Naturally sourced biosubstances for regulating freezing points in food researches: Fundamentals, current applications and future trends

Foods have been commercially frozen for over 140 years. While improper frozen storage often causes food quality loss, the frozen damage induced by ice crystal growth is a serious problem. Freezing point (FP) regulation that promotes and inhibits ice nucleation, and controls ice crystal growth and recrystallization, may alleviate this problem. Some naturally sourced biosubstances with eco-friendly, green, nontoxic and highly effective characteristics are verified to regulate FP, showing potential for application in foods and food-related areas. This review introduces three groups of FP-regulating biosubstances, including ice-nucleating proteins (INPs), anti-freezing proteins (AFPs) and natural deep eutectic solvents (NADES). Existing knowledge of these biosubstances and updated information concerning their mechanisms for regulating FP are summarized. In addition, current applications of these natural FP regulators in foods or in food-related areas are presented, involving food processing, packaging and transgenic foods. Future applications of these biosubstances in the food and food-related researches are briefly discussed. The effect of natural FP regulators in improving food quality is worthy of further investigation into more extensive food applications, especially for INPs and NADES. The current review indicates that natural FP regulating biosubstances reveal application potential in foods and food-related areas. Future studies should mainly focus on bio-based or bio-inspired anti-freezing, micro/none ice-based cold storage and energy conservation in the food and food-related researches.