Optimization of deodorization process and flavor mechanism of raw and cooked salted kelp based on microbial fermentation and GC-IMS technology

The fishy odor of salted kelp, mainly derived from halogenated hydrocarbons, sulfur-containing compounds, and free fatty acids, limits its sensory quality and market value. This study evaluated microbial deodorization using six food-grade strains— Pichia kluyveri, Saccharomyces cerevisiae, Wickerhamomyces anomalus, Lactiplantibacillus plantarum, Limosilactobacillus fermentum and Pediococcus pentosaceus —in single and co-fermentation systems. GC-IMS, relative odor activity values, and sensory evaluation identified 1-octen-3-one as the dominant off-odor compound. Fermentation significantly reduced 1-octen-3-one while increasing aroma-active volatiles such as isovaleraldehyde, isopentanol, and isopropyl propionate, likely through enzymatic degradation and microbial biosynthesis. Sensory analysis confirmed improvements in aroma and overall acceptability with minimal changes in color and texture. These findings clarify microbial modulation mechanisms of kelp flavor and support the development of value-added fermented kelp products.