A single tin paper independent packaging self-baking plate date preparation method suitable for an oven and an air fryer

Abstract

This invention discloses a method for preparing individually packaged, self-baked jujubes in aluminum foil, suitable for ovens and air fryers, belonging to the field of deep-processed jujube food technology. Using jujubes from Jishan, Shanxi Province as raw material, the method involves sequential processes of material selection and grading, low-temperature pre-drying at 50–55℃, low-temperature ripening and aroma locking at 55–60℃, individual packaging in food-grade aluminum foil, and cooling and boxing at room temperature to obtain the finished product. A 1–2mm ventilation gap is left at the foil wrapping seal. This invention uses Jishan jujubes naturally containing 18 kinds of amino acids needed by the human body. The entire process involves segmented low-temperature processing to inhibit the Maillard reaction, resulting in a much higher retention rate of amino acids, flavonoids, and vitamins compared to commercially available high-temperature processed roasted jujubes. The high-temperature resistant aluminum foil can be directly used in household ovens and air fryers for baking, and the micro-gap balances moisture release, preventing scorching and juice splashing. The product is individually packaged, storage is stable, and consumption is convenient. Consumers can adjust the baking texture themselves, solving industry pain points such as high nutrient loss, poor heat resistance of packaging, and easy loss of flavor in traditional roasted jujubes, making it suitable for large-scale food processing production.

Description

Technical Field

[0001] This invention belongs to the field of deep-processed jujube food technology, specifically involving a process for preparing Jishan jujubes that can be individually packaged in tin foil and baked by the user and is compatible with household ovens and air fryers. Background Technology

[0002] Jishan jujubes are a national geographical indication specialty fruit, with thick, dense flesh that naturally contains all 18 essential amino acids, flavonoids, polyphenols, polysaccharides, and various trace elements, resulting in a balanced nutritional profile. Currently, commercially available deep-processed roasted jujube products suffer from several technological shortcomings: 1. High-temperature processing leads to nutrient loss: Traditional roasted dates are dehydrated at a one-time high temperature of 80-140℃, resulting in a violent Maillard reaction and a loss of 25%-40% of amino acids, as well as a large amount of vitamin C and flavonoids. Conventional low-temperature drying processes lack corresponding dehumidification and humidity control measures, making the humidity of the drying environment uncontrollable. This easily leads to a hard and dry surface on the date, uneven internal moisture, and the absence of a closed, airless, low-temperature ripening process, resulting in dry and tough flesh and a serious loss of natural date aroma.

[0003] 2. Packaging is not heat-resistant and inconvenient for baking: Most commercially available roasted dates are sealed in PE plastic composite bags, which cannot be directly placed in ovens or air fryers for heating; the dates lose moisture quickly during baking and are prone to burning, and the sugar will separate and stick to the baking tray and air fryer basket, making cleaning difficult.

[0004] 3. Storage and usage defects: The bulk packaging design means that once opened, the jujubes are exposed to oxygen and moisture, causing rapid oxidation. The remaining jujubes are also prone to moisture absorption and spoilage, resulting in high material loss.

[0005] 4. Fixed and unadjustable texture: Existing roasted dates are fully cooked ready-to-eat products produced in factories. Re-roasting will further aggravate nutrient loss, and the soft and crispy texture cannot be adjusted independently.

[0006] 5. Current technological gaps: There is currently no complete process for semi-finished roasted dates made from Jishan jujubes, including segmented low-temperature drying with dehumidification and humidity control, closed-loop low-temperature ripening without airflow, individual packaging with breathable micro-slit tin foil, and compatibility with household baking equipment.

[0007] 6. Ancient medical texts such as *Ben Cao Yan Yi* and *Ben Cao Gang Mu* record the ancient method of slowly drying dried dates over a gentle fire, known as "slow fire drying." The term "driing over a gentle fire" is explained in these texts as a method of slowly baking and drying dates over a gentle fire, which is precisely the traditional method of roasting dates. This provides a traditional theoretical reference for the low-temperature humidity control processing approach of this invention. Summary of the Invention

[0008] A method for preparing individually wrapped self-baking plate dates in tin foil, suitable for ovens and air fryers.

