Applications of Seaweeds in Food and Nutrition

Applications of Seaweeds in Food and Nutrition provides an overview on the cultural, biological and engineering dimensions relating to seaweed as a food. With the need for sustainable and healthy foods growing, this comprehensive resource explores how seaweeds can deliver not only nutritional benefits, but also antiviral and antibacterial properties as a food additive and within food processing and manufacturing. Recent developments show that the use of seaweed extracts as a compound can prevent browning. It use in other areas such as a thickening and gelling agents in foods and cosmetics is also encouraging.

There are hundreds of different varieties of seaweed known to mankind, yet very little literature is available on the processing of these "crops." This book provides these valuable and practical insights.

• Introduces the origin of seaweed consumption and its biology
• Examines common seaweed varieties of industrial interest and their chemical composition
• Explores the potential of robotics and AI techniques in seaweed aquaculture

• Language: English
• Publisher: Elsevier Science
• Release date: Sep 7, 2023
• ISBN: 9780323972079

Book preview

Applications of Seaweeds in Food and Nutrition

Edited by

Daniel Ingo Hefft

School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom, Campden BRI, Product Research, Chipping Campden, United Kingdom

Charles Oluwaseun Adetunji

Applied Microbiology, Biotechnology and Nanotechnology Laboratory, Department of Microbiology, Edo University Iyamho, Auchi, Edo, Nigeria

Table of Contents

Cover image

Title page

Copyright

List of contributors

About the editors

Preface

Chapter 1. History of seaweeds as a food

Introduction: What are seaweeds and why are they eaten?

Seaweeds as foods in human evolution

Seaweeds as a food in prehistoric times

Historical and traditional uses of seaweeds as food

Current seaweed market

Seaweeds in gastronomic innovation

Seaweed tradition and innovation in cookbooks

Seaweeds for future and sustainable eating: When blue is green

Chapter 2. Evolution, biology, and genetics of seaweeds

Introduction

Origin

Age

Red algae

Green algae

Brown algae

Multicellularity

Ecological implications of multicellularity

Life cycle

Seaweed genetics

Seaweed molecular genetics

Summary

Chapter 3. Impact of environmental and marine pollution on seaweed farming

Introduction

Marine pollution

Environmental pollution

Impact of pollutants on seaweeds

Discussion

Conclusion

Chapter 4. Seaweeds and the United Nations' Sustainable Development Goals 2 and 3—2022 and beyond

Introduction

SDG goals 2 and 3—Roles for seaweeds

Protein

Fats

Carbohydrates

Improved nutrition

Good health and well-being for all!

Discussion

Chapter 5. Impact of climate change on seaweeds and their future

Introduction

Impact of anthropogenic stressors on the marine ecosystem

Climate change factors that impact seaweeds

Response mechanism

Seaweed farming to reverse climate change

Discussion and way ahead

Conclusion

Chapter 6. Seaweed aquaculture for human foods in land based and IMTA systems

Definition of the subject and its importance

Introduction

Past and present use of seaweeds

Seaweed aquaculture

Introduction of the IMTA concept

Physiological considerations for the production of seaweeds in land-based cultivation systems

Examples of successful on-land cultivation enterprises

Future potential directions

Glossary

Chapter 7. Nutritional composition of selected seaweeds

Nutritional composition of selected seaweeds

Lipids and fatty acids in seaweed

Conclusion

Chapter 8. Alginate in food and beverage formulations

Introduction

Regulatory considerations of alginate in food

The rise of alginate in the food industry—a brief historic review

Alginate as a functional ingredient in food

Alginates in some selected products

Alginates in human diet

Conclusion

Chapter 9. Seaweed extracts-treated food and their benefits for shelf life and animal/human consumption

Introduction

Seaweed extracts boost plant nutritional value and provide biofortification

Seaweeds in the diets of various animals

Seaweed extracts against postharvest deterioration

Concluding remarks and future trends

Chapter 10. Proteins extracted from brown seaweed and their potential uses as foods and nutraceuticals

