Food packaging has become an increasingly indispensable basic component of our daily life, which is closely related to the global urbanization trend. The reason for that is simple: when half of the world’s population lives in cities, while the cities are unable to provide the land and environment required for agricultural development, we’ll have to process and package our food and put them on supermarket shelves for people to purchase. That’s an increasingly convenient choice for people living a busy life in cities.
Good packaging can enhance the cleanness and freshness of food, while offering branding opportunities for food manufacturers. In addition, good food packaging can prevent food spoilage and extend shelf life, thereby reducing waste of food. According to statistics, up to 1.3 billion tons of food is wasted every year on a global scale, which can feed 1 billion people lacking in food.
When we go to the grocery store and buy products such canned soups, cookies, juice and other foods and beverages, we interact with different forms of food packaging. For example, milk is usually packaged in plastic or glass, but shelf-stable versions of the product may also be found in packaging such as cans. Food packaging is durable, strong, and protective, and it also plays a role in safety, convenience, efficiency, and consumer information. It additionally acts to block light and protect nutrients and colors in food products—keeping a food’s quality consistent throughout a product’s shelf life.
Packaging materials used in food industry comes in a variety of material, shapes and colours that serve different functions in context to preserving the properties of the food item that they carry inside. Since food often falls in the impulse buying category, the core purpose of packaging is presentation, preservation, and safety of the food.
Deciding the appropriate material for packaging is therefore a product of what you seek to accomplish from it. This purpose could vary from shielding the food against moisture, temperature, oxygen, light, and biological micro organisms.
Conventional packaging materials used in food industry are metal, paper, glass and plastics.
Paper
Paper is one of the oldest packaging materials in use since the 17th century. Paper/paperboard is typically used for dry food or wet-fatty foods. Popularly used material is corrugated boxes, paper plates, milk/folding cartons, tubes, sacks, labels, cups, bags, leaflets and wrapping paper. Features that make paper packaging useful:
- Paper tears effortlessly along the fibres
- Folding is easiest from end to end fibres
- Fold durability is highest across fibres
- Stiffness level is good (cardboard)
- Also, paper can be laminated to improve additional strength and barrier properties. It can be gloss or matt-finished. Other materials used are foils, plastics for laminating paperboard.
Paper is a versatile packaging material, with uses ranging from parchment papers to carton board for products such as frozen and fast food to corrugated boxes such as pizza boxes. Paper is permeable and has great strength-to-weight properties and low costs.
Paper is usually treated with materials such as waxes, resins and lacquers to provide protective and functional properties. For example, glassine is greaseproof paper used as a liner in baked and fast foods. Paper is also made from renewable resources, meaning it can be regrown and will never run out. When it comes to recycling paper food packaging, most of the paper is recycled into non-food product packaging due to mineral oils and other substances that could potentially migrate into other food.
Glass
Glass is another popular packaging material in use for ages. The initial evidence of glass-making is found in 7000 B.C. Glassblowing of bottles was invented by the Romans in 50 B.C. in the modern-day Lebanon. To date, glass is one of the most dependable and least toxic materials for packaging food and drinks.
Products with high-value are still packaged in glass containers because of its plush look and aroma-preservation property. Glass comprises of soda, lime and silica – with other additional elements based on the requisite characteristics and is manufactured via melting these materials at very high temperature followed by container formation. Glass is preferred as a packaging material for the following reasons:
- Inertness
- Can be sterilized
- Barrier to moisture and gas
- Imperviousness
- Tamper-resistant
- Microwavable
- Pressure impervious to a certain degree
- Can be beaten into diverse shape
- Transparency makes the product inside clearly visible
- High recycle value
- The versatility of glass to design features also makes it a popular choice with any packaging design agency.
Nicholas Appert began using glass as a food preservation method in the early 1800s when he used glass bottles with corks secured with wire as a way to contain and heat foods in order to preserve them. Glass provides a barrier against gasses and microorganisms, can be sterilized, and is easy to reuse. Glass is 100% recyclable without loss of quality or purity compared with some of its other packaging counterparts—but it also requires a good amount of energy for recycling.
Metals
Metal packaging also dates back to ancient times, when boxes and cups were made from silver and gold, (although these materials were not commonly used due to their value). Other metals and stronger alloys were developed over time, during which iron, tin and steel came into use. Metal canisters were invented around the 1760s but were unpopular due to the toxicity of the metals used. It wasn’t until the 1800s that these containers became popular. They were first used by Appert as a way to preserve foods in the form of tin containers. Like glass, metals have good barrier properties, are heat-resistant, and can be heat-treated and sealed for sterility. Aluminum is used for foil and soft drinks, while tin plate is used for processed foods and aerosol cans (like whipped cream). The majority of aluminum-, steel- and tin- generated food packaging is recycled. Metal materials are recyclable, but they may require extra processing, such as pinhole formation for aluminum foil or sorting and separating for laminated and metallized films.
Metal food and beverage cans are coated with an organic layer that protects the integrity of the cans from the effects of food and prevents chemical reactions that may occur between the metal and the food. These liners play a huge role in making cans stronger by reinforcing their structure and making them safer from pathogens and other contaminants, including Clostridium botulinum.
Varied shapes of metal-based food packaging are available in the market, such as enclosures, cans, containers, tubes, films and caps. Cans can be aluminium or steel of the kind mostly used for wet/liquid food and beverages. These days, progressive manufacturers use recyclable material, layered with organic material to avoid contact between the food and metal. Metal choice is dependent on:
- Strength and rigidity
- Blocking gas and moisture
- Pressure resilient
- Temperature resistant / tolerant
- Corrosion resistance thru coatings
- Can be sterilised
- Can be right away decorated/labelled
Along with these functional features, a packaging design agency must also come up with attractive design features for the pack to make it a compelling pull factor for the customer.
Plastics
Plastic is another popular material used in food packaging. It finds widespread use in bottles, bowls, pots, trays, foils, cups, bags and pouches. Indeed 40% of all plastic manufactured is used in the packaging industry. In fact, it is the most versatile and commonly used material due to its lightness, inexpensiveness and heat resilience.
In the 19th century, plastic was mainly used for military and wartime purposes. Vinyl chloride was discovered in the 1830s and later developed into molded bottles that today are used in some water and vegetable oil containers. It wasn’t until the 1950s, though, when plastics became popularized in the food industry in the form of styrene, which functioned in boxes, cups and trays. The plastic bottles we see today are mainly made of PET (polyethylene terephthalate) and entered the food industry over the past 50 years. Plastic materials also are used because they can provide barriers to moisture, gasses and chemicals. Some plastics, such as polyvinylidene chloride, are also heat-sealable and allow for high temperatures during a process called hot filling. Foods such as sauces, salsas and jams, and beverages such as juices and isotonics (sports drinks) are hot-filled.
Attributes that make it an apt choice for food packaging are as follows:
- Lightweight
- Can be moulded into unlimited shapes
- Chemical-resistance
- Can create rigid containers or flexible films
- Process ease
- Impact-resistant
- Directly decorated/labelled
- Heat-scalable
Most plastics can be recycled but require high amounts of energy. There also may be concerns about contamination of plastics during the recycling process. However, the FDA has guidance and protocols to monitor the situation.
