Regulating ice formation for enhancing frozen food quality: Materials, mechanisms and challenges

Freezing reduces the temperature of the food system and extends the shelf life of food. However, the inevitable formation of ice crystals could impact food quality. Small-size ice crystals are more acceptable in frozen foods than large aggregates with irregular shapes. Undesired ice crystals could not only change food structure and cause serious quality deterioration, including texture alteration, nutrient loss and off-flavour. Ice-regulating materials have been proven to regulate ice nucleation, growth and recrystallization, which show promising applications in the food industry. The theoretical information on ice formation, particularly ice nucleation and recrystallization, was described. Current ice-regulating materials, such as active proteins, saccharides, and natural deep eutectic solvents (NADES), and their mechanisms of regulating ice formation were summarized. Based on the ice damage to foodstuffs with different microstructures, the applications of active ice-regulating materials in improving the quality of frozen food were also discussed. Ice-regulating materials showed superior actions in regulating ice formation and their addition alleviated ice damage and improved the quality of frozen foods by accelerating or inhibiting freezing. Moreover, the current challenges and future perspectives of ice formation regulation for high-efficiency food freezing were proposed.