Effects of cryoprotectants on freeze–thaw stability and quality attributes of salted kimchi cabbage for kimchi processing during frozen storage

Cryoprotectants, such as sugars and sugar alcohols, can mitigate freezing-induced damage in frozen kimchi. However, research on sugar-assisted salting in salted kimchi cabbage (SKC) remains limited. We evaluated the effects of cryoprotectants on the freeze – thaw stability of SKC intended for kimchi processing during 4 months of frozen storage. SKC was supplemented with glucose (GLU), trehalose (TRE), sucrose (SUC), sorbitol (SOR), or xylose (XYL) and compared with untreated control. Thawing loss (TL), hardness, pH, salinity, soluble solids, moisture, total viable bacteria (TVB), lactic acid bacteria (LAB), DPPH radical-scavenging activity, total phenolic content, and microstructure were assessed. TL increased and hardness decreased in all samples. Cryoprotectant treatment significantly reduced drip formation and improved texture retention, with GLU and XYL showing the strongest physical stabilization. They increased soluble solids and lowered the initial moisture, supporting improved control of water status. TVB declined slightly, whereas LAB were more sensitive and were best retained in SOR-treated SKC. The antioxidant indices decreased after freezing, but the losses were partially mitigated by cryoprotectant treatments. Moisture status and TL governed texture and functional retention. Overall, cryoprotectant treatments can be a practical strategy for stabilizing SKC during frozen kimchi processing and storage.