Why Performance Packaging?

Performance packaging slows down the food spoilage process, ensures food safety & hygiene, helps food retain quality & freshness in today's busy lifestyle.

Why do we need packaging?

Food packaging is a protective barrier against environmental factors, such as microbial contamination, water vapour, oxygen, odorous substances or light.

Different states of rot of an apple

The different types of food spoilage

Food waste bags pile Deterioration due to the activity and/or presence of microorganisms (bacteria and molds), which affects the quality & safety of food.

Food waste bags pile Chemical reactions between food components, such as rancidification caused by the oxidative deterioration of lipids by atmospheric oxygen.

Food waste bags pileChanges caused by enzymes that accelerate chemical reactions such as browning, resulting in a loss of quality in fruits & vegetables.
Food waste bags pileThe excessive loss or gain of moisture, which affects the quality of food through softening, toughening, breakdown, swelling or shrinkage.

The history / evolution of packaging

Origins of packaging

The container can be traced to wine production, which began around 5,000 B.C., in the area known today as Georgia and Armenia. By 3,000 B.C. Egypt also entered the business, and by the second century B.C., Rome exported two million liters a year. This was possible using an ingenious packaging: the clay amphora, first developed around 1,500 BC. The clay amphora was a tough, easy to store and handle. However, by the third century, the Romans left the amphora for a packaging with the wooden barrel.

Origins of packaging
Antique art show where the first packages appear

The industrial revolution

This era is marked by the development of new manufacturing processes and new materials. Although glass-making began in 7000 B.C. as an offshoot of pottery, it was not until the nineteen century that glass material became valuable. Glass and iron gained a reputation as the main materials of this era because production were driven by standardized and mechanized procedures. Thus, it was unsurprising that glass containers of all shapes and sizes became economically attractive for consumer products. From the early 1900s until the late 1960s, glass containers dominated the market for liquid products.

The industrial revolution also brought paper bags, which were first manufactured in England in 1844. Nevertheless, the most revolutionary change of this time was induced by Nicholas Appert, a Parisian chef and confectioner- inventor of the hermetic food preservation method.

One of the greatest military geniuses in history, Napoleon Bonaparte said that armies march on their stomachs, since food is essential to maintain the morale and fitness of the troops. This led Napoleon to offer a prize of 12,000 francs for anyone who discovered a food preservation procedure.

Manufacture of glass bottles

After several experiments, Appert found a solution. The procedure consisted of cooking the food in normal casseroles, pouring them in thick glass jars with a wide mouth and covering them with corks attached with wire and sealing wax. This way, they were tightly closed tightly and heated in boiling water some time. With this technique, food was not only preserved, but maintained its organoleptic properties (taste, texture, smell and color) for months.

Nonetheless, this system had certain defects: production was slow, and the containers were fragile. Glass packaging was unsuitable, since the preserved food were destined for long and complex expeditions in ships and war situations. In 1810, a successful canning container made with another material emerged, which addressed the deficiencies of glass packaging. The British merchant Peter Durand invented the tin can: a cylinder closed at both ends, made of tin-coated iron, whose pieces are joined by welding.

Rusty tin packaging

This new material (tin) has several advantages over the glass used by Appert: lightness. The tin can does not break due to its mechanical resistance, easy heat conduction, corrosion resistance compared to other metals.

This invention benefited millions of people by improving the quality of life, prevented famine and a large number of diseases that could spread with food stored in poor hygiene conditions.

Pressure cooking explained
Pressure cooking explained

The plastic revolution

Plastic is an innovative packaging material compared to metal, glass, and paper. Several plastics were discovered in the nineteenth century: styrene in 1831, vinyl chloride in 1835, and celluloid in the late 1860s. However most plastics were reserved for military and wartime use and none of these materials became widespread until the twentieth century.

Plastics did not really take off until after World War I, with the use of oil, a substance easier to process than coal in raw materials. Plastics served as a substitute for wood, glass and metal during the difficult times of World War I and II. After World War II, newer plastics, such as polyurethane, polyester, silicones, polypropylene and polycarbonate, joined polymethyl methacrylate, polystyrene and PVC in generalized applications. Many more would follow and in the 1960s, plastics were available to everyone because of their low cost and opinion as a symbol of the consumer society.

A different types of plastic packaging

From daily tasks to our most unusual needs, plastics have increasingly provided performance characteristics that meet the needs of the consumer at all levels. Plastics are used in such a wide range of applications because they are exceptionally capable of offering many different properties that offer unmatched consumer benefits with other materials. They are also unique because their properties can be customized for each individual end use application.

Performance Packaging

What is?

Plastics, unlike other materials, have been continuously evolving since their invention to meet the demanding requirements of food packaging. Today, modern polymers and processing technologies produce performance packaging to optimize food protection, convenience and efficiency.

The basic design of a multilayer film consists of a structure ranging from three to 12 layers formed by an outer layer of material that provides structural, thermal and printing properties; a central layer constituting the barrier layer; and an inner layer with good sealability.

Woman with different packed food

Using these thin layers, each with specific characteristics, significantly increases shelf life and freshness of food by controlling the transmission rate of oxygen, carbon dioxide and moisture, while also improving the mechanical and physical properties of the film against puncture, tear and heat.

What is it made of?

Using these thin layers, each with specific characteristics, significantly increases shelf life and freshness of food by controlling the transmission rate of oxygen, carbon dioxide and moisture while also improving the mechanical and physical properties of the film including puncture, tear and heat resistance.

