounts for ≥90%. If agglomeration is severe, extend the homogenization time by 2-3 min.

[0035] (iv) Active preservation and drying Vacuum low-temperature drying: Equipment preparation: A vacuum drying oven is used, equipped with a vacuum pump (ultimate vacuum ≤ -0.1MPa) and a temperature control system. Preheat the drying oven to 30-40℃, start the vacuum pump to evacuate to -0.08~-0.09MPa, maintain for 30 minutes and check for leaks.

[0036] Drying procedure: Spread the homogenized powder evenly on a stainless steel tray (thickness ≤1cm), place it in a drying oven, maintain a vacuum of -0.08~-0.09MPa and a temperature of 30-40℃, and dry for 3-5 hours. During this period, open the vent valve once every 1 hour to release moisture (time ≤10s) to avoid excessive humidity in the oven, which would affect drying efficiency. After drying, slowly introduce nitrogen to break the vacuum (to prevent rapid air entry and oxidation), remove the material, and test the moisture content using a moisture meter (target ≤5%).

[0037] Antioxidant and color-protecting: Transfer the dried powder into a double cone mixer, accurately weigh 0.02%-0.05% of the powder mass of natural antioxidant (vitamin C and rosemary extract mixed at a mass ratio of 1:1, both food grade), and slowly add it into the mixer through the hopper. Set the speed to 30 r / min and mix for 5-10 minutes to ensure that the antioxidant is evenly dispersed (sampling and testing: the antioxidant content deviation of samples from different parts is ≤5%).

[0038] (v) Screening and Packaging The mixed micro-powder is then sieved through a 100-200 mesh vibrating screen: 5-10μm powder is sieved through a 200 mesh screen (75μm aperture), 10-20μm powder through a 150 mesh screen (106μm aperture), and 20-50μm powder through a 100 mesh screen (150μm aperture). The material remaining on the screen is returned to the micro-grinding step for reprocessing. After sieving, the powder is placed in aluminum-plastic composite bags (barrier: oxygen permeability ≤5cm). 3 / (m 2 •24h•atm), moisture permeability ≤3g / (m 2 • 24h) Vacuum nitrogen-filled packaging: Using a vacuum nitrogen-filled packaging machine, first evacuate to -0.09MPa, hold for 10s, then fill with nitrogen (purity ≥99.99%) to 0.02MPa, seal the bag opening (heat sealing temperature 180-200℃, heat sealing time 3s), and finally the oxygen content inside the bag should be ≤1%. After packaging, label the product particle size and production date, and store in a warehouse at ≤25℃ and relative humidity ≤60%, away from light.

[0039] Example 1: Preparation of 10-20μm highly active defatted Torreya grandis powder 1. Raw material pretreatment: Take 10kg of cold-pressed (pressing temperature 45℃) cake from Torreya grandis, remove impurities by passing it through a 10-mesh vibrating screen, and test the initial moisture content as 10.2%, crude fat as 48.5%, crude protein as 24.3%, and crude fiber as 18.6%; place it in an HSX-150 constant temperature and humidity chamber, set at 45℃ and 55% relative humidity, and condition for 3 hours, turning it over once every 30 minutes during the conditioning period. The final moisture content was 7.1%.

[0040] 2. Low-temperature coupling degreasing: Low-temperature screw pressing: An LYJ-100 type double-screw low-temperature oil press was used. The pressing chamber was preheated to 35℃, the cooling system was started, and the screw speed was adjusted to 20 r / min. The pressing pressure gradient was 20 MPa (feeding section) → 25 MPa (pressing section) → 30 MPa (discharge section), with a feeding speed of 60 kg / h. After pressing, the crude oil and primary defatted cake were separated by a 3000 r / min centrifuge, collecting 6.8 kg of cake, with a fat residue of 9.8%.

[0041] Supercritical CO2 extraction: A HA221-50-06 type supercritical CO2 extraction device was used. The primary defatted cake was pulverized to 3mm particles and loaded into a 50L extraction vessel (30L loading capacity), and the vessel door was closed. The equipment was started, the condenser temperature was 8℃, and liquefied CO2 was injected by the high-pressure pump. The extraction pressure was set to 30MPa, the temperature to 42℃, and the CO2 flow rate to 12L / h. Extraction lasted for 2 hours. The pressure in the primary separation vessel was 6MPa and the temperature to 38℃, and the pressure in the secondary separation vessel was 4MPa and the temperature to 32℃. After extraction, the pressure was released at a rate of 3MPa / h, and 6.2kg of secondary defatted cake was taken out. The fat residue was found to be 2.8%.

