A processing method for removing arecoline in betel nut

Abstract

The present application belongs to the technical field of processing methods of betel nuts, and particularly relates to a processing method for removing arecoline in betel nuts. The processing method comprises the following steps: cleaning and sterilizing the sorted betel nuts, soaking the cleaned and sterilized betel nuts in a cleaning solution; then cutting the soaked betel nuts, taking out the betel nut kernels, and placing the betel nuts without betel nut kernels in a composite enzymatic solution for enzymolysis, and then placing them in an acidic leaching solution for gradient leaching to remove the arecoline in the betel nuts without betel nut kernels. The processing method can greatly remove the arecoline in betel nuts, and the overall substrate loss of betel nuts in the processing method is extremely low.

Description

Technical Field

[0001] This invention belongs to the technical field of areca nut processing methods, specifically relating to a processing method for removing arecoline from areca nuts. Background Technology

[0002] Areca nut, a specialty snack food in southern my country, has a mature industrial processing industry. The mainstream industrial processing flow for areca nut is standardized as follows: fresh fruit harvesting - raw material cleaning - high-temperature drying to produce dried fruit - cutting and removing the core from the dried fruit - seasoning and braising - finished product packaging. Leading companies in the industry, such as Kouweiwang and Binzhilang, all use this processing method in their existing processes and publicly available patent documents. Removing the core from the dried fruit is a common and established technique in the industry. However, this long-standing drying and core-removing processing method is limited by the properties of the raw materials and the sequence of processes, resulting in several difficult-to-eradicate industry drawbacks, including the following:

[0003] First, after the fresh areca nuts are dried and dehydrated, the flesh hardens and the fibers shrink. The hard flesh is prone to cracking, breaking, and missing pieces during the cutting and core removal process, resulting in a large amount of raw material loss, inconsistent appearance of finished products, difficulty in controlling product quality stability, high raw material loss, and low product yield, which significantly increases production cost.

[0004] Secondly, traditional processes require drying the fruit before removing the core. Before drying, the core is nestled inside the flesh, creating a sealed cavity that retains moisture. This damp, enclosed space becomes a breeding ground for mold and aflatoxin. Once the mold invades the flesh fibers, it penetrates deeper into the flesh tissue as the drying process solidifies. Subsequent cleaning and braising processes cannot completely remove the mold and its metabolic toxins, resulting in a high risk of excessive mycotoxins in the finished product and significant food safety hazards.

[0005] Furthermore, the areca nut core is the main accumulation site of arecoline, various alkaloids, and precursors for the synthesis of nitrosamines, accounting for over 80% of the total alkaloid content. During the drying and shrinking process of the dried fruit, a large amount of alkaloids in the core will permeate outwards and solidify in the gaps between the fruit pulp fibers. Subsequent washing and braising cannot remove the solidified alkaloids, making it difficult to remove the harmful substances of arecoline. The final product generally has the problem of excessive alkaloid residues, which not only has a strong irritant, bitter, and spicy taste, but also poses food safety risks. Its safety and taste are poor, which is a long-standing technical problem that the industry has been unable to solve properly.

[0006] In the existing publicly available areca nut processing technologies, the core removal operation is basically carried out after the dried fruit is dried or after brining. The areca nut has a large amount of arecoline residue, and the highly stable arecoline in the pulp is not removed, and it is highly irritating to eat. Summary of the Invention

[0007] Based on the above technical background, the main objective of this invention is to provide a processing method for removing arecoline from areca nuts, so as to solve the shortcomings of existing areca nut processing methods, such as large arecoline residue and low removal rate of arecoline with strong stability in the pulp.

[0008] To achieve the aforementioned objectives, the technical solution adopted by this invention includes: This invention provides a processing method for removing arecoline from areca nuts, the processing method comprising the following steps: Step 1: Wash and sterilize the sorted areca nuts, and then soak the washed and sterilized areca nuts in the washing solution. Step 2: Cut the soaked areca nuts in half, remove the areca kernels, and obtain areca nuts with the areca kernels removed; Step 3: Place the areca nuts with the kernels removed into a compound enzymatic hydrolysate for enzymatic hydrolysis, and then place them into an acidic extraction solution for gradient extraction to remove arecoline from the areca nuts with the kernels removed. Step 4: Soak the areca nuts (without kernels) after gradient extraction in step 3 in a low-temperature color-protecting solution. Then, briefly pre-cook the soaked areca nuts (without kernels) to remove the green color and dry them. Step 5: Add spices to the dried areca nuts (with the areca kernels removed) from Step 4 and process them at a low temperature. Then, roast the seeds at a low temperature to fix the aroma, apply glue, add syrup, simmer to release the aroma, and sterilize to obtain areca nut slices after removing arecoline.

[0009] The steps described above are described in detail below.

[0010] In step 1, select areca nuts that are uniformly mature and free from rot and mold, and grade them according to their diameter.

[0011] The selected areca nuts are cleaned and sterilized. The cleaning and sterilization method is as follows: first, the areca nuts are sprayed under high pressure, and then soaked in ozone water at room temperature for 5 to 15 minutes. The pesticide residues, wax and bacteria on the surface of the areca nuts can be removed by high pressure spraying and soaking in ozone water at room temperature.

[0012] Preferably, after high-pressure spraying, the sample is immersed in ozone water at room temperature for 10 minutes.

[0013] The cleaning solution is selected from one or both of water and ethanol.

[0014] Preferably, the ethanol is low-concentration ethanol, and the concentration of the ethanol is 20-40% low-concentration ethanol.

[0015] More preferably, the cleaning solution is a low-concentration ethanol with a concentration of 30%.

[0016] Based on the physicochemical property that arecoline is easily soluble in ethanol, a low-concentration ethanol aqueous solution of 30% at room temperature is used as the cleaning solution to meet the needs of alkali removal from whole areca nuts. By soaking in low-concentration ethanol, the bound and free arecoline in the surface and shallow pores of the areca nut pulp can be deeply washed away. The alkali removal effect is far better than that of pure water. Moreover, low-concentration ethanol will not dissolve a large amount of tannins, polysaccharides and other impurities in areca nuts, and no large amount of impurities will be carried over during the dissolution process.

