WiSys Technologies

Novel Antimicrobial Food Packaging with Enhanced Safety

WiSys Technology Foundation is seeking a strategic partner to further develop, manufacture, market, and distribute an antifungal plastic for packaging that prolongs shelf life while preventing migration of preservatives to food.

WiSys Technology Number: T160012US01
Patent Filed: February 17, 2016
Patent Pending
Stage of Development:

A prototype has been developed and tested for antifungal effectiveness in fruit. Further development and experimentation are needed for other foods, including cheeses and meats, as well as other possible non-food applications. Continued research and development would benefit from industry collaborations.


  • In the global food economy, there is an ever-increasing demand for food that is both healthy and sustains a long shelf life. While antifungal treatments are often used to prevent spoilage, there is a concern among consumers that adding these preservatives directly to food may sacrifice its nutritional value and/or safety. To address this concern, antifungal compounds are either applied at low concentrations only to the outside of food, or they are integrated into a coating that surrounds the food. However, there are additional disadvantages and challenges to both of these strategies.
  • When cheeses and sausages are coated with the antifungal natamycin, for example, they are immersed in a solution consisting of a natamycin suspension in water. However, a given batch of this water solution can only be used once, in order to avoid contamination of subsequent food ingredients and because it can be destabilized by presence of bacteria. Immersion on a large scale thus requires disposal of high water volumes and is wasteful. In attempts to decrease waste, antifungal compounds may instead be integrated into coatings that surround the food. Techniques under recent development have tried coating food with natamycin-linked films or whey powder. However, both of these coatings rely on a weak linkage of the natamycin, which allows the antifungal to migrate directly to the food, raising the potential for contamination and causing both consumer and regulatory concerns. As such, there is a clear and unmet need for the development of an effective, low-waste antifungal product that avoids transfer of preservatives onto food providing for both increased safety and shelf life.
  • One way to reach these goals may be to integrate antifungal compounds into the food’s packaging. In the United States, over half of all food products were packaged in plastic in 2014, making plastics a strong target for integration of antifungal compounds. If this type of product could be developed, it would contribute to the growing global antimicrobial plastics market, which is forecast to reach $3.6 billion by 2020. A lingering challenge in this realm, however, is typically-hydrophilic antifungal compounds are difficult to chemically bind to plastics, which are hydrophobic. Therefore a strategy capable of providing a strong bond between an antifungal compound and plastic would be critical to creating the desired packaging product


  • A UW-Stout researcher has developed a practical and cost effective method for surface modification of commonly used plastics using UV induced photo-grafting. Preliminary studies have demonstrated that this method is capable of generating a plastic product with strong covalent linkages to an antifungal compound. Proof of concept studies have focused on the use of low density polyethylene (LDPE), which is conventionally used for cling wrap, and the antifungal, natamycin, which is a natural substance generally recognized as safe (GRAS) by the US Food and Drug Administration and designated as a natural preservative by the European Union.
  • In initial studies during storage at 3 degrees Celsius for 1-2 weeks, the natamycin-bound LDPE plastic inhibited growth of the fungus Penicillium chrysogenum by 60% in agar and by 100% in cantaloupe, and similar outcomes were observed for yeast Saccharomyces cerevisiae. These results demonstrate the clear efficacy of the antifungal grafted plastic, making it a compelling candidate for a product that prevents spoilage while also avoiding migration of preservatives to food. Similar strategies could be used to develop other polyolefin plastics grafted with other antifungal compounds, and they could be applied beyond food, in areas including but not limited to textiles as well as healthcare.


  • Antifungal packaging;
  • Cheese, sausage, ham, cantaloupe, melons, other foods with flat surfaces;
  • Livestock feed, wood, paint, leather;
  • Single and multilayer packaging systems with tight contact between food and packaging film, such as cling wrap, shrink wrap, vacuum packaging, vacuum skin packaging;
  • Antifungal plastics in medical devices or healthcare packaging;
  • Potential utility across multiple types of polyolefin plastics and antifungal compounds.


  • Maintains efficacy of antifungal compound while minimizing migration to food;
  • Reduces waste.
UW-Stout UW-Stout
Joongmin Shin
Associate Professor, Engineering & Technology Department