Preparation method of fiber-removing betel nut powder

Abstract

The invention belongs to the technical field of areca nut processing, and discloses a preparation method of fiber-removing areca nut powder, which comprises the following steps: pretreating raw materials, grading and screening green fruits, old fruits and residual fruits, trimming, pre-cleaning, soaking with sodium bicarbonate, sterilizing with ozone water, and draining. Quickly freezing the fresh fruits until the center is not more than-40 DEG C and temporarily storing Performing vacuum freeze drying until the moisture is 8-12%; impacting and crushing until the particle size is less than or equal to 2mm; carrying out superfine grinding, and removing slag through a 200-mesh sieve and a 500-mesh sieve to obtain powder of 300-500 meshes; and carrying out vacuum nitrogen-filled packaging after homogenizing and mixing. The method can remove the vast majority of crude fibers, reserve more than or equal to 85% of arecoline and more than or equal to 80% of polysaccharide, improve the utilization rate of raw materials by more than 30%, adapt to large-scale production, and take food safety and income of betel nut farmers into account.

Description

Technical Field

[0001] This invention belongs to the field of areca nut processing technology, specifically relating to a method for preparing defibrinated areca nut powder. Background Technology

[0002] Areca nut, a specialty cash crop in some southern regions, is crucial to the livelihoods of millions of areca farmers and the stable income of large-scale planting bases. However, its traditional processing methods have long faced multiple bottlenecks and are no longer suitable for the healthy development of the industry. Traditional dried areca nut processing only selects green fruits with intact appearances. A large number of mature but slightly damaged fruits are discarded directly because they "do not meet the raw material standards." According to actual industry data, these discarded fruits account for about 30% of the total output, which not only causes a serious waste of agricultural resources but also directly reduces the planting income of areca farmers.

[0003] More importantly, traditional dried areca nuts contain a large amount of coarse, hard lignin-like fibers. When consumers chew them, these fibers repeatedly rub against and even puncture the oral mucosa. Long-term consumption can easily lead to health problems such as oral ulcers and oral fibrosis. This safety hazard has become a core obstacle restricting the large-scale development of the areca nut industry. Previously, the industry had proposed transformation and upgrading requirements in response to the safety issues of traditional dried areca nuts. If innovative, low-harm products cannot be launched in a timely manner, the entire areca nut industry will face the risk of stagnant production capacity.

[0004] Meanwhile, the industry has tried to develop healthy raw materials by extracting polysaccharides and polyphenols from areca nuts. However, such extraction processes are complex and energy-intensive, resulting in high costs. Furthermore, the extracted products do not meet the industry's conventional definition of areca nut raw materials and can only be applied for as new food additives. They cannot be directly used as raw materials for mass production of end products, making it difficult to meet the needs of large-scale industry development. Summary of the Invention

[0005] To overcome the above-mentioned technical problems, the present invention provides a method for preparing defibrotic areca nut powder.

[0006] The present invention adopts the following technical solution: The preparation method of the fiber-reducing areca nut powder includes the following steps: (1) Raw material pretreatment: Select areca nuts containing green fruit, old fruit and damaged fruit, and after grading and screening, trimming and removing damaged fruit and broken parts, pre-wash, soak in food grade sodium bicarbonate solution, soak in ozone water for sterilization, and finally drain. (2) Quick-freezing of fresh fruit: After draining, the areca nuts are laid out flat and sent into a quick-freezing equipment. They are quick-frozen at ≤-55℃ and wind speed of 3-5m / s until the center temperature of the fruit is ≤-40℃. Then they are temporarily stored in an environment of -20℃. (3) Vacuum freeze drying: Transfer the quick-frozen areca nuts into a vacuum freeze dryer. First, sublimate and dry them for 6-8 hours under a vacuum of 15-25 Pa and a temperature of -30°C to -25°C. Then, decompose and dry them for 4-6 hours under the same vacuum and temperature of 25-30°C until the moisture content of the material is 8%-12%. Then, cool them to room temperature. (4) Impact crushing of dried fruit: The dried areca nuts are fed into the impact crusher and crushed at a hammer speed of 1200-1500 r / min and a distance of 5-8 mm between the hammer and the wear-resistant liner. The crushed material is graded by a 10-mesh sieve to ensure that the particle size of the crushed material is ≤2 mm. The material on the sieve is returned for secondary crushing. (5) Ultrafine grinding and grading: The crushed areca nut coarse particles are fed into an air jet mill and ground under the conditions of air pressure of 0.6-0.8MPa, grinding chamber temperature of 25-35℃ and grading wheel speed of 8000-10000r / min. The particles are then passed through a 200-mesh sieve to remove coarse fibers and a 500-mesh sieve for grading to obtain ultrafine powder with a particle size of 300-500 mesh, and the coarse fiber removal rate is ≥90%. (6) Homogenization and aseptic packaging: After the ultrafine powder is transferred into the mixing equipment for homogenization and mixing, it is vacuum-sealed with nitrogen using barrier packaging materials in a clean area to obtain defibered areca nut powder.