[0017] The conditions for immersing the cleaned and sterilized areca nuts in the cleaning solution are as follows: the areca nuts are immersed in the cleaning solution 1-3 times, with the whole areca nuts submerged at room temperature in the dark for 15-25 minutes. During immersion, the system is gently agitated every 5-15 minutes. This immersion method promotes solvent penetration into the pores of the areca nuts, dissolving arecoline. This invention removes arecoline to a progressively deeper level by repeatedly immersing the areca nuts in ethanol. After cleaning, the whole areca nuts are removed, and residual ethanol is quickly rinsed off with a small amount of purified water. They are then placed in a cool, ventilated place to air dry thoroughly until there is no alcohol odor, no moisture, and the pores are clear before sealing for later use. This method is suitable for experimental scenarios requiring a significant reduction in the initial arecoline content of the raw materials, offering a higher alkali removal rate and greater controllability.

[0018] Preferably, the conditions for soaking the cleaned and sterilized areca nuts in the cleaning solution are as follows: the areca nuts are soaked and cleaned twice with ethanol, the whole areca nuts are submerged at room temperature in the dark, and the soaking and cleaning time is 20 minutes. During the soaking and cleaning period, the soaking container is gently shaken once every 10 minutes.

[0019] This invention utilizes the mild antibacterial properties of ethanol to kill microorganisms on the surface of areca nuts, while also helping to wash away free arecoline adhering to the surface of areca nuts.

[0020] After soaking and cleaning, gently rinse the areca nuts 1-3 times with sterile purified water at room temperature, each time for 1-3 minutes.

[0021] Preferably, the soaked and cleaned areca nuts are gently rinsed twice with sterile purified water at room temperature, each rinse lasting 2 minutes. Rinsing with purified water removes ethanol from the surface of the areca nuts. Rinsing also removes dust, microorganisms, attached impurities, and free arecoline from the surface of the areca nuts, reducing the impurity base for subsequent enzymatic hydrolysis and extraction.

[0022] In step 2, existing technologies often remove the areca kernel from the green areca fruit after drying. However, this invention removes the kernel before drying, directly cutting and removing the kernel from the fresh areca fruit. This breaks the sealed, humid environment of the areca core, blocking mold growth at its source and directly eliminating potential mold, aflatoxin, and their metabolic toxins inside the core. Existing technologies remove the core after drying, allowing mold to invade the pulp, making toxin removal difficult. This invention, by removing the kernel while the fruit is still fresh, achieves source control of mold, fundamentally solving the persistent problem of internal mold in areca nuts.

[0023] Meanwhile, the areca kernel is enriched with over 80% arecoline, alkaloids, and nitrosamine precursors, which is the core reason for the pungent and irritating taste and excessive alkaloid content in finished areca products. Current areca kernel removal processes often involve removing the kernel after drying the areca nut. After drying, the kernel solidifies and shrinks, allowing arecoline from the kernel to penetrate and adhere to the pulp fibers, making complete removal difficult. This invention completely removes the kernel from fresh areca nuts while they are still moist, physically removing the vast majority of arecoline-rich tissue in one step. This natural physical alkalization significantly reduces arecoline residue in the finished product, effectively improving product safety.

[0024] In step 3, the composite enzymatic hydrolysate is prepared by dissolving a composite enzyme preparation in a phosphate buffer. The composite enzyme preparation comprises esterase, pectinase, and cellulase mixed in a mass ratio of (1-3):1:1. In this composite enzymatic hydrolysate, the esterase activity is ≥10000 U / g, the pectinase activity is ≥5000 U / g, the cellulase activity is ≥8000 U / g, the pH of the phosphate buffer is 7.0, and the mass concentration of the composite enzyme preparation in the composite enzymatic hydrolysate is 1-3%.

[0025] Preferably, the compound enzyme preparation comprises esterase, pectinase and cellulase mixed in a mass ratio of 2:1:1. In the compound enzymatic hydrolysate, the esterase activity is 15000 U / g, the pectinase activity is 7000 U / g, the cellulase activity is 10000 U / g, and the mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 2%.

[0026] After soaking and washing, the free alkali on the surface of the areca nut has been largely removed. The remaining arecoline is mostly encapsulated by the dense network structure of pectin and cellulose in the pulp, primarily in a deeply bound and encapsulated state. Single or binary enzyme preparations are insufficient to completely break down the fiber barrier in areca nuts. This invention limits the complex enzymatic hydrolysate to a ternary complex enzyme system of esterase, pectinase, and cellulase. This ternary complex enzyme system is a neutral and mild enzymatic hydrolysis system. Pectinase can degrade the pectin barrier on the surface of the pulp, cellulase can break down the dense fiber bundles of the pulp, enlarge micropores, and allow for deeper penetration channels, and esterase specifically targets and hydrolyzes the characteristic ester bonds of arecoline, degrading the active structure of the alkaloid. The three enzymes work synergistically to completely break down the tissue's encapsulation of arecoline without damaging the main fiber skeleton of the areca nut or affecting its chewing texture. This allows for deep degradation of deep arecoline, significantly improving the alkali removal rate, and simultaneously opening up channels for arecoline dissolution in subsequent extraction.

[0027] During the preparation of this compound enzyme hydrolysate, stir at low speed for 4 to 7 minutes until the enzyme preparation is completely and uniformly dissolved, preferably at low speed for 5 minutes until the enzyme preparation is completely and uniformly dissolved in the compound enzyme hydrolysate. Prepare and use immediately to maximize the preservation of the overall activity of the compound enzyme and avoid enzyme activity decay affecting the degradation effect.

[0028] The areca nuts with the kernels removed are completely immersed in the compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposure of pulp, and avoiding uneven local enzymatic hydrolysis. The ratio of areca nuts with the kernels removed to the compound enzymatic hydrolysate is 1:(8-12) (g:mL). The enzymatic hydrolysis temperature is set at 25-35℃, the low-speed oscillation frequency is 40-60 r / min, and the constant temperature permeation enzymatic hydrolysis time is 6-7h.

[0029] Preferably, the areca nuts with the kernels removed are placed in a compound enzymatic hydrolysate for enzymatic hydrolysis. The ratio of the areca nuts with the kernels removed to the compound enzymatic hydrolysate is 1:10 (g:mL). The enzymatic hydrolysis temperature is set at 30℃, the low-speed oscillation frequency is 50 r / min, and the constant temperature permeation enzymatic hydrolysis time is 6.5 h.

