A novel process for preserving the freshness of areca nuts

Abstract

This application discloses a novel process for preserving the freshness of areca nuts, belonging to the field of areca nut food processing technology. The process includes: selecting fresh areca nuts for steam cleaning with alkali and pH adjustment; boiling in edible alkaline water to remove bitterness; using a four-stage vacuum freeze-drying technology to replace traditional steam-explosion molding, achieving fiber softening and shaping while removing moisture gradients; preparing a mild, alkali-free brine and marinating it through vacuum tumbling; and preparing solid brine granules that are adhered to the inner cavity of the areca nuts and individually packaged. This application effectively solves the problems of cumbersome traditional refined areca nut processes, flavor degradation due to high temperatures, easy breakage during mechanical molding, and dry taste, preserving the moist and chewy state and original flavor of semi-fresh areca nuts, improving eating comfort and product stability.

Description

Technical Field

[0001] This application belongs to the field of areca nut food processing technology, specifically involving a novel areca nut freshness-locking process. Background Technology

[0002] Areca nut, a plant fruit with a long history of consumption, enjoys a wide consumer base and a deep cultural foundation in certain regions. Traditional areca nut processing primarily relies on dried areca nuts as raw material, which are then processed into the finished product through a series of complex physical and chemical steps. Existing typical technologies usually involve rehydrating the dried areca nuts, followed by using high-temperature steam explosion technology to expand and soften the fruit, then mechanically pressing it to fix its shape, and finally coating the surface with a resin and flavoring agent through a surface-applying process. The entire production process involves closely linked steps such as washing, boiling, processing, shaping, and adding brine, aiming to transform the dry, hard raw material into a chewable product with a specific texture and flavor. This process system has developed relatively fixed operating procedures and equipment configurations through long-term industrial production.

[0003] However, in the current technology, the traditional refining process of areca nuts often faces the dilemma of cumbersome procedures and irreversible damage to the texture of raw materials. Due to the reliance on high-temperature steam explosion and mechanical forced molding, the areca nut fiber structure is easily damaged, a large amount of flavor substances are lost, and the surface coating is easy to peel off. At the same time, the finished products often have problems such as strong oral irritation, dry chewing sensation, and lack of the original aroma of fresh fruit, which makes it difficult to meet consumers' growing demand for high quality and original taste. Summary of the Invention

[0004] This application provides a novel fresh-locking process for areca nuts, which can solve the technical problems existing in the traditional refined areca nut processing, such as complicated procedures, flavor loss due to high-temperature steam explosion, easy breakage due to mechanical pressing, easy peeling of surface coating, strong oral irritation, and dry chewing.

[0005] To achieve the above objectives, this application provides the following technical solution: This application provides a novel fresh-locking process for areca nuts, comprising the following steps: S1 Raw material selection and bubble-alkali cleaning: Fresh areca nuts free from mold, insect infestation, and uniform size are selected as raw materials and placed in a bubble-type cleaning machine. Citric acid is added to adjust the pH of the system to 5.5-6.5, and the bubble cleaning is performed for 8-12 minutes. After removal, the areca nuts are rinsed with running water for 2-4 minutes and drained to obtain clean areca nuts; S2 Sterilization and blanching pretreatment: The areca nuts are placed in a stainless steel boiling tank, and 1.5-5g of edible alkali is added per kilogram of water to remove the astringency of the areca nuts and neutralize the pH value. The areca nuts are boiled for 20-50 minutes; S3 Freeze-drying technology: The traditional refined areca nut processes of steam-explosion, molding, and surface treatment are eliminated. The pickled areca nuts are laid flat on a tray and sent into a vacuum freeze dryer. The temperature is set to four stages, with the first stage freezing temperature being - Pre-freezing at 15~-20℃ with a vacuum pressure of 20-30 Pa for 1-1.5 hours; second-stage freezing at -20-25℃ with a vacuum pressure of 40-50 Pa for 2-2.5 hours; third-stage freezing at a vacuum of 30-40 Pa with a sublimation drying temperature of 25-40℃ for 2-3 hours, reducing moisture by about 30%; fourth-stage freezing at a shelf temperature of 45℃~55℃ for 0.5-2 hours, reducing moisture by 10%; S4 freeze-dried areca nuts retain a semi-fresh, moist, and tough state, with naturally softened and shaped fibers and a bright color, eliminating the need for mechanical pressing and surface coating; while retaining some of the fruity aroma of fresh fruit, it also retains some of the herbal astringency and effectively reduces the moisture content of the fruit itself; S5 Preparation of soaking brine: Prepare a gelatinous solution; for every kilogram of raw fruit, use 0.8-3g of gelatin, 1.2-3g of xanthan gum, 0.1-0.6g of agar, 0.3-2g of cyclamate, 0.4-1g of sucralose, 0.2-2g of fructose, 0.5-2g of stevia, 0.6-2g of herbal extracts (such as Malva nut extract and peppermint extract), 1.2-2g of natural flavorings (such as sweet orange oil, coconut oil, osmanthus essential oil, plum flavoring, lemon oil, and brown sugar and black sugar flavoring), stir at 500-700 rpm for 3-6 minutes, adjust the pH to 6.5-7.5 with citric acid to obtain a mild, non-alkaline brine; S6 Vacuum tumbling and marinating: Put the whole areca nuts and alkali-free brine into a vacuum variable track tumbling machine and evacuate to -0.08~-0.0.09MPa, 8-10rpm tumbling for 40-50min; cooling to 4-6℃ and standing for 1-3h, then removing and air-drying to remove excess brine, resulting in pickled areca nuts with a richer flavor; S7 solid brine granule coagulation and packaging: mix gelatin, maltose, menthol, tangerine peel powder, coffee powder, cooling agent, shell powder, and edible flavoring, then add maltitol powder, stir at 80-100rpm for 16-20min, add 1000g of ultrapure water and 15-24g of raw material, stir and granulate, pass through a 30-mesh sieve, and dry at 25-55℃ for 1-2h to obtain individual brine granules; attach these brine granules to the inner cavity of the areca nut using gelatin or traditional brine; individually package the freeze-dried areca nuts in aluminum foil composite PE bags to obtain the finished wet areca nut product.