[0009] 3.1 Technical problem to be solved by the invention 3.1.1. This addresses the problems of traditional high-temperature roasting of dates, which leads to the decomposition and loss of heat-sensitive nutrients such as amino acids, flavonoids, and vitamins, and the lack of humidity control and dehumidification design in conventional low-temperature drying, resulting in uneven drying of dates and poor taste of the finished product. 3.1.2. To address the shortcomings of plastic packaging in heat resistance, such as easy scorching and juice splashing when baked without heat, which contaminates kitchen utensils; 3.1.3. Through dual regulation of drying and dehumidification and maturation with closed micro-wind circulation, the moisture content of the finished product is precisely controlled within the range of 17% to 23%, which simultaneously softens the pulp fiber, balances the internal moisture of the jujube, locks in the original aroma of the jujube, and inhibits non-enzymatic browning and amino acid oxidation. 3.1.4. Select small and medium-sized Jishan jujubes (6–13g) and grade them uniformly. Each jujube is heated evenly, and each jujube is individually packaged to delay the oxidation and decay of nutrients during storage and allow consumers to adjust the baking taste themselves. 3.1.5. Fill the industry's shortcomings in the current jujube processing industry, which lacks supporting processes for drying and humidity control, and ripening without air circulation, resulting in large nutrient loss, limited home baking scenarios, and poor adaptability to fruit shape and size.

[0010] 3.2 Technical Solution A method for preparing individually wrapped self-baking dates in aluminum foil, suitable for ovens and air fryers, includes the following steps: S1 Selection and Grading: Shanxi Jishan jujubes are selected as raw materials. The fruit is removed by hand with grading equipment. Insect-infested, damaged and moldy fruits are removed. The whole jujubes weighing 6-13g are selected. The surface dust and impurities are rinsed with clean water and spread on the ventilation rack to drain the surface free moisture at room temperature.

[0011] S2 Low-Temperature Pre-drying: Drained dates are laid flat in a single layer on a drying rack and dried with constant hot air at 50–55℃ for 18–24 hours. During this time, the dehumidification system is turned on to maintain the relative humidity of the drying environment at ≤45%. The moisture content of the dates is monitored in real time, and the average moisture content of the entire batch of dates is controlled to drop to 17%–23% before they can be discharged. This process adds a dehumidification and humidity control operation to the original low-temperature drying. The reference drying time is slightly adjusted according to the ambient humidity, while the core drying temperature and finished product moisture content remain unchanged.

[0012] S3 Low-Temperature Ripening and Aroma Locking: Pre-dried dates are transferred to a sealed constant-temperature ripening chamber while still warm and statically ripened at 55–60℃ for 4–8 hours. During this period, the dehumidification system is turned off, and only a small airflow is maintained in the ripening chamber to promote the softening of fruit pulp fibers, the even distribution of moisture inside the date, the enrichment of natural fruit aroma, the reduction of non-enzymatic browning reaction, and the inhibition of amino acid oxidative decomposition.

[0013] S4 Single-piece foil packaging: Each jujube is individually wrapped in food-grade high-temperature microwave-resistant foil, with a 1-2mm ventilation gap left at the seal; the gap allows moisture from baking to escape, preventing the foil from bulging and cracking, preserving the jujube aroma, and reducing nutrient loss during re-baking.

[0014] S5 Cooling and Packaging: After packaging, the product is naturally cooled to room temperature. Damaged products are manually sorted and removed. The outer packaging box is then sealed to obtain the semi-finished self-baking jujube product that can be directly heated in an oven or air fryer.

[0015] 3.3 Beneficial Effects 3.3.1. Raw material specifications are suitable for baking: 6-13g small and medium-sized Jishan geographical indication jujubes are selected. The fruit is small and uniform in size. After being wrapped in tin foil, each fruit is heated evenly, and there will be no difference in ripeness between large and small jujubes when baking. The raw materials are rich in 18 kinds of essential amino acids, iron, zinc, flavonoids and polyphenols, with excellent nutritional base.

