What makes consumers choose one food product rather than another from the supermarket shelf? What makes them pick up a specific bag of carrots or packet of steaks? Could it relate to the product looking presentable and fresh in its clear plastic packaging, whereas the deselected item was packed in an unclear and moisture-covered packaging?
Sometimes otherwise appetizing foods can’t be seen clearly due to fogged packaging and loose their consumer appeal. This may eventually lead to the product becoming unsalable and subsequently thrown away, adding to the growing issue of food waste.
The packaging of food products has a significant influence on consumers’ purchasing behaviour. Conditions and storage throughout the whole shelf-life can change the appearance of products and their packaging. Plastic packaging for food products can lose its transparency due to fogging when stored in cold conditions, or the transparency can be influenced by the temperature of the food. This fogging is due to moisture condensation from air and food. It is a frequent occurrence with transparent plastic containers and bags for fresh fruits and vegetables as well as ready meals –grilled meat and fish or fried vegetables with sauces.
Another issue for manufacturers occurs during on-shelf storage of plastic packaging for products with longer shelf-life. The plastic can become dusty during long storage, as plastics tend to attract dust through its static properties. This is particular visible on coloured containers, bottles and canisters Food producers need to address these problems as they can have a severe impact on consumer acceptance.
Anti-static and anti-fogging properties
Fogging and dusting problems can be reduced or eliminated by adding anti-fogging and anti-static properties to plastic packaging by means of functional additives tailored for additive masterbatches and polymers. These additives have the same chemical structure as food emulsifiers and both the hydrophilic and lipophilic aspects work as surface active ingredients in plastics. They migrate to the packaging surface and prevent fogging and dust formation. The flow of the additives to the surface is constantly renewing and continuous as they are a part of the packaging material, thereby providing a long-term solution. The additives need to be homogeneously distributed in the plastic packaging to achieve good performance. This can be difficult, though, as their concentration is relatively low, such as 0.4% for polyethylene film. To target these issues, the functional additive masterbatch has been developed. It obtains a high concentration of the active substance, pre-dispersed into a polymer.
Palsgaard’s food approved anti-fogging and anti-static additives are made from either polyglycerol ester of fatty acids or distilled monoglyceride (DMG), known as glycerol monostearate (GMS) in the polymer industry, and are designed to prevent the formation of water droplets or the collection of dust on the food packaging.
The anti-static and anti-fogging performance in the final packaging will depend on numerous variables, such as the raw materials of the active agents, the type of polymer used – polyethylene or polypropylene – and the complete recipe as well as the production process and final properties of the plastic. Similar to food emulsifiers, the Palsgaard's polymer additives are produced from different vegetable oils, such as rape seed, sunflower and palm oil, and will perform differently. This makes is possible to develop tailor made solutions to match the requests of the end users.