[0006] This application provides a novel process for preserving the freshness of areca nuts. This process involves selecting fresh areca nuts and subjecting them to bubble-soaked alkali washing and pH adjustment. This effectively removes surface contaminants and neutralizes the acidity of the nut, resulting in a clean and chemically stable initial raw material. Further processing with edible alkali water boiling eliminates the astringency of the areca nut and balances the pH. The product utilizes a four-stage vacuum freeze-drying technology to replace the traditional high-temperature steam explosion and mechanical pressing process. By controlling the freezing temperature, vacuum pressure, and sublimation drying temperature in stages under low-temperature and low-pressure conditions, the areca nut fiber naturally softens and sets during the gradient dehydration process. This avoids the damage of heat-sensitive flavor substances caused by high temperatures and achieves precise moisture removal, thus preserving the moist and resilient state, bright color, and some of the herbal astringent flavor of the semi-fresh fruit. Furthermore, a mild, alkali-free brine containing various colloids, sweeteners, and plant extracts is formulated and combined with vacuum tumbling and low-temperature settling technology to promote efficient penetration of the brine into the fruit, thereby giving the product a rich texture and reducing oral irritation. Subsequently, solid brine granules made from gelatin, menthol, and other ingredients are adhered to the inner cavity of the areca nut and then bonded using aluminum foil composite PE. The bags are individually packaged to allow for the gradual release of flavor and long-term preservation of the product during chewing. This effectively solves the problems of fiber damage, flavor loss, coating peeling, and dry taste caused by high temperature and pressure in traditional processes, improving the product's eating comfort, flavor stability, and overall quality, and achieving efficient transformation from fresh fruit to high-quality wet areca nuts.

[0007] This invention patent application constructs a complete closed-loop system from raw material cleaning, blanching, freeze-drying and shaping to vacuum pickling and solid-state curdling. The synergistic effect of each step not only simplifies the production process and reduces equipment investment, but also preserves the natural texture and flavor characteristics of betel nut to the greatest extent while ensuring food safety. It has significant systemic advantages and industrial application value. Detailed Implementation The technical solutions in the embodiments of this application will be clearly and completely described below. Example

[0008] The novel betel nut freshness-locking process of this invention, as described in the embodiments of this application, mainly includes the following core technical elements: alkaline cleaning and pH adjustment of raw materials via bubble-forming, pretreatment with edible alkaline water boiling, four-stage vacuum freeze-drying technology, preparation of alkali-free mild brine, vacuum-assisted tumbling and marinating, and solid brine granule coagulation and individual packaging. These technical elements work together to constitute the overall technical solution of this invention, aiming to solve problems existing in traditional refined betel nut processing, such as cumbersome procedures, flavor loss due to high-temperature steam explosions, easy breakage during mechanical pressing, easy peeling of the surface coating, strong oral irritation, and dry chewing.