[0042] 3. Grading and homogenization: Coarse crushing: SF-130 hammer mill with 4mm screen aperture is used. After crushing, the powder passes through a 40-mesh sieve and 6.1kg of coarse powder is collected (0.1kg of material on the sieve is returned for re-crushing).

[0043] Low-temperature micro-pulverization: A QLM-100 airflow ultra-micro pulverizer was used, with the classifier wheel speed set to 10000 r / min, the refrigeration system cooled to 32℃, the airflow pressure to 1.0 MPa, the feeding speed to 25 kg / h, and 6.0 kg of micro powder collected after pulverization.

[0044] Homogenization and dispersion: Transfer to a JRJ300-I high-speed homogenizer, add 300g of deionized water, set the speed to 10000r / min, homogenize for 12min, and stop the machine to stir once every 3min during the process; after homogenization, the particle size distribution was measured by a Mastersizer3000 laser particle size analyzer, and the proportion of particles in the 10-20μm range was 92.3%.

[0045] 4. Active freshness preservation and drying: Vacuum low-temperature drying: A DZF-6050 vacuum drying oven was used. The oven was preheated to 35°C and evacuated to -0.085 MPa. The homogenized powder was spread evenly on a tray (0.8 cm thick) and dried for 4 hours. During this period, the air was released once every 1 hour (10 seconds). The final moisture content was 4.8%.

[0046] Antioxidant and color protection: Transfer to SYH-50 double cone mixer, weigh 1.8g of natural antioxidant (0.9g of vitamin C + 0.9g of rosemary extract), add slowly, set the speed to 30r / min, mix for 8min, and take samples to test the antioxidant content in different parts with a deviation of 3.2%.

[0047] 5. Screening and Packaging: The material is screened through a 150-mesh vibrating screen, and 5.9 kg of the undersize material is collected (0.1 kg of the oversize material is returned for micro-grinding). A DZQ-400 vacuum nitrogen-filled packaging machine is used to vacuum to -0.09 MPa (10 s), fill with nitrogen to 0.02 MPa, and heat seal at 190℃ (3 s). The oxygen content inside the bag is measured to be 0.8%.

[0048] 6. Final product testing: Fat residue 2.7%, Vitamin E retention rate 92.5%, Phytosterol retention rate 87.3%, Prunol derivative retention rate 82.1%, Particle size 10-20μm (accounting for 91.8%), Solubility 93.2%, Peroxide value 0.18g / 100g.

[0049] Example 2: Preparation of 5-10μm ultrafine highly active defatted Torreya grandis powder 1. Raw material pretreatment: Take 15kg of torreya grandis cake produced by low-temperature hot pressing (pressing temperature 55℃), remove impurities by 10-mesh vibrating screen, and test the initial moisture content as 8.9%, crude fat as 52.3%, crude protein as 22.7%, and crude fiber as 19.5%; put it into an HSX-150 constant temperature and humidity chamber, 40℃, relative humidity as 50%, and condition for 4 hours, turning it every 30 minutes. The final moisture content is 6.5%.

[0050] 2. Low-temperature coupling degreasing: Low-temperature screw pressing: LYJ-100 type double screw low-temperature oil press, with the pressing chamber preheated to 35℃, cooling system activated, screw speed 18r / min, pressure gradient 20MPa→28MPa→30MPa, and feeding speed 50kg / h. After pressing, centrifugation (3000r / min) is performed, collecting 10.2kg of primary defatted oil cake, with a fat residue of 8.7%.

[0051] Supercritical CO2 extraction: HA221-50-06 type apparatus, cake powder crushed to 2mm particles, loading capacity 32L (50L vessel), condenser temperature 6℃. Extraction pressure 32MPa, temperature 40℃, CO2 flow rate 14L / h, extraction time 2.2h; primary separation vessel 7MPa, 36℃, secondary separation vessel 5MPa, 30℃. Depressurization rate 2.5MPa / h, 9.5kg of secondary defatted cake powder was taken out, and the fat residue was measured at 2.5%.