[0030] During enzymatic hydrolysis, low-speed oscillation promotes the uniform penetration of the ternary compound enzymatic hydrolysate into the surface and deep tissues of the fruit pulp. Pectinase and cellulase gradually loosen the fiber pores and break down the encapsulation barrier during this process, while esterase continuously degrades the deeply bound arecoline. The three enzymes work together to achieve a synergistic effect. The gentle oscillation mode avoids mechanical vibration that could cause the fruit pulp to soften and crack, thus strictly ensuring the integrity and original taste of the whole areca nut.

[0031] Immediately after enzymatic hydrolysis, remove the areca nuts (with the kernel removed) and soak them in water at 80–90°C for 2–5 minutes to completely inactivate the enzymes, terminate the enzymatic hydrolysis reaction, and prevent excessive enzymatic hydrolysis that would lead to excessive decomposition of the areca nut pulp and pectin, resulting in a sticky and mushy texture that would affect the taste of the areca nut. The water used is preferably sterile purified water.

[0032] Preferably, after enzymatic hydrolysis, the areca nuts with the kernels removed are taken out and soaked in sterile purified water at 85°C for 3 minutes to completely inactivate the enzymes and terminate the enzymatic hydrolysis reaction.

[0033] After enzyme inactivation, gently rinse 1-3 times with sterile purified water at room temperature, preferably 2 times, to remove residual enzyme solution and arecoline degradation products on the surface. Air dry in a ventilated and cool place for later use. At this time, the whole areca nut is intact, the pulp is firm, and the original taste is undamaged.

[0034] The acidic extract is selected from one or more of lactic acid, hydrochloric acid, and acetic acid.

[0035] Preferably, the acidic extract is one or both of lactic acid and hydrochloric acid.

[0036] After washing and enzymatic hydrolysis, the pores of the areca pulp are completely opened, and most of the encapsulated arecoline in the areca pulp has been degraded into easily soluble small molecule products. However, a small amount of residual alkaloids with extremely strong binding stability still remain. To achieve a significant removal of arecoline, this invention uses one or a mixture of inorganic hydrochloric acid or organic lactic acid as a mixed extraction solution. Inorganic hydrochloric acid can rapidly protonate and dissolve free alkaloids, while organic lactic acid can slowly penetrate and complex stubborn residual alkaloids. At the same time, through stepwise extraction with a gradient acidity from weak to strong, arecoline components with different stabilities can be peeled off layer by layer.

[0037] The areca nuts, after enzymatic hydrolysis and drying with the kernels removed, are placed in an acidic extract solution for gradient extraction. The gradient extraction includes a first-stage extraction and a second-stage extraction, as detailed below: The first stage extraction conditions are as follows: food-grade lactic acid is added to water and stirred evenly to obtain a lactic acid solution extract with a pH of 5.0–5.5. This first stage is a weakly acidic complexing extract that gently penetrates deep into the pulp. The areca nuts, after enzymatic hydrolysis and drying with the kernels removed, are completely immersed in the lactic acid solution extract. The ratio of areca nuts to the lactic acid solution extract is 1:(10–14) (g:mL). Extraction is carried out at a constant temperature water bath at 50–60℃ for 40–60 minutes. The low concentration of organic lactic acid has mild permeability and can penetrate deep into the loose pores of the pulp, complexing and binding with the relatively stable residual arecoline, slowly dissolving the deep residual alkaloids in the areca nut pulp.

[0038] The second stage of extraction is conducted using a moderately acidic enhanced extraction solution. Food-grade dilute hydrochloric acid and food-grade lactic acid are combined and added to water to adjust the pH of the compound extraction solution to 3.5–4.0. Extraction with this compound solution achieves deep dissolution of residual stubborn alkaloids. The compound acid system avoids the drawbacks of single strong acids corroding the pulp and single weak acids failing to completely remove alkaloids. The areca nuts (without kernels) after the first stage of extraction are directly transferred to a hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5–4.0. The ratio of the areca nuts (without kernels) to the hydrochloric acid-lactic acid compound extraction solution is 1:(10–14) (g:mL). Static extraction is continued at a constant temperature of 50–60℃ for 35–45 minutes. The compound extraction solution rapidly protonates the remaining highly stable stubborn arecoline, breaking the bonds between the residual alkaloids and the pulp matrix, thus completely dissolving all residual arecoline.

[0039] Preferably, the extraction conditions in the first stage are as follows: food-grade lactic acid is added to water and stirred evenly to obtain a lactic acid solution with pH=5.0 to 5.5. The areca nuts that have been enzymatically hydrolyzed and dried and have had their kernels removed are completely immersed in the lactic acid solution. The ratio of areca nuts with kernels removed to the lactic acid solution is 1:12 (g:mL). The extraction is carried out at 55°C for 50 min under constant temperature water bath conditions.

[0040] Preferably, the second-stage extraction conditions are as follows: extraction is carried out using a medium-acidity enhanced extraction solution, food-grade dilute hydrochloric acid and food-grade lactic acid are added to water, the pH of the compound extraction solution is adjusted to 3.5-4.0, the areca nuts with the kernels removed after the first-stage extraction are taken out and directly transferred to the hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5-4.0, the ratio of the areca nuts with the kernels removed to the hydrochloric acid-lactic acid compound extraction solution is 1:12 (g:mL), and static extraction is continued for 40 minutes at a constant temperature of 55℃.

[0041] Immediately after gradient extraction, remove the areca nuts (with the kernel removed) and gently rinse the surface with sterile purified water at room temperature to neutralize any remaining acidic extract. Then, place the areca nuts in a cool, ventilated place to air dry naturally.

[0042] In step 4, the areca nuts with the kernels removed after extraction are placed in a low-temperature color-protecting solution and soaked at room temperature for 15-25 minutes.

[0043] Preferably, the areca nuts after extraction and removal of the areca kernels are placed in a low-temperature color-protecting solution and soaked at room temperature for 20 minutes.

[0044] The low-temperature color-protecting solution is selected from one or more of saline, sulfite, and acid solutions.

[0045] Preferably, the low-temperature color-protecting solution is saline solution.

[0046] After soaking and removing the areca kernels, the areca nuts are briefly boiled for 10-20 minutes under steam or water at 80-90℃ to remove the bitter taste, sterilize, and soften the fibers.

[0047] Preferably, the soaked areca nuts with the pits removed are briefly blanched and pre-cooked for 15 minutes under steam or boiling conditions at 85°C.

[0048] The areca nuts, after being briefly sterilized and pre-cooked and with the kernels removed, are dried at 75–85°C until the moisture content of the areca nuts is 12–15%.