[0007] Preferably, in step (1), the concentration of the food-grade sodium bicarbonate solution is 0.8%-1.0%, and the soaking time is 10-15 minutes; the concentration of the ozone water is 0.4-0.6 mg / L, and the soaking time is 6-8 minutes; the draining is carried out using a centrifugal drainer at a speed of 800-1000 r / min for 3-5 minutes, and the residual moisture on the surface after draining is ≤5%.

[0008] Preferably, in step (2), the quick-freezing equipment is a tunnel-type low-temperature quick-freezing machine, and the quick-freezing time is 2.5-4 hours; the storage time in the -20℃ environment is ≤24 hours, and the areca nuts are prevented from thawing during the storage process.

[0009] Preferably, in step (3), the thickness of the areca nuts laid on the material rack of the vacuum freeze dryer is ≤5cm; the cooling process is carried out in a Class 100,000 clean area, and the material temperature is controlled at 20-25℃ after cooling.

[0010] Preferably, in step (4), the impact crusher is a reversible impact crusher, the wear-resistant liner is made of rubber, the feeding speed during crushing is 50-80 kg / h, and ≥95% of the crushed material can pass through a 10-mesh sieve.

[0011] Preferably, after the impact crushing of dried fruit in step (4) and before the ultrafine grinding in step (5), a fiber softening pretreatment step is also included: the coarse areca nut particles are fed into a microwave processor and processed for 2-3 minutes at a power of 400-500W and a temperature of 40-45℃, during which the material is turned over once every 30 seconds, and then rapidly cooled to 25℃ after processing.

[0012] Preferably, in step (5), the air jet mill is a fluidized bed air jet mill with a feeding speed of 30-60 kg / h; the coarse fiber retained by the 20-mesh sieve is used to extract dietary fiber, and the coarse powder on the 500-mesh sieve is returned to the air jet mill for re-grinding.

[0013] Preferably, in step (6), the homogenization and mixing are carried out using a double-helix conical mixer with a mixing speed of 18-22 r / min and a mixing time of 25-30 minutes; during the mixing process, the particle size distribution is sampled and tested, and the relative standard deviation is ≤5%.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention employs a four-stage processing technique—"quick freezing, freeze drying, impact crushing, and ultrafine pulverization"—to remove over 90% of the coarse and hard fibers from areca nuts. The final product contains ≤2.5% coarse fiber, and the remaining small amount of fiber, after softening treatment, has a particle size controlled within 25μm (300-500 mesh), completely eliminating its ability to puncture the oral mucosa. This fundamentally solves the problem of oral damage caused by friction from traditional dried areca nuts. Simultaneously, the entire process utilizes low-temperature treatment (quick freezing ≤ -55℃, freeze drying ≤ 30℃, pulverization ≤ 35℃), maximizing the retention of active ingredients such as arecoline and polysaccharides. Arecoline retention rate is ≥85%, and polysaccharide retention rate is ≥80%, ensuring safety while maintaining the unique flavor and efficacy of areca nuts.

[0015] 2. This invention breaks through the limitations of traditional processes that only use unripe fruit. Through grading, screening, and trimming processes, previously discarded old and damaged fruit is transformed into qualified raw materials, improving the utilization rate of areca nut agricultural resources. Taking actual processing as an example, after processing 1000kg of mixed raw materials, the previously discarded damaged fruit can be fully utilized in processing, ultimately producing qualified de-fibered areca nut powder. Furthermore, the coarse fiber retained during crushing and grinding can be further used to extract dietary fiber, reducing waste. The improved raw material utilization rate directly increases planting income for areca farmers, effectively safeguarding their livelihoods.

