In-situ Micro-thermography Reveals Inverse Relationship Between Ice Nucleation and Ice Growth in Frozen Foods

According to a USDA report, $161 billion worth of food products was not available for human consumption in 2010 due to food loss. One potential way to reduce food loss is to prevent damage during the freezing process. This study presents quantitative measurements of the two primary processes involved in freezing: ice nucleation and ice growth. Using a newly developed micro-thermography system, we measured in-situ rates of ice nucleation and growth. Our findings indicate that ice nucleation and ice growth are distinct and opposing processes. Specifically, ice nucleation rates in beef and zucchini were significantly higher than those in broccoli and potato, whereas ice growth was faster in broccoli and potato compared to beef and zucchini. Analyzing the chemical composition of these foods enables the application of established crystal growth principles on freezing of foods. Therefore, designing a customized freezing process for each food product will lead to improved quality.