[0049] Preferably, the areca nuts that have been briefly sterilized and pre-cooked and have had their kernels removed are dried at 80°C until the moisture content of the areca nuts is 12-15%.

[0050] In step 5, spices are added to the dried green fruit slices from step 4 and fermented at a low temperature of 20–30°C for 48–72 hours.

[0051] Preferably, compound bio-enzymes and spices are added to the dried green fruit slices from step 4 and fermented at a low temperature of 25°C for 60 hours.

[0052] After being fermented at low temperature, the green fruit slices are roasted at 45-55℃ to fix the aroma until the moisture content is reduced to 8-10%.

[0053] Preferably, the green fruit slices that have been fermented at low temperature are roasted at 50°C to fix the aroma until the moisture content is reduced to 8-10%.

[0054] Food-grade varnish and natural flavoring are applied thinly to the surface of green olive slices after low-temperature roasting and aroma fixation. Then, brine is injected, and the slices are air-dried or sealed and simmered at 30-40°C to reduce the moisture content to 6%-8%.

[0055] Preferably, food-grade varnish and natural flavoring are thinly applied to the surface of green olive slices after low-temperature roasting and aroma fixation, followed by the injection of brine, and then air-drying or simmering in a sealed container at 35°C to reduce the moisture content to 6%–8%.

[0056] The preferred sterilization method is ultraviolet sterilization.

[0057] The beneficial effects of this invention are as follows: (1) Unlike the prior art where the pit is removed after the areca nut is dried, the present invention removes the pit before the areca nut is dried, that is, while the areca nut is still wet. Removing the pit while the areca nut is wet can remove more than 80% of the arecoline accumulated in the areca nut kernel tissue. At the same time, it can prevent the areca nut kernel from growing mold, aflatoxin and its metabolic toxins in a closed and humid environment, and block the mold from invading the pulp. In order to remove the highly stable arecoline in the areca nut pulp, the present invention first uses a compound enzymatic hydrolysate for enzymatic hydrolysis and finally uses a compound acid extraction method to remove the highly stable arecoline in the areca nut pulp. Enzymatic hydrolysis with compound enzymatic hydrolysate can directionally degrade bound and encapsulated arecoline. Finally, compound acid extraction can further remove deeper and more stable bound arecoline, thus improving the removal rate of arecoline. This processing method can remove more than 95% of arecoline in areca nut.

[0058] (2) Before removing the areca kernel, the present invention first removes the free alkali on the surface of the areca fruit by washing. After removing the areca kernel, the areca nut is first enzymatically hydrolyzed using a compound enzymatic hydrolysate, and then is removed by a staged acidic extraction. This processing order is crucial to the removal rate of areca nut and the taste of the areca nut slices. Changing the order of enzymatic hydrolysis and acidic extraction will reduce the removal rate of areca nut and the taste of the areca nut slices. Enzymatic hydrolysis first can open up the internal pores of the areca nut pulp, so that the encapsulated areca nut in the areca nut pulp can be degraded into easily soluble small molecule products. However, a small amount of residual alkaloids with extremely strong binding stability still exist. Subsequently, acidic extraction can further and significantly remove areca nut. Detailed Implementation

[0059] The present invention will now be described in detail, and its features and advantages will become clearer and more apparent from these descriptions.

[0060] This invention provides a processing method for removing arecoline from areca nuts, the processing method comprising the following steps: Step 1: Select fresh areca nuts harvested within 3 days. These raw materials have not undergone high-temperature ripening, drying, or pre-brining treatment. The natural moisture content of the fresh areca nuts should be ≥60%. Remove rotten, insect-infested, or defective nuts. Select areca nuts of uniform maturity without rot or mold, and grade them according to their diameter.

[0061] The selected areca nuts were cleaned and sterilized using the following method: first, the areca nuts were subjected to high-pressure spraying, and then soaked in ozone water at room temperature for 5–15 minutes. The cleaned and sterilized areca nuts were then immersed in the cleaning solution under the following conditions: the areca nuts were rinsed 1–3 times with the cleaning solution, and the whole areca nuts were submerged at room temperature in the dark for 15–25 minutes. During the immersion process, the immersion system was gently agitated every 5–15 minutes.

[0062] After soaking and cleaning, gently rinse the areca nuts 1-3 times with sterile purified water at room temperature, each time for 1-3 minutes.

[0063] Step 2: Cut the soaked areca nuts while they are still wet and remove the areca kernels to obtain areca nuts with the kernels removed.

[0064] Step 3: Completely immerse the areca nuts (without the kernels removed) in the compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposed pulp to avoid uneven local hydrolysis. The ratio of areca nuts (without kernels removed) to the compound enzymatic hydrolysate is 1:(8-12) (g:mL). Set the hydrolysis temperature to 25-35℃, the low-speed oscillation frequency to 40-60 r / min, and the isothermal hydrolysis time to 6-7 hours. The compound enzyme preparation comprises esterase, pectinase, and cellulase mixed in a mass ratio of (1-3):1:1. In this compound enzymatic hydrolysate, the esterase activity is ≥10000 U / g, the pectinase activity is ≥5000 U / g, and the cellulase activity is ≥8000 U / g. The pH of the phosphate buffer is 7.0, and the mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 1-3%. During the preparation of this compound enzymatic hydrolysate, stir at low speed for 4-7 minutes until the enzyme preparation is completely and uniformly dissolved. Prepare and use immediately. After enzymatic hydrolysis, remove the green fruit slices and soak them in water at 80-90℃ for 2-5 minutes to completely inactivate the enzyme and terminate the enzymatic hydrolysis reaction. After inactivation, gently rinse 1-3 times with sterile purified water at room temperature to remove residual enzyme solution and arecoline degradation products from the surface, and then air dry in a ventilated and cool place for later use.

[0065] The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, are placed in an acidic extract for gradient extraction. The gradient extraction includes a first-stage extraction and a second-stage extraction. The first-stage extraction conditions are as follows: food-grade lactic acid is added to water and stirred evenly to obtain a lactic acid solution extract with a pH of 5.0 to 5.5. The first stage is a weakly acidic complex extract that gently penetrates deep into the pulp. The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, are completely immersed in the lactic acid solution extract. The ratio of areca nuts to lactic acid solution extract is 1:(10-14) (g:mL). The extraction is carried out at a constant temperature water bath at 50-60℃ for 40-60 minutes.

