A production method of zongzi and a packaging can of zongzi

Abstract

The application discloses a production method of zongzi, and steps include: step S1, preparing zongzi leaf extract; step S2, obtaining zongmi by fully soaking clean glutinous rice in zongzi leaf extract; step S3, preparing a can body which is in shape matching with zongzi and is made of metal material, filling the prepared zongmi into the can body, sealing the can body by using an aluminum foil sealing film, and preparing a packaging can which contains zongmi; and step S4, cooking and sterilizing the prepared packaging can at high temperature, and obtaining a packaging can which contains steamed zongzi. The application also discloses a packaging can of zongzi. The application has the beneficial effect of extending the shelf life at room temperature, simplifying the production process and facilitating consumption by means of the canning method without wrapping zongzi leaves.

Description

Technical Field

[0001] This invention relates to a method for producing zongzi (sticky rice dumplings) and a packaging can for zongzi, belonging to the technical field of food processing and production as well as food storage containers. Background Technology

[0002] Traditional zongzi (sticky rice dumplings) production relies primarily on hand-wrapping glutinous rice in fresh bamboo leaves. However, bamboo leaves themselves have poor oxygen barrier properties, making the finished product highly susceptible to mold and spoilage upon contact with airborne oxygen. Its shelf life at room temperature is extremely short, typically only a few days, severely restricting its distribution and sales. To extend shelf life, an improved solution has emerged: placing the traditionally leaf-wrapped zongzi in an additional layer of aluminum foil, which offers better oxygen barrier properties. While this method improves oxygen barrier properties and extends shelf life at room temperature to some extent through the isolation provided by the aluminum foil, it also significantly increases packaging material costs and the complexity of the production process. It requires adding bagging and sealing operations after the original wrapping steps, hindering production efficiency and cost control. Furthermore, it doesn't address the inconvenience of manually removing the bamboo leaves inside. Summary of the Invention

[0003] The purpose of this invention is to provide a method for producing zongzi (sticky rice dumplings) and a packaging can for zongzi, so as to simultaneously achieve the effects of extending the shelf life at room temperature, simplifying the production process, and making it convenient to eat by using a canning method that eliminates the need for wrapping zongzi leaves.

[0004] The present invention is achieved through the following technical solution.

[0005] A method for producing zongzi (sticky rice dumplings), comprising the following steps:

[0006] Step S1: Prepare the extract from the leaves of the zongzi plant;

[0007] Step S2: Soak the clean glutinous rice thoroughly in the extract of bamboo leaves to obtain zongzi rice;

[0008] Step S3: Prepare a can that matches the shape of the zongzi, fill the prepared zongzi rice into the can, and seal the can with aluminum foil sealing film to obtain a packaging can containing zongzi rice.

[0009] Step S4: Sterilize the prepared packaging cans by steaming at high temperature to obtain packaging cans containing steamed rice dumplings.

[0010] As a further improvement of the present invention, step S1: chop or crush the clean bamboo leaves, soak or steam them in hot water, and obtain bamboo leaf extract after filtration.

[0011] As a further improvement of the present invention, step S3: the sealing film seals the can body through a hot pressing process.

[0012] A packaging jar for containing steamed zongzi (sticky rice dumplings) includes a jar body with a mouth and a sealing film made of aluminum foil, the shape of the jar body matching the shape of the steamed zongzi inside.

[0013] As a further improvement of the present invention, the tank is made of metal.

[0014] As a further improvement of the present invention, the can body has a can edge extending outward from the edge of the can opening, and a rolled edge extending further outward from the outer edge of the can edge and formed by curling, the sealing film is attached to the can edge, and the overall height of the rolled edge is higher than the height of the can edge, which is suitable for the rolled edge to form a horizontal spatial isolation between the edge of the sealing film and the edge of the can.

[0015] As a further improvement of the present invention, the can edge includes a main support portion extending horizontally outward from the edge of the can opening, and a transition portion extending outward from the outer side of the main support portion and gradually rising, wherein the rolled edge is formed by extending outward from the outer side of the transition portion and being rolled.

