Ice recrystallization inhibition: Structure-activity studies of synthetic compounds

Abstract

The preservation of frozen foods is an important and relevant issue in many countries. With the mass amounts of food that is produced in the United States, a method that can efficiently store this food over long periods of time is necessary, and thus freezing food in bulk quantities has become popular. The ability to freeze food products is one of the best long-term solutions for maintaining the shelf life of nutritious foods, and it is the only large-scale process that ensures foods of varying seasons are available year-round (Hasani et al., 2022). It is estimated that the market share of frozen foods will be USD 224.2 billion by 2025 (Hasani et al., 2022). However, storing frozen foods for extended periods of time is detrimental to the food, specifically because of ice recrystallization (IR), a natural process that occurs in ice crystals. When similarly sized ice crystals are kept at a constant temperature, over time, larger crystals will grow while smaller crystals will shrink, but the percentage of ice remains constant. The effects of IR are significant, as it reduces the quality of frozen foods; when the crystals melt as the frozen food is defrosted, there is a loss of nutrients, taste, and a reduction in the food’s ability to hold water (Gruneberg et al., 2021). In addition, when large crystals form, it causes the frozen food to have a coarse, grainy texture, which is apparent in foods such as ice cream. These negative effects are heightened during the foods’ progression from manufacture to storage, as temperature of the food fluctuates considerably. In addition, IR is detrimental to cellular-based foods that originate in plants and animals because the larger crystals can rupture cell walls, which causes nutrients to be lost. Antifreeze proteins (AFPs), antifreeze glycoproteins (AFGPs), and some synthetic compounds inhibit ice growth and may act as a solution to the problem at hand. As such, AF(G)Ps and other synthetic compounds were extensively studied in this project.