Description:FIELD OF THE INVENTION

[0001] The present invention relates to a sustainable food packaging material composition and synthesis method thereof for manufacturing an environmentally responsible material intended for food packaging, by combining plant-based resources to provide a durable, safe, and eco-friendly alternative to conventional packaging.

BACKGROUND OF THE INVENTION

[0002] The global food industry faces significant challenges in preserving and transporting fresh produce, which often leads to high levels of food waste due to spoilage. There has been a growing demand for sustainable and eco-friendly packaging materials, especially in the food industry. Traditional packaging often relies on non-biodegradable plastics, which contribute significantly to environmental pollution and waste accumulation. Sustainable alternatives made from natural fibers and biodegradable components are increasingly sought to reduce the ecological impact. Such materials aim to provide adequate protection and durability while being environmentally safe and easily decomposable. The challenge lies in developing packaging compositions that combine strength, flexibility, and water resistance, all while using renewable and readily available resources.

[0003] Traditionally, food packaging materials have been made using synthetic polymers derived from petrochemicals. While these materials offer good mechanical properties and water resistance, they pose serious environmental hazards due to their non-biodegradable nature. Additionally, attempts have been made to produce biodegradable packaging using single natural fibers or starch-based materials. However, these materials often suffer from poor mechanical strength, low durability, and limited resistance to moisture, which restrict their practical use in food packaging applications. Some existing natural fiber-based packaging materials involve complex processing steps or use chemical additives that may not be food-safe or environmentally friendly. Moreover, controlling the uniformity and quality of such materials can be challenging, leading to inconsistent packaging properties.

[0004] WO2017163095A1 discloses a completely biodegradable disposable food containers or boxes made from natural fibers or fibrous materials, where the natural fibers include, but are not limited to: jute, coir, banana, and/or bagasse that have considerably different properties and structure than cardboard. The fibers can be used alone or in combination with other fibers or polymers, and can be combined with a binder and/or filler to form a composite for making any shape, size or configuration biofiber food container. The biodegradable containers made are not restricted to food applications, but could also be used for packaging commodity products such as electronics, textiles, metallic products etc. Although WO’095 discloses the use of natural fibers for packaging, it lacks detailed disclosure regarding the processing methods that ensure uniform structural integrity, food-grade safety, and improved moisture resistance suitable for fresh produce packaging.

[0005] US20220017277A1 discloses a biodegradable packaging for food having a container body made from a sheet that closes on itself, creating an inner compartment and an opening in the manner of a bag, the sheet being made from natural plant fibre mesh, lined and coated with starch, from the group including cotton, linen, hemp and jute, or combinations thereof, and more preferably of jute, the mesh having orifices or holes of a size between 2 mm and 15 mm, and more preferably between 5 mm and 15 mm. The mesh may be dyed or coloured and may include various additional components: textile strap to include legends, trademarks or indications on the product contained therein, reinforcement bands on its sides, handle, etc. The invention also relates to the method for obtaining the packaging, which includes a starch impregnation step to reinforce the resistance of the mesh and additionally a dyeing phase. Although US’277 discloses the fabrication of biodegradable mesh packaging using plant fibers. However, the cited art lacks in providing a packaging material having balanced mechanical strength and moisture resistance without compromising biodegradability and food safety.

[0006] Conventionally, many compositions have been developed for producing biodegradable food packaging using natural fibers or starch-based materials. However, the cited arts have certain limitations pertaining processing of raw materials, structural uniformity, and compatibility with food-grade requirements. Many of the known compositions either rely heavily on agricultural by-products with inconsistent fiber quality or require the addition of synthetic reinforcements to achieve the necessary strength and water resistance.

[0007] In order to overcome the aforementioned drawbacks, there exists a need in the art to develop a composition that requires to be capable of utilizing renewable, locally available plant-based fibers through a simple, eco-friendly process for achieving sufficient mechanical strength, flexibility, and moisture resistance suitable for food packaging applications.

OBJECTS OF THE INVENTION

[0008] The principal object of the present invention is to overcome the disadvantages of the prior art.

[0009] An object of the present invention is to develop a composition that is capable of providing effective protection for fresh produce while minimizing environmental impact.

[0010] Another object of the present invention is to develop a composition that is capable of naturally controlling moisture levels to reduce spoilage caused by excess humidity.