Introduction

Extraction of seaweed proteins

Nutritional quality of protein extracted from U. pinnatifida

Potential food and feed applications of protein extracted from U. pinnatifida

Potential nutraceutical value and applications of protein extracted from U. pinnatifida

Conclusions and futures perspectives

Chapter 11. Safety and allergenicity of seaweeds

Introduction

Toxicity concerns

Allergenicity and seaweed

Allergy treatment and seaweeds

Conclusion

Chapter 12. Processing of seaweeds in industrial food application

Introduction

Main components of seaweeds

Effect of seaweeds and seaweed extract incorporation on textural, nutritional, and organoleptic characteristics of food products

Conclusion

Chapter 13. Seaweed-derived snack foods: products and processing

Introduction

Seaweeds that are consumed as foods

The nutritional profile of seaweeds

Propensity to snacks

Seaweed-derived snack products

Advantages of consumption of seaweed-based snacks

Challenges of developing a seaweed-based snack

Conclusion

Chapter 14. Seaweeds derived by-products

Utilization of seaweeds

By-products from seaweeds: main products types and statistics

Chapter 15. Seaweed fermentation for the development of novel food products

Introduction

Seaweeds as a substrate for fermentation

The role of lactic acid bacteria in seaweed fermentation

The role of yeast in seaweed fermentation

The role of filamentous fungi in seaweed fermentation

Concluding remarks

Funding

Chapter 16. Potentials of robotics and AI techniques for monitoring seaweeds

Introduction

Available technologies and methods

Methods to collect raw data

Processing the collected data

Using AI for rapid and precise decisions

Use areas for AI in seaweed management

Future trends

Challenges

Way ahead

Conclusion

Chapter 17. Seaweed derived sustainable packaging

Introduction

Plastic pollution

Biodegradability standards

Types of packaging

Preparation of seaweed based films and coatings for food packaging

Applications of seaweeds in food packaging

Front runners in seaweed based food packaging

Regulations and bans on single use plastics

Drawbacks and resolutions

Conclusion and future perspective

Chapter 18. Seaweeds in food contact materials: properties, applications and migrations aspects

Introduction

Seaweeds as food contact materials

Effects of seaweeds on food contact materials

Applications of seaweed-based food contact materials

Migration of active compound from seaweeds

Conclusion and future perspective

Index

Copyright

Elsevier

Radarweg 29, PO Box 211, 1000 AE Amsterdam, Netherlands

The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom

50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States

Copyright © 2024 Elsevier Inc. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

ISBN: 978-0-323-91803-9

For information on all Elsevier publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: Nikki P. Levy

Acquisitions Editor: Simonetta Harrison

Editorial Project Manager: Lindsay C. Lawrence

Production Project Manager: Omer Mukthar

Cover Designer: Vicky Pearson Esser

Typeset by TNQ Technologies

List of contributors

Charles Oluwaseun Adeutnji,     Applied Microbiology, Biotechnology and Nanotechnology Laboratory, Department of Microbiology, Edo University Iyamho, Auchi, Edo, Nigeria

Nitin Agarwala,     National Maritime Foundation, New Delhi, Delhi, India

Balamurugan Ayyakkalai,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

Uthman Badmus,     School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland

Francisco J. Barba,     Nutrition and Food Science Area, Faculty of Pharmacy, Universitat de València, València, Spain

Jonas Blomme

Phycology Research Group, Department of Biology, Ghent University, Ghent, Belgium

Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium

VIB Center for Plant Systems Biology, Ghent, Belgium

Kenneth Boyd,     Environmental Research Institute, University of the Highlands and Islands, Inverness, United Kingdom

Afroditi Chatzifragkou,     Department of Food and Nutritional Sciences, University of Reading, Whiteknights, United Kingdom

M. Lynn Cornish,     SEADLING, Kota Kinabalu, Sabah, Malaysia

Alan T. Critchley,     Verschuren Centre for Sustainability in Energy and Environment, Sydney, NS, Canada