[0016] As a further improvement of the present invention, the portion of the sealing film attached to the rolled edge includes a main body portion attached to the main support portion and an edge portion attached to the transition portion and raised relative to the main body portion, and is adapted such that the transition portion is configured such that when the rolled edge is pressed down by an external force, the transition portion undergoes a corresponding deformation and the adhesion between the transition portion and the edge portion is compromised or weakened.

[0017] As a further improvement of the present invention, the rolled edges are curled and partially overlapped, and the overlapping portions of the rolled edges are configured to form a thickened portion connecting the transition portion, and to concentrate stress on the transition portion when the rolled edges are pressed down by an external force.

[0018] As a further improvement of the present invention, the sealing film is integrally connected to an ear extending relative to the edge, which is suitable for being pulled to detach the sealing film from the can body. Furthermore, the portion where the ear and the edge of the sealing film are connected is bent to form a folded portion, so that the ear is attached to the surface of the sealing film, and the rolled edge forms a horizontal spatial isolation between the folded portion and the rolled edge.

[0019] The beneficial effects of this invention are:

[0020] Firstly, regarding shelf life, the sealing system consisting of the metal can and aluminum foil sealing film provides oxygen barrier properties, blocking the main environmental factors that cause zongzi to spoil, thus extending its shelf life at room temperature. Secondly, in terms of production process, this method completely eliminates the complicated manual wrapping of zongzi leaves, instead using a method of extracting flavor liquid from the zongzi leaves to soak the glutinous rice and then directly canning it, significantly reducing the difficulty of operation and technical threshold, laying the foundation for continuous and automated production, effectively improving efficiency and reducing labor costs. For consumers, there is no need to tediously peel off the sticky zongzi leaves when eating; simply tear open the sealing film to eat, greatly improving convenience and hygiene, making it particularly suitable for outings, travel, and other scenarios. Attached Figure Description

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein:

[0022] Figure 1 This is a flowchart illustrating the production method of Implementation Method 1;

[0023] Figure 2 This is a schematic diagram of the packaging can according to embodiment 2;

[0024] Figure 3 This is a partial cross-sectional view of the packaging can according to Embodiment 2;

[0025] Figure 4 This is a schematic diagram of the packaging can according to embodiment 3;

[0026] Figure 5 This is a partial cross-sectional view of the lugs corresponding to the packaging can in Embodiment 3. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0028] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0029] Implementation method 1:

[0030] This embodiment illustrates a method for producing zongzi (sticky rice dumplings), referring to... Figure 1 The method includes four main steps:

[0031] Step S1: Prepare the extract from the leaves of the zongzi plant;

[0032] Step S2: Soak the clean glutinous rice thoroughly in the extract of bamboo leaves, allowing the glutinous rice to absorb the aroma and nutrients of the bamboo leaves, thus obtaining zongzi rice;

[0033] Step S3: Prepare a metal can that matches the shape of a zongzi (sticky rice dumpling). Fill the can with the prepared rice and seal it with aluminum foil sealing film to obtain a packaging can containing rice.

[0034] Step S4: The prepared packaging cans are sterilized by steaming at high temperature, so that the rice dumplings are cooked inside the cans, and finally the packaging cans containing the cooked rice dumplings are obtained.

