Carbon dots/konjac glucomannan/starch anti-freezing gel: development and cryoprotective coating for beef preservation

This study innovatively combined carbon dots (CDs) with konjac glucomannan (KGM) to modify corn starch (S), thereby developing a novel antifreeze gel system. Comprehensive characterization revealed that the combined application of CDs and KGM reduced the gel's syneresis rate, facilitated the formation of a densely interconnected hydrated network, and inhibited ice crystal growth and water migration. Experimental results demonstrated that after three freeze-thaw cycles, the S + K1.0 + CDs composite system delayed starch chain rearrangement, reduced crystallinity by up to 33.61%, and decreased the short-range ordered structure, as indicated by a 27.34% reduction in the R_1048/1022 ratio, thereby suppressing starch retrogradation. In beef preservation applications, the S + K1.0 + CDs group showed a 34.15% reduction in thawing loss and a 23.98% reduction in total bacterial count after three freeze-thaw cycles, effectively maintaining beef quality. This research establishes a theoretical foundation for designing innovative antifreeze gels and contributes to improving the frozen storage quality of starch-based foods and meat products.