[0052] 3. Grading and homogenization: Coarse grinding: SF-130 type grinder, 4mm screen, after grinding, pass through 40 mesh screen, collect 9.4kg of coarse powder.

[0053] Low-temperature micro-pulverization: QLM-100 airflow pulverizer, classifier wheel speed 12000r / min, cooled to 30℃, airflow pressure 1.1MPa, feed rate 20kg / h, collected micro-powder 9.3kg.

[0054] Homogenization and dispersion: JRJ300-I type homogenizer, add 465g of deionized water, speed 12000r / min, homogenize for 10min, stir once every 3min; laser particle size analyzer detected that the proportion of 5-10μm range was 93.1%.

[0055] 4. Active freshness preservation and drying: Vacuum drying: DZF-6050 drying oven, 38℃, -0.09MPa, drying for 3.5h, venting for 10s every 1h, moisture content measured at 4.5%.

[0056] Antioxidant and color protection: Add 3.72g of antioxidant (1.86g of vitamin C + 1.86g of rosemary extract) to a SYH-50 mixer, mix at 30r / min for 10min, and the content deviation is 2.8%.

[0057] 5. Screening and Packaging: Screening with a 200-mesh vibrating screen, collecting 9.2 kg of undersize material, and vacuum-packed with nitrogen (oxygen content 0.7%).

[0058] 6. Final product testing: Fat residue 2.4%, Vitamin E retention rate 93.7%, Phytosterol retention rate 88.5%, Prunol derivative retention rate 83.6%, Particle size 5-10μm (accounting for 92.5%), Solubility 94.8%, Peroxide value 0.16g / 100g.

[0059] Example 3: Preparation of 20-50μm highly active defatted Torreya grandis powder 1. Raw material pretreatment: 50kg of cold-pressed torreya cake was sieved through a 10-mesh screen to remove impurities. The moisture content was 11.3%, crude fat 46.8%, crude protein 25.1%, and crude fiber 17.8%. The cake was then conditioned at 48℃ and 58% relative humidity for 2.5 hours until the moisture content was adjusted to 7.8%.

[0060] 2. Low-temperature coupling degreasing: Low-temperature screw pressing: LYJ-100 type oil press, speed 25r / min, pressure gradient 20MPa→25MPa→30MPa, feeding speed 80kg / h, after centrifugation separation, 34.2kg of defatted cake is produced, with 11.5% fat residue (9.2% residue after one repressing).

[0061] Supercritical CO2 extraction: 50L extraction vessel, 35L loading, extraction pressure 28MPa, temperature 44℃, CO2 flow rate 15L / h, extraction 2.5h; Separation vessel parameters: first stage 7MPa / 39℃, second stage 4MPa / 33℃, 31.5kg of degreased cake after secondary degreasing, fat residue 2.9%.

[0062] 3. Grading and homogenization: Coarse grinding: SF-130 type grinder, passing through a 40-mesh sieve, coarse powder 31.2kg.

[0063] Low-temperature micro-pulverization: QLM-100 airflow pulverizer, classifier wheel speed 8000r / min, cooled to 34℃, airflow pressure 0.9MPa, feed rate 30kg / h, micro-powder 31.0kg.

[0064] Homogenization and dispersion: JRJ300-I type homogenizer, add 1550g of deionized water, speed 9000r / min, homogenize for 15min, particle size detection 20-50μm accounted for 94.6%.

[0065] 4. Active freshness preservation and drying: vacuum drying at 32℃ and -0.08MPa for 5 hours, moisture content 4.9%; add 12.4g antioxidant and mix for 7 minutes.

[0066] 5. Screening and Packaging: Screening with a 100-mesh sieve, collecting 30.8 kg of product, and vacuum-packing with nitrogen (oxygen content 0.9%).

[0067] 6. Final product testing: Fat residue 2.8%, Vitamin E retention rate 91.2%, Phytosterol retention rate 86.7%, Prunol derivative retention rate 81.3%, Solubility 91.5%, Peroxide value 0.19g / 100g.

[0068] Example 4: Preparation of 5-10μm highly active defatted Torreya grandis powder (high moisture cake raw material) 1. Raw material pretreatment: 8 kg of torreya grandis low-temperature hot pressing (58℃) cake with an initial moisture content of 13.5% (exceeding the standard) was first vacuum dried at 40℃ and -0.08MPa for 1 hour to reduce the moisture content to 10.1%; then it was conditioned at 42℃ and 52% relative humidity for 3.5 hours to adjust the moisture content to 6.9%.