[0016] 3. Compared to areca nut extract processing, this invention eliminates the need for complex extraction and purification steps, reducing overall raw material costs. Compared to traditional areca nut processing, it eliminates the need to screen for high-priced unripe fruit, and the optimized energy consumption of the process further reduces overall costs. Taking large-scale production as an example, the cost of preparing the same weight of ultrafine powder is significantly lower than that of traditional areca nut processing on the same scale, effectively enhancing the product's market competitiveness and facilitating its subsequent promotion as a core raw material in end products such as areca nut gum and areca nut snacks. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, a specific embodiment will be used to describe the invention in detail below. It should be noted that this embodiment is intended to illustrate the specific implementation process of this invention, and the scope of protection of this invention is not limited thereto.

[0019] This embodiment uses areca nuts produced in the areca nut planting area of ​​eastern Hainan as raw materials, covering three categories: green nuts, mature nuts, and damaged nuts. It is implemented in a production line with an annual output of 500 tons of fiber-reduced areca nut powder, and strictly follows food safety production standards throughout the process. The specific operating procedures are as follows: I. Raw material pretreatment 1000 kg of fresh areca nuts harvested within 24 hours in Wenchang, Hainan Province, were selected, including 400 kg of green areca nuts, 350 kg of mature areca nuts with a diameter of 2-3 cm, and 250 kg of areca nuts with slight skin damage but intact flesh. All areca nuts were first poured into a vibrating grading sieve and graded using a double-layered sieve with 10 and 20 mesh screens: green areca nuts with a diameter ≥3 cm and undamaged mature areca nuts that passed through the sieve were classified as Grade 1 and proceeded directly to the next stage; mature areca nuts with a diameter of 2-3 cm and slightly damaged areca nuts that remained in the middle of the sieve were classified as Grade 2 and transferred to the fruit and vegetable trimming table; debris, blackened skin, and moldy areca nuts that felt soft to the touch were directly removed, resulting in the removal of 80 kg of substandard areca nuts.

[0020] When trimming the grade II fruit, a food-grade stainless steel knife was used to cut away the blackened outer skin and dried stem along the damaged edges to ensure the maximum retention of pulp on each trimmed fruit. A total of 920 kg of qualified raw material was obtained after trimming. All qualified raw material was sent to a bubble washing machine, filled with room temperature water at 20-25℃, and the bubble generator with an air pressure of 0.3-0.5 MPa was turned on. After stirring and washing for 6 minutes, the wastewater was discharged. Then, a 0.9% food-grade sodium bicarbonate solution was added to the washing machine, and the fruit was soaked at room temperature for 12 minutes to degrade surface pesticide residues. It was then rinsed with running water for 4 minutes until the pH of the rinsing water stabilized at 7.0. Finally, the raw material was transferred to an ozone water soaking tank and soaked in 0.5 mg / L ozone water for 7 minutes to kill surface microorganisms. It was then rinsed once with sterile water.

[0021] After washing, the areca nuts are sent to a centrifugal drainer and drained at 900 r / min for 4 minutes until there is no free water on the surface of the fruit. At this time, the weight of the material is 890 kg.

[0022] II. Quick-freezing fresh fruit After draining, spread the areca nuts evenly on 304 stainless steel trays, 5 kg per tray, with a 1.5 cm gap between the nuts to avoid stacking and affecting the freezing effect. Place the trays sequentially into a tunnel-type low-temperature quick-freezing machine, setting the quick-freezing temperature to -58℃ and the air velocity to 4 m / s. After starting the machine, check the center temperature of the nuts every 30 minutes using a probe thermometer. Stop the quick-freezing process when the center temperature drops to -40℃. The entire process takes 3 hours. After quick-freezing, quickly transfer the nuts to a -20℃ cold storage for temporary storage for 18 hours to prevent the fibrous structure from rebounding during thawing.

[0023] III. Vacuum freeze drying The quick-frozen areca nuts were removed from the cold storage and transferred to the material rack of the vacuum freeze dryer within 10 minutes, ensuring the material layer thickness did not exceed 4 cm. After shutting down the dryer, the vacuum level was first reduced to 20 Pa, and the sublimation stage program was initiated: the temperature was maintained at -28°C for 7 hours, allowing the ice crystals inside the nuts to gradually sublimate. Then, the desorption stage began, with the temperature slowly increased to 28°C, and the vacuum level maintained for another 5 hours. During this period, the moisture content of the material was sampled and tested every hour. When the moisture content stabilized at 10%, drying was stopped, the vacuum was broken, and the material was cooled to 23°C in a Class 100,000 cleanroom. At this point, the material weighed 267 kg, and the moisture removal rate was approximately 70%.