[0009] Step S1: Raw Material Selection and Bubble Alkali Cleaning: Select fresh areca nuts that are free from mold, insects, and are uniform in size as raw materials. Place them in a bubble cleaning machine, add citric acid to adjust the pH to 5.5-6.5, and bubble clean for 8-12 minutes. After removal, rinse with running water for 2-4 minutes and drain to obtain clean areca nuts. Step S2: Sterilization and Blanching Pretreatment: Place the areca nuts in a stainless steel boiling tank, add 1.5-5g of edible alkali per kilogram of water to remove the astringency of the areca nuts and neutralize the pH value. Boil the areca nuts for 20-50 minutes. Step S3: Freeze-drying Technology: Eliminate the traditional steam-explosion, pressing, and surface-forming processes of refined areca nuts. Lay the cured areca nuts flat on a tray and send them into a vacuum freeze dryer. Set the temperature to four stages, with the first stage freezing temperature... Pre-freezing at 15~-20℃ with a vacuum pressure of 20-30 Pa for 1-1.5 hours; second stage freezing at -20-25℃ with a vacuum pressure of 40-50 Pa for 2-2.5 hours; third stage vacuum control at 30-40 Pa, sublimation drying at 25-40℃ for 2-3 hours to reduce moisture by about 30%; fourth stage shelf temperature: 45℃~50℃ for 0.5-2 hours to reduce moisture by 10%; maximum temperature not exceeding 55℃ to prevent arecoline volatilization and fiber scorching; after freeze-drying in step S4, the areca nuts retain a semi-fresh, moist, and tough state, with naturally softened and shaped fibers and a bright color, eliminating the need for mechanical pressing and surface coating; while retaining some of the fruity aroma of fresh fruit, it also retains some of the herbal astringency and effectively reduces the moisture content of the fruit itself; step S5 Preparation of soaking brine: Prepare a gelatinous solution; for each kilogram of raw fruit, use 0.8-3g of gelatin, 1.2-3g of xanthan gum, 0.1-0.6g of agar, 0.3-2g of cyclamate, 0.4-1g of sucralose, 0.2-2g of fructose, 0.5-2g of stevia, 0.6-2g of herbal extracts (such as Malva nut extract and peppermint extract), 1.2-2g of natural flavorings (such as sweet orange oil, coconut oil, osmanthus essential oil, plum flavoring, lemon oil, and brown sugar and black sugar flavoring), stir at 500-700 rpm for 3-6 minutes, adjust the pH to 6.5-7.5 with citric acid to obtain a mild, non-alkali brine; Step S6 Vacuum tumbling and marinating: Put the whole areca nuts and alkali-free brine into a vacuum variable track tumbling machine and vacuum it to -0.08~-0.0.9MPa, 8-10rpm tumbling for 40-50min; cooling to 4-6℃ and standing for 1-3h, then removing and air-drying to remove excess brine from the surface to obtain pickled areca nuts; Step S7: Solid brine granule coagulation and packaging: Mix gelatin, maltose, menthol, tangerine peel powder, coffee powder, cooling agent, shell powder, and edible flavoring, then add maltitol powder, stir at 80-100rpm for 16-20min, add 1000g of ultrapure water and 15-24g of raw material, stir and granulate, pass through a 30-mesh sieve, and dry at 25-55℃ for 1-2h to obtain individual brine granules; attach these brine granules to the inner cavity of the areca nut using gelatin or traditional brine; individually package the freeze-dried areca nuts in aluminum foil composite PE bags to obtain the finished wet areca nut product. In this invention, by combining bubble cleaning and pH control, surface contaminants are removed, and the acidity of the fruit is neutralized, improving the chemical stability of subsequent processing. A four-stage gradient freeze-drying technology replaces traditional high-temperature steam explosion and mechanical pressing, utilizing the principle of water sublimation under low temperature and low pressure to achieve natural softening and morphological shaping of the fibers. This avoids the damage of heat-sensitive components such as arecoline to high temperatures and prevents fiber charring, thus preserving the herbal astringency and fruity aroma while reducing moisture content. The alkali-free brine formula combined with a vacuum tumbling process uses negative pressure difference to accelerate the penetration of the brine into the fruit, significantly reducing oral irritation and improving eating comfort. The solid brine granule design allows for a gradual release of flavor during chewing; in particular, the synergistic effect of menthol and arecoline produces a refreshing effect. Individual packaging ensures the product's hygiene, safety, and storage stability.

[0010] Unless otherwise specified, all materials, reagents and instruments used in the embodiments of this invention can be obtained through commercial channels.