[0035] In step S1, the preparation of the zongzi leaf extract can be further refined. For example, fresh or dried zongzi leaves can be selected, washed, and then chopped or crushed to increase the surface area available for soaking. They can then be soaked in hot water or steamed for a certain time. Finally, the solid residue is removed by filtration to obtain a clear extract, which helps to maximize the extraction of effective components from the zongzi leaves. In step S2, the soaking time is controlled between 2-6 hours to ensure that the glutinous rice absorbs the flavor evenly. After soaking, the rice needs to be drained to avoid excessive moisture affecting subsequent filling. Furthermore, after soaking, appropriate seasonings such as salt, baking soda, sugar, and soy sauce are added to the glutinous rice according to the different flavors of zongzi. In step S3, the can construction needs to consider the shape of the zongzi, such as a three-dimensional triangle, rectangle, or other traditional zongzi shape. During filling, automated equipment can be used to accurately fill the can with the rice, maintaining appropriate tightness. The sealing film uses aluminum foil to ensure a completely sealed can opening, preventing outside air from entering. In addition, different fillings such as meat filling, egg yolk, and red bean paste need to be added when filling the glutinous rice according to the different flavors of zongzi. The steaming and sterilization process in step S4 is usually carried out under high pressure and high temperature, with the temperature controlled between 100℃ and 125℃, and the time is about 10 to 30 minutes. This not only cooks the rice, but also kills microorganisms and extends the shelf life.

[0036] In this embodiment, the steamed rice dumplings are sealed by a metal container and an aluminum foil sealing film. This combination provides excellent oxygen barrier properties, effectively preventing oxygen penetration and inhibiting microbial growth and oxidation. Compared to traditional bamboo leaf packaging, which only allows for short-term storage, this significantly extends the shelf life of the rice dumplings at room temperature. The entire production process eliminates the need for wrapping the rice dumplings with bamboo leaves, avoiding the complex steps of traditional hand-wrapping, such as folding bamboo leaves and tying with rope. This greatly reduces the difficulty of the process, making it more suitable for large-scale industrial production and improving efficiency and consistency. Users can eat the rice dumplings directly by simply tearing open the sealing film without removing the bamboo leaves. This is not only simple and quick but also avoids the hassle of washing hands with bamboo leaves sticking to them. It is especially suitable for users to eat while traveling or in the office, improving convenience and hygiene. In addition, this method preserves the traditional flavor of the rice dumplings because the bamboo leaf extract imparts a fragrance similar to bamboo leaves to the glutinous rice during the soaking process, allowing the product to simplify packaging without sacrificing taste.

[0037] In this embodiment, considering the need to improve the efficiency and quality of the bamboo leaf extract, step S1 is further refined to involve chopping or pulverizing clean bamboo leaves, soaking or steaming them in hot water, and then filtering to obtain the bamboo leaf extract. Specifically, after washing, the bamboo leaves can be mechanically chopped or pulverized into fine particles, which increases the contact area between the leaves and the hot water, thereby accelerating the dissolution of flavor substances and nutrients. The temperature of the hot water can be controlled between 60°C and 100°C, and the soaking time can be controlled between 0.5 and 3 hours, or steaming can be used to treat the leaves at boiling point for 10 to 30 minutes to fully extract the volatile aroma and antioxidant components from the bamboo leaves. The filtration step can use a sieve or filter cloth to remove solid residues and obtain a clear extract, avoiding impurities from affecting the subsequent soaking process. The method for preparing the extract of zongzi leaves in this embodiment not only improves extraction efficiency and shortens production time, but also ensures that the extract has a rich and consistent flavor. This helps the glutinous rice to absorb the essence of the zongzi leaves more evenly in step S2, thereby improving the taste and quality of the final zongzi. Since the extraction process is controllable, it also reduces the waste of zongzi leaves and lowers the cost of raw materials.

[0038] In this embodiment, to further improve sealing performance and ease of operation, the sealing film in step S3 is sealed to the can using a hot-pressing process. The hot-pressing process involves placing an aluminum foil sealing film on the can opening, then applying a certain temperature and pressure using a heating element to fuse the sealing film with the edge of the can opening, forming an airtight seal. Specific parameters include a temperature set between 150°C and 200°C, a pressure of 0.2 MPa to 0.5 MPa, and a duration of several seconds to ensure the sealing film adheres firmly and prevents any leakage. The advantages of this process are reliable sealing, effective blocking of oxygen, moisture, and microorganisms, and extended product shelf life. Simultaneously, hot-pressing is simple to operate, easily integrated into automated production lines, improving production efficiency, reducing manual intervention, and lowering packaging costs. Compared to traditional manual sealing or other sealing methods, the hot-pressing process also ensures a smooth and aesthetically pleasing seal, improving the product's appearance.