Olivier De Clerck,     Phycology Research Group, Department of Biology, Ghent University, Ghent, Belgium

Ajay S. Desai

College of Fisheries Science, Dr. Balasaheb Sawant Konkan Agricultural University, Ratnagiri, Maharashtra, India

Department of Fish Processing Technology and Microbiology, Ratnagiri, Maharashtra, India

Di Fan,     School of Biology, Food and Environment, Hefei University, Hefei, China

Giulia Fornaciari,     MMR Research, London, United Kingdom

Ralf Greiner,     Department of Food Technology and Bioprocess Engineering, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Karlsruhe, Germany

Daniel Ingo Hefft

School of Chemical Engineering, University of Birmingham, Birmingham, United Kingdom

Campden BRI, Product Research, Chipping Campden, United Kingdom

Anicia Q. Hurtado,     Integrated Services for the Development of Aquaculture and Fisheries (ISDA) Inc., Jaro, Iloilo, Philippines

Amit K. Jaiswal

School of Food Science and Environmental Health, Faculty of Science, Technological University Dublin-City Campus, Dublin, Ireland

Environmental Sustainability and Health Institute (ESHI), Technological University Dublin-City Campus, Dublin, Ireland

Swarna Jaiswal

School of Food Science and Environmental Health, Faculty of Science, Technological University Dublin-City Campus, Dublin, Ireland

Environmental Sustainability and Health Institute (ESHI), Technological University Dublin-City Campus, Dublin, Ireland

Mayushi Malshika Jayakody,     Department of Food Science and Technology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka

Mohamed Koubaa,     ESCOM, UTC, Compiègne, France

Marco F.L. Lemos,     MARE—Marine and Environmental Sciences Centre, ARNET–Aquatic Research Network, ESTM, Politécnico de Leiria, Peniche, Portugal

Jun Lu,     Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand

Ole G. Mouritsen,     Department of Food Science, Taste for Life, Design and Consumer Behaviour, University of Copenhagen, Frederiksberg, Denmark

Jayashree Nath,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

Keshavan Niranjan,     Department of Food and Nutritional Sciences, University of Reading, Whiteknights, United Kingdom

Sri Sailaja Nori,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

Nasim Pasdar,     Department of Agricultural Engineering and Technology, Payame Noor University (PNU), Tehran, Iran

Rui Pereira,     A4F Algafuel S.A., Lisbon, Portugal

Kalpani Y. Perera

School of Food Science and Environmental Health, Faculty of Science, Technological University Dublin-City Campus, Dublin, Ireland

Environmental Sustainability and Health Institute (ESHI), Technological University Dublin-City Campus, Dublin, Ireland

Dileswar Pradhan

School of Food Science and Environmental Health, Faculty of Science, Technological University Dublin-City Campus, Dublin, Ireland

Environmental Sustainability and Health Institute (ESHI), Technological University Dublin-City Campus, Dublin, Ireland

José Lucas Pérez-Lloréns,     Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Cádiz, Spain

Hemanth Giri Rao,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

João Reboleira

MARE—Marine and Environmental Sciences Centre, ARNET–Aquatic Research Network, ESTM, Politécnico de Leiria, Peniche, Portugal

Department of Food and Nutritional Sciences, University of Reading, Whiteknights, United Kingdom

Vijay Kumar Reddy,     Department of Fish Processing Technology, College of Fisheries, Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana, Punjab, India

Shahin Roohinejad,     Division of Food and Nutrition, Burn and Wound Healing Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Shubham Sharma

School of Food Science and Environmental Health, Faculty of Science, Technological University Dublin-City Campus, Dublin, Ireland

Environmental Sustainability and Health Institute (ESHI), Technological University Dublin-City Campus, Dublin, Ireland

Susana F.J. Silva,     MARE—Marine and Environmental Sciences Centre, ARNET–Aquatic Research Network, ESTM, Politécnico de Leiria, Peniche, Portugal

Willem Stock,     Phycology Research Group, Department of Biology, Ghent University, Ghent, Belgium