[0011] Key ingredients include: fresh areca nuts (selected from seasonal areca nuts that are free from mold and insects and are uniform in size), edible alkali (sodium carbonate, food grade), citric acid (food grade), gelatin (edible gelatin, gel strength ≥240 bloom), xanthan gum (food grade), agar (food grade), cyclamate, sucralose, fructose, steviol glycosides, Malva nut extract, peppermint extract, sweet orange oil, coconut oil, osmanthus essential oil, preserved plum flavor, lemon oil, brown sugar flavor, black sugar flavor, maltose, menthol, dried tangerine peel powder (dried tangerine peel aged over three years), coffee powder, cooling agent (WS-3 or WS-23), shell powder (food grade calcium carbonate), maltitol powder, and ultrapure water.

[0012] The equipment includes: a bubble cleaner, a stainless steel seed boiling tank, a vacuum freeze dryer (with four-stage temperature control), a vacuum variable-track tumbler, a high-speed shear mixer, a granulator, a vibrating screen, a low-temperature oven, an electronic balance, a pH meter, and an aluminum foil composite PE bag sealing machine.

[0013] Characterization and testing methods include: moisture content determination using the direct drying method of GB 5009.3; sensory evaluation by an evaluation team of 10 trained professionals, who scored color, odor, taste, toughness, and irritation; arecoline content determination using high performance liquid chromatography (HPLC); and microbiological indicators in accordance with the GB 4789 series standards.

[0014] Example 1:

[0015] This embodiment provides a method for preserving the freshness of wet areca nuts under optimal process parameters, in order to verify the core effect of the technical solution of the present invention.

[0016] The steps are as follows: S1 Raw Material Selection and Bubble Alkali Cleaning: Select 10kg of fresh areca nuts that are free from mold, insects, and uniform in size as raw materials, put them into a bubble cleaning machine, add citric acid to adjust the pH of the system to 6.0, and bubble clean for 10 minutes; after taking them out, rinse them with running water for 3 minutes, and drain them to obtain clean areca nuts.

[0017] S2 Sterilization and Blanching Pretreatment: Put the green areca nuts into a stainless steel boiling pot, add 10L of water and 30g of edible alkali (i.e., 3g per kilogram of water), boil and maintain for 35 minutes to remove the astringent taste of the areca nuts and neutralize the pH value, then remove and drain.

[0018] S3 Freeze-drying Technology: The processed areca nuts are laid flat on a tray and fed into a vacuum freeze dryer. The first stage freezing temperature is -15~-20℃, with a vacuum pressure of 20-30 Pa, for 1-1.5 hours of pre-freezing. The second stage freezing temperature is -20-25℃, with a vacuum pressure of 40-50 Pa, for 2-2.5 hours of pre-freezing. The third stage vacuum is controlled at 30-40 Pa, with a sublimation drying temperature of 32℃, and drying for 2.5 hours, at which point the material moisture content decreases by approximately 30%. The fourth stage: the shelf temperature is 48℃, and the time is 1.2 hours, further reducing the moisture content by 10%, with the total moisture content controlled between 15% and 18%. This process eliminates the traditional steam explosion, molding, and dial gauge processes.

[0019] S4 Status Confirmation: After freeze-drying, the areca nuts retain a semi-fresh, moist and tough state, with the fibers naturally softening and shaping, resulting in a bright color. No mechanical pressing or surface coating is required, and some of the fruity aroma and herbal astringency of the fresh fruit are preserved.

[0020] Preparation of S5 soaking brine: Weigh out 2g gelatin, 2g xanthan gum, 0.4g agar, 1g cyclamate, 0.6g sucralose, 1g fructose, 1g stevia, 1g Malva nut extract, 1g peppermint extract, 1.5g sweet orange oil, 0.6g coconut oil, 0.6g osmanthus essential oil, 0.4g preserved plum flavoring, 0.4g lemon oil, and 0.6g brown sugar flavoring per kilogram of raw fruit. Mix the above materials, add an appropriate amount of water, stir at 600 rpm for 5 minutes, and adjust the pH to 7.0 with citric acid to obtain a mild, non-alkaline brine.

[0021] S6 Vacuum Tumbling and Marinating: Put the whole areca nuts and alkali-free brine (liquid-solid ratio of about 1:1.5) into a vacuum variable track tumbling machine, evacuate to -0.085MPa, and tumble at 9rpm for 45min; then cool to 5℃ and let stand for 2h, then take them out and let them air dry to remove excess brine from the surface, thus obtaining the marinated areca nuts.

[0022] S7 Solid Brine Granule Coagulation and Packaging: Mix 50g gelatin, 200g maltose, 10g menthol, 15g dried tangerine peel powder, 10g coffee powder, 2g cooling agent, 5g shell powder, and 5g edible flavoring. Add 700g maltitol powder and stir at 90rpm for 18min. Add 20g ultrapure water (based on 1000g dry powder) and stir to granulate. Pass through a 30-mesh sieve and dry at 40℃ for 1.5h to obtain individual brine granules. Adhere these brine granules to the inner cavity of the areca nut using a small amount of gelatin solution. Finally, individually package the freeze-dried areca nuts in aluminum foil composite PE bags to obtain the finished wet areca nut product.

