Zou will present her results at the fall meeting of the American Chemical Society (ACS). ACS Fall 2025 is being held Aug. 17-21; it features about 9,000 presentations on a range of science topics.
The jelly ice project started with a question posed to Zou and Sun by Luxin Wang, a food scientist at the University of California, Davis. Wang saw ice melting in grocery store seafood display cases and worried about meltwater spreading pathogens and contaminating the entire case. She asked whether the researchers could create a reusable material that functions like regular ice but doesn’t produce a potentially contaminated puddle.
The inspiration for the new material came from freezing tofu. Sun, a materials scientist also at UC Davis who advised Zou’s graduate research, explains that “frozen tofu keeps its water inside, but when you thaw it, it releases the water. So, we tried to solve that issue with another material: gelatin.”
Gelatin proteins have two properties that the researchers wanted: They are food safe, and their long strands link together, forming hydrogels with tiny pores that hold water, unlike tofu. Early tests of the hydrogels made with this natural polymer (also called a biopolymer) were a success. The water stayed inside the pores as it went through phase changes, from liquid to ice and back again, without damaging the structures or leaking out the hydrogel.
Through the years, Zou has optimized the gelatin-based hydrogels’ formula and production methods. Now, she has a practical, one-step process to create jelly ice that’s 90% water and can be repeatedly washed with water or diluted bleach, frozen and thawed. The cooling material jiggles and squishes at room temperature. But when cooled below the freezing point of water, 32 degrees Fahrenheit (0 degrees Celsius), it transitions to a firmer, more solid state.
“Compared to regular ice of the same shape and size, jelly ice has up to 80% of the cooling efficiency — the amount of heat the gel can absorb through phase change,” says Zou, who will talk more about this when she presents the newest version of jelly ice at ACS Fall 2025. “And we can reuse the material and maintain the heat absorbance across multiple freeze-thaw cycles, so that’s an advantage compared to regular ice.”
The team can produce jelly ice in 1-pound (0.45-kilogram) slabs, similar to the cold gel packs currently for sale that have bulky plastic sleeves. However, the new cooling material has advantages over cooling packs or dry ice: It’s customizable for any shape or design, and it’s compostable. In one set of experiments, the composted gel improved tomato plant growth when applied to the potting soil. And because the cooling material doesn’t contain synthetic polymers, it shouldn’t generate microplastics.
Zou and Sun say that jelly ice, while initially developed for food preservation applications, shows promise for medical shipping, biotechnology, and use in areas with limited water available for forming ice.
Currently, there are licenses for the jelly ice technology. Zou hopes that this means the cooling material will be available to consumers as a meltwater-free, food contact-safe, compostable alternative to ice. Though, she acknowledges there are still some steps in market analysis, product design and large-scale production tests before it can be commercialized.
But as the gelatin-based jelly ice makes its way toward the market, Zou has also become interested in other natural biopolymers. She expanded her research into plant proteins that are agricultural by-products, such as soy proteins, to make more sustainable materials. Her focus is shifting toward developing soy proteins for removable countertop coatings and cellular scaffolds for cultivated meat. She’ll present more about that work at ACS Fall 2025.
“In my research, I realized how powerful Mother Nature is in designing biopolymers and the vast possibilities they offer,” says Zou. “I believe there will be amazing products derived from biopolymers as the materials themselves are teaching us how to work with them.”
The research was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture, a Henry A. Jastro Graduate Research Award from UC Davis, and a Food Systems Innovation Award from the Innovation Institute for Food and Health at UC Davis.
A Headline Science YouTube Short about this topic will be posted on Monday, Aug. 18. Visit the ACS Fall 2025 program to learn more about this presentation, “Sustainable bio-derived polymeric materials improving food security, food safety, and circular bioeconomy,” Zou’s additional presentation “Dextrose-conjugated plant-protein 2D scaffolds for improved cultivated meat applications,” and other science presentations.
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Title
Sustainable bio-derived polymeric materials improving food security, food safety, and circular bioeconomy
Abstract
Functional polymeric materials play a critical role in food systems, supporting processes such as post-harvest handling, processing, shipping, and retail. The development of bio-based sustainable functional materials has become a long-term goal in materials research, driven by growing concerns over global warming and plastic pollution. Agricultural byproducts, rich in biomacromolecules such as proteins and carbohydrates, represent a significant yet underutilized resource, particularly for high-value applications. Motivated by these challenges, this research focused on (1) improving the processability of natural biomacromolecules and (2) exploring their potential applications as functional materials to enhance sustainability, food security, and food safety while advancing the circular bioeconomy. Soy proteins were studied as a model biomacromolecule requiring improved processability, using physical (e.g., ultrasound and high-speed shearing) and chemical (e.g., pH adjustments and plasticizer incorporation) treatments. Synergistic effects from combined approaches demonstrated potential for broader biomacromolecule processing. Three proof-of-concept sustainable materials were developed, showcasing the potential of bio-based functional polymeric materials to benefit food and agricultural systems: 1) a type of novel reusable cooling media (“Jelly Ice Cubes”) designed from gelatin hydrogels, offering customizable cooling, elimination of meltwater, reusability, microbial resistance, and compostability; 2) a removable coating was developed to combat bacterial contamination and prevent biofilm formation on hydrophobic food-contact surfaces; and 3) the scaffolding materials for the future sustainable food developed via cellular agriculture. These innovations highlight the transformative role of bio-based functional materials in addressing critical challenges within food systems by promoting sustainability, reducing waste, and enhancing food security and safety.
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