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. The main goal of food packaging is to provide a practical means of protecting and delivering food goods at a reasonable cost while meeting the needs and expectations of both consumers and industries. Additionally, current trends like sustainability, environmental impact reduction, and shelf-life extension have gradually become among the most important aspects in designing a packaging system.
Packaging of food products has seen a vast transformation in technology usage and application from the Stone Age to the industrial revolution:
7000 BC: The adoption of pottery and glass which saw industrialization around 1500 BC.
1700s: The first manufacturing production of tinplate was introduced in England (1699) and in France (1720). Afterwards, the Dutch navy start to use such packaging to prolong the preservation of food products.
1804: Nicolas Appert, in response to inquiries into extending the shelf life of food for the French Army, employed glass bottles along with thermal food treatment. Glass has been replaced by metal cans in this application. However, there is still an ongoing debate about who first introduced the use of tinplates as food packaging.
1870: The use of paper board was launched and corrugated materials patented.
1880s: First cereal packaged in a folding box by Quaker Oats.
1890s: The crown cap for glass bottles was patented by William Painter.
1950s: The bag-in-box system was invented by American chemist William R. Scholle – initially for acid liquids, but quickly also used for food liquids.
1960s: Development of the two-piece drawn and wall-ironed metal cans in the US, along with the ring-pull opener and the Tetra Brik Aseptic carton package.
1970s: The barcode system was introduced in the retail and manufacturing industry. PET plastic blow-mold bottle technology, which is widely used in the beverage industry, was introduced.
1990s: The application of digital printing on food packages became widely adopted.
Plastic packaging saw its inaugural use during World War II, even though materials employed in its manufacturing (such as cellulose nitrate, styrene and vinyl chloride) were discovered in the 1800s.
Packaging and package's labeling have several objectives:
Packaging design may vary largely depending on the function that are fashioned into different types of packages and containers, and depending on the food products and their function, such as:
Since almost all food products is packed in some fashion, food packaging is both fundamental and pervasive. Additionally, by enabling the creation and standardization of brands, it provides the opportunity to realized significant advertising, extensive distribution, and mass merchandising. Therefore, a distinction between the various type (or level) of packaging needs to be made.
Primary packaging is directly in contact with the food products, creating the ideal headspace for them while providing protection from external alteration. Additionally, primary packaging, also known as retail packaging or consumer units, is responsible for the marketing aspects of food packaging. Typically, the packaging materials used in the primary level include cardboard cartons, plastic trays, glass bottle and multi-layerd structure (Tetra Pak).
Secondary packaging contains a number of primary packages into one box being made usually out of corrugated cardboard. Thus, the secondary level is a physical distribution carrier for the primary packages, making more easy to handle during the transportation. Occasionally it can be used as an aid in retail outlets or super market for the display of basic goods.
The outermost package, known as tertiary packaging, makes it easier to handle, store, and distribute both primary and secondary packages in bulk safely, providing further protection of the product while creating an easy way to transport large quantities of materials. The most familiar type of tertiary packaging comprises a wrapped pallet of corrugated case.
A choice of packaging machinery requires consideration of technical capabilities, labor requirements, worker safety, maintainability, serviceability, reliability, ability to integrate into the packaging line, capital cost, floorspace, flexibility (change-over, materials, etc.), energy usage, quality of outgoing packages, qualifications (for food, pharmaceuticals, etc.), throughput, efficiency, productivity, and ergonomics, at a minimum.
Packaging machines may be of the following general types:
Reduced packaging and sustainable packaging are becoming more frequent, although excessive overpackaging is still common. The motivations can be government regulations, consumer pressure, retailer pressure, and cost control. Reduced packaging often saves packaging costs. In the UK, a Local Government Association survey produced by the British Market Research Bureau compared a range of outlets to buy 29 common food items, and found that small local retailers and market traders "produced less packaging and more that could be recycled than the larger supermarkets."