[0011] Another object of the present invention is to develop a composition that is capable of exhibiting antimicrobial properties to inhibit bacterial and fungal growth, thereby extending the shelf life of produce.

[0012] Another object of the present invention is to develop a composition that is capable of being biodegradable and environmentally friendly, ensuring safe disposal without harming the ecosystem.

[0013] Another object of the present invention is to develop a composition that is capable of being customized in thickness and permeability to meet the specific packaging needs of different types of produce.

[0014] Yet another object of the present invention is a composition that is capable of being produced using natural and readily available raw materials through a cost-effective manufacturing process suitable for large-scale production.

[0015] The foregoing and other objects, features, and advantages of the present invention will become readily apparent upon further review of the following detailed description of the preferred embodiment as illustrated in the accompanying drawings.

SUMMARY OF THE INVENTION

[0016] The present invention relates to a sustainable food packaging material composition and synthesis method thereof for providing a sustainable packaging made through a controlled preparation approach for offering a practical substitute to traditional packaging while promoting environmental conservation and reducing long-term ecological impact.

[0017] According to an embodiment of the present invention, a sustainable food packaging material composition comprising: i) water chestnut peel fiber, ii) lotus stem fiber, iii) plasticizer, iv) crosslinking agent, v) binding agent, vi) water, the plasticizer is preferably glycerol, the crosslinking agent is citric acid, the binding agent is corn starch.

[0018] According to another embodiment of the present invention, a method for synthesis of the sustainable food packaging material composition comprises of the steps: a) chopping the water chestnut peel into small pieces, b) cutting the lotus stem into small sections and drying thoroughly, followed by grinding into a coarse powder to extract fibers, c) boiling water chestnut peel pieces in water at 60-90°C for 2–3 hours and adding Sodium Hydroxide (NaOH) to break down the peel and extract the fibers, d) filtering the water chestnut peel fibers using fine mesh, and washing the extracted fibers with clean water to remove alkali residues, followed by drying to obtain the water chestnut peel fibers, e) boiling the lotus stem pieces in water at 70-80oC for 1-3 hours, followed by filtering the lotus stem fibers using fine mesh and drying to obtain the lotus stem fiber, f) separately soaking the dried fibers in a solution containing plasticizer in water and crosslinking agent for 20-40 minutes, followed by draining the fibers dry again for 1–2 hours to remove excess plasticizer, g) blending the water chestnut fiber and lotus stem fiber to obtain a fiber blend, h) dissolving binding agent in distilled water, followed by heating at 80–90°C for 15–20 minutes to obtain a starch paste, i) mixing the starch paste with the fiber blend to obtain a homogenous mixture and placing the mixture into molds according to the desired shape and thickness of the packaging material, followed by allowing the molded material to dry in order to obtain the sustainable food packaging material composition, the fibers are dried at 60°C for 4–5 hours, or air-dried for 2–3 days, until the moisture content is reduced to about 10-12%, the molding is carried out either at at room temperature or using a hydraulic press for uniformity, the molding is preferably carried out using a hydraulic press by applying moderate pressure for 30 minutes, the packaging material is also treated with acetone (100mL) to wash away any residues and enhance the material's strength for additional durability or resistance to water.

[0019] While the invention has been described and shown with particular reference to the preferred embodiment, it will be apparent that variations might be possible that would fall within the scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The following description includes the preferred best mode of one embodiment of the present invention. It will be clear from this description of the invention that the invention is not limited to these illustrated embodiments but that the invention also includes a variety of modifications and embodiments thereto. Therefore, the present description should be seen as illustrative and not limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.

[0021] In any embodiment described herein, the open-ended terms "comprising," "comprises,” and the like (which are synonymous with "including," "having” and "characterized by") may be replaced by the respective partially closed phrases "consisting essentially of," consists essentially of," and the like or the respective closed phrases "consisting of," "consists of, the like.

[0022] As used herein, the singular forms “a,” “an,” and “the” designate both the singular and the plural, unless expressly stated to designate the singular only.

[0023] The present invention relates to a sustainable food packaging material composition and synthesis method thereof using a blend of natural ingredients for replacing synthetic food packaging, thus offering an effective solution that aligns with eco-conscious practices, ensures product safety, and supports global efforts in reducing plastic waste.

[0024] According to an embodiment of the present invention, a sustainable food packaging material composition comprising: i) water chestnut peel fiber, ii) lotus stem fiber, iii) plasticizer, iv) crosslinking agent, v) binding agent, and vi) water.