[0066] The second stage extraction conditions are as follows: Extraction is carried out using a moderately acidic enhanced extraction solution. Food-grade dilute hydrochloric acid and food-grade lactic acid are added to the water to adjust the pH of the compound extraction solution to 3.5–4.0. The areca nuts (without kernels) removed after the first stage extraction are directly transferred to the hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5–4.0. The ratio of the areca nuts (without kernels) to the hydrochloric acid-lactic acid compound extraction solution is 1:(10–14) (g:mL). Static extraction is continued at a constant temperature of 50–60℃ for 35–45 min.

[0067] Step 4: Place the extracted areca nuts (without the areca seeds) in a low-temperature color-protecting solution (salt water) and soak for 15-25 minutes. Then, briefly pre-cook the soaked areca nuts under steam or water at 80-90°C for 10-20 minutes. Finally, dry the pre-cooked areca nuts at 75-85°C until the moisture content is 12-15%.

[0068] Step 5: Add spices to the dried areca slices from Step 4 and ferment at a low temperature of 20-30℃ for 48-72 hours. After fermentation, roast the areca slices at a low temperature of 45-55℃ until the moisture content is reduced to 8-10%. Apply a thin layer of food-grade varnish and natural flavoring to the surface of the roasted areca slices, then pour in brine. Air dry or seal and simmer at 30-40℃ until the moisture content is reduced to 6%-8%. Finally, sterilize with ultraviolet light to obtain areca slices free of arecoline.

[0069] Example The present invention is further illustrated below with specific examples. These embodiments are merely illustrative and not intended to limit the scope of the invention. Except for fresh areca nuts, all raw materials used in the embodiments of the present invention were purchased.

[0070] Example 1 A processing method for removing arecoline from areca nuts, the processing method comprising the following steps: Step 1: Select fresh areca nuts harvested within 3 days. These raw materials have not undergone high-temperature ripening, drying, or pre-brining treatment. The natural moisture content of the fresh areca nuts should be ≥60%. Remove rotten, insect-infested, or defective nuts. Select areca nuts of uniform maturity without rot or mold, and grade them according to their diameter.

[0071] The selected areca nuts were cleaned and sterilized using the following method: first, the areca nuts were subjected to high-pressure spraying, and then soaked in ozone water at room temperature for 10 minutes. The cleaned and sterilized areca nuts were then immersed in the cleaning solution under the following conditions: the areca nuts were rinsed twice with ethanol, and the whole areca nuts were submerged at room temperature in the dark for 20 minutes. During the immersion process, the system was gently agitated every 10 minutes.

[0072] After soaking and cleaning, the areca nuts are gently rinsed twice with sterile purified water at room temperature, each time for 2 minutes.

[0073] Step 2: Cut the soaked areca nuts while they are still wet and remove the areca kernels to obtain areca nuts with the kernels removed.

[0074] Step 3: Completely immerse the areca nuts (without the kernels removed) in the compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposed pulp to avoid uneven local hydrolysis. The ratio of areca nuts (without kernels removed) to the compound enzymatic hydrolysate is 1:10 (g:mL). Set the hydrolysis temperature to 30℃, the low-speed oscillation frequency to 50 r / min, and the isothermal hydrolysis time to 6.5 h. The compound enzymatic hydrolysate is prepared by dissolving a compound enzyme preparation in phosphate buffer. The compound enzyme preparation is obtained by mixing esterase, pectinase, and cellulase in a mass ratio of 2:1:1. In this compound enzymatic hydrolysate, the esterase activity is 15000 U / g, the pectinase activity is 7000 U / g, and the cellulase activity is 10000 U / g. The mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 2%. During the preparation of this compound enzymatic hydrolysate, stir at low speed for 5 min until the enzyme preparation is completely and uniformly dissolved in the compound enzymatic hydrolysate. Prepare and use immediately. After enzymatic hydrolysis, remove the areca nuts (with the kernel removed) and soak them in sterile purified water at 85°C for 3 minutes to completely inactivate the enzymes and terminate the enzymatic hydrolysis reaction. After enzyme inactivation, gently rinse twice with sterile purified water at room temperature to remove residual enzyme solution and arecoline degradation products from the surface, and then air dry in a ventilated, cool place for later use.

[0075] The areca nuts, after being enzymatically hydrolyzed and dried with the areca kernels removed, were placed in an acidic extract solution for gradient extraction. The gradient extraction included a first-stage extraction and a second-stage extraction. The conditions for the first-stage extraction were as follows: food-grade lactic acid was added to water and stirred evenly to obtain a lactic acid solution with a pH of 5.0 to 5.5. The areca nuts, after being enzymatically hydrolyzed and dried with the areca kernels removed, were completely immersed in the lactic acid solution. The ratio of areca nuts to lactic acid solution was 1:12 (g:mL). The extraction was carried out at 55°C for 50 min under constant temperature water bath conditions.

[0076] The second stage extraction conditions are as follows: extraction is carried out using a medium-acidity enhanced extraction solution. Food-grade dilute hydrochloric acid and food-grade lactic acid are added to water to adjust the pH of the compound extraction solution to 3.5-4.0. The areca nuts with the kernels removed after the first stage extraction are taken out and directly transferred to the hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5-4.0. The ratio of the areca nuts with the kernels removed to the hydrochloric acid-lactic acid compound extraction solution is 1:12 (g:mL). Static extraction is continued for 40 min at a constant temperature of 55℃.

[0077] Step 4: Place the extracted areca nuts (without the areca seeds) in a low-temperature color-protecting solution (salt water) and soak for 20 minutes. Then, briefly pre-cook the soaked areca nuts under steam or water at 85°C for 15 minutes. Finally, dry the pre-cooked areca nuts at 80°C until the moisture content is 12-15%.

[0078] Step 5: Add compound bio-enzymes and spices to the dried green fruit slices from Step 4 and ferment at 25℃ for 60 hours. Roast the fermented green fruit slices at 50℃ to fix the aroma until the moisture content is reduced to 8-10%. Apply a thin layer of food-grade varnish and natural flavoring to the surface of the roasted green fruit slices, then inject brine, and air-dry or seal and simmer at 35℃ until the moisture content is reduced to 6-8%. Finally, sterilize with ultraviolet light to obtain areca nut slices free of arecoline.

