This study provides a preliminary assessment of the nutritional composition and amino acid profiles of six economically important seaweed species collected from the coastal waters of Phu Yen Province, central Vietnam. Protein, lipid, ash, and amino acid compositions were determined by an accredited analytical laboratory using standardized analytical procedures. The studied species included Chaetomorpha aerea, Caulerpa racemosa, Turbinaria ornata, Sargassum mcclurei, Gracilaria tenuistipitata, and Gracilaria salicornia. Protein content varied considerably among species, ranging from 0.84% to 17.20% dry weight (DW), with G. tenuistipitata exhibiting the highest value. Lipid content remained below 1% in all species, whereas ash content indicated substantial mineral accumulation, particularly in brown seaweeds. Sixteen amino acids were identified, including essential amino acids such as lysine, leucine, isoleucine, and valine. Glutamic acid and aspartic acid were the dominant amino acids across all species. Principal component analysis (PCA) indicated compositional differences among species. This dataset represents one of the first baseline studies on seaweed nutritional composition from central Vietnam. The findings contribute to understanding regional marine bioresources and suggest that selected seaweed species may serve as alternative protein sources for food and aquaculture applications. This preliminary study provides indicative compositional trends rather than statistically validated differences.