[0025] The plasticizer is preferably glycerol, the crosslinking agent is citric acid, the binding agent is corn starch.

[0026] According to another embodiment of the present invention, a method for synthesis of the sustainable food packaging material composition comprises of the steps: a) chopping the water chestnut peel into small pieces, b) cutting the lotus stem into small sections and drying thoroughly, followed by grinding into a coarse powder to extract fibers, c) boiling water chestnut peel pieces in water at 60-90°C for 2–3 hours and adding Sodium Hydroxide (NaOH) to break down the peel and extract the fibers, d) filtering the water chestnut peel fibers using fine mesh, and washing the extracted fibers with clean water to remove alkali residues, followed by drying to obtain the water chestnut peel fibers, e) boiling the lotus stem pieces in water at 70-80oC for 1-3 hours, followed by filtering the lotus stem fibers using fine mesh and drying to obtain the lotus stem fiber, f) separately soaking the dried fibers in a solution containing plasticizer in water and crosslinking agent for 20-40 minutes, followed by draining the fibers dry again for 1–2 hours to remove excess plasticizer, g) blending the water chestnut fiber and lotus stem fiber to obtain a fiber blend, h) dissolving binding agent in distilled water, followed by heating at 80–90°C for 15–20 minutes to obtain a starch paste, i) mixing the starch paste with the fiber blend to obtain a homogenous mixture and placing the mixture into molds according to the desired shape and thickness of the packaging material, followed by allowing the molded material to dry in order to obtain the sustainable food packaging material composition.

[0027] The fibers are dried at 60°C for 4–5 hours, or air-dried for 2–3 days, until the moisture content is reduced to about 10-12%.

[0028] The molding is carried out either at at room temperature or using a hydraulic press for uniformity. The molding is preferably carried out using a hydraulic press by applying moderate pressure for 30 minutes.

[0029] For additional durability or resistance to water, the packaging material could be treated with acetone (100mL) to wash away any residues and enhance the material's strength.

EXAMPLE

[0030] The sustainable food packaging material composition is composed of: i) 100g of Water Chestnut Peel (chopped), ii) 100g of Lotus Stem Fiber (dried and ground), iii) 10g of Glycerol as plasticizer, iv) 2g of Citric Acid as crosslinking agent, v) 15g of corn starch (binding agent), and vi) 1L water for boiling and soaking.

[0031] The packaging material composition is made from water chestnut peel and lotus stem fibre offers a sustainable, biodegradable alternative to traditional plastic packaging. The manufacturing of the packaging material composition involves several steps described below.

Preparation of Raw Materials

[0032] The peel of the water chestnut is collected and processed to extract its valuable bioactive compounds, including antioxidants, polyphenols, and flavonoids. These compounds naturally inhibit microbial growth and reduce oxidation, which are primary factors in food spoilage.

[0033] The lotus stem is harvested to extract its robust, cellulose-rich fibres. These fibres undergo cleaning and processing into various forms such as sheets, films, or woven structures, which is moulded into different packaging formats like wraps, bags, or boxes. The lotus stem fibres also possess moisture-absorbing and antimicrobial properties, helping to control humidity and prevent excess moisture build-up that leads to spoilage.

[0034] Water Chestnut Peel and Lotus Stem Fiber need to be cleaned and prepared for extraction of fibers. Chop water chestnut peel into small pieces (around 2–3 cm). The lotus stems should be cut into small sections and dried thoroughly, then ground into a coarse powder to extract fibers.

Fiber Extraction from Water Chestnut Peel and Lotus Stem:

[0035] Water Chestnut Peel: Boiling water chestnut peel in 1L of water and add 5g of Sodium Hydroxide (NaOH) to break down the peel and extract the fibers. Maintain the temperature at 80°C for 2 hours. After boiling, filter out the fiber through a fine mesh. Wash the extracted fibers thoroughly with clean water to remove the alkali residue.

[0036] Lotus Stem: Boil the lotus stem pieces in 1L of water to soften them. Maintain the temperature at 80°C for 2 hours. Filter out the fibers and wash thoroughly with clean water.

Fiber Cleaning and Drying

[0037] Once the fibers are extracted, they need to be dried at room temperature or in a drying oven. Drying temperature is maintained at 60°C for 4.5 hours, or air-dried for 2-3 days, until the moisture content is reduced to about 10-12%. The water chestnut peel extract is infused into the lotus stem fibres through coating or blending techniques. This integration enhances the packaging material’s ability to resist bacterial growth, mold, and oxidation while maintaining the necessary flexibility and strength to protect delicate produce.

