Packaging has been one of the most important tools at the disposal of the product manufacturer to make its product stand out in the shelf. Beyond shelf appeal, packaging also provides protection and containment for the contents. Packaging can be broadly categorised into the following types - passive, active, intelligent, and smart.
Passive Packaging: It refers to the traditional packaging that involves the use of a covering material, characterised by some inherent insulating, protective or ease-of-handling qualities. The most common example of this type of packaging is a simple plastic bag and it is the type of packaging that everyone is most familiar with.
Active Packaging: This package reacts to various stimuli—to keep the internal environment favourable for the products. A typical example would be a packaging with oxygen scavenger (an oxygen scavenger can absorb oxygen inside a package to increase the shelf-life of the item).
Intelligent Packaging: This refers to the concept of making innovations in the design of packaging that renders it more useful for the consumer. The intelligent packaging refers to increasing the functionality of the package by simply changing the structure of the package, without the addition of any technology.
Smart Packaging: The packaging that is made much more functional and useful which involves the use of technology that adds features such that packaging becomes an irreplaceable part of the whole product. Smart packaging performs additional functions, responds to stimuli generated by the environment or from the product being packaged, and reflects the change in a manner that makes the product more convenient and useful for the consumer or firms in the supply chain. Smart packaging relies on the use of chemical, electrical, electronic, or mechanical technology, or any combination of them.
Types of Smart Packaging
Based on a survey of the literature, nano markets believe that there are two broad (and overlapping) categories of smart packaging.
The first type of smart packaging is specifically focussed on integrating the packaging into some kind of IT system for inventory or sales management. This kind of smart packaging typically employs RFID or Electronic Article Surveillance (EAS) technology to turn an otherwise conventional packaging into smart packaging, allowing it to be traced through the value chain or through the exit-doors of a retail store.
The second type makes use of a variety of technologies to make the packaging inherently smart. This may also involve RFIDs, but goes further than this to include an overflow of technologies ranging from those that provide self-heating capabilities, that indicate the freshness of a product, that provide instructions and pricing on a small integrated screen. This division of smart packaging can be made in terms of whether it utilises a single technology or whether it uses a combination of two or more of them.
Smart packaging opens up new opportunities for enhancing inventory tracking, product safety and security, user-friendliness and brand enhancement. Its impact is already being felt now in packaging for sectors as diverse as retailing, food and beverage, pharmaceuticals, cosmetics etc. The use of smart packaging is also being pushed forward by changes in demographics and environmental concerns.
Self-Heating Technologies
The package design consists of an aluminium foil beverage cup placed inside an insulated plastic container. A double-wall arrangement is used to insulate the container. Anhydrous calcium chloride salt is placed in the chamber. The lower region of the cup contains a water reservoir. Heat is generated by reacting calcium chloride with water. To initiate the reaction, the package is first turned upside down, and pushed on the pin which ruptures the calcium chloride chamber. Water then flows into the calcium chloride chamber and the resulting reaction generates heat.
Spin-off technology from the military meals-ready-to-eat (MRE) programmes using highly-reactive exothermic reactions, based on magnesium oxidation or the reaction between potassium permanganate and glycerine, has created a niche but growing market for self-heating food products for emergency services and the outdoors sector.
The increasingly convenience-oriented domestic market requires a means to heat all types of food and beverages including high viscosity liquids and solid products – i.e. thick soups, snacks including wraps, fajitas, stuffed pitta bread, ready meals, pasta, rice and stews. To date, the technologies for self-heating have been confined to lime/water reactions, where heat output is lower but the reaction is safer. But heating times can be long for solid food products, since heat is transferred from the heating source to the product purely by conduction.
Self-Cooling Technologies
The dissolution of ammonium nitrate and ammonium chloride in water will result in endothermic reactions. Earlier fluorocarbon gas was used but due to environmental problems use is terminated.
