Biobased coating for packaging and foodstuffs

A team of researchers at the University of Hohenheim has developed a new coating system that is both impermeable to water and heat-resistant, mechanically resilient and also suitable for consumption or compostable.

Sustainability is also a major challenge in the food and packaging industry. Although plastic packaging is being replaced by bio-based and compostable materials, these materials have to meet high functional requirements. For example, the product, or packaging, must be reliably protected against gas and moisture migration. The innovative and universally applicable barrier layer developed by the University of Hohenheim is both impermeable to water and heat-resistant, mechanically resilient and also suitable for consumption or compostable.

The barrier layer was originally developed for use in food as a heat-resistant moisture barrier. As part of a product development competition, so-called "crumb sticks" were created, which are chicken drumsticks made from chicken meat with an edible bone made from a crispy baked breadstick. Softening of the two components with different moisture content was prevented by the coating system described, which was specially developed for this application.

In the further course of the research, however, additional application possibilities crystallized, particularly also in the field of sustainable, bio-based packaging systems. In this case, the coating system is sprayed on and, together with a biobased carrier material, results in water- and gas-blocking packaging.

The Hohenheim scientists used oloegels in the development of this consumable protective layer. These are fats that are structured by certain gelling agents. Some of these already have established applications in the food sector, for example in the substitution of animal fats and palm oil. A new application is as a heat-resistant coating to prevent the migration of water within a food product or from a food product into a packaging material.

Existing production processes (mainly from packaging and polymer technology) can be used for the production of oleogels. The layer can be applied either by glazing, laminating, overcoating or spraying and is suitable for food as well as in the food packaging sector or for convenience food packaging. In addition, its use in the pet food sector is conceivable.

The innovative material can be used in the food sector to separate components with different characteristics. Many processed foods are multi-component systems defined by different characteristics. This includes many snack and convenience food products, which often have a dry and a moist (creamy) component. During production and storage of these products, care must be taken to ensure that moisture from one component does not migrate into the dry areas of the product. This can be prevented with the barrier layer of oleogel. Even during processing operations such as baking or frying, the characteristics of the individual components of the food product are retained. Another application of this coating material is in the animal feed sector. Here, too, numerous possible applications are conceivable, such as coating the packaging against moisture, but also separating individual components of the feed.

This new coating has several properties whose combination has not been possible before: it is impermeable to water, heat-resistant, mechanically resilient and at the same time edible. By changing the composition or adding additives (such as flavoring or coloring agents), the oleogel coating can be adapted to the specific application. The composition of the oleogel is purely vegetable due to the use of vegetable oils and ethyl cellulose.

A patent application has been filed for the invention (EP 21207193.0 pending). Technologie-Lizenz-Büro (TLB) GmbH supports the scientists and the University of Hohenheim in patenting and marketing the current development. TLB is charged with the exploitation of this pioneering technology and offers companies licensing opportunities. (OM-05/23)