[0023] The results showed that the wet areca nut product obtained in this embodiment had a natural bluish-brown color, no surface cracks, and a moist, tough, and elastic feel. Testing revealed that the finished product had a moisture content of 16.5% and a arecoline retention rate of 92%. Sensory evaluation showed that it possessed a rich fruity and herbal aroma, initially feeling moist and soft upon chewing, followed by the dissolution and release of solid brine particles, bringing a rich, layered sensation and a refreshing, invigorating effect, without any obvious dryness or strong oral irritation.

[0024] This embodiment successfully achieved the softening and shaping of areca nut fibers and the efficient penetration of flavor through the synergistic effect of four-stage gradient freeze-drying and vacuum tumbling and pickling, proving the effectiveness of the process of the present invention in preserving the characteristics of fresh fruit.

[0025] Example 2:

[0026] The purpose of this embodiment is to verify the technical effect of the defined S1 step cleaning pH value lower limit.

[0027] Under the same preparation conditions as in Example 1, only citric acid was added in step S1 to adjust the pH of the system from 6.0 to 5.5, and the bubble washing time was kept at 10 min to obtain the product wet areca nut.

[0028] The results showed that the product had good surface cleanliness, achieved the expected acid-base neutralization effect, maintained stable fruit structure during subsequent processing, and had a sensory score comparable to that of Example 1. This demonstrates that the technical solution of the present invention still has good feasibility and cleaning and neutralization effect under the lower limit condition of pH 5.5.

[0029] Example 3:

[0030] The purpose of this embodiment is to verify the technical effectiveness of the limited upper limit of the pH range for cleaning in step S1.

[0031] Under the same preparation conditions as in Example 1, only citric acid was added in step S1 to adjust the pH of the system from 6.0 to 6.5, and the bubble washing time was kept at 10 min to obtain the product wet areca nut.

[0032] The results showed that the product also achieved effective surface cleaning and acid neutralization, without any darkening of color or softening of texture caused by excessive alkalinity of the cortex. The final product maintained a good wet toughness, proving that the technical solution of the present invention is stable and reliable under the upper limit of pH 6.5.

[0033] Example 4:

[0034] The purpose of this embodiment is to verify the technical effect of the limited lower limit of the amount of edible alkali added in step S2.

[0035] Under the same preparation conditions as in Example 1, only the amount of edible alkali added in step S2 was adjusted from 3g per kilogram of water to 1.5g, and the cooking time was kept at 35min to obtain wet areca nut.

[0036] The results showed that although the amount of alkali used was low, it could still effectively remove some of the astringent taste. The finished product had a slightly herbal astringent taste, which was in line with the product positioning of "retaining some astringent taste". Moreover, the fruit fiber was not excessively corroded, which proved the feasibility of the low alkali formula.

[0037] Example 5:

[0038] The purpose of this embodiment is to verify the technical effect of limiting the upper limit of the amount of edible alkali added in step S2.

[0039] Under the same preparation conditions as in Example 1, only the amount of edible alkali added in step S2 was adjusted from 3g per kilogram of water to 5g, and the cooking time was kept at 35min to obtain wet areca nut.

[0040] The results showed that higher concentrations of alkaline solution removed the astringency more thoroughly and softened the fruit slightly more. However, through the shaping effect of the subsequent freeze-drying process, the finished product still maintained its complete shape and moist, chewy texture, without any gelatinization or breakage. This proves that the process is controllable within the range of high alkalinity.

[0041] Example 6:

[0042] The purpose of this embodiment is to verify the technical effect of the lower limit of the freezing temperature in the first stage of the defined S3 step.

[0043] With all other preparation conditions the same as in Example 1, only the freezing temperature in the first stage of step S3 was adjusted from -18°C to -15°C, and the pre-freezing time was kept at 1.2 h, to obtain the product wet areca nut.

[0044] The results showed that the center of the areca nut could still be initially frozen at -15℃. Although the ice crystal formation rate was slightly slower than at -18℃, the porous structure of the final freeze-dried product was still well formed, and there was no significant difference in rehydration and taste, proving that the lower limit of the temperature met the process requirements.

[0045] Example 7:

[0046] The purpose of this embodiment is to verify the technical effect of the lower limit of the freezing temperature and the lower temperature conditions of the first stage of the limited S3 step.

[0047] With all other preparation conditions the same as in Example 1, only the freezing temperature in the first stage of step S3 was adjusted from -18°C to -20°C, and the pre-freezing time was kept at 1.2 h, to obtain the product wet areca nut.