[0069] 2. Low-temperature coupling degreasing: Low-temperature screw pressing: rotation speed 16r / min, feeding speed 45kg / h, 5.5kg of degreased cake after one pass, with 8.9% fat residue.

[0070] Supercritical CO2 extraction: extraction pressure 33MPa, temperature 41℃, CO2 flow rate 13L / h, extraction time 2.1h, secondary defatted cake 5.1kg, fat residue 2.3%.

[0071] 3. Grading and homogenization: Coarse grinding through a 40-mesh sieve, air jet milling (grading wheel 12000r / min, temperature 31℃, pressure 1.1MPa), homogenization (11000r / min, 11min), with a particle size of 5-10μm accounting for 92.8%.

[0072] 4. Active freshness preservation and drying: Dry at 36℃ and -0.085MPa for 3.8h, moisture content 4.6%; add 0.04% antioxidant and mix for 9min.

[0073] 5. Screening and Packaging: Screened through a 200-mesh sieve, product 5.0kg, vacuum nitrogen-filled packaging.

[0074] 6. Final product testing: Fat residue 2.2%, Vitamin E retention rate 92.8%, Phytosterol retention rate 87.9%, Prunol derivative retention rate 82.9%, Solubility 94.1%, Peroxide value 0.17g / 100g.

[0075] Comparative Example 1: Traditional hot pressing + solvent degreasing process Raw materials: 10 kg of cold-pressed Torreya grandis cake, the same as in Example 1.

[0076] Process steps: High-temperature drying: Drying in an 80℃ forced-air drying oven for 2 hours, reducing the moisture content to 5.2%.

[0077] Hot pressing and degreasing: Ordinary screw oil press (without cooling system), pressing chamber temperature 120℃, pressure 25MPa, speed 30r / min, pressing once, degreased cake 7.2kg, fat residue 12.5%.

[0078] Solvent degreasing: The cake was crushed to 80 mesh, and 6 times its weight of n-hexane (food grade) was added. The mixture was refluxed at 60°C for 2 hours. The solvent and cake were separated by filtration. The cake was dried at 80°C for 3 hours to remove the solvent, resulting in 6.5 kg of degreased cake.

[0079] Grinding: Grind to 100 mesh (150μm) using a regular hammer mill, without homogenization or anti-oxidation treatment, and packaged in standard plastic bags.

[0080] Test results: Fat residue 4.8% (defatting rate 89.9%), Vitamin E retention rate 58.3%, Phytosterol retention rate 62.5%, Peach tannin derivative retention rate 47.8%, Particle size 120-180μm, Solubility 65.2%, Peroxide value 0.63g / 100g, n-hexane residue 18mg / kg (exceeding the limit standard of GB2760).

[0081] Comparative Example 2: Single Supercritical CO2 Degreasing Process Raw materials: 10 kg of cold-pressed Torreya grandis cake, the same as in Example 1.

[0082] Process steps: Pretreatment: only screening to remove impurities, no low-temperature conditioning, initial moisture content 10.2%.

[0083] Single supercritical CO2 degreasing: Unpressed cake (5mm particle size) is directly loaded into the extraction vessel, the extraction pressure is 30MPa, the temperature is 42℃, the CO2 flow rate is 12L / h, and the extraction time is 4h (extending the time to improve the degreasing rate).

[0084] Crushing and drying: 80-mesh hammer mill crushed, dried at 60℃ for 2 hours by forced air drying, no homogenization or anti-oxidation treatment, conventional packaging.

[0085] Test results: Fat residue 3.2% (defatting rate 93.4%), Vitamin E retention rate 88.6%, Phytosterol retention rate 83.2%, Prunol derivative retention rate 77.5%, Particle size 80-120μm, Solubility 72.4%, Peroxide value 0.35g / 100g.

