Edible, Biodegradable Food Packaging - Headline Science

Overview

Researchers developed an edible, biodegradable food-packaging film made from the milk protein casein. The film functions as a high-performance oxygen barrier, is sustainable and edible, and offers a potential route to reduce plastic packaging waste and food spoilage.

Key concepts and discoveries

• Casein-based films provide an exceptional oxygen barrier for food packaging.

• The films can block oxygen up to ~500 times better than conventional plastics.

  Casein-based films can block oxygen up to ~500 times better than conventional plastics, helping to reduce spoilage.

• Films are biodegradable and edible, offering a sustainable alternative to traditional plastic packaging.

Methodology and material improvements

• Initial approach
  • Pure casein films produced a strong, effective oxygen barrier.
  • However, these films were brittle, hard to handle, and dissolved too quickly in water.
• Optimization
  • Blending casein with citrus pectin improved mechanical strength.
  • The blend increased resistance to humidity and high temperatures.
• Forms and application methods
  • Cast as pouches or wraps.
  • Sprayed as thin coatings onto foods (e.g., cereal bars or flakes).
  • Produced as single-serve edible wrappers that dissolve in hot water (for instant soup or coffee).

Potential applications and practical considerations

• Replace sugar coatings on cereals by spraying casein-based coatings to keep cereals crunchy in milk.
• Single-serve edible wrappers could eliminate packaging waste by dissolving in hot water, but would still require an outer sanitary package (plastic or cardboard) for shelf protection.
• Use in shipping to help keep foods fresh while lowering the amount of plastic sent to landfills.

Context and sources

• Work presented at the 252nd National Meeting of the American Chemical Society.
• Coverage by Headline Science (produced by the American Chemical Society).

Researchers and contributors

• Peggy Tomasula (lead researcher)
• Laetitia Bonnaillie (co-leader)
• U.S. Department of Agriculture (research team)
• American Chemical Society (252nd National Meeting; Headline Science producer)