[0048] The results showed that lower freezing temperatures resulted in finer ice crystals, which helped protect cell wall structures and improved the integrity of the finished fiber, demonstrating the positive effect of low-temperature pre-freezing on improving product texture.

[0049] Example 8:

[0050] The purpose of this embodiment is to verify the technical effect of the upper limit of the sublimation drying temperature range in the third stage of step S3.

[0051] With all other preparation conditions the same as in Example 1, only the sublimation drying temperature in step S3 was adjusted from 32°C to 40°C, and the drying time was kept at 2.5 h, to obtain the product wet areca nut.

[0052] The results showed that sublimation drying at a higher temperature of 40℃ accelerated the rate of moisture removal, but due to the limitations of the vacuum environment, no scorching occurred on the surface of the fruit. The arecoline retention rate decreased slightly but remained within an acceptable range (approximately 88%), and the finished product had a slightly darker color, proving that the upper limit of this temperature was within a controllable range.

[0053] Example 9:

[0054] The purpose of this embodiment is to verify the technical effect of the upper limit of shelf temperature in the fourth stage of step S3.

[0055] With all other preparation conditions the same as in Example 1, only the shelf temperature in the fourth stage of step S3 was adjusted from 48°C to 55°C and the time was maintained for 1.2 hours to obtain the product wet areca nut.

[0056] The results showed that at the extreme temperature of 55℃, the moisture content of the finished product further decreased to 14%, and the surface of the fruit tightened slightly, but no fiber scorching or large-scale volatilization of arecoline occurred. This indicates that the upper limit of the temperature is the critical safety value to prevent quality deterioration, and verifies the rationality of the temperature range.

[0057] Example 10: The purpose of this embodiment is to verify the technical effect of the lower limit of the brine stirring speed in step S5.

[0058] With other preparation conditions the same as in Example 1, only the stirring speed in step S5 was adjusted from 600 rpm to 500 rpm, and the stirring time was kept for 5 minutes to obtain the brine and carry out subsequent pickling.

[0059] The results showed that at a speed of 500 rpm, the dispersion uniformity of colloids and flavorings was slightly lower than that at 600 rpm, but there was no obvious stratification after standing, and the flavor distribution of the final product was basically uniform, proving that the lower limit of this speed can meet the production requirements.

[0060] Example 11: The purpose of this embodiment is to verify the technical effect of limiting the upper limit of the brine stirring speed in step S5.

[0061] With other preparation conditions the same as in Example 1, only the stirring speed in step S5 was adjusted from 600 rpm to 700 rpm, and the stirring time was kept for 5 minutes to obtain the brine and carry out subsequent pickling.

[0062] The results showed that high-speed stirring at 700 rpm made the colloidal solution more uniform and delicate. The bubble content increased slightly but did not affect the subsequent vacuum tumbling effect. The smoothness of the finished product was improved, proving that high speed is beneficial to the optimization of brine quality.

[0063] Example 12: The purpose of this embodiment is to verify the technical effect of the defined lower limit of vacuum degree in step S6.

[0064] With all other preparation conditions the same as in Example 1, only the vacuum degree in step S6 was adjusted from -0.085MPa to -0.08MPa, and the tumbling time was kept at 45min to obtain the product wet areca nut.

[0065] The results showed that at a vacuum of -0.08 MPa, the brine penetration depth was slightly shallower than at -0.085 MPa, but the fruit still had obvious flavor penetration inside and the outer layer had a rich flavor, proving that the lower limit of this vacuum degree can achieve the basic pickling effect.

[0066] Example 13: The purpose of this embodiment is to verify the technical effect of the limited upper limit of vacuum degree in step S6.

[0067] With all other preparation conditions the same as in Example 1, only the vacuum degree in step S6 was adjusted from -0.085MPa to -0.09MPa, and the tumbling time was kept at 45min to obtain the product wet areca nut.

[0068] The results showed that a higher vacuum level significantly promoted the penetration of the brine into the core of the fruit, resulting in better consistency of flavor inside and outside the finished product, and more complete release of juice during chewing, proving the beneficial effect of high vacuum level on improving pickling efficiency.

[0069] Example 14: The purpose of this embodiment is to verify the technical effect of limiting the lower limit of the range of water addition for solid brine particles in step S7.

[0070] With all other preparation conditions the same as in Example 1, only the amount of ultrapure water added in step S7 was adjusted from 20g / 1000g raw material to 15g / 1000g raw material to obtain solid brine particles and package them.