[0039] Implementation Method 2:

[0040] This embodiment illustrates a packaging can for zongzi (sticky rice dumplings), see reference. Figures 2-3 This packaging can, used to hold steamed zongzi (sticky rice dumplings), comprises a metal can 1 with a mouth and an aluminum foil sealing film 2. The shape of the can 1 matches the shape of the steamed zongzi inside. The shape of the can 1 is designed to resemble traditional zongzi, such as a cone, cylinder, or polyhedron, to ensure the zongzi are tightly packed inside, reducing gaps and preventing movement during transportation. The sealing film 2, made of aluminum foil, is thin, flexible, easy to tear, and provides excellent sealing performance. This packaging design not only enhances the product's oxygen barrier properties, allowing the zongzi to be stored at room temperature for a long time, but also makes it convenient for users to eat directly without additional tools. Due to the matching shape, the zongzi are heated evenly during steaming, ensuring consistent taste and avoiding the problem of some parts being overcooked or undercooked that may occur with traditional packaging.

[0041] In this embodiment, in order to further improve the durability and corrosion resistance of the tank 1, the tank 1 is made of metal.

[0042] In this embodiment, the can body 1 has a can edge 11 extending outward from the edge of the can opening. The can edge 11 is typically an annular strip structure that surrounds the can opening. The outer edge of the can edge 11 is rolled to form a rolled edge 12, making the rolled edge 12 a continuous and uniform annular protrusion. The sealing film 2 is attached to the can edge 11 during assembly and is sealed by heat sealing. In addition, the overall height of the rolled edge 12 is higher than the height of the can edge 11. The height difference can be limited by designing the rolling radius of the rolled edge 12. The rolled edge 12 protrudes upward and outward. Since the rolled edge 12 protrudes from the can edge 11 in horizontal space, it forms a horizontal spatial isolation for the edge of the sealing film 2, which can surround or semi-close the edge part of the sealing film 2, thereby physically isolating it from the external environment. Since the sealing film 2 is a rigid film made of aluminum foil, its edges may be relatively sharp, easily causing users to cut their fingers when handling the packaging can. The height difference between the rolled edge 12 and the can edge 11 hides or protects the edge of the sealing film 2, reducing the risk of direct contact. This not only improves the safety of the can 1 but also extends the service life of the sealing film 2. Furthermore, this horizontal spatial isolation effect can also prevent dust, moisture, or contaminants from penetrating the edge of the sealing film 2 to a certain extent, further ensuring food hygiene.

[0043] In this embodiment, the can edge 11 includes a main support portion 111 extending horizontally outward from the edge of the can opening, and a transition portion 112 extending outward from the outer edge of the main support portion 111 and gradually rising. The rolled edge 12 is formed by rolling the outer edge of the transition portion 112. The main support portion 111 is typically a flat annular platform, used to provide a stable base for attaching the sealing film 2. The transition portion 112 connects the main support portion 111 and the rolled edge 12, and its shape gradually rises or slopes outward from the inner edge to the outer edge. This transition structure avoids sharp angles, and the rolled edge 12 starts rolling from the outer edge of the transition portion 112, forming a continuous structure. By providing the transition portion 112, the connection between the can edge 11 and the rolled edge 12 is no longer a straight abrupt change, but rather a gradual transition area, which significantly improves the overall structural strength. When the tank 1 is subjected to external pressure (such as during logistics transportation or food filling), the transition section 112 can disperse the stress and reduce stress concentration in the main support section 111 and the root section, thereby preventing metal fatigue or cracking. More specifically, the transition section 112 has an arc-shaped transition from its inner side to its outer side, giving it better mechanical properties.

