Proteomic profiling of New Zealand endemic Porphyra/Pyropia (karengo) seaweeds: A predictive framework for functional food applications

• New Zealand (NZ) Porphyra/Pyropia are protein- and fibre-rich with low fat and free sugars, comparable to commercial Pyropia . • NZ Porphyra/Pyropia are enriched in sulphur-containing and umami-associated amino acids. • Porphyra GRB contain higher level of phycocyanin, suggesting distinct functional potential. • In silico analysis predicts phycobiliproteins to have low allergenicity risk and may release ACE and DPP-IV inhibitory peptides during gastrointestinal digestion Porphyra/Pyropia seaweeds are promising sources for functional foods development, offering a rich macro- and micronutrient profiles. In New Zealand (NZ), endemic Porphyra/Pyropia species (karengo), exhibit considerable variability driven by geography, seasonality, and climate, which may influence their nutritional quality. Despite their use as traditional foods, the NZ Porphyra/Pyropia remain underutilized commercially, in part due to the lack of biomolecular characterisation, particularly their bioactive protein components, hindering evidence-based species selection for seaweed farming commercialisation and functional food development. This study presents the first proteomic characterization of three NZ Porphyra/Pyropia species: Pyropia virididentata, Pyropia cinnamomea , and Porphyra GRB complex. Mass spectrometry-based proteomics analysis identified differences in the phycobiliprotein composition among the species, with the Porphyra GRB complex containing higher levels of phycocyanin. Using the protein sequence information, in silico gastrointestinal digestion analysis predicted that phycobiliproteins from NZ Porphyra/Pyropia seaweeds can potentially release bioactive peptides capable of inhibiting angiotensin-converting enzyme (ACE) and dipeptidyl peptidase-IV (DPP-IV) activities. Sequence-based allergenicity prediction indicated possible cross-reactivity between NZ Porphyra/Pyropia β-phycoerythrin and β-phycocyanin against the β-phycocyanin allergen from spirulina, which is associated with a low incidence of allergy. Proximate analysis revealed that NZ Porphyra/Pyropia seaweeds have high protein (26-30.2%) and carbohydrate (48.3-50.9%) contents, and low fat and free sugar levels. Amino acid profiling further showed that NZ Porphyra/Pyropia seaweeds are relatively rich in sulphur-containing amino acids and umami-associated amino acids. Overall, these findings highlight the potential of NZ Porphyra/Pyropia seaweeds as a novel plant-based protein source for functional food applications.