Shrikumar Suryanarayan,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

Mark Taggart,     Environmental Research Institute, University of the Highlands and Islands, Inverness, United Kingdom

Mihiri Priyanwadha Gunathilake Vanniarachchy,     Department of Food Science and Technology, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka

Vantharam Venkata,     Sea6 Energy Private Limited, Centre for Cellular and Molecular Platforms (C-CAMP), NCBS-TIFR, GKVK Campus, Bangalore, Karnataka, India

Liu Xiaojie,     School of Marine Science and Engineering, Nanjing Normal University, Nanjing, China

Charles Yarish

AOPE, Woods Hole Oceanographic Institution, Woods Hole, MA, United States

The GreenWave Organization, New Haven, CT, United States

Department of Ecology and Evolutionary Biology, The University of Connecticut, Stamford, CT, United States

About the editors

Daniel Ingo Hefft

Daniel Hefft is a Food Engineer from Germany. He got his undergraduate degree from Technische Hochschule Ostwestfalen-Lippe with specialization in cereal technology. He has an MSc degree from the University of Reading. Daniel has a doctorate degree in Chemical Engineering from the University of Birmingham.

He has been awarded Research Fellowships and Research Affiliation with the University of Birmingham. Daniel has extensive years of experience in the food industry, having worked for a range of leading companies in the food manufacturing sector. His special area of interest resolves around food process design and engineering. He is the founder and former CTO of Rheality Ltd., which utilizes a novel technology based on acoustic sensing and machine learning for rheology measurements. Daniel is also the Founder of the Engineering for Food and Drinks Special Interest group at the Institution of Agricultural Engineers and its current chair. Since 2018, he gained professional recognition as a Chartered Engineer with the Institution of Agricultural Engineers. Further, he is involved as a member in the Association of German Food Technologists (GDL e.V.), the Society of Dairy Technology (SDT), and the Institute of Physics (IOP). He is the recipient of the 2022 President's Award of the IAgrE in recognition for his services to the Food Engineering profession.

Daniel has published more than 70 research papers and book chapter contributions and his work has been cited more than 300 times. He serves the Scientific Publications Committee of the Society of Dairy Technology.

In 2022, Daniel has been awarded with an Honorary Research Fellowship in Chemical Engineering at the University of Birmingham. Daniel currently works as a Product Research Team Lead at Campden BRI, a world-leading expert in providing services to the food and drinks sector.

Charles Oluwaseun Adetunji

Charles Oluwaseun Adetunji is Senior Academic of Edo State University Uzairue (EDSU), Nigeria. Charles' research utilizes the application of biological techniques and microbial bioprocesses toward the actualization of the sustainable development goals (SDGs) and agrarian revolution.

He served as the Acting Director of Intellectual Property and Technology Transfer, the Head of the Department of Microbiology, Sub-Dean of the Faculty of Science of Edo State University Uzairue. He is currently the Chairman of the Grant Committee and the Ag. Dean of the Faculty of Science at Edo State University Uzairue. He is a Visiting Professor and the Executive Director for the Center of Biotechnology of the Precious Cornerstone University, Ibadan. He is presently an external examiner to many academic institutions around the globe including the Department of Microbiology of the University of Namibia.

He has won several scientific awards and grants from renowned academic bodies such as the Council of Scientific and Industrial Research (CSIR) India, Department of Biotechnology (DBT), India, the World Academy of Science (TWAS), Netherlands Fellowship Programme (NPF), the Agency for International Development Cooperation, and Royal Academy of Engineering among many others. He has published many scientific journal articles and conference proceedings in refereed national and international journals with over 390 manuscripts. His works have been cited more 2300+ times.

His research interests include microbiology, biotechnology, postharvest management, food sciences, bioinformatics, and nanotechnology. He was recently appointed as the President and Chairman Governing Council of the Nigerian Bioinformatics and Genomics Network Society. He was recently appointed as the Director for International Affiliation and Training Centre for Environmental and Public Health, Research and Development, Zaria.

