Preparation of antifreeze glycopeptides from crayfish shells peptides with dextran by non-enzymatic and its applications for frozen pork

• The glycopeptides were successfully synthesized with CSPs and dextran by non-enzymatic. • Glycosylation improved the stability and flavor of the glycopeptides. • Glycopeptides showed a higher antifreeze performance compared to antifreeze peptides. • Glycopeptides demonstrate excellent water retention properties during the freeze-thaw process of frozen pork. In this study, antifreeze peptides extracted from crayfish shells (CSPs) were glycosylated through dextran using the Maillard Reaction (MR), successfully producing antifreeze glycopeptides (GCSPs) with excellent antifreeze activity and satisfying flavor. Infrared and fluorescence spectroscopies indicated that CSPs and dextran mainly formed covalent C–N and C–O bonds to generate GCSPs. Compared with CSPs, GCSPs formed more O–H and C=O bonds, resulting in a more compact microstructure and a higher molecular weight. With a thermal hysteresis activity of 1.23°C and glass transition temperature of –19.5°C, as determined using differential scanning calorimetry, GCSPs also had better frost resistance than CSPs. Thermogravimetric analysis showed that glycosylation significantly enhanced the thermal stability of CSPs. Additionally, GCSPs generated pyran derivatives, terpenoids, and aldehydes with special aromas through the MR, substantially diminishing the fishy odor of CSPs. In the preservation of frozen pork, GCSPs considerably reduced water loss, improved the water-holding capacity and enhanced its firmness, resilience, and chewiness. Low-field nuclear magnetic resonance spectroscopy also confirmed that GCSPs effectively reduced the loss of free water during thawing and maintained moisture stability. Overall, GCSPs have excellent antifreeze and water-retention properties and the potential to be widely used to preserve frozen foods.