Inverse Relationship Between Ice Nucleation and Ice Growth Rates 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 to the food product during the freezing process. This study presents quantitative measurements of the two primary processes involved in freezing of foods: ice nucleation and ice growth. Using a newly developed micro-thermography system, we measured in-situ ice nucleation and growth rates. We found that 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. Thus, ice nucleation and ice growth in the foods tested here, were found to be opposing processes. By analyzing the chemical composition of these foods, we applied established crystal growth and nucleation principles to explain the reasons causing the inverted relationship between ice nucleation and ice growth. Therefore, designing a customized freezing process for each food product will lead to improved quality of the product, thereby limiting food loss.