He is a member of many scientific and professional bodies including the American Society for Microbiology, the Biotechnology Society of Nigeria, and the Nigerian Society for Microbiology. Presently, he also serves as the General/Executive Secretary of the Nigerian Young Academy.

Over the last 15 years, Charles has built strong working collaborations with reputable research groups in numerous and leading universities across the globe. He is the convener for Recent Advances in Biotechnology annual conference that is visited by thousands. He is the current President of the Nigerian Post-Harvest and Food Biotechnology Society.

Preface

Undoubtedly we can state that the future is on our plates. The choices of food we eat heavily impact the society we live in, the environment that surrounds us, and even impacts the livelihoods of others.

Hence, food goes way beyond a simple energy intake. Food's essentiality can be easily derived from Maslow's Hierarchy of Needs, as it occupies the foundation of the pyramid.

The United Nations Department of Economic and Social Affairs projects that the world population is expected to reach 9.7 billion in 2050, and a peak at nearly 11 billion people living on this planet is projected around the year 2100. Such population increases do not just mean that there is a need to feed more people, but also to look at alternative ways how to feed these people. Food is more than energy and a safe and secure supply of vitamins and minerals will be very crucial to maintain public health. Increases in population also mean that arable farming land will become shorter, and a natural limit will be reached at some point regarding yields of harvest per acre.

Seaweeds thrive in the exposed areas of the seacoast, from the splash zone to the tidal zone to the sublittoral. Seaweeds grow particularly lush on colder seashores, where nutrient-rich deep water rises. The lower limit for algae growth is around 0.1 % of the incident surface light. The depth that can be reached depends on the turbidity and turbulence of the water; however, it proves that most Western World coasts are suitable for seaweeds to grow and being cultivated. In very clear water, the algae can also colonize deeper zones, and they rarely penetrate to a depth of around 200 m. An exception is some types of golf rod (Sargassum), which are not attached to the subsoil, but can freely swim over large areas in the open sea. This shows how versatile seaweeds are and that there is an untapped opportunity for new farming practices and food production methods. One may imagine offshore food factories, where seaweeds are processed on oil platform-like structures and being looked after. This might be in particular an interesting concept where shores are not easily accessible but do offer perfect growing conditions for seaweeds.

Seaweeds are a major food source for sea urchins, which have become for some years already a pest in many coastal lines. Since the species Pycnopodia helianthoides (sunflower starfish), a key predator of sea urchins, is currently affected by a mass extinction due to a virus and global warming, sea urchins populations have exploded, leading to an obvious threat to seaweeds stocks. It must become a priority to address these issues and again it shows how fragile food security is and how human action affects the larger environment.

Yet, the sea offers in seaweeds a potential nutritious source of foods. Exploiting the sea and the greens within it allows us to take another leap away from the Malthusian trap. There is an obvious disparity between the knowledge of seaweeds as a source of food between western and eastern civilizations. Seaweeds have been an essential part of Asian diets for centuries, most notably in Japan, Korea, and China. However, when looking at western civilizations, very few people are aware of seaweeds being fit for human consumption. Admittedly, in recent years, there have been increases in seaweeds-based products on the supermarket shelves, yet these products are niche and mostly found in the Asian/World Foods section. The most common and notable instances of Westerners consuming seaweed are typically when they eat sushi or other popularized Asian dishes. However, seaweeds, including western products, deliver important extracts for many food formulations, since alginates (polysaccharide fraction) are popular viscosity regulators for processed foods.

This fact is in particular unfortunate looking at historic context: Seaweeds have been an essential part in British (relating to the geographies that form today's United Kingdom of Great Britain and Ireland), Irish, Scandinavian, and Icelandic diet, having delivered a source of nutritious food for the poor. This negative connotation between poverty and seaweeds might have led to this decline in food choice and food awareness.