Polyethylene (PE) Polyethylene is chemically the simplest polymer, and therefore one of the most common plastics due to its low price and simplicity in its manufacture. PE has a very good flexibility, moisture barrier and sealing properties. Polypropylene (PP) The second simplest polymer (polypropylene molecule has one carbon atom more than ethylene) and the second-most widely produced plastic. It offers strength, toughness, high melt temperature, low gas and liquid permeability, while its excellent sealing characteristics makes it an attractive option for use in multilayer films. However, its opacity may be a detriment in some applications.
Polyamides are a family of polymers also known by their most famous member, Nylon. Thanks to the presence of amide groups, they offer a unique combination of resistance and flexibility, highly transparent, oxygen prevention, carbon dioxide transfer and retain their shape even at elevated temperatures.
EVOH stands for Ethylene-vinyl alcohol and is a flexible, crystal clear, glossy, thermoplastic copolymer. EVOH is known for having some of the best barrier resistance to gases such as oxygen, nitrogen, and carbon dioxide, which makes it particularly suited for food packaging.
Different materials often do not adhere well to each other, which results in delamination and poor mechanical properties. Improving adhesion between poorly adhering layers require the use of special adhesive polymers or tie resins, mainly polyethylene copolymers.

How it protects food?

Traditionally, cold prevents the appearance of microorganisms in food, since food products subjected to lower temperatures of about 12 °C have low microbial growth. However, there are many microbes that grow rapidly below 1 °C, so additional methods are necessary to prevent their occurrence.

One of the techniques that has revolutionized food preservation in recent decades is known as the “modified atmosphere packaging” (MPA), defined as the packaging of a perishable product in an atmosphere that has been modified, so that its composition is different from the air (78% N2, 21% O2, <1% CO2). This technique ensures dramatic increase in the shelf life of fresh foods without the use of preservatives.

This technology is used mainly with performance packaging, since the multilayer configuration provides the customized gas barrier necessary to keep the specific gas composition of each kind of product in the interior of the container during the lifetime of the food. Oxygen, nitrogen, and carbon dioxide are the three main gases used commercially, although trace gases such as carbon monoxide, nitrous oxide, and sulphur dioxide are other possible gases for MAP of foods. Vacuum packaging is also considered to be a form of MAP, since the removal of air from the environment itself is a modification of the atmosphere.

Oxygen concentration is usually reduced, since it generally stimulate the growth of aerobic bacteria. The exception are red meats, which usually benefit from a MAP containing 70-80% O2 to maintain myoglobin protein in its oxygenated form. This is done because this oxygenated protein is responsible for the bright red color which is associated with fresh red meat.

Nitrogen is an inert tasteless gas used for displacing oxygen in the pack and therefore inhibit the growth of aerobic microorganisms. It is also a supporting or filling gas, as it diffuses very slowly through plastic films and remain longer in the packaging.

The oxidation processes are the most common form of food deterioration. Foods with high lipid content, especially those high in unsaturated fatty acids such as avocados, olives or fatty fish are susceptible to this form of deterioration.

Considering that oxygen is the most common and essential component for the progress of lipid oxidation, packaging that reduces or limits oxygen exposure is a good strategy to prevent and suppress these reactions.

After air has been replaced or reduced through MAP or vacuum packaging, an oxygen barrier is created to maintain a low internal oxygen concentration within the package. Poor seals without adequate oxygen barriers will give way to the oxygen partial pressure differential in the atmosphere, allowing oxygen to enter and counter any of the previously achieved benefits of MAP or vacuum packaging.

The reliable shield against oxygen penetration in performance packaging is the EVOH layer, since this copolymer delivers outstanding oxygen barrier properties: EVOH has more than 10,000 times the oxygen gas barrier properties of polyethylene, the most common plastic used in packaging. However, EVOH loses this gas barrier properties with exposure to moisture. For this reason, EVOH is often placed in between the inner and outer layers made of PE or PP, which have superior moisture barrier properties.

A frequent cause of degradation of food products is a change in their water content (water loss, gain, or migration). Moisture transfer occurs in foods due to gradients in chemical potential, which is directly related to the food’s water activity (aw). The term water activity (aw) refers to the water in food which is not bound to food molecules and range from 0.00 (absolutely dry) to 1.00 (pure water). As a potential energy measurement, the water activity gradient is a driving force for water movement from regions of high water activity to regions of low water activity. When the water activity of the food and the air surrounding it are equal, they are in equilibrium but, for example, if honey (aw ≈ 0.6) is exposed to humid air (aw ≈ 0.7), it will absorb water from the air. A very effective method to control moisture absorption, and probably the most common method, is the correct selection of the combination of materials to form the structural layers of the package. In performance packaging polyethylene and polypropylene are used as moisture barriers since their moisture vapor transmission rates are excellent. When this is not enough, High Density Polyethylene is used, since thanks to its higher density it offers improved moisture barrier over LDPE and PP.

How is it made?

The extrusion process makes it possible to combine all the highly engineered materials in one single film with extraordinary properties. Developed in the 1960s, coextrusion is the process of forming an extrudate composed of more than one thermoplastic melt stream. This allow to produce a plastic film containing two or more distinct plastic layers without requiring any intermediate steps—in contrast to lamination, where two or more plastic films are produced first, and then adhered together. In coextrusion, the structure is handled as a unique unit, so there is no need for individual layers to be self-supporting, permitting them to be much thinner and cheaper. As an example, coextrusion has been used recently in some cheese packages to reduce the overall thickness of the package by 33%, while still maintaining the oxygen and moisture barrier.

Multi-layer film manufacturing process
Mono-layer film manufacturing process

In coextrusion, materials are delivered from the extruder to a manifold or directly to the die, and combined through blown or cast techniques in such a way that the resins do not blend together, permitting each layer to retain its individual identity and characteristic properties.

Performance packaging production
Sausage packaging process in performance packaging