Seaweeds for food: from production to consumer

Summary

The present report addresses a central challenge for the European seaweed and food sectors: how to enable the broader use of seaweed biomass as safe, flavourful, functional and sustainable ingredients in manufactured food products. This work synthesises state-of-the-art knowledge and industry experiences across the seaweed food value-chain, from post-harvest handling to consumer acceptance and sustainability assessment. Seaweeds are inherently low-calorie raw materials, dense in micro­nutrients with the potential to deliver essential minerals, vitamins, dietary fibres and bioactive compounds when used at low and realistic inclusion levels. Seaweed ingredients can enhance nutritional quality, contribute to salt reduction, and provide natural flavour and textural functionality, while supporting cleaner-label food formulation. However, unlocking this potential requires carefully designed processing routes, robust food safety management, and targeted communication strategies. Post-harvest processing is identified as a critical step for maintaining safety and quality of seaweed biomass. Fresh seaweed deteriorates rapidly, making early stabilisation essential. This report demonstrates that tailored processing strategies, ranging from gentle treatments (e.g., mild seawater blanching) that preserve flavour and water-soluble nutrients to more intensive approaches (e.g., pulsed electric field (PEF) and high temperature blanching) aimed at fibre enrichment or bioactive extraction, enable the development of ingredients adapted to specific food applications and iodine-targeted inclusion levels. Processing steps such as mild seawater blanching, fermentation, acid preservation and emerging technologies (e.g., PEF, ultrasound, high-pressure processing) can substantially improve microbial safety and manage iodine levels while maintaining nutritional and sensory quality, provided that industrial feasibility and energy efficiency are addressed. Food safety is a central conside­ration for the expansion of seaweed-based foods in Europe. Seaweeds represent one of the few natural, plant-based dietary sources of iodine, offering an important opportunity to help address iodine insufficiency, which remains a public-health concern in the majority of European populations. At the same time, iodine levels can be high and vary widely across seaweed species and processing conditions, particularly in kelps, and therefore require careful management. The reviewed evidence show that iodine content in seaweed ingredients can be effectively controlled through species selection, tailored processing (e.g., blanching), and appropriate inclusion levels. In this context, seaweeds can provide a safe and valuable source of dietary iodine, while green and red species, which generally contain lower iodine levels, offer additional flexibility for product development and diversification beyond kelp-dominated systems. Iodine content is identified as the primary factor limiting the inclusion level of seaweed ingredients in formulated foods, particularly for kelp species. As a consequence, the contribution of other nutrients such as protein, dietary fibre, vitamins and most minerals is inherently constrained by iodine-related safety considerations rather than by technological feasibility or nutritional potential. This underscores the importance of species selection, iodine-targeted processing and realistic portion-based assessments when evaluating both nutritional benefits and regulatory compliance of seaweed-based food products. Accordingly, nutritional claims and sustainability narratives should be framed in relation to iodine-limited inclusion levels in final food products rather than on the compositional richness of raw seaweed biomass alone. Food safety considerations extend beyond iodine to include potentially toxic elements such as cadmium, lead, mercury and inorganic arsenic. Based on current consumption scenarios and available occurrence data, edible seaweeds commercia­lised in Europe generally represent a minor contribution to dietary exposure to these contaminants. Risks are strongly species- and site-dependent and can be effectively managed through appropriate sourcing, batch-wise monitoring and good manufacturing practices. While some processing methods may modestly influence contaminant levels, upstream control and end-product assessment remain the most effective risk-management strategies. This contrasts with a common perception of seaweeds as inherently high-risk foods with respect to contaminants. Sensory quality emerges as a key driver of consumer acceptance. Seaweeds offer strong potential as natural sources of umami flavour, salt replacement and texture, but sensory outcomes are highly dependent on species, processing and storage. The report demon­strates how processing choices influence flavour intensity, aroma profiles and texture, and highlights opportunities for flavour develop­ment inspired by traditional Asian practices. Establishing a harmonised sensory vocabulary and quality framework for edible seaweeds is recommended to support consistent product development and market positioning. Consumer studies show that seaweed-based foods are still a niche market in Europe and Nordic countries, but generally benefit from positive consumer perception. Current consumers of seaweed-based products value sustainability, health and culinary novelty, while a greater acceptance among European consumers depends on how seaweed product will fit into everyday culinary practices. Taste quality, product familiarity, price competitiveness and retail presence emerge as decisive factors. These findings underline the importance of application-driven product development and carefully adapted communication strategies, including realistic portion size, frequency of consumption and nutritional contribution. Further­more, food producers should make deliberate choices about whether seaweed is positioned as a visible selling point or integrated more discreetly as a functional ingredient depending on end-product and targeted consumer segments. In terms of environmental perfor­mance, cultivated seaweed has clear potential to support resource-efficient food systems and circular bioeconomy pathways, particularly through nutrient uptake and low reliance on land and freshwater resources. At the same time, the overall sustainability of seaweed-based food ingredients is strongly influenced by downstream processing choices. Energy-intensive operations such as drying and freezing account for a substantial share of environmental impacts, making process optimisation a key lever for improvement. Therefore, this report stresses the need for transparent, evidence-based sustainability assessments to support claims related to biodiversity and environmental benefits when substituting or replacing seaweed as ingredient in food products. Further­more, the short-term carbon storage from producing seaweeds to food applications should be distinguished from long-term climate mitigation. Overall, this work demonstrates that seaweeds can become viable, high-quality food ingredients for the food industry, if processing is tailored to product goals, safety risks are proactively managed, sensory quality is prioritised, and sustainability performance is credibly documented. The report provides a knowledge base to support innovation, guide industry investment, inform regula­tory development, and accelerate the responsible integration of sea­weed into Nordic and European food systems through safe, application-driven and evidence-based use.

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DOI : doi.org/10.6027/temanord2026-5...
NVA : hdl.handle.net/11250/5487895