Crude oil–based polymers are known to degrade very slowly and have already brought detrimental impacts onto the environment (i.e., plastic pollution of the seas, littering) and life (i.e., microplastics presence in living organisms). Again, seaweeds play a more and more increasing role in the race for sustainable and functional biopolymers. Being a product of abundance and renewable, seaweeds are a logic choice to exploit. Currently, seaweeds films are not standard, but commercial products such as NotPLA highlight that there is a route to scale to contain foods. However, seaweed-derived biopolymer films are still limited in their functionality when compared to many laminated and nonlaminated crude oil–based polymer films.

Applications of Seaweeds in Food and Nutrition aims to be used as a practical handbook to educate the next generation of food scientists, food technologists, food engineers, nutritionists, and material scientists. However, we hope this book inspires beyond the set target audience and hopes to reach out to anyone interested in the topic of seaweeds!

This book gives insights into the most recent developments in the field of seaweeds in relevance to food sciences and nutrition. The content of this book covers topics on anthropology and seaweeds, nutritional aspects, economic aspect of farming seaweeds, and the practical incorporation of seaweeds in products.

Chapter 1: History of seaweeds as a food

Ole G. Mouritsen ¹ , M. Lynn Cornish ² , Alan T. Critchley ³ , and José Lucas Pérez-Lloréns ⁴       ¹ Department of Food Science, Taste for Life, Design and Consumer Behaviour, University of Copenhagen, Frederiksberg, Denmark      ² SEADLING, Kota Kinabalu, Sabah, Malaysia      ³ Verschuren Centre for Sustainability in Energy and Environment, Sydney, NS, Canada      ⁴ Instituto Universitario de Investigación Marina (INMAR), Universidad de Cádiz, Cádiz, Spain

Abstract

Seaweeds are multi-cellular macroalgae that, together with unicellular forms, all perform photosynthesis and are the foundation of the Earth's food web. Together, they are responsible for a major part of organic production on the planet. The algae produce essential macromolecules that are the constituents of our food, which are then funneled through various trophic levels of the food web and may end up as human food. Due to their abundance in all climatic zones, their diversity, and their availability along most coast lines, seaweeds have, since primordial times, been intertwined with human lives and development both as sustenance and as a material that has served a multitude of purposes for human activities. This chapter provides a brief sketch of the history of seaweeds as a food for humans and links their unique properties to the evolution of the human brain, to human health and wellbeing, to being a savior in times of famine, and to providing a possible means 41 of rescue in times of unprecedented climate change and food crises.

Keywords

Cooking; Food; Gastronomy; Green transition; Human evolution; Industry; Seaweeds; Sustainable eating; Taste

Introduction: What are seaweeds and why are they eaten?

Neither microalgae nor macroalgae are well-defined biological domains (kingdoms), and their names reflect a time of biological classification where a division was made between plants (i.e., members of the Plantae Kingdom) and ‘nonplants,’ i.e., mosses, lichen, ferns, and seaweeds that were earlier considered as oddities. Even their vernacular term puts seaweeds (or wracks) in a bracket of formerly overlooked or little appreciated photosynthetic living entities. Even more confusing may be that some microalgae are technically a kind of bacteria whereas others are more plant-like (phytoplankton).

Algae in the form of unicellular, blue-green algae (cyanobacteria) go back at least 3 billion years, and they proliferated in a period from 2 to 0.5 billion years ago (Mouritsen & Pérez-Lloréns, 2023). Since they produce molecular oxygen, these organisms changed completely the conditions for life on planet Earth. The multi-cellular seaweeds arrived on the scene much later. There are about 12,000 different seaweed species, and their classification into red, brown, and green seaweeds is, at best, an ill-defined classification with a weak relationship to their actual genetic relatedness (Fig. 1.1). The phylum of red seaweeds (i.e., the Rhodophyta) appeared around 1.5 billion years ago and multiplied rapidly about 700 million years ago. The phylum of green seaweeds (i.e., the Chlorophyta) appeared considerably later, around 900 million years ago. The brown seaweeds (i.e., Ochrophyta) arose only 500 million years ago. The higher plants (i.e., members of the Kingdom Plantae) evolved from green and red seaweeds, whereas the brown seaweeds departed at least 1.5 billion years ago from the evolutionary path that led to the red and green seaweeds. Hence these disparate groups of polyphyletic origin are hardly related at all, yet they are grouped together as ‘seaweeds’ out of convenience.