In the last decades, the growing demand from the consumers and governments for more sustainable and eco-friendly packaging design has driven the food industry to re-design and propose alternative packaging solutions. However, in designing a brand new packaging system, several variables need to be taken in consideration. As shown in the optimum packaging design chart, an ideal packaging design should only use the right amount of the appropriate materials to provide the desired performance for a specific product.
Food packaging is often necessary or even essential for protecting food, keeping it safe and thus preventing substantial food losses. However, food packaging today is strongly associated with both environmental risks and health risks for consumers. To help packaging professionals address this challenge, a Responsible food packaging platform (FitNESS Food Packaging) was created in 2017 by 11 European partners, to provide both general and in-depth training courses on the design of responsible food packaging. Developed with funding from the European Union Erasmus+ program, this platform includes learning to optimise many sometimes contradictory criteria across all aspects of food packaging from its production and use through to its reuse, recycling, and disposal.
Food packaging is created through the use of a wide variety of plastics and metals, papers, and glass materials. Recycling these products differs from the act of literally reusing them because the recycling process has its own algorithm which includes collecting, sourcing, processing, manufacturing and marketing these products. According to the Environmental Protection Agency of the United States, the recycling rate has been steadily on the rise, with data reporting that in 2018, the recycling rate of generated packaging and containers was 53.9 percent.
The product's quality and safety are the package's most important responsibility. However, there have been growing demands for packaging to be designed, manufactured, consumed, and recycled in a more sustainable fashion due to the increasing pollution connected with packaging and food wastes. It has been estimated that only 10.33% of all municipal solid waste (MSW), which makes up to 30.3% of the total waste, is recycled into new products globally. However, depending on the level of packaging and the materials that are being used during their manufacturing, the end-of-life of a package may differ completely. Despite the fact that a recycling process is usually the desired path, lots of complications may lead to less sustainable destines.
A critical requirement in food packaging is represented by the barrier properties against the permeation of gases, water vapor, and aroma compounds of the packaging system. In fact, the chemical interactions between the products and the environment are the principal reasons for improper shelf-life and spoilage phenomena. Therefore, the evaluation of the gas exchange by means of the permeation of gas molecules is a crucial aspect in designing a product.
The permeation of a gas molecule through a packaging system is a physical process made up of three independent phenomena: the adsorption of the molecule to the packaging's outer surface; the diffusion of the molecule through the packaging's section; and the desorption in the internal headspace. Under the assumption of steady state condition, the physical processes involved in the permeation can be modeled by simple equations. Particularly, the diffusion of a permeant's molecule is dependent to the concentration difference between the two sides of the packaging system, which acts as a driving force, thus creating a diffusive flux following the first Fick's law of diffusion.
Furthermore, other assumptions are needed, such as the absence of chemical interaction between the penetrant and the packaging material and the fact that the diffusion flow must follow only one direction. The adsorption/desorption processes of a permeant's molecule normally exhibit a linear dependency with the partial pressure gradient across the barrier layer while keeping the assumption of steady-state transport condition and exhibiting a concentration lower than the penetrant's maximum solubility, thereby adhering to Henry's law of solubility.
The type of permeant, the barrier layer's thickness, the specific permeabilities of the packaging films against gases or vapors, the packaging's permeable area, the temperature, and the pressure or concentration gradient between the barrier's interior and external sides can all have an impact on a system's permeability.
The gas exchange occurring between the packaging system and the external environment has a significant impact on the quality and safety of food products. Uncontrolled physico-chemical and biological processes such as oxidation of vitamins, excessive microbial growth, and spoilage of the packed food may lead to improper conditions inside the packaging headspace, hence reducing their shelf-life. Therefore, the packaging system should be designed to create the ideal conditions for the selected product, avoiding excessive gas exchange.
Among the permeants that could affect the organoleptic properties of food, oxygen and water vapor represent the most important ones. These permeants affect several bio-chemical processes in food products, such as ripening, degradation, hydration/dehydration, microbial growth, vitamins oxidation; they also have an impact on the organoleptic properties, hence causing off-flavours, excessive weight loss, textural changing and generally shortening the shelf life.