[0024] IV. Impact Crushing of Dried Fruits The cooled and dried areca nuts are fed into a reversible impact crusher at a constant speed via a conveyor belt. The conveyor belt speed is adjusted to 1 meter per minute, and the feed rate is stabilized at 60 kg / h. The crusher hammer speed is set to 1300 r / min, and the distance between the hammer and the wear-resistant rubber liner is adjusted to 6 mm, ensuring that the particle size of the crushed material is controlled within 2 mm. During the crushing process, the material is graded in real time through a 10-mesh screen inside the machine. Material with a particle size larger than 2 mm on the screen is returned to the crushing chamber for secondary crushing via a scraper conveyor. Finally, 260 kg of uniform areca nut coarse particles are obtained, of which ≥95% of the particles can pass through the 10-mesh screen.

[0025] V. Fiber softening pretreatment The coarse areca nut particles were fed into an industrial microwave processor, with the microwave power set to 450W and the temperature to 43℃. After starting the equipment, the material was agitated every 30 seconds to ensure uniform heating. The total processing time was 2.5 minutes. After processing, the material was immediately transferred to a clean cooling table and rapidly cooled to 25℃ with sterile air at room temperature. At this point, the fibers in the material became soft due to the breakage of hydrogen bonds, significantly reducing the difficulty of subsequent pulverization.

[0026] VI. Ultrafine grinding and slag removal The softened areca nut coarse particles are fed into a fluidized bed air jet mill via a feeder, with the feed rate controlled at 45 kg / h, the air pressure set at 0.7 MPa, the grinding chamber temperature at 30℃, and the classifying wheel speed at 9000 r / min. The pulverized material is first passed through a 200-mesh classifying sieve under the influence of the airflow, where coarse fibers with higher density and irregular shapes are retained, collecting a total of 26 kg of coarse residue. This residue can be used for dietary fiber extraction. The undersized powder continues to pass through a 500-mesh finished product sieve to remove a small amount of substandard coarse powder, ultimately yielding 228 kg of ultrafine powder.

[0027] Sampling and testing of the finished powder: The crude fiber content was determined by acid-base digestion method, and the result was 2.2%, with a removal rate of 91.2%; the arecoline content was determined by high performance liquid chromatography, and the retention rate reached 86%; the polysaccharide retention rate was determined by phenol-sulfuric acid method, and all indicators met the requirements.

[0028] VII. Homogenization and Aseptic Packaging 228 kg of ultrafine powder was combined with 572 kg of powder produced in other periods of the same batch, bringing the total weight to 800 kg. This mixture was then poured into a double-helix conical mixer, with a speed of 20 r / min and a mixing time of 28 minutes. During the mixing process, five samples were taken from different locations within the equipment to test the particle size distribution. The relative standard deviation was 2.8%, ensuring powder uniformity.

[0029] The mixed powder is packaged in a Class 100,000 cleanroom: operators first undergo handwashing and disinfection, followed by air shower purification, and then don sterile work clothes, gloves, and goggles; aluminum foil composite packaging bags with 92% barrier properties are used. The bags are first vacuumed to -0.095 MPa using an aseptic packaging machine, then filled with food-grade nitrogen gas of 99.95% purity, and subsequently sealed at 125°C for 3 seconds. Labels are affixed to the packaging bags, indicating the batch number, production date, crude fiber content, arecoline content, and traceability code for subsequent quality traceability.

[0030] After packaging, samples were tested for microbial indicators: Escherichia coli <30 MPN / 100g, mold <20 CFU / g, and pathogenic bacteria were not detected, meeting food hygiene standards. The finished product was then stored in a cool, dry warehouse with the temperature controlled at 22℃ and the relative humidity maintained at 60%, ensuring a shelf life of up to 12 months.