[0016] 3.3.2. Low-temperature pre-drying with dehumidification and humidity control ensures uniform drying and lower nutrient loss: The entire process is carried out at a low temperature of 50–55℃, with simultaneous and continuous dehumidification to control the ambient humidity to ≤45%, avoiding localized dampness and sugar return in jujubes under high humidity conditions; the drying time can be flexibly adjusted according to the ambient humidity, and the moisture content of the entire batch of jujubes is uniformly and stably maintained at 17%–23%; the amino acid retention rate is over 90%, and the heat-sensitive nutrient loss is ≤15%, making it less prone to sugar return and mold growth during long-term storage.

[0017] 3.3.3. Sealed micro-wind circulation ripening, balancing moisture, locking in aroma and protecting nutrients: Pre-dried dates with residual heat are directly placed into a sealed ripening chamber, with the dehumidification closed and only a weak internal circulation air retained to prevent the aroma from being lost with the exhaust air; slowly softening the fruit pulp fibers, balancing the moisture inside and outside the date, greatly reducing non-enzymatic browning, and completely locking in the original date aroma. After re-roasting, the flesh is soft and tender and not dry, with a flavor superior to conventionally dried and roasted dates.

[0018] 3.3.4. Tin foil micro-slit sealing solves baking pain points: High-temperature resistant tin foil can be baked directly with the packaging on, without the need to open the bag or lay parchment paper; the breathable micro-slit balances moisture and aroma, preventing bag bursting, burning, and sugar syrup sticking to kitchen utensils.

[0019] 3.3.5. Double-layer protection reduces nutrient loss during reheating: Tin foil isolates dry hot air, creating a high-humidity microenvironment inside the oven during reheating, inhibiting browning reaction, and resulting in significantly lower nutrient loss during secondary heating compared to products baked without tin foil.

[0020] 3.3.6. Stable storage and convenient use: Tin foil isolates oxygen, moisture and light, and each piece can be taken out and used immediately. The rate of nutrient decay is only 1 / 3 of that of plastic bag packaging, and no additional preservatives are required; the standardized small fruit size of 6-13g makes it an appropriate amount for a single person to consume at one time.

[0021] 3.3.7. Flexible and adjustable cooking: The semi-finished product is designed to be baked in an air fryer at 160℃ for 5–8 minutes or in an oven at 150℃ for 8–12 minutes, allowing you to freely obtain two textures: soft and juicy or crispy and caramelized.

[0022] 3.3.8. Controllable process adapted to large-scale production: The drying and dehumidification and ripening micro-wind circulation parameters are standardized, and the 6-13g fruit size grading and screening process is simple. It can be connected to the existing jujube deep processing production line to enhance the added value of Jishan jujube deep processing. 4. Description of the attached figures Figure 1 This is a schematic diagram of a method for preparing self-baking dates that are individually packaged in tin foil and suitable for ovens and air fryers. Figure label: 1. Jishan jujube body; 2. Food-grade high-temperature resistant tin foil encapsulation shell; 3. 1~2mm standard breathable micro-slits; 4. Reinforced and press-sealed edges; 5. Fruit limiting and receiving groove. 5. Detailed Implementation

[0023] Example 1 (Optimal Example) S1 Selection and Grading: Select first-grade jujubes from Jishan, remove defective fruits, select whole jujubes weighing 10-13g each, rinse with clean water, and then air-dry. S2 Low-temperature pre-drying: hot air temperature 52℃, drying time 20h, dehumidification system is turned on throughout the process, relative humidity of the drying environment is stable at ≤45%, and the batch of dates is discharged after the average moisture content is tested to be 20%; S3 Low-temperature ripening and aroma locking: Pre-dried dates are transferred to a sealed ripening chamber while still warm and ripened at 58℃ with a gentle air circulation for 6 hours, after which the dehumidification system is turned off. S4 single foil encapsulation: a 1.5mm ventilation gap is left at the seal; S5 Cooling and Packaging: Cool at room temperature for 2 hours, sort out damaged packages, and then seal and pack them.

[0024] How to use: No need to remove the foil. Bake in an air fryer at 160℃ for 5–8 minutes or in an oven at 150℃ for 8–12 minutes. The flesh is soft, sweet and fragrant, and the amino acids in the dates are preserved intact.