The Future
In the future, both self-heating and self-cooling containers are likely to be largely made from plastic for lightness and portability, with metal only used in critical areas requiring high thermal conduction or stiffness. The quest for the cost-effective, single-serve self-cooling beverage container will continue. The market penetration of the self-cooling container, as forecasted by prominent market research organisations and beverage companies, would be likely to increase to about five per cent of total container consumption while the unit price of the self-cooling container is expected to fall to around 20-25 cents. If this happens, world market share of the self-cooling container could be around 15 billion per year.
Smart Labels
For the food sector, there are now smart labels, that indicate temperature excursions (hot or cold), help extend freshness and protect against mould growth and other spoilage such as anti-microbial, moisture and oxygen absorbing labels, and labels that can indicate product freshness, ripeness or deterioration for perishable food.
Time-Temperature Indicators
Food waste is a major problem for the developed world and one that smart labels and labelling could help reduce by providing more accurate information to the consumer about the condition and freshness of food. The kinetics of food degradation is overwhelmingly determined by storage temperature, not storage time. Since the majority of perishable packed food has a ‘best before’ or ‘use by’ date, indicating time and not temperature, the result is that much perfectly edible and safe-to-eat food is thrown away by consumers because it has reached its printed ‘use by’ date, regardless of actual condition.
Ripeness Indicators
Some smart label developments have taken inspiration from nature, where there are many colour change chemical reactions at work associated with food degradation and ripening. As an example, the ripening of many fruits is accompanied by the emission of ethylene gas – easily detected by animals but not by humans, who therefore have real difficulty in deciding whether certain types of fruit are ripe in the absence of a colour change.
Scientists in New Zealand developed and commercialised the ripe sense label, which is responsive chemically to ethylene inside the pack. Since fruit and vegetable are a major source of post-consumer food waste, this innovation ought not only to help consumers enjoy fruit more but also reduce the tendency for them to throw away unripe or overripe fruit.
Freshness Indicators
Oxygen is the nemesis of food freshness, rapidly accelerating microbial and enzymatic degradation and other undesirable reactions. For this reason, controlled or modified atmosphere packaging (MAP) is a commonly used packaging format for perishable food. A colour-change label to detect oxygen has been developed and if there is a leak or the seal integrity of the pack has been compromised, the label changes colour from transparent to blue as air replaces the modified atmosphere gases. Other smart freshness labels rely on the detection, and subsequent colour change if present, of certain metabolites – the gaseous byproducts of microbial activity within packaged fresh food. For example, the formation of hydrogen sulphide in fresh poultry products and volatile amines in fresh meat and fish, are known to be early indicators of microbiological activity and hence reduced freshness. The hydrogen sulphide indicator will indicate the status of the product.
The sensor, made of food grade materials, is inexpensive, costing typically less than 1 per cent of the average cost of packaged meat or poultry. The marketing research indicates that more than 95 per cent of consumers would opt to purchase a product with a freshness indicator instead of a product without.
Freshness of Fish and Seafood Products
There is much interest from the fisheries industry in developing rapid methods to evaluate real-time freshness of fish and seafood products. Emphasis is on the ones that would reflect and account for the products history and their storage conditions from harvest-to-home. The development of a smart packaging that monitors the microbial breakdown products in the headspace of packaged fish. When fish spoils it releases a variety of basic volatile amines which are detectable with appropriate pH indicating sensors. These are prepared by entrapping within a polymer matrix a pH-sensitive dye that responds, through visible colour changes to the spoilage volatile compounds that contribute to a quantity known as total volatile basic nitrogen (TVB-N). The sensor accurately tracks the increase in amines concentration in the package headspace.
Embedded Antimicrobials can Detect and Destroy Bad Bacteria
Scientists are developing coatings that contain antimicrobial agents to go inside packaging to detect when bacteria levels reach a critical point and release the agents. Perishable foods can then be monitored to ensure that they have not been spoiled.
There are also developments in oxygen-scavenging technologies, and the use of antimicrobial films and diagnostic packaging that provide colour changes triggered by the presence of certain pathogens.
The future promises even more new technologies that when applied to food packaging will keep us safer. Perhaps soon, food-borne outbreaks will be avoided by applying such marvellous innovations.