Thus, whereas green seaweeds are genetically close to higher plants, red seaweeds and, in particular, brown seaweeds are genetically very different. A popular saying is that brown seaweeds, e.g., sugar kelp (Saccharina latissima), are genetically distinct from green seaweeds, such as sea lettuce (Ulva lactuca), as plants and animals are from each other. Seaweeds are abundant in the coastal regions of all salty waters across the planet, and they thrive wherever there is enough sunlight and nutrients in the water (Mouritsen, 2013; Pérez-Lloréns et al., 2018). The different species occupy a huge range of different conditions of habitat, e.g., with respect to water depth, substrata, nutrients, hydrodynamics, exposure to air at low tide, etc. Most of the seaweeds are benthic, that is, they are anchored to the bottom or any other solid material that may be in the water (e.g., piers, buoys, other seaweeds, etc.). They thrive in nutrient-rich, turbulent waters.

Being easily accessible from the coast, and with many occurring in the intertidal domain, it is no surprise that many seaweeds have attracted our early ancestors as a food source. As we shall come back to below, it is impossible to know when and how human beings first considered eating seaweeds, but as nonspecific omnivores, we have always searched our environment for edible materials. Probably, early members of the human lineage who were coastal dwellers quickly realized that, in contrast to many plants and fungi, seaweeds are seldom poisonous, and observations of other birds and animals snacking on these sea ‘weeds’ provided some proof. They may even have found that they are delicious (Dunn & Sanchez, 2021), filling, and do not disrupt their digestive systems. It could be argued that our ancestors have eaten seaweeds from primordial times simply because there is a bounty of seaweeds where inquisitive humans would normally be expected to forage.

Figure 1.1  An abundance of seaweeds on the ocean floor off the coast of France. The large brown alga, wakame (Undaria pinnatifida), is growing along side several different species of red and green seaweeds. Photo courtesy Yves Fontana.

When it comes to various and selected seaweeds as acceptable food sources in modern times, it appears that the peoples on the planet can be divided into four groups: (i) a group in Southeast Asia and Polynesia where seaweeds enter the daily diet and have done so for millennia; (ii) a group that has a continuous, historical record of consuming seaweeds, but in recent centuries only in small amounts (e.g., Iceland, Ireland, Brittany, and Chile); and (iii) a group that eats no seaweeds directly although (a considerable but variable) part of their food may consist of highly processed foods where the rheological properties of seaweeds serve a functional purpose. This latter group may, in earlier times, have eaten seaweeds, but the tradition is well forgotten for reasons unknown. Then there is a fourth group (iv), mostly consisting of people in more affluent countries, who over the last 50 years, gradually but slowly, have included some seaweeds in their diets for health and possibly for reasons of taste (deliciousness). Very recently, some members of groups (ii)–(iv) may have developed an increased interest in a variety of seaweeds as foods driven by international gastronomic trends (i.e., the so-called ‘phycogastronomy,’ see Mouritsen et al., 2019) and a search for more sustainable eating behavior (Mouritsen and Schmidt, 2020).

This chapter will focus on the culinary uses of selected seaweeds as food for humans and only refer to the vast literature regarding the uses of seaweeds as feed and supplements for animals and fish. Furthermore, our perspective will be on those seaweeds used as whole foods and not as nutraceuticals, medicines, food supplements, or functional agents in formulated foods, which are dealt with in other chapters of the present book.