[0025] Example 2 (Process Lower Limit Parameters) S1 Selection and Grading: Jishan jujubes, select whole fruits weighing 6-9g each, wash and drain; S2 Low-temperature pre-drying: 50℃ constant temperature hot air drying for 24 hours, continuous dehumidification to control the ambient humidity ≤45%, and control the average moisture content of the whole batch of dates to 17% before discharge; S3 Low-temperature aging and aroma locking: Achieve aging at 55℃ with a gentle breeze for 8 hours, then turn off the dehumidifier; S4 aluminum foil sealing with a 1mm micro-seam; S5 ambient temperature cooling sorting and packing.

[0026] S1 Selection and Grading: Jishan jujubes, select whole fruits weighing 9-13g each, wash and drain; S2 Low-temperature pre-drying: 55℃ constant temperature hot air drying for 18 hours, moisture removal and control ≤45%, batch average moisture content 23% before discharge; S3 Low-temperature aging and aroma locking: Achieve aging at 60℃ with a micro-wind circulation for 4 hours, then turn off the dehumidification system; S4 aluminum foil sealing with a 2mm micro-seam; The finished product is obtained by natural cooling, sorting, and packaging of S5.

Claims

1. A method for preparing single tin foil individually packed self-roasted plate dates suitable for use in an oven and an air fryer, characterized by, Includes the following steps: S1 Selection and Grading: Shanxi Jishan jujubes are selected as raw materials. The grading equipment is used to remove insect-infested, damaged and moldy fruits. The whole jujubes with a single fruit weight of 6-13g are selected. The surface dust and impurities are rinsed with clean water and spread on the ventilation rack to drain the surface free moisture at room temperature. S2 Low-temperature pre-drying: Drained dates are laid flat in a single layer on the drying rack and dried with hot air at a constant temperature of 50–55℃ for 18–24 hours. During this period, the dehumidification system is turned on to maintain the relative humidity of the drying environment at ≤45%. The moisture content of the dates is monitored in real time, and the average moisture content of the entire batch of dates is controlled to drop to 17%–23% before the date can be discharged. S3 Low-temperature ripening and aroma locking: Pre-dried dates are transferred to a sealed constant temperature ripening chamber while still warm and statically ripened at 55–60℃ for 4–8 hours; during this period, the dehumidification system is turned off and only a small airflow is maintained in the ripening chamber to promote the softening of fruit pulp fibers, the even distribution of moisture inside the date, the enrichment of natural fruit aroma, the reduction of non-enzymatic browning reaction, and the inhibition of amino acid oxidation and decomposition. S4 Single-piece foil packaging: Each jujube is individually wrapped in food-grade high-temperature microwave-resistant foil, with a 1-2mm ventilation gap left at the seal; the gap allows moisture from baking to escape, preventing the foil from bulging and cracking, preserving the jujube aroma, and reducing nutrient loss during re-baking. S5 Cooling and Packaging: After packaging, the product is naturally cooled to room temperature. Damaged products are manually sorted and removed. The outer packaging box is then sealed to obtain the semi-finished self-baking jujube product that can be directly heated in an oven or air fryer.

2. The method for preparing individually packaged self-baking plate dates using tin foil, suitable for ovens and air fryers, as described in claim 1, is characterized in that... In step S1, select Jishan jujubes with a single fruit weight of 10–13g.

3. The method for preparing individually packaged self-baking tray dates using tin foil, suitable for ovens and air fryers, as described in claim 1, is characterized in that... Step S2: The hot air drying temperature is 52℃, the drying time is 20 hours, the relative humidity of the drying environment is ≤45%, and the average moisture content of the whole batch of dates is controlled at 20% before discharge.

4. The method for preparing individually packaged self-baking tray dates using tin foil, suitable for ovens and air fryers, as described in claim 1, is characterized in that... Step S3: Low-temperature curing temperature 58℃, curing time 6 hours, curing chamber closed for dehumidification, only maintaining internal micro-wind circulation.

5. The method for preparing individually packaged self-baking plate dates using tin foil, suitable for ovens and air fryers, as described in claim 1, is characterized in that... In step S4, the width of the breathable micro-slit is 1.5mm.

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