[0086] Comparative Analysis Table: The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A method for preparing highly active defatted Torreya grandis powder, characterized in that, Includes the following steps: S1. Raw material pretreatment: Select fresh cakes and pie from cold-pressed or low-temperature hot-pressed Torreya grandis (≤60℃), and remove impurities by screening and low-temperature conditioning to a moisture content of 6%-8%; S2, Low-temperature physical coupling degreasing: First, pre-degrease through low-temperature spiral pressing, then deep degrease through supercritical CO2 to obtain secondary degreased cake with ≤3% fat residue; S3, graded micro-pulverization and homogenization: sequentially coarsely pulverized and then micro-pulverized at low temperature to 5-50μm, and then eliminated by high-speed homogenization to eliminate agglomeration; S4. Active Freshness Locking and Drying: Vacuum low-temperature drying is used until the moisture content is ≤5%, and natural antioxidants are added and mixed evenly; S5. Sieving and Packaging: After grading and sieving, vacuum nitrogen-filled packaging is used to obtain highly active defatted torreya powder.

2. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S1, the raw materials are screened by removing impurities through a 10-mesh vibrating screen. The initial moisture content of the raw materials is 8%-12%, crude fat is 45%-55%, crude protein is 20%-28%, and crude fiber is 15%-22%. The low-temperature conditioning is carried out at 40-50℃ and 50%-60% relative humidity for 2-4 hours, and the materials are turned over once every 30 minutes.

3. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S2, the low-temperature screw pressing adopts a double screw low-temperature oil press with a pressing chamber temperature ≤50℃, a screw speed of 15-25r / min, a pressing pressure of 20-30MPa, a pressure gradient of 20MPa in the feeding section → 25MPa in the pressing section → 30MPa in the discharging section, a feeding speed of 50-80kg / h, and 8%-12% fat residue in the cake after pre-degreasing.

4. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S2, the conditions for supercritical CO2 deep degreasing are as follows: extraction vessel pressure 25-35 MPa, temperature 40-45℃, CO2 flow rate 10-15 L / h, extraction time 1.5-2.5 h; primary separation vessel pressure 5-8 MPa, temperature 35-40℃, secondary separation vessel pressure 3-5 MPa, temperature 30-35℃; CO2 purity ≥99.9%, and cake filling amount 60%-70% of the extraction vessel volume.

5. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S3, the coarse crushing is carried out using a hammer mill with a screen aperture of 4mm, and the crushed material passes through a 40-mesh sieve; the low-temperature micro-crushing is carried out using an airflow ultra-micro pulverizer with a crushing chamber temperature ≤35℃, an airflow pressure of 0.8-1.2MPa, a classifying wheel speed of 8000-12000r / min, and a feeding speed of 20-30kg / h.

6. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S3, the high-speed homogenizer rotates at 8000-12000 r / min, and the homogenization time is 10-15 min. During homogenization, 5% of the powder mass of deionized water is added. The machine is stopped and stirred once every 3 min. After homogenization, the target particle size range accounts for ≥90%.

7. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S4, the vacuum degree of the vacuum low-temperature drying is -0.08~-0.09MPa, the temperature is 30-40℃, the drying time is 3-5h, and water vapor is released once every 1h, each time ≤10s; the natural antioxidant is vitamin C and rosemary extract mixed in a mass ratio of 1:1, the amount added is 0.02%-0.05% of the powder mass, the mixing speed is 30r / min, and the mixing time is 5-10min.

8. The method for preparing highly active defatted Torreya grandis powder according to claim 1, characterized in that, In step S5, the grading and sieving uses a 100-200 mesh vibrating screen, a 200 mesh screen for 5-10μm powder, a 150 mesh screen for 10-20μm powder, and a 100 mesh screen for 20-50μm powder; the vacuum degree of the vacuum nitrogen-filled packaging is ≤-0.09MPa, the oxygen content after nitrogen filling is ≤1%, the heat sealing temperature is 180-200℃, and the heat sealing time is 3s.

9. The method for preparing highly active defatted Torreya grandis powder according to claim 3, characterized in that, The double-screw low-temperature oil press is equipped with a circulating water cooling system with a temperature control accuracy of ±1℃. After pressing, the crude oil and cake are separated by a 3000r / min centrifugal separator. If the residual fat in the cake exceeds the standard, it is returned to be pressed again once.

10. The method for preparing highly active defatted Torreya grandis powder according to claim 4, characterized in that, Before the supercritical CO2 deep degreasing, the first-degreased cake is crushed into particles ≤5mm; after extraction, the pressure relief rate is ≤5MPa / h. If the fat residue in the second-degreased cake is >3%, the extraction time is extended by 0.5h and the extraction is repeated.