New Freezing Method Improves Food Safety and Quality

Shifting to a new food freezing method could make for safer and better quality frozen foods, according to a new study by USDA’s Agricultural Research Service (ARS) and scientists at the University of California–Berkeley.

The new freezing method, called isochoric freezing, works by storing foods in a sealed, rigid container, typically made of hard plastic or metal, completely filled with a liquid such as water. Unlike conventional freezing in which food is exposed to the air and freezes solid at temperatures below 32^o F, isochoric freezing preserves food without turning it to solid ice. As long as the food stays immersed in the liquid portion, it’s protected from ice crystallization, a major threat to food quality.

Isochoric freezing also allows for higher quality storage of fresh foods such as tomatoes, sweet cherries, and potatoes that are otherwise difficult to preserve with conventional freezing.

Another benefit of isochoric freezing is that it also kills microbial contaminants during processing.

The method was first developed to cryopreserve tissues and organs for transplants. Since then, researchers have applied for a joint patent to apply isochoric freezing to food preservation. The research team is now developing the best applications for this technology in the frozen foods industry.