Nutritional profiling of red seaweeds Grateloupia turuturu and Porphyra umbilicalis: literature-based insights into their potential for novel applications and partial replacement of conventional agricultural crops

13 pages, 4 tables, 1 figure

Red seaweeds Grateloupia turuturu and Porphyra umbilicalis are consumed in East Asia as seasonings, vegetables and for wrapping sushi. Contrary to conventional agricultural crops, seaweed harvesting and farming can serve as a more environmentally friendly alternative. However, it is necessary to broaden the knowledge of G. turuturu and P. umbilicalis nutritional profile, comparing them to conventional agri-food products. The proximate composition of both seaweeds was determined using AOAC methods, while lipid classes, tocopherols and minerals were analysed by colorimetry, RP-HPLC-FLD and ICP-OES/ICP-MS, respectively. Dietary fibre was the most relevant nutritional parameter, representing almost 50% dw of P. umbilicalis. In G. turuturu, dietary fibre was mostly soluble and ash content was higher (30.98% dw) compared to P. umbilicalis (21.61% dw), while the latter had predominantly insoluble fibre and greater protein content (22.32% vs. 20.16% dw). Free fatty acids were the dominant lipid class and tocopherols occurred at residual levels. Na, Zn, Fe and I were the most abundant minerals in both seaweeds. A literature-anchored comparison of nutritional value with conventional agricultural crops (e.g., wheat, white rice, tomatoes) was theoretically estimated, showing greater protein, fibre and ash levels in seaweeds. The exploitation of seaweeds could promote environmental sustainability comparatively to conventional agricultural products, keeping or promoting the health benefits

This work was financed by European Investment Funds FEDER/COMPETE/POCI under project POCI- 01 - 0145-FEDER- 006958 (CITAB), and by Fundação para a Ciência e Tecnologia (FCT) to CECAV (UIDB/00772/2020; doi:https://doi.org/10.54499/UIDB/00772/2020), CITAB (UIDB/04033/2020; https://doi.org/10.54499/UIDB/04033/2020) and UID Centro de Estudos do Ambiente e Mar (CESAM) + LA/P/0094/2020. Additionally, FCT is accredited for a doctoral grant to João Ferreira (SFRH/BD/144882/2019)

Peer reviewed