Jelly-based ice cubes: Scientists fight food waste with reusable cooling medium

26 Nov 2021 --- Researchers have developed jelly-based ice cubes that do not melt, are compostable, antimicrobial and prevent cross-contamination in fresh food packaging. The inventors are touting the solution’s “revolutionary” potential in preventing food and water waste, reducing carbon emissions and controlling the spread of pathogens.

The researchers filed a patent for the design and concept in July based on studies from the University of California, Davis, US. The United States Department of Agriculture’s National Institute of Food and Agriculture awarded a US$485,000 grant for the research, and proof-of-concept work began in January 2020. 

The study authors say their research began after seeing the quantity of water waste used in traditional ice at fish processing plants and the microbial contamination occurring due to its melting. 

Gang Sun, a professor in the Department of Biological and Agricultural Engineering, comments: “When ice melts, it’s not reusable. We thought we could make a so-called solid ice to serve as a cooling medium that is reusable.”

Water and gelatin combined
The jelly-based ice cubes are constructed using 90% water and 10% gelatin hydrogels, which achieve latent heat fusion and cooling efficiency comparable with traditional ice. 

The solution survived the normal pressure equivalent to a food load as tall as 1 meter (22 pounds) on top throughout repeated freeze–thaw cycles during an initial study. 

After each freeze-thaw cycle, the jelly-based ice cubes could be effectively rehydrated, cleaned, or sanitized with small amounts of water or diluted bleach rinse. As temperature changes, the blocks also change color. Each cube can be reused around a dozen times before being disposed of in any waste stream. Researchers are now looking to use agricultural waste as a coolant material for the cubes.

The researchers say they are “ideal” for food preparation companies, shipping businesses and food producers. 

“You can use it for 13 hours for cooling, collect it, rinse it with water and put it in the freezer for the next use,” adds Sun.

The researchers hope to eventually use recycled agriculture waste or byproducts as the coolant material to circularize production. 

“We want to make sure this is sustainable,” says Luxin Wang, an associate professor in the Department of Food Science and Technology.

Fighting fish waste
One of the main inspirations behind the research was the quantity of ice used at fish processing plants and the resulting water waste. Moreover, melting ice spreads pathogens among produce and through drainage systems.

Sun adds that mold is frequently found in plastic ice packs used to chill school lunches for children and shipping packages.

The jelly-based ice cubes invention joins a number of previous industry attempts to improve the environmental and hygiene impacts of fish packaging and other chilled products. 

This year, Aptar Food and Beverage passed testing procedures for its SeaWell active packaging system – a novel active packaging solution utilizing integrated technology that traps and prevents accumulation of excess liquids inside the package, reducing microbial growth and chemical degradation, and aiding in odor control. 

Recently, Amazon started putting frozen plastic water bottles in chilled packs in Singapore, claiming this to be an environmental improvement since the bottles are 100% recyclable, unlike the former chilled gel packs. However, Greenpeace slammed the company for “greenwashing.” 

By Louis Gore-Langton