Natural cryoprotectants for frozen food preservation: Mechanisms, advances and emerging trends

Freezing remains a fundamental preservation method for maintaining food quality and safety, but ice crystal formation and recrystallization cause structural and biochemical damage that compromise texture and functionality. Natural cryoprotectants, including proteins, peptides, oligosaccharides, polysaccharides, and emerging systems such as γ-polyglutamic acid and natural deep eutectic solvents (NADES), have gained increasing attention as alternatives to conventional sugars and polyols, whose sweetness, caloric load and clean-label limitations restrict their applicability. This review synthesizes advances reported from 2019 to 2025, integrating molecular-level mechanisms (ice recrystallization inhibition, thermal hysteresis, hydrogen-bonding interactions and water-structuring effects) with their performance across diverse food matrices. Evidence indicates that plant- and animal-derived antifreeze proteins, small antifreeze peptides, and saccharide-based systems can effectively modulate ice formation, reduce protein denaturation, preserve texture, and enhance water retention in both cellular and non-cellular foods. Polysaccharides and oligosaccharides additionally provide rheological stabilization and water redistribution control, while multifunctional blends provide synergistic cryoprotection. It also identifies current challenges related to scalability, cost, and regulation, outlining future directions toward sustainable and efficient cryoprotective strategies that align with health-driven and environmental trends in the modern food industry. Overall, natural cryoprotectants represent a promising technological route for improving frozen food quality while aligning with sustainability, reduced-calorie formulations, and consumer demand for cleaner labels.