[0079] The dietary fiber, soluble polysaccharides, and tannins of the areca nut slices prepared in this embodiment were tested. The test results showed that the retention rate of dietary fiber was 97.8%, the retention rate of soluble polysaccharides was 95.2%, and the retention rate of flavor matrices such as tannins was 96.5%, with extremely low overall matrix loss. This indicates that the processing method described in this invention does not damage the main nutrients and flavor matrices of areca nut, solving the problems of large matrix loss and serious flavor loss in traditional processes.

[0080] Example 2 A processing method for removing arecoline from areca nuts, the processing method comprising the following steps: Step 1 is the same as in Example 1.

[0081] Step 2: Cut the soaked areca nuts while they are still wet and remove the areca kernels to obtain areca nuts with the kernels removed.

[0082] Step 3: Completely immerse the areca nuts (without the kernels removed) in the compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposed pulp to avoid uneven local hydrolysis. The ratio of areca nuts (without kernels removed) to the compound enzymatic hydrolysate is 1:8 (g:mL). Set the hydrolysis temperature to 25℃, the low-speed oscillation frequency to 60 r / min, and the isothermal hydrolysis time to 6 hours. The compound enzyme preparation comprises esterase, pectinase, and cellulase mixed in a mass ratio of 1:1:1. In this compound enzymatic hydrolysate, the esterase activity is 10000 U / g, the pectinase activity is 5000 U / g, and the cellulase activity is 8000 U / g. The pH of the phosphate buffer is 7.0, and the mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 1%. During the preparation of this compound enzymatic hydrolysate, stir at low speed for 4 minutes until the enzyme preparation is completely and uniformly dissolved. Prepare and use immediately. After enzymatic hydrolysis, remove the areca nut slices and soak them in 80℃ water for 5 minutes to completely inactivate the enzymes and terminate the enzymatic hydrolysis reaction. After enzyme inactivation, gently rinse 13 times with sterile purified water at room temperature to remove residual enzyme solution and arecoline degradation products on the surface. Then, air dry in a cool, ventilated place for later use.

[0083] The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, were placed in an acidic extract for gradient extraction. The gradient extraction included a first-stage extraction and a second-stage extraction. The first-stage extraction conditions were as follows: food-grade lactic acid was added to water and stirred evenly to obtain a lactic acid solution extract with a pH of 5.0 to 5.5. The first stage was a weakly acidic complex extract that gently penetrated deep into the pulp. The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, were completely immersed in the lactic acid solution extract. The ratio of areca nuts to lactic acid solution was 1:10 (g:mL). The extraction was carried out at 50°C for 60 min under constant temperature water bath conditions.

[0084] The second-stage extraction conditions were as follows: A moderately acidic enhanced extraction solution was used, with food-grade dilute hydrochloric acid and food-grade lactic acid added to the water to adjust the pH of the compound extract to 3.5–4.0. The areca nuts (without kernels) removed after the first-stage extraction were directly transferred to the hydrochloric acid-lactic acid compound extract at pH 3.5–4.0. The ratio of the areca nuts (without kernels) to the hydrochloric acid-lactic acid compound extract was 1:10 (g:mL). Static extraction was continued at a constant temperature of 50℃ for 45 minutes.

[0085] Steps 4 and 5 are the same as in Example 1.

[0086] Example 3 A processing method for removing arecoline from areca nuts, the processing method comprising the following steps: Step 1 is the same as in Example 1.

[0087] Step 2: Cut the soaked areca nuts while they are still wet and remove the areca kernels to obtain areca nuts with the kernels removed.

[0088] Step 3: Completely immerse the areca nuts (without the pits removed) in the compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposed pulp to avoid uneven local hydrolysis. The ratio of areca nuts (without the pits removed) to the compound enzymatic hydrolysate is 1:12 (g:mL). Set the hydrolysis temperature to 35℃, the low-speed oscillation frequency to 40 r / min, and the isothermal hydrolysis time to 7 hours. The compound enzyme preparation comprises esterase, pectinase, and cellulase mixed in a mass ratio of 3:1:1. In this compound enzymatic hydrolysate, the esterase activity is 20000 U / g, the pectinase activity is 10000 U / g, and the cellulase activity is 12000 U / g. The pH of the phosphate buffer is 7.0, and the mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 3%. During the preparation of this compound enzymatic hydrolysate, stir at low speed for 7 minutes until the enzyme preparation is completely and uniformly dissolved. Prepare and use immediately. After enzymatic hydrolysis, remove the green fruit slices and soak them in 90℃ water for 2 minutes to completely inactivate the enzyme and terminate the enzymatic hydrolysis reaction. After enzyme inactivation, gently rinse three times with sterile purified water at room temperature to remove residual enzyme solution and arecoline degradation products on the surface, and then air dry in a ventilated and cool place for later use.

[0089] The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, were placed in an acidic extract for gradient extraction. The gradient extraction included a first-stage extraction and a second-stage extraction. The first-stage extraction conditions were as follows: food-grade lactic acid was added to water and stirred evenly to obtain a lactic acid solution extract with a pH of 5.0 to 5.5. The first stage was a weakly acidic complex extract that gently penetrated deep into the pulp. The areca nuts, after being enzymatically hydrolyzed and dried with the kernels removed, were completely immersed in the lactic acid solution extract. The ratio of areca nuts to lactic acid solution extract was 1:14 (g:mL). The extraction was carried out at 60°C for 40 min under constant temperature water bath conditions.

[0090] The second stage extraction conditions were as follows: A moderately acidic enhanced extraction solution was used, with food-grade dilute hydrochloric acid and food-grade lactic acid added to the water to adjust the pH of the compound extract to 3.5–4.0. The areca nuts (without kernels) removed after the first stage extraction were directly transferred to the hydrochloric acid-lactic acid compound extract at pH 3.5–4.0. The ratio of areca nuts (without kernels) to the hydrochloric acid-lactic acid compound extract was 1:14 (g:mL). Static extraction was continued at a constant temperature of 60℃ for 35 minutes.

[0091] Steps 4 and 5 are the same as in Example 1.

[0092] Comparative Example Comparative Example 1 Arecoline in areca nuts was removed in a manner similar to that in Example 1, except that in this comparative example, the areca nuts were dried before the kernels were removed, and step 2 was replaced by drying the soaked areca nuts, cutting the areca nuts after drying, and removing the kernels to obtain areca nuts with the kernels removed.

[0093] Comparative Example 2 Arecoline in areca nuts is removed in a manner similar to that in Example 1, except that in step 3, no cellulase is added to the compound enzyme preparation, and the compound enzyme preparation is obtained by mixing esterase and pectinase in a mass ratio of 2:1.