[0044] In this embodiment, to facilitate user opening of the sealing film 2 and improve safety, the portion of the sealing film 2 attached to the can edge 11 includes a main body attached to the main support portion 111 and an edge portion attached to the transition portion 112 and raised relative to the main body. The main body is flatly attached to the main support portion 111 and fixed by adhesive or heat sealing, providing the main sealing function. The edge portion naturally rises due to the raised shape of the transition portion 112, forming a certain angle with the main body. The angle depends on the slope of the transition portion 112, typically between 5 and 20 degrees. Based on the edge portion attached to the transition portion 112, the transition portion 112 is configured such that when the rolled edge 12 is subjected to manual downward pressure, the transition portion 112 undergoes corresponding elastic or plastic deformation, causing the adhesion between the edge portion and the transition portion 112 to be compromised or weakened. For example, downward pressure can cause the transition portion 112 to bend inward, weakening the adhesive force of the adhesive. More specifically, when using the packaging can, the user can first press down on the rolled edge 12 with their finger, using leverage to deform the transition portion 112. Because the edge itself is raised, its adhesion area with the transition portion 112 is small or the adhesion force is weak. When the transition portion 112 deforms, gaps or peeling are easily formed at the adhesion interface, causing the edge to loosen. Then, the user can easily pry open the edge with their fingernail and tear off the entire sealing film 2. This mechanism solves the problem of the sealing film 2 being difficult to tear. In particular, in this embodiment, the edge of the sealing film 2 is horizontally isolated by the rolled edge 12, making it not only difficult to tear but also harder to handle compared to traditional sealing films 2. For hard films, the user does not need to directly contact the sharp edges, reducing the risk of scratches. For soft films, the raised edge avoids adhesion caused by complete adhesion, making the tearing process smoother. Furthermore, the deformation of the transition portion 112 under the pressure of the rolled edge 12 ensures ease of operation and does not affect the sealing of the can body 1, as the main body remains firmly attached, thus improving the user experience and making the packaging can easier to open.

[0045] In this embodiment, to more effectively disrupt adhesion and optimize force transmission, the rolled edges 12 are rolled and locally overlapped. The overlapping portions of the rolled edges 12 are configured such that a thickened portion 121 connecting the transition portion 112 is formed on the rolled edges 12, and stress is concentrated on the transition portion 112 when the rolled edges 12 are subjected to external pressure. During the rolling process of the rolled edges 12, by controlling the degree of rolling, a layered structure can be formed in a specific area. By rolling a portion of the rolled edges 12 inward and overlapping it with another portion to form the thickened portion 121, the rigidity of that portion is increased. In contrast, since the transition portion 112 is thinner than the thickened portion 121, when the user presses down on the rolled edges 12, the thickened portion 121 directs pressure to the transition portion 112, causing stress concentration on the transition portion 112 and making it easier for the transition portion 112 to bend or deform. This stress concentration effect amplifies the damage to the adhesion of the edge, making the sealing film 2 easier to tear. This setting is similar to the lever principle, using the thickened part 121 as a fulcrum to optimize force efficiency. This not only reduces the downward pressure required by the user, but also makes the tearing process smoother, making it especially suitable for the elderly or children.

[0046] Implementation Method 3:

[0047] This embodiment illustrates a packaging can for zongzi (sticky rice dumplings), see reference. Figures 4-5 and combined Figures 2-3 In this embodiment of the packaging can, based on the packaging can provided in embodiment 2, the sealing film 2 has an integrally connected lug 3 extending from its edge. This lug 3 is adapted to be pulled to detach the sealing film 2 from the can body 1. The lug 3 can be an extension of the sealing film 2 material, formed by cutting or molding, and its size and shape are suitable for user gripping, such as rectangular or tongue-shaped. Furthermore, the portion where the lug 3 connects to the edge of the sealing film 2 is bent to form a folded portion 31, so that the lug 3 is attached to the surface of the sealing film 2. The folded portion 31 is achieved by bending or folding, so that the lug 3 is flat against the sealing film 2, reducing space occupation and avoiding snagging during transportation. The lug 3 provides another opening method: the user can directly pull the lug 3 to tear off the sealing film 2 as a whole, which is suitable for scenarios where the can opening needs to be completely opened.

