Edible packaging refers to

packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a coo ...

which is edible and

biodegradable Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...

Edible food packaging

Several manufacturers are developing or producing

food packaging Food packaging is a packaging system specifically designed for food and represents one of the most important aspects among the processes involved in the food industry, as it provides protection from chemical, biological and physical alterations ...

that is edible. One example is made based on the seaweed, Eucheuma cottonii.

Traditional water containers

About 50 billion single-use plastic water bottles made of

polyethylene terephthalate Polyethylene terephthalate (or poly(ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P), is the most common thermoplastic polymer resin of the polyester family and is used in synthetic fibre, fibres for clothing, packaging, conta ...

(PET) are produced in the United States each year, and most are discarded. According to the National Association for PET Container Resources, the recycling rate for PET has held steady at 31% since 2013. Polyesters like PET can be broken down through hydrolytic degradation: the

ester linkage In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distinc ...

is cut by a water molecule. The reaction proceeds differently in acidic or alkaline conditions, but works best at temperatures between 200 and 300 °C. Under environmental conditions the process is undetectably slow. PET is considered to be essentially non-biodegradable, with

plastic bottle A plastic bottle is a bottle constructed from high-density or low density plastic. Plastic bottles are typically used to store liquids such as water, soft drinks, motor oil, cooking oil, medicine, shampoo or milk. They range in sizes, from very ...

s estimated to take as long as 450 years to decompose. Because of this, other packaging materials are being sought.

Calcium alginate gel

Alginates are the natural product of brown algae and have been used extensively in wound dressing, drug delivery and tissue engineering, as well as food applications. Sodium alginate is an unbranched

copolymer In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are som ...

of 1,4-linked-β-d-mannuronate (M) and α-l-guluronate (G) sugars. Sodium alginate (NaAlg) coagulates when exposed to calcium chloride (CaCl₂) and forms calcium alginate (CaAlg₂) and sodium chloride (NaCl), according to the following reaction: 2NaAlg + CaCl₂ → CaAlg₂ + 2NaCl

Safety and biodegradability

The biocompatibility of alginate gels has been studied extensively and their safety for consumption is well established. As natural

polysaccharide Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wat ...

s resistant to breakdown by human digestive enzymes, alginates are classified as

dietary fiber Dietary fiber (fibre in English in the Commonwealth of Nations, Commonwealth English) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical co ...

. Although undigested if eaten, an alginate capsule will gradually decompose as the calcium diffuses out of the gel matrix in the reverse of the reaction above. CaAlg₂ + 2NaCl → 2NaAlg + CaCl₂ Because it is a single-strand polymer, alginate can be depolymerized (broken into smaller units) by a variety of chemical reactions. Both acid and alkaline mechanisms can break down the linkages between the mannuronate (M) and guluronate (G) monomers. Free radical oxidation is another way the alginate can be degraded in the environment. Many bacterial species produce an enzyme (alginate lyase) which can break the molecule down into single sugar components, which can act as an energy source for the organism.

Kodo millet-based edible packaging

In 2025,

researchers Research is creative and systematic work undertaken to increase the stock of knowledge. It involves the collection, organization, and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness to ...

team, consisting of Kirtiraj K. Gaikwad and Bhushan P. Meshram from th
Indian Institute of Technology (IIT) Roorkee
invented Kodo millet-based edible cups as an sustainable and cost-effective alternative to traditional plastic cups and bowls to reduce

plastic waste Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags and microbeads) in the Earth's environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are cate ...

. This

sustainable packaging Sustainable packaging is packaging materials and methods that result in improved sustainability. This involves increased use of life cycle inventory (LCI) and life cycle assessment (LCA) to help guide the use of packaging which reduces the envi ...

approach utilizes

Paspalum scrobiculatum ''Paspalum scrobiculatum'', commonly called kodo millet or koda millet,A. E. Grant (1898), "Poisonous Koda millet". Letter to ''Nature'', volume 57, page 271.Harry Nelson Vinall(1917), ''Foxtail Millet: Its Culture and Utilization in the United S ...

(Kodo millet),

guar gum Guar gum, also called guaran, is a galactomannan polysaccharide extracted from guar beans that has thickening and stabilizing properties useful in food, feed, and industrial applications. The guar seeds are mechanically dehusked, hydrated, mi ...

, and hibiscus powder to enhance structural integrity and environmental sustainability. This research, demonstrates how underutilized crops can be harnessed to develop

, edible alternatives to conventional plastic packaging. The study emphasizes the environmental benefits of using natural polymers to produce packaging that can either be consumed or composted, reducing long-term

waste Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor Value (economics), economic value. A wast ...

. The combination of guar gum and hibiscus powder improves the

mechanical strength Mechanical may refer to: Machine * Machine (mechanical), a system of mechanisms that shape the actuator input to achieve a specific application of output forces and movement * Mechanical calculator, a device used to perform the basic operations of ...

and

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Moisture is defined as water in the adsorbed or absorbed phase. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some comme ...

resistance of the cups, making them viable for real-world applications in the food and beverage industry. This development aligns with the

circular economy A circular economy (also referred to as circularity or CE) is a model of resource Production (economics), production and Resource consumption, consumption in any economy that involves sharing, leasing, Reuse, reusing, repairing, refurbishing, and ...

model by promoting the use of

renewable resource A renewable resource (also known as a flow resource) is a natural resource which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of t ...

s and reducing reliance on fossil-fuel-based plastics. Researchers highlight the potential for such innovations to mitigate plastic pollution while offering

sustainable Sustainability is a social goal for people to co-exist on Earth over a long period of time. Definitions of this term are disputed and have varied with literature, context, and time. Sustainability usually has three dimensions (or pillars): env ...

solutions for packaging industries globally.

References