[0031] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to the above embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing desiccant areca nut powder, characterized in that, Includes the following steps: (1) Raw material pretreatment: Select areca nuts containing green fruit, old fruit and damaged fruit, and after grading and screening, trimming and removing damaged fruit and broken parts, pre-wash, soak in food grade sodium bicarbonate solution, soak in ozone water for sterilization, and finally drain. (2) Quick-freezing of fresh fruit: After draining, the areca nuts are laid flat and sent into a quick-freezing equipment. They are quick-frozen at ≤-55℃ and wind speed of 3-5m / s until the center temperature of the fruit is ≤-40℃. Then they are temporarily stored in an environment of -20℃. (3) Vacuum freeze drying: Transfer the quick-frozen areca nuts into a vacuum freeze dryer. First, sublimate and dry them for 6-8 hours under a vacuum of 15-25 Pa and a temperature of -30℃ to -25℃. Then, decompose and dry them for 4-6 hours under the same vacuum and temperature of 25-30℃ until the moisture content of the material is 8%-12%. Then, cool them to room temperature. (4) Impact crushing of dried fruit: The dried areca nuts are fed into the impact crusher and crushed at a hammer speed of 1200-1500 r / min and a distance of 5-8 mm between the hammer and the wear-resistant liner. The crushed material is graded through a 10-mesh sieve to ensure that the particle size of the crushed material is ≤2 mm. The material on the sieve is returned for secondary crushing. (5) Ultrafine grinding and grading: The crushed areca nut coarse particles are fed into an air jet mill and ground under the conditions of air pressure of 0.6-0.8MPa, grinding chamber temperature of 25-35℃ and grading wheel speed of 8000-10000r / min. The particles are then passed through a 200-mesh sieve to remove coarse fibers and a 500-mesh sieve for grading to obtain ultrafine powder with a particle size of 300-500 mesh, and the coarse fiber removal rate is ≥90%. (6) Homogenization and aseptic packaging: After the ultrafine powder is transferred into the mixing equipment for homogenization and mixing, it is vacuum-sealed with nitrogen using barrier packaging materials in a clean area to obtain defibered areca nut powder.

2. The method for preparing the fiber-reducing areca nut powder according to claim 1, characterized in that, In step (1), the concentration of the food-grade sodium bicarbonate solution is 0.8%-1.0%, and the soaking time is 10-15 minutes; the concentration of the ozone water is 0.4-0.6 mg / L, and the soaking time is 6-8 minutes; the draining is carried out using a centrifugal drainer at a speed of 800-1000 r / min for 3-5 minutes, and the residual moisture on the surface after draining is ≤5%.

3. The method for preparing the desiccant areca nut powder according to claim 1, characterized in that, In step (2), the quick-freezing equipment is a tunnel-type low-temperature quick-freezing machine, and the quick-freezing time is 2.5-4 hours; the storage time in the -20℃ environment is ≤24 hours, and the areca nuts are prevented from thawing during the storage process.

4. The method for preparing the desiccant areca nut powder according to claim 1, characterized in that, In step (3), the thickness of the areca nuts laid on the material rack of the vacuum freeze dryer is ≤5cm; the cooling process is carried out in a Class 100,000 clean area, and the material temperature is controlled at 20-25℃ after cooling.

5. The method for preparing the fiber-reducing areca nut powder according to claim 1, characterized in that, In step (4), the impact crusher is a reversible impact crusher, and the wear-resistant liner is made of rubber. The feeding speed during crushing is 50-80 kg / h, and ≥95% of the crushed material can pass through a 10-mesh sieve.

6. The method for preparing the fiber-reducing areca nut powder according to claim 1, characterized in that, After the impact crushing of dried fruit in step (4) and before the ultrafine grinding in step (5), a fiber softening pretreatment step is also included: the coarse areca nut particles are fed into a microwave processor and processed for 2-3 minutes at a power of 400-500W and a temperature of 40-45℃, during which the material is turned over once every 30 seconds, and then rapidly cooled to 25℃ after processing.

7. The method for preparing the fiber-reducing areca nut powder according to claim 1, characterized in that, In step (5), the air jet mill is a fluidized bed air jet mill with a feeding speed of 30-60 kg / h; the coarse fiber retained by the 20-mesh sieve is used to extract dietary fiber, and the coarse powder on the 500-mesh sieve is returned to the air jet mill for re-grinding.

8. The method for preparing the desiccant areca nut powder according to claim 1, characterized in that, In step (6), the homogenization and mixing are carried out using a double-helix conical mixer with a mixing speed of 18-22 r / min and a mixing time of 25-30 minutes; during the mixing process, the particle size distribution is sampled and tested, and the relative standard deviation is ≤5%.

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