Progress towards Edible Plastics Dr. S. S. Verma, Department of Physics, S.L.I.E.T., Longowal, Distt.-Sangrur (Punjab)-148106 Use of plastics in everyday life is increasing and we are unable to dispose of plastics in an environmental friendly nature. Use of plastics as excessive packaging material and its discard is building up somewhere in the environment. There’s a lot of interest in edible food packaging. The problem right now for consumers is with taste, texture, and appearance. Researchers have to come up with a menu of delicious skins and even more delicious flesh. If edible plastics can replace a large portion of that then it's excellent news for our environment. Plastics have been used in food packaging for years. Sometimes a tub of ice cream or a pot of yoghurt is so tasty that we spend several minutes scraping out the inside and then, if nobody’s looking, lick the lid. Wouldn’t it be even better if we could simply eat the lot, container and all? It would cut down onthe amount of waste we produce and the enjoyment of our food would last that little bit longer. For years, people have been taking soluble pill capsules and recently, dissolvable strips to sweeten breath and whiten teeth are on market shelves. Edible wrapping mimics properties of petroleum products without environmental concerns. Edible plastic technology will offer no packets to rip open and toss, just dissolve an oatmeal pouch, a drink stick, or cocoa mix in hot water. Stir until the flavorful wrapping dissolves. The pouches replace packaging that actually touches the food, but an outer box is needed to keep them clean on the supermarket shelf. Designs produces ultra-thin flavored membranes that surround liquids or solids shielding them from oxygen, oils, and moisture to extend their shelf life. These packets are washable, so the outer container can act like the skin of a fruit to just wash and eat them. The inner edible membrane, like a grape skin, is held together by intermolecular electrostatic forces. Positively charged calcium ions bind with alginate, an anionic (negatively charged) polysaccharide from brown algae. The outer compostable shell is made of the residue from sugarcane crushing. According to various study reports, hundreds of millions of tons-worth of plastic bags are discarded every year. But say a new era is on the horizon, heralded by the development of their nontoxic, edible plastic. The result is a strong plastic that protects both food and the environment.The invention of edible food packaging will transform how we eat and cut down the amount of plastic we throw away. The packaging, created by researchers is designed to imitate how fruit and vegetables are ‘packaged’ in nature with a protective outer layer or skin we can eat. The idea is to use the model of how nature wraps foods. It is a completely new way of packaging and eating. Scientists have already developed a range of yoghurt pots, juice cartons, water bottles and ice cream containers that mimic natural packaging by enclosing food and liquid in an edible membrane. The containers are designed to be a similar shape to the fruits they seek to copy and are created using an edible plastic, which is a combination of algae and calcium. This is mixed with food particles, such as cocoa or fruit, so that the packaging tastes like what is inside. 1
They can be used to package both solids and liquids including soup, cheese, cocktails, fizzy drinks and coffee. Those containing liquids can be pierced with a straw and the contents drunk before they are eaten. The membranes can be washed under a tap and eaten, just like the skin of an apple. So far, the researchers working on the packaging at a laboratory have created examples including filling an orange membrane with orange juice, a tomato-flavoured skin with soup and mini-membranes the size of grapes that are full of wine. Biodegradable plastics exist because traditional ones take between 20 and 1,000 years to break down in the wild, often blocking waterways and killing animals as that all happens. Bioengineers have taken inspiration from natural food packaging found in fruit – such as peaches and grapes – and engineered edible food packaging. We can basically surround any food or beverage with a skin like a grape skin that’s fully edible, and then consume it. That's why industrial designers and microbiologists have designed a way to break down plastic -- and create edible mushrooms in the process. To be precise, the team created something called the Fungi Mutarium: a glass dome that houses hollow egg-like pods containing bits of plastic in their cavities. These "pods" serve as food to nourish the fungi, as they're made of agar, sugar and starch, similar to those agar plates used to culture organisms in labs. Mycelia (the thread-like parts of a mushroom that another team used to create biodegradable drones) mixed in liquid are then dropped into the pods, eating through the agar and the plastic pieces as they grow. The result is edible mycelia with a neutral taste. Obviously, small domes and pods like the team's prototype can't solve the world's plastic problem, especially since it takes months for the fungi to eat through small pieces of plastic. The scientists are now looking for ways to speed up the process by manipulating the temperature, humidity and other elements of the environment inside the dome. They're also considering genetically modifying the fungi to make them grow faster. The soft skin of edible plastics is made from vegetal elements such as fruit, nuts, grains, and even chocolate, using only a tiny portion of chitosan (chemical polymer) oralginate (algae extract). These particles carry an electrostatic charge and can be gelatinized with ions of e.g. calcium or magnesium, in order to create the skin. In fact there is no limit to the flavours, and the team continues to expand its range. The goal is to widely popularize the idea of edible food packaging, and eventually release domestic machines for food packaging, enabling consumers themselves to limit excessive food packaging one taste treat after the other. Imagine putting a pizza in the oven without having to remove the plastic casing that protects the pizza from contamination. The plastic film consists of tomatoes and, when heated, it will become part of the pizza. This edible plastic has been developed by researchers. In fact, the researchers have made edible plastic films from foods such as spinach, papaya and guava as well as tomatoes. The material of edible plastics has physical features similar to conventional plastics, such as resistance and texture, and is equal in its ability to protect food. The fact that it can be eaten opens a vast field to be explored by the packaging industry. The research that produced edible plastic was developed within the network of nanotechnology made up of dehydrated food mixed with a nanomaterial which has the setting function. The greatest challenge of this research is to find the ideal formulation, the recipe of ingredients and proportions so that the material had the required features. The result is a completely dehydrated food with the advantage of keeping its nutritional properties. Before discovering how to make edible plastic, the research team developed biodegradable polymers, driven by the demand for packaging easily absorbed into the
2
environment in a short time. Finally, they arrived at edible plastic, after incorporating higher standards of safety and hygiene in the manufacturing process. Acknowledgement: The use of information retrieved through various references/sources of internet in this article is highly acknowledged.
3