Compositional Analysis of Brown and Red Seaweeds

The compositional dataset encompasses monosaccharide and elemental analysis of nine European seaweed species for bioprocessing applications. Seaweed samples were collected from industrial and academic partners across multiple European coastal regions. The harvested biomass was pre-processed by drying and milling into flakes or powder to ensure uniformity. Monosaccharides were released using multiple hydrolysis protocols, including autoclave-based and 2-step concentrated sulfuric acid hydrolysis. A 2-step sulfuric acid protocol optimized for seaweed, was applied to all species at ~5 g/L dry biomass to standardize sample processing. The released sugars were quantified using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Correction factors were applied to account for monosaccharide degradation under acidic hydrolysis conditions. Macro- and micro-element contents were determined via ICP-MS on hydrolysed samples. Total organic carbon and nitrogen were measured using TOC/TN analysis, with protein estimated from TN using a universal conversion factor. All measurements were performed in triplicate for reproducibility. The resulting data were harmonized to units of g/kg dry biomass for sugars and g/kg (macro) or mg/kg (trace) for elements. Repeated measurements were averaged, and quality control checks ensured consistency across species. Missing values or analytical limitations are documented to inform downstream interpretation. This dataset provides standardized compositional profiles suitable for integration into bioprocess modelling, feedstock selection, and comparative analysis across seaweed species.