[0094] Comparative Example 3 Arecoline in areca nuts was removed in a manner similar to that in Example 1, except that in step 3, the areca nuts that had been enzymatically hydrolyzed and dried with the kernel removed were placed in an acidic extract for a single extraction, without gradient extraction.

[0095] The extraction conditions are as follows: extraction is carried out using a medium-acidity enhanced extraction solution. Food-grade dilute hydrochloric acid and food-grade lactic acid are added to water to adjust the pH of the compound extraction solution to 3.5-4.0. The areca nuts with the kernels removed after the first stage of extraction are taken out and directly transferred to the hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5-4.0. The ratio of the areca nuts with the kernels removed to the hydrochloric acid-lactic acid compound extraction solution is 1:12 (g:mL). Static extraction is continued for 90 min at a constant temperature of 55℃.

[0096] Comparative Example 4 Arecoline in areca nuts was removed in a manner similar to that in Example 1, except that in step 3, the areca nuts without kernels were not enzymatically hydrolyzed, and only the areca nuts without kernels were acidically extracted.

[0097] Comparative Example 5 Arecoline in areca nuts was removed in a manner similar to that in Example 1, except that in step 3, only the areca nuts with the kernels removed were enzymatically hydrolyzed, and the areca nuts with the kernels removed were not subjected to acidic extraction.

[0098] Comparative Example 6 Arecoline in areca nuts was removed in a manner similar to that in Example 1, except that in step 3, the areca nuts with the kernels removed were first subjected to acidic extraction with an acidic extract, and then the areca nuts with the kernels removed were subjected to enzymatic hydrolysis with a compound enzymatic hydrolysate.

[0099] Replace step 3 with: completely immersing the areca nuts (without the areca kernels) in an acidic extract solution for gradient extraction. The gradient extraction includes a first stage extraction and a second stage extraction. The conditions for the first stage extraction are: adding food-grade lactic acid to water and stirring until a lactic acid solution with pH = 5.0 to 5.5 is obtained; completely immersing the enzymatically hydrolyzed and dried areca nuts (without the areca kernels) in the lactic acid solution; the ratio of areca nuts (without the areca kernels) to the lactic acid solution is 1:12 (g:mL); and extracting at 55°C for 50 min under constant temperature water bath conditions.

[0100] The second stage extraction conditions are as follows: extraction is carried out using a medium-acidity enhanced extraction solution. Food-grade dilute hydrochloric acid and food-grade lactic acid are added to water to adjust the pH of the compound extraction solution to 3.5-4.0. The areca nuts with the kernels removed after the first stage extraction are taken out and directly transferred to the hydrochloric acid-lactic acid compound extraction solution with a pH of 3.5-4.0. The ratio of the areca nuts with the kernels removed to the hydrochloric acid-lactic acid compound extraction solution is 1:12 (g:mL). Static extraction is continued for 40 min at a constant temperature of 55℃.

[0101] Areca nuts, after acid extraction and removal of the kernels, were placed in a compound enzymatic hydrolysate for enzymatic hydrolysis, ensuring no stacking or exposed pulp to avoid uneven local hydrolysis. The ratio of areca nuts to hydrolysate was 1:10 (g:mL). The hydrolysis temperature was set at 30℃, the low-speed oscillation frequency at 50 r / min, and the isothermal hydrolysis time at 6.5 h. The compound enzymatic hydrolysate was prepared by dissolving a compound enzyme preparation in phosphate buffer. The compound enzyme preparation was obtained by mixing esterase, pectinase, and cellulase in a mass ratio of 2:1:1. In this compound enzymatic hydrolysate, the esterase activity was 15000 U / g, the pectinase activity was 7000 U / g, and the cellulase activity was 10000 U / g. The mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate was 2%. During the preparation of this compound enzymatic hydrolysate, the mixture was stirred at low speed for 5 min until the enzyme preparation was completely and uniformly dissolved in the compound enzymatic hydrolysate. The solution was prepared and used immediately. After enzymatic hydrolysis, remove the areca nuts (with the kernel removed) and soak them in sterile purified water at 85°C for 3 minutes to completely inactivate the enzymes and terminate the enzymatic hydrolysis reaction. After enzyme inactivation, gently rinse twice with sterile purified water at room temperature to remove residual enzyme solution and arecoline degradation products from the surface, and then air dry in a ventilated, cool place for later use.

[0102] Experimental Example Experimental Example 1: Quantitative Test and Results of Arecoline Removal Rate The arecoline removal rates of Examples 1-3 and Comparative Examples 1-6 were tested respectively. The test method was as follows: the arecoline content of arecoline in arecoline samples before and after treatment was quantitatively detected by high performance liquid chromatography (HPLC). The detection method was based on page 365 of the 2015 edition of the Chinese Pharmacopoeia, Part I: Determination of arecoline in arecoline. The arecoline in arecoline in arecoline before and after arecoline removal in each example was measured. Then, the arecoline removal rate of each example group was calculated according to the following formula (1). The test results are shown in Table 1.

[0103] Arecoline removal rate = (Arecoline content in areca nut before removal - Arecoline content in areca nut after removal) / Arecoline content in areca nut before removal 100%.

[0104] Table 1

[0105] As can be seen from Table 1, the arecoline removal rate of the processing methods described in Examples 1 to 3 is over 98.95%, which is much higher than the arecoline removal rate of Comparative Examples 1 to 6, indicating that the processing method described in this invention can significantly remove arecoline from areca nuts.

[0106] Compared with Example 1, Comparative Example 1 removed the areca kernel after drying, and the areca nut removal rate of Comparative Example 1 was much lower than that of Example 1. The above results show that removing the areca kernel after drying will significantly reduce the areca nut removal rate.

[0107] Compared with Example 1, the enzymatic hydrolysis preparation used in step 3 of Comparative Example 2 did not include cellulase. The arecoline removal rate of Comparative Example 2 was lower than that of Example 1. The above results indicate that the compound enzymatic hydrolysate obtained by using esterase, pectinase and cellulase in the enzymatic hydrolysis process is more conducive to improving the removal rate of arecoline.