[0071] The results showed that when less water was added, the particles were slightly harder and dissolved more slowly, but the flavor was still fully released after chewing for 2-3 minutes, which is suitable for consumers who like a long-lasting cool sensation, proving the feasibility of this lower limit of water addition.

[0072] Example 15: The purpose of this embodiment is to verify the technical effect of limiting the upper limit of the range of water added to solid brine particles in step S7.

[0073] With all other preparation conditions the same as in Example 1, only the amount of ultrapure water added in step S7 was adjusted from 20g / 1000g raw material to 24g / 1000g raw material to obtain solid brine particles and encapsulate them.

[0074] The results showed that when more water was added, the granules were softer, melted quickly in the mouth, and released flavor rapidly, making them suitable for consumers who wanted an instant burst of flavor. This proved that the upper limit of the water addition could meet the needs of different flavor releases.

[0075] Example 16: This embodiment aims to verify, through comparative experiments, the significant advantages of the process of the present invention over traditional processes and comparative examples in terms of physicochemical properties, sensory quality, and functionality.

[0076] The test samples include: Example 1: Wet areca nuts (semi-fresh fruit) prepared. Comparative Example 1: Traditional dried areca nuts (made through smoking, steam explosion, molding, and dial marking processes). Comparative Example 2: Wet areca nuts that were not freeze-dried but were directly soaked in brine after steaming (simulating conventional boiling and soaking process). Comparative Example 3: The fourth stage of high-temperature drying in the S3 freeze-drying technology (i.e., the maximum temperature only rises to 25°C) is omitted, and the rest is the same as in Example 1; Comparative Example 4: S7 solid brine particles were omitted, and the brine was directly sprayed onto the surface of the areca nuts before packaging.

[0077] Test items and methods: 1. Moisture content: determined according to GB 5009.3.

[0078] 2. Arecoline retention rate: determined by HPLC, with the arecoline content of fresh green fruit as 100% as the baseline.

[0079] 3. Fiber integrity score: Fiber breakage is observed under a microscope and scored in conjunction with a chewing test (1-10 points, 10 points being the best).

[0080] 4. Sensory evaluation: A group of 10 people will give a comprehensive score for color, aroma, taste (moisture, chewiness), irritation, and aftertaste (out of 100 points).

[0081] 5. Stability of brine adhesion: After 2 hours of simulated transport vibration, the surface brine loss rate was measured.

[0082] The test results are shown in Table 1.

[0083] Table 1 Comparison of performance test results between each embodiment and the comparative example Example 1 16.5 92.3 9.5 94 < 1 The texture is just right – moist yet firm, with a rich and complex flavor profile. Comparative Example 1 12.0 65.4 6.0 72 - It has a dry and hard texture, a strong smoky flavor, and is highly irritating. Comparative Example 2 28.5 88.1 7.2 78 15.6 If the moisture content is too high, it is prone to mold and will have a soft and mushy texture. Comparative Example 3 21.0 91.5 8.8 85 3.2 High moisture content leads to poor long-term storage stability. Comparative Example 4 16.8 91.8 9.4 82 12.5 It tastes good initially, but the braising liquid is prone to falling off and the aftertaste is short-lived. As shown in Table 1, Example 1 significantly outperforms the Comparative Example in all indicators. Specifically, compared to the traditional drying process of Comparative Example 1, Example 1, through a four-stage freeze-drying technology, avoids the damage to arecoline caused by high-temperature steam explosion, increasing the retention rate by approximately 27% and significantly improving the fiber integrity score, thus solving the problem of dryness and roughness in traditional products. Compared to the conventional boiling and soaking process of Comparative Example 2, Example 1, through precise moisture gradient control, maintains the moisture content at a suitable 16.5%, ensuring a moist and chewy texture while avoiding the microbial risk and soggy texture caused by excessive moisture. The results of Comparative Example 3 indicate that if the fourth stage of moderately heated drying is omitted, the moisture content of the finished product is difficult to reduce to a safe range, affecting shelf life, thus confirming the necessity of the final step of heated dehydration in the four-stage temperature control. Comparative Example 4 demonstrates the effectiveness of the solid brine granule design; its extremely low brine loss rate ensures the stability of flavor during storage and transportation, avoiding the defects of easy peeling and uneven distribution in traditional spray coating processes.

[0084] Furthermore, in the sensory evaluation, Example 1 received the highest overall score. The product of Example 1 has a bright and natural color, without any black spots or scorch marks; upon initial chewing, it has the sweet and moist sensation of fresh fruit. As chewing progresses, the solid brine particles gradually dissolve, releasing a complex aroma of mint, dried tangerine peel, etc., with a significant cooling and refreshing effect, without the throat-locking sensation and strong irritation of traditional betel nuts. This progressive experience of "fruity aroma followed by medicinal aroma, moistness followed by coolness" is an unexpected technical effect that traditional processes cannot achieve.