[0048] In addition, since the overall height of the rolled edge 12 is higher than the height of the can edge 11, the folded portion 31 of the lug 3 is also covered by the rolled edge 12, reducing the risk of being scratched or damaged during handling or use.

[0049] It should be noted that the packaging can provided in this embodiment offers a more convenient operation: the user can first press down on the rolled edge 12 with their fingers, using leverage to deform the transition portion 112. Because the edge itself is raised, gaps or peeling are easily created at the adhesion interface, thus loosening the edge. Then, by pulling the lug 3, the loosened edge detaches, causing the entire sealing film 2 to peel off. This makes the opening process more controllable and effortless, reducing the force required by the user, making it particularly suitable for the elderly or children. This avoids the problems associated with traditional sealing films 2 and lugs 3: if the sealing film 2 is adhered too firmly, or if the user pulls the lug 3 too forcefully, pulling the lug 3 may only tear a small opening in the sealing film 2, rather than completely detaching the entire sealing film 2.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing zongzi (sticky rice dumplings), characterized by the following steps: include: Step S1: Prepare the extract from the leaves of the zongzi plant; Step S2: Soak the clean glutinous rice thoroughly in the extract of bamboo leaves to obtain zongzi rice; Step S3: Prepare a can that matches the shape of the zongzi, fill the prepared zongzi rice into the can, and seal the can with aluminum foil sealing film to obtain a packaging can containing zongzi rice. Step S4: Sterilize the prepared packaging cans by steaming at high temperature to obtain packaging cans containing steamed rice dumplings.

2. The method for producing zongzi according to claim 1, characterized in that, Step S1: Chop or crush the clean bamboo leaves, soak or steam them in hot water, and filter to obtain bamboo leaf extract.

3. The method for producing zongzi according to claim 1, characterized in that, Step S3: The sealing film seals the can body using a hot-pressing process.

4. A packaging can for zongzi (sticky rice dumplings), characterized in that, The packaging can, used in the production method according to any one of claims 1-3, is for containing steamed zongzi (sticky rice dumplings), and includes a can body with a mouth and a sealing film made of aluminum foil, wherein the shape of the can body matches the shape of the steamed zongzi contained inside.

5. The packaging can according to claim 5, characterized in that, The tank is made of metal.

6. The packaging can according to claim 5, characterized in that, The can has a can edge extending outward from the edge of the can opening, and a rolled edge extending further outward from the outer edge of the can edge and formed by curling. The sealing film is attached to the can edge, and the overall height of the rolled edge is higher than the height of the can edge, which is suitable for the rolled edge to form a horizontal spatial isolation between the edge of the sealing film and the edge of the can.

7. The packaging can according to claim 6, characterized in that, The can edge includes a main support portion that extends horizontally outward from the edge of the can opening, and a transition portion that continues to extend outward from the outer side of the main support portion and gradually rises. The rolled edge is formed by continuing to extend from the outer side of the transition portion and being rolled.

8. The packaging can according to claim 7, characterized in that, The portion of the sealing film attached to the rolled edge includes a main body portion attached to the main support portion and an edge portion attached to the transition portion and raised relative to the main body portion. It is adapted such that the transition portion is configured such that when the rolled edge is pressed down by an external force, the transition portion undergoes a corresponding deformation and the adhesion between the transition portion and the edge portion is compromised or weakened.

9. The packaging can according to claim 8, characterized in that, The rolled edges are curled and partially overlapped, and the overlapping portions of the rolled edges are configured to form a thickened portion connecting the transition portion, and to concentrate stress on the transition portion when the rolled edges are pressed down by an external force.

10. The packaging can according to claim 8 or 9, characterized in that, The sealing film has an integrally connected lug extending from its edge, which is adapted to be pulled to detach the sealing film from the can body. Furthermore, the portion where the lug connects to the edge of the sealing film is bent to form a folded portion, so that the lug is attached to the surface of the sealing film, and the rolled edge forms a horizontal spatial isolation between the folded portion and the folded portion.

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