Fiber Treatment and Modification

[0038] Soaking the dried fibers in a solution containing 10g Glycerol in 100mL water and 2g Citric Acid for 30 minutes at room temperature (25°C). This enhances flexibility and creates a crosslinking structure. After soaking, drain the fibers and let them dry again for 1.5 hours to remove excess glycerol.

Blending of Fibers and Starch

[0039] Water chestnut peel fibers and Lotus stem fibers are blended in equal quantities, typically around 50 grams each. Separately, a binder is prepared using 15 grams of corn starch. The corn starch is dissolved in approximately 100 mL of water and heated to a temperature of 85°C for about 15 minutes until a thick starch paste forms. Once the paste reaches the desired consistency, it is thoroughly mixed with the dried and pre-treated fibers to form a uniform and homogenous blend. This mixture serves as the base for shaping the final biodegradable packaging material composition.

Molding and Drying:

[0040] The homogenous fiber-starch blend is placed into molds shaped according to the desired packaging form and thickness. Molding is performed at room temperature or, for better uniformity, using a hydraulic press. When a press is used, moderate pressure is applied for approximately 30 minutes to ensure proper shape formation and compaction. After molding, the material is either air-dried or placed in an oven and dried at 60°C for 7 hours. This drying phase is critical to achieve the necessary hardness, ensuring that the material becomes sturdy while retaining a certain degree of flexibility, making it suitable for packaging applications.

Post-Treatment:

[0041] For enhanced performance, including improved durability and resistance to moisture, an optional post-treatment step may be included. In this step, the molded and dried packaging material composition is treated with 100 mL of acetone. This acetone wash removes any remaining residues and helps reinforce the structural integrity of the material. The result is a more robust and water-resistant biodegradable packaging product, extending its usability under varying environmental conditions.

Final Packaging Material Properties:

[0042] The finished product is designed to be biodegradable and eco-friendly, combining strength and flexibility with resistance to tearing. The material’s thickness is adjusted depending on molding conditions but typically falls within a range of 1–5 mm, making it ideal for various types of food packaging. The result is a sustainable alternative to conventional plastic packaging with reliable mechanical performance.

[0043] The sustainable packaging material composition is designed to regulate moisture by allowing limited air exchange, which minimizes excess condensation while maintaining the necessary respiration of the produce, thereby reducing the likelihood of mold and fungal growth. Additionally, the presence of natural antioxidants from the water chestnut peel helps in protecting the produce from oxidation, preserving its color, freshness, and nutritional quality. The inherent antimicrobial properties of both lotus stem fiber and water chestnut peel further contribute to the reduction of bacterial and fungal contamination, effectively extending the shelf life of the packaged produce and lowering the rate of spoilage.

[0044] The preservation mechanism of the packaging material composition is designed to enhance the shelf life and quality of stored produce through natural moisture control and antimicrobial action. The lotus stem fibers present in the composition have an inherent ability to absorb excess moisture, effectively preventing the buildup of condensation within the packaging. This natural humidity regulation helps maintain a stable and favorable environment around the produce, significantly slowing down its degradation. Additionally, the antimicrobial properties of both the lotus stem fiber and water chestnut peel contribute to improved food safety. The antioxidants in the water chestnut peel assist in delaying oxidative spoilage, while the lotus stem fibers inhibit microbial growth on the surface of the packaging, collectively reducing the risk of bacterial and fungal contamination.

[0045] The composition is made entirely from biodegradable components such as water chestnut peel and lotus stem fiber, ensures that the packaging naturally decomposes after use and safely composted. This eliminates the risk of environmental pollution often associated with synthetic plastic waste. Furthermore, by sourcing these materials from agricultural byproducts, the invention not only reduces the dependency on non-renewable petrochemical-based plastics but also promotes waste valorization. This approach supports a circular economy model, where discarded plant materials are transformed into a useful product, thereby minimizing environmental impact and encouraging sustainable practices in the packaging industry.

[0046] In an embodiment of the present invention, the thickness of the packaging material composition is varied to suit the nature of the produce being packed. For instance, the material may be formed into a thinner sheet for packaging lightweight or low-moisture content items such as fruits, where minimal structural support is required.