[0085] In summary, this invention, through a unique integrated process of "washing-blanching-gradient freeze-drying-vacuum tumbling-solid coagulation," successfully solves the technical problems of cumbersome procedures, significant flavor loss, and strong dryness and irritation in existing technologies. It provides a high-quality, fresh-locking, low-irritation wet areca nut product with significant inventiveness and practicality. Experimental results show that the wet areca nut prepared by this invention effectively reduces oral irritation while maintaining its unique flavor and texture, thus it can be used to prepare a snack food for preventing and / or relieving oral fatigue and refreshing the mind.

Claims

1. A novel process for making fresh betel quid, characterized by, The novel areca nut freshness-locking process includes the following steps: The first step is the selection of raw materials and the bubble-washing with alkali: Add an appropriate amount of alkaline water to neutralize the acidity of the areca nuts, making them neutral and thoroughly cleaning the surface of the areca nuts; select fresh areca nuts that are free from mold, insects, and are of uniform size as raw materials, put them into a bubble-washing machine, add citric acid to adjust the pH of the system to 5.5-6.5, and bubble wash for 8-12 minutes; after taking them out, rinse them with running water for 2-4 minutes, and drain them to obtain clean areca nuts; The second step is sterilization and blanching pretreatment: Put the green areca nuts into a stainless steel boiling pot, add 1.5-5g of edible alkali per kilogram of water to remove the astringency of the areca nuts and neutralize the pH value, and boil the green areca nuts for 20-50 minutes. The third step involves freeze-drying. The pickled areca nuts are laid flat on a tray and placed into a vacuum freeze dryer. The temperature is set in four stages: the first stage is freezing at -15 to -20°C with a vacuum pressure of 20-30 Pa for 1-1.5 hours; the second stage is freezing at -20 to 25°C with a vacuum pressure of 40-50 Pa for 2-2.5 hours; the third stage is controlling the vacuum at 30-40 Pa and the sublimation drying temperature at 25-40°C for 2-3 hours, reducing the moisture content by about 30%; the fourth stage is at a shelf temperature of 45°C to 55°C for 0.5-2 hours, reducing the moisture content by 10%. The fourth step involves freeze-drying the areca nuts while maintaining their semi-fresh, moist, and resilient state. The fibers soften and solidify naturally, resulting in a bright color. This process eliminates the need for mechanical pressing and surface coating. While retaining some of the fruity aroma of fresh fruit, it also preserves some of the astringent taste of herbs and effectively reduces the moisture content of the fruit itself. Step 5, Preparation of soaking brine: Prepare the fermentation colloidal solution; for each kilogram of raw fruit, use 0.8-3g of gelatin, 1.2-3g of xanthan gum, 0.1-0.6g of agar, 0.3-2g of cyclamate, 0.4-1g of sucralose, 0.2-2g of fructose, 0.5-2g of stevia, 0.6-2g of herbal extracts (such as Malva nut extract and peppermint extract), 1.2-2g of natural flavorings (such as sweet orange oil, coconut oil, osmanthus essential oil, plum flavoring, lemon oil, and brown sugar and black sugar flavoring), stir at 500-700 rpm for 3-6 minutes, adjust the pH to 6.5-7.5 with citric acid to obtain a mild, alkali-free brine; Step 6, Vacuum tumbling and marinating: Put the whole areca nuts and alkali-free brine into a vacuum variable track tumbling machine, vacuum to -0.08~-0.09MPa, tumble at 8-10rpm for 40-50min; cool down to 4-6℃ and let stand at a low temperature for 1-3h, take them out and let them air dry naturally to get the marinated areca nuts; Step 7: Solid brine granules coagulation and packaging: Mix gelatin, maltose, menthol, dried tangerine peel powder, coffee powder, cooling agent, shell powder, and edible flavoring, then add maltitol powder and stir at 80-100 rpm for 16-20 minutes. Add 15-24g of ultrapure water to 1000g of raw material and stir to granulate. Pass through a 30-mesh sieve and dry at a low temperature of 25-55℃ for 1-2 hours to obtain individual brine granules. Adhere these brine granules to the inner cavity of the areca nut using gelatin or traditional brine. Seal the freeze-dried areca nuts individually in aluminum foil composite PE bags to obtain the finished wet areca nut product.

2. A novel process for making fresh betel quid as claimed in claim 1, wherein: In the third step, the shelf temperature in the fourth stage is selected to be 45℃~50℃, and the maximum temperature shall not exceed 55℃, in order to prevent arecoline volatilization and fiber scorching.