Impact of thawing methods and packaging sizes on the physicochemical and microbial quality of frozen kimchi

• Thawing methods affect kimchi moisture retention, texture, and microbial integrity. • MWT resulted in the greatest moisture and microbial loss, reducing kimchi quality. • RT and RFT preserved bioactive compounds and overall kimchi quality the best. • Larger packaging showed significant moisture and microbial losses in all methods. The method used for thawing kimchi is crucial in determining the final quality of products made from frozen kimchi. While many studies have explored various thawing techniques, research specifically focused on the thawing process of frozen kimchi remains limited. This study investigated the effects of natural air (NT), refrigerator (RT), running water (RWT), microwave (MWT), and radio-frequency thawing (RFT) on the texture, moisture content, and biological properties of frozen kimchi. Kimchi was packaged into 100-, 200-, and 300 gram units, revealing significant differences in thawing loss, moisture content, and texture across both package sizes and thawing methods. MWT resulted in the greatest moisture loss (up to 14.36 %) and the most extensive microbial degradation, whereas RT and RFT effectively preserved moisture, texture, and bioactive compounds with minimal quality deterioration. Overall, larger package sizes were associated with increased thawing losses and decreased microbial viability across all thawing methods. These findings highlight the importance of selecting appropriate thawing techniques to maintain the quality of kimchi during frozen storage and distribution.