[0047] In another embodiment of the present invention, the packaging material composition is produced with a greater thickness to provide enhanced durability and structural integrity for packaging heavier or moisture-rich produce such as root vegetables or leafy greens, which require additional protection during storage and transportation.

[0048] In yet another embodiment of the present invention, the permeability of the packaging material composition is adjusted to match the respiratory needs of different produce. The fiber blend ratio, porosity of the molded structure, or additional perforations may be controlled during the molding process to ensure optimal airflow or moisture retention, depending on the shelf-life requirements of the packaged items.

[0049] The present invention offers several notable advantages and improvements over existing food packaging solutions, as detailed below:

• Natural Preservation Properties: The composition integrates antioxidants derived from water chestnut peel and antimicrobial properties of lotus stem fibre, which together effectively reduce microbial growth, oxidation, and spoilage, thereby extending the shelf life of perishable produce.
• Moisture Regulation: Lotus stem fibres naturally absorb excess moisture, maintaining optimal humidity levels within the packaging. This prevents condensation, reducing the risk of mold and bacterial growth, unlike traditional plastic packaging that traps moisture.
• Biodegradable and Compostable: This packaging material is fully biodegradable and compostable, offering a sustainable alternative to conventional plastics which contribute to long-term environmental pollution. It promotes eco-friendly waste management by naturally breaking down without harmful residues.
• Locally Sourced, Renewable Materials: By using agricultural byproducts such as water chestnut peels and lotus stem fibres, the invention supports a circular economy, reduces dependence on non-renewable resources, and adds value to otherwise discarded materials.
• Customizable for Different Types of Produce: The packaging material could be tailored in terms of thickness, permeability, and moisture control to suit the specific requirements of various fruits, vegetables, and flowers, providing a more adaptable and effective solution than generic packaging.

[0050] Although the field of the invention has been described herein with limited reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. , Claims:1) A sustainable food packaging material composition, comprising:

i) water chestnut peel fiber;

ii) lotus stem fiber;

iii) plasticizer;

iv) crosslinking agent;

v) binding agent; and

vi) water.

2) The sustainable food packaging material composition as claimed in claim 1, wherein the plasticizer is preferably glycerol.

3) The sustainable food packaging material composition as claimed in claim 1, wherein the crosslinking agent is citric acid.

4) The sustainable food packaging material composition as claimed in claim 1, wherein the binding agent is corn starch.

5) A method for synthesis of the sustainable food packaging material composition as claimed in claim 1, comprising the steps:

a) chopping the water chestnut peel into small pieces;
b) cutting the lotus stem into small sections and drying thoroughly, followed by grinding into a coarse powder to extract fibers;
c) boiling water chestnut peel pieces in water at 60-90°C for 2–3 hours and adding Sodium Hydroxide (NaOH) to break down the peel and extract the fibers;
d) filtering the water chestnut peel fibers using fine mesh, and washing the extracted fibers with clean water to remove alkali residues, followed by drying to obtain the water chestnut peel fibers;
e) boiling the lotus stem pieces in water at 70-80oC for 1-3 hours, followed by filtering the lotus stem fibers using fine mesh and drying to obtain the lotus stem fiber;
f) separately soaking the dried fibers in a solution containing plasticizer in water and crosslinking agent for 20-40 minutes, followed by draining the fibers dry again for 1–2 hours to remove excess plasticizer;
g) blending the water chestnut fiber and lotus stem fiber to obtain a fiber blend;
h) dissolving binding agent in distilled water, followed by heating at 80–90°C for 15–20 minutes to obtain a starch paste;
i) mixing the starch paste with the fiber blend to obtain a homogenous mixture and placing the mixture into molds according to the desired shape and thickness of the packaging material, followed by allowing the molded material to dry in order to obtain the sustainable food packaging material composition.

6) The method as claimed in claim 5, where the fibers are dried at 60°C for 4–5 hours, or air-dried for 2–3 days, until the moisture content is reduced to about 10-12%.

7) The method as claimed in claim 5, wherein the molding is carried out either at at room temperature or using a hydraulic press for uniformity.

8) The method as claimed in claim 5 and 7, wherein the molding is preferably carried out using a hydraulic press by applying moderate pressure for 30 minutes.

9) The method as claimed in claim 5, wherein for additional durability or resistance to water, the packaging material can be treated with acetone (100mL) to wash away any residues and enhance the material's strength.