At the grocery store, most foods come wrapped
in plastic packaging. Not only does this create a lot of waste, but thin plastic films are
not great at preventing spoilage. To address these issues, scientists are now developing
a biodegradable film made of milk proteins and and you can eat it, to boot. Led by Peggy Tomasula, the team at the U.S.
Department of Agriculture developed an environmentally friendly film made of the milk protein casein.
These films are up to 500 times better than plastics at keeping oxygen away from food
and, because they are derived from milk, are biodegradable, sustainable and edible. The
researchers are presenting their work at the 252nd National Meeting of the American Chemical
Society. Although the researchers’ first attempt
using pure casein resulted in a strong and effective oxygen blocker, it was relatively
hard to handle and would dissolve in water too quickly. So they made a few improvements,
adding citrus pectin into the blend to make the packaging even stronger, and more resistant
to humidity and high temperatures. The material has a number of unique applications.
In addition to being used as plastic pouches and wraps, this casein coating could be sprayed
onto food, such as cereal bars or flakes. Right now, cereals keep their crunch in milk
due to a sugar coating. Instead of all that sugar, manufacturers could spray on casein-protein
coatings to prevent soggy cereal. Co-leader of the study, Laetitia Bonnaillie,
says the team is currently testing applications such as single-serve, edible food wrappers.
Individual dried soup portions, or instant coffee wrapped in the film can be added to
hot water where the film readily dissolves, eliminating the packaging waste. Because single-serve
pouches would need to stay sanitary on store shelves, they would have to be encased in a larger plastic
or cardboard container to prevent them from getting wet or dirty. Tomasula and her team hope in the future their
casein based film helps foods keep fresh during shipping while decreasing the amount of plastic
waste entering landfills. Headline Science is produced by the American
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