Process-resolved characterization of physicochemical and volatile profile changes in laver (Pyropia spp.) during commercial manufacturing

Laver ( Pyropia spp.) holds substantial cultural and economic value in Korea. However, research on the biochemical and sensory changes occurring during the early stages of laver processing remain limited. In this study, we investigated physicochemical and volatile profile changes in laver across four key commercial processing stages: seawater storage, rinsing, aging/blending, and drying. Soluble amino acid profiling revealed significant increases in total amino acid content from Steps 1 to 4, particularly in glutamic acid, alanine, γ-aminobutyric acid, and phenylalanine. The processing stages were successfully differentiated based on amino acid and volatile profiles. Volatile compound analysis demonstrated distinct, stage-specific aroma shifts. Early stages featured light, alcoholic volatiles such as acetaldehyde and furan, whereas later stages produced complex odorants, including propanoic acid, cis-3-hexenol, and (1-methylethyl)benzene. High–molecular-weight volatiles formed during drying may serve as thermally stable markers. These findings provide a scientific basis for monitoring product quality and optimizing flavor development in laver manufacturing. • Investigated biochemical and volatile changes during laver processing. • Analyzed four key commercial stages: storage, rinsing, aging, and drying. • SAA profiling revealed increases in glutamic acid, alanine, and GABA. • VOC analysis showed distinct aroma shifts across processing stages. • Identified thermally stable volatiles as potential quality markers.