To quantify the barrier properties of a packaging system, both oxygen and water vapor permeation are commonly assessed by measuring the oxygen transmission rate (OTR) and water vapor transmission rate (WVTR), respectively.
The oxygen transmission rate of a gas through the packaging is defined as the amount of oxygen permeating per unit of permeable area and unit of time in a packaging system considering standardized test conditions (23 °C and 1 atm partial pressure difference). It is an effective tool to estimate the barrier properties of a certain material. The determination of the OTR is usually carried out by means of a steady-state and isostatic method, reported by the ASTM D 3985 or ASTM F 1307, containing respectively standardized protocol for the measurements of the OTR of several kind of packaging.
The typical instrumentation consists in a permeation cell composed by two distinct chambers separated by the tested material; one of the chambers is then filled with a carrier gas (e.g., nitrogen), while the other one with oxygen, hence creating the necessary driving force to let the oxygen permeate across the barrier's material.
Concurrently to the oxygen barrier property, the permeability of water vapor through a food packaging system should be minimized to effectively prevent physical and chemical changes connected to an excessive moisture content. The moisture barrier properties of a material can be assessed by measuring the water vapor transmission rate (WVTR), which can be defined as the amount of water vapor per unit of area and unit of time passing through the packaging film.
The WVTR measurements, like the OTR, adhere to the standards for standardized tests as outlined in the ASTM E96 (standard methods for water vapor transmission of materials). An impermeable test dish (such as a stainless steel cup) and a test chamber where temperature and relative humidity (RH) can be adjusted in accordance with the standard specification, make up the basic instrumentation used in such tests.
Although both oxygen and water vapor represent the most studied permeants in food packaging application, other gases such as carbon dioxide (CO2) and nitrogen (N2) have also great relevance in the preservation of food products. In fact, N2 and CO2 have been employed in modified atmosphere packaging (MAP) technology to establish the correct conditions inside the package's headspace to lessen food spoiling.
It is critical to maintain food safety during processing, packaging, storage, logistics (including cold chain), sale, and use. Conformance to applicable regulations is mandatory. Some are country specific such as the US Food and Drug Administration and the US Department of Agriculture; others are regional such as the European Food Safety Authority. Certification programs such as the Global Food Safety Initiative are sometimes used. Food packaging considerations may include: use of hazard analysis and critical control points, verification and validation protocols, Good manufacturing practices, use of an effective quality management system, track and trace systems, and requirements for label content. Special food contact materials are used when the package is in direct contact with the food product. Depending on the packaging operation and the food, packaging machinery often needs specified daily wash-down and cleaning procedures.
Health risks of materials and chemicals that are used in food packaging need to be carefully controlled. Carcinogens, toxic chemicals, mutagens etc. need to be eliminated from food contact and potential migration into foods. Besides, the consumers need to be aware of certain chemical products that are packaged exactly like food products to attract them. Most of them have pictures of fruits and the containers also resemble food packages. However, they can get consumed by kids or careless adults and lead to poisoning. Microplastics and nanoparticles from plastic containers are an increasing concern.
Packaging lines can have a variety of equipment types: integration of automated systems can be a challenge. All aspects of food production, including packaging, are tightly controlled and have regulatory requirements. Uniformity, cleanliness and other requirements are needed to maintain Good Manufacturing Practices.
Product safety management is vital. A complete Quality Management System must be in place. Hazard analysis and critical control points is one methodology which has been proven useful.Sperber, William H.; Stier., Richard F. (December 2009). "Happy 50th Birthday to HACCP: Retrospective and Prospective". FoodSafety magazine. pp. 42–46. Retrieved 11 January 2015. Verification and validation involves collecting documentary evidence of all aspects of compliance. Quality assurance extends beyond the packaging operations through distribution and cold chain management.