[0108] Compared with Example 1, Comparative Example 3 did not use a gradient extraction method during the extraction process, but only used a medium-acidity enhanced extraction solution. The arecoline removal rate of Comparative Example 3 was much lower than that of Example 1. The above results indicate that in the extraction process, using a gradient extraction method, first using hydrochloric acid for extraction, and then using a medium-intensity enhanced extraction solution, is more conducive to improving the removal rate of arecoline than using hydrochloric acid alone.

[0109] Compared with Example 1, Comparative Example 4 did not perform enzymatic hydrolysis on the areca nut fruit after removing the areca kernel; it only performed acid extraction on the areca nut fruit after removing the areca kernel. The arecoline removal rate of Comparative Example 4 was much lower than that of Example 1. The above results indicate that enzymatic hydrolysis before acid extraction is more conducive to improving the removal rate of arecoline.

[0110] Compared with Example 1, Comparative Example 5 did not perform acid extraction on the areca nut fruit with the areca kernel removed, but only performed enzymatic hydrolysis on the areca nut fruit with the areca kernel removed. The arecoline removal rate of Comparative Example 5 was much lower than that of Example 1. The above results indicate that performing acid extraction after enzymatic hydrolysis is more beneficial to improving the arecoline removal rate than performing enzymatic hydrolysis alone.

[0111] Compared with Example 1, Comparative Example 6 reversed the order of acid extraction and enzymatic hydrolysis. Comparative Example 6 performed acid extraction first, followed by enzymatic hydrolysis. The arecoline removal rate of Comparative Example 6 was lower than that of Example 1. The above results indicate that the order of acid extraction and enzymatic hydrolysis affects the arecoline removal rate. Only enzymatic hydrolysis followed by acid extraction is more conducive to improving the arecoline removal rate.

[0112] The above results indicate that the arecoline removal method of the present invention, through the synergistic effect of multi-enzyme synergistic cell wall disruption and gradient acidity layer-by-layer dissolution, can completely remove the deep-bound and highly stable encapsulated arecoline that cannot be removed by conventional processes. The alkali removal effect is far superior to that of traditional treatment processes. The arecoline removal method of the present invention can achieve a significant removal of arecoline.

[0113] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A processing method for removing arecoline from areca nuts, characterized in that, The processing method includes the following steps: Step 1: Wash and sterilize the sorted areca nuts, and then soak the washed and sterilized areca nuts in the washing solution. Step 2: Cut the soaked areca nuts in half, remove the areca kernels, and obtain areca nuts with the areca kernels removed; Step 3: Place the areca nuts with the kernels removed in a compound enzymatic hydrolysate, and then place them in an acidic extraction solution for gradient extraction to remove arecoline from the areca nuts.

2. The processing method according to claim 1, characterized in that, In step 1, The cleaning solution is selected from one or two of water and ethanol; The ethanol concentration is 20-40% low-concentration ethanol; The conditions for soaking the cleaned and sterilized areca nuts in the cleaning solution are as follows: soak the areca nuts in the cleaning solution 1 to 3 times, immerse the whole areca nuts at room temperature in the dark, and soak for 15 to 25 minutes. During the soaking process, gently shake the soaking system once every 5 to 15 minutes.

3. The processing method according to claim 1, characterized in that, In step 3, The compound enzymatic hydrolysate is prepared by dissolving a compound enzyme preparation in a phosphate buffer solution. The compound enzyme preparation includes esterase, pectinase and cellulase mixed in a mass ratio of (1-3):1:

1. In this compound enzymatic hydrolysate, the esterase activity is ≥10000 U / g, the pectinase activity is ≥5000 U / g, the cellulase activity is ≥8000 U / g, the pH of the phosphate buffer is 7.0, and the mass concentration of the compound enzyme preparation in the compound enzymatic hydrolysate is 1-3%.

4. The processing method according to claim 1, characterized in that, In step 3, The areca nuts with the kernels removed were completely immersed in the compound enzymatic hydrolysate for enzymatic hydrolysis. The ratio of areca nuts with the kernels removed to the compound enzymatic hydrolysate was 1:(8-12) (g:mL). The enzymatic hydrolysis temperature was set at 25-35℃, the low-speed oscillation frequency was 40-60 r / min, and the constant temperature permeation enzymatic hydrolysis time was 6-7h.

5. The processing method according to claim 1, characterized in that, In step 3, After enzymatic hydrolysis, remove the areca nuts (with the kernel removed) and soak them in water at 80-90℃ for 2-5 minutes to completely inactivate the enzymes and terminate the enzymatic hydrolysis reaction.

6. The processing method according to claim 1, characterized in that, In step 3, The areca nuts, after enzymatic hydrolysis and removal of the areca kernels, are placed in an acidic extract solution for gradient extraction, which includes a first-stage extraction and a second-stage extraction. The first stage extraction conditions are as follows: food-grade lactic acid is added to water and stirred evenly to obtain a lactic acid solution extract with pH=5.0-5.

5. The areca nuts (without kernels) after enzymatic hydrolysis are completely immersed in the lactic acid solution extract. The ratio of areca nuts (without kernels) to lactic acid solution is 1:(10-14) (g:mL). The extraction is carried out at a constant temperature water bath at 50-60℃ for 40-60 min.

7. The processing method according to claim 6, characterized in that, In step 3, The second stage extraction conditions are as follows: food-grade dilute hydrochloric acid and food-grade lactic acid are added to water to adjust the pH of the compound extract to 3.5-4.

0. The areca nuts with the kernels removed after the first stage extraction are then transferred into the compound extract at pH 3.5-4.

0. The ratio of areca nuts with the kernels removed to the compound extract is 1:(10-14) (g:mL). Static extraction is continued at a constant temperature of 50-60℃ for 35-45 minutes.

8. The processing method according to claim 1, characterized in that, The processing method further includes the following steps: Step 4: Soak the areca nuts (without kernels) after gradient extraction in step 3 in a low-temperature color-protecting solution. Then, briefly pre-cook the soaked areca nuts (without kernels) to remove the green color and dry them. Step 5: Add spices to the dried areca nuts (with the areca kernels removed) from Step 4 and process them at a low temperature. Then, roast the seeds at a low temperature to fix the aroma, apply glue, add syrup, simmer to release the aroma, and sterilize to obtain areca nut slices after removing arecoline.

9. The processing method according to claim 8, characterized in that, In step 4, After soaking, the areca nuts with the kernels removed are briefly blanched and pre-cooked for 10-20 minutes under steam or boiling conditions at 80-90℃, and then dried at 75-85℃ until the moisture content of the areca nuts with the kernels removed is 12-15%.

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