Effect of long-term supercooling preservation using a stepwise algorithm on the freshness of kimchi cabbage

Kimchi cabbage is a Korean traditional fermented vegetable that is rich in nutrients and probiotics. Temperature changes caused microbial growth adversely affect the quality of kimchi. Therefore, controlling the preservation temperature is important to prevent over-fermentation of kimchi. Supercooling has emerged as an alternative storage method; however, maintaining the supercooled state of food is challenging. In this study, a stepwise cooling algorithm for supercooling preservation was developed and applied. All samples were maintained in a supercooled state, and no ice nucleation was detected. Assessments of CO2 content, pH, and titratable acidity revealed that supercooled samples exhibited more delayed fermentation than refrigerated samples. However, moisture content and hardness of the unfrozen (refrigerated and supercooled) samples were not significantly different. Microbial analysis and community composition indicated that the supercooling treatment delayed kimchi fermentation by approximately three months. Conclusively, supercooling is effective for maintaining the freshness of kimchi cabbage during long-term storage. This study contributes to the optimization of kimchi preservation strategies, offering potential benefits for both consumers and producers in terms of product quality, shelf life, and food safety.