Seaweeds as foods in human evolution

On the timescale of the evolution of seaweeds, the evolutionary path of human beings is comparatively very short. The most primitive form of Homo appeared probably around 4–6 million years ago, and Homo sapiens possibly around 100,000–200,000 years ago (Wrangham, 2009). A critical factor in the development of our lineage has been the evolution of a relatively large brain. To achieve this, very specific building blocks in the diet were required, which fostered this development. Certain seaweeds commonly in the diet may have contributed to such advancements in human development (Cornish et al., 2017). As we shall come back to below, it is virtually impossible to assess if our ancestors in prehistoric times were using seaweeds as foods, and less so to set a time at which humans first started eating seaweeds. The main reason is that macroalgae, consisting of only soft tissues, quickly degrade over even short timescales. Moreover, possible remains of seaweed-based material at human settlements could have been used as a building material, firewood, for ceremonial purposes, or medical aids rather than providing for direct food needs (Dillehay et al., 2008). In contrast to bones, shells, and scales, soft-bodied seaweeds leave few marks or indentations to suggest being processed or eaten as food.

However, there is some indirect and circumstantial evidence that points to seaweeds as an important factor in the evolution of the human lineage, in particular the evolution of the human brain (Cornish et al., 2017). The building of nerve cells, neural circuitry, and complex, large brains require specific molecular building blocks. Furthermore, the proper functioning of a complex human brain requires certain compounds consistently in abundance within the diet. In addition, running a brain demands a lot of energy. Most of these building blocks and the energy must come from the food, although our body can itself synthesize some nonessential biological molecules.

The most striking aspect of nerve cells, as compared to other cells, is their large content of superunsaturated fatty acids (i.e., the long-chained, so-called omega-3 and omega-6 fatty acids). These fatty acids are essential in the sense that we cannot synthesize them ourselves but must get them from the diet. Only algae, both micro- and macroalgae, can synthesize these fatty acids (Grossman, 2016), and from the algae, the essential fatty acids must move up through the various trophic levels of the food web. Compared to other animals, Homo sapiens has a very large brain:body weight ratio, i.e., about 2%, which is typically 10 times larger than for most other animals. We share this unique feature with the dolphin (Crawford & Marsh, 1989). The availability of large amounts of superunsaturated fatty acids would be required for developing and maintaining the functioning of a large brain. Furthermore, there is evidence that these special fatty acids are also important for the complexity of the brain, which is key for supporting cognitive functions (Cornish et al., 2017).

Being a prime and abundant source of supersaturated acids, the marine environment is tightly linked to human development and the evolution of a large and complex brain (Crawford, 2007; Crawford and Marsh, 1989). However, it is accepted that this need not necessarily imply that our ancestors used seaweeds directly as food, but most certainly indirectly by our consumption of marine animals, which from each of their positions in the food web ultimately obtained their fatty acids from algae, including seaweeds. These abundant sources could be marine animals, e.g., fish, shellfish, crustaceans, snails, mollusks, etc. This observation can be considered circumstantial evidence of the type that cannot be definitively proven.

Indeed, there is more circumstantial evidence. Brain development and functioning require, in addition to superunsaturated fatty acids, special nutrients that are abundant in seafood, such as zinc, magnesium, iodine, taurine, and vitamin B12 (Cornish et al., 2017), and various seaweeds contain a bounty of these substances. Hence, seaweeds appear to contain several of the very important chemical components required in a diet necessary for human growth, nutrition, and cognitive development. However, the calorific content of seaweeds is low, and they could therefore only be part of a full diet, although potentially a very important part that must be supplemented with other marine seafood as well as fruits and starchy land plants for optimum human growth and development.

Seaweeds as a food in prehistoric times

Several books and thematic articles have provided accounts of different facets of the human interaction with seaweeds (see e.g., Mouritsen, 2013; Mouritsen & Pérez-Lloréns, 2023; Mouritsen et al., 2021; O'Connor, 2017; Pereira, 2016; Pérez-Lloréns et al., 2018, 2020). It has recently been pointed out that seaweeds have often come to the rescue of human health and society in times of crisis (Mouritsen et al., 2021). There is hardly any application in human activities where some seaweeds have not played some kind of important, influential role over time. These applications not only include seaweeds as direct food but also as medicinal aids, building and insulation materials, fuel, containers, jewelry and toys, currency, source of minerals and fine chemicals, ecosystem services for pollution clean-up, and even for combating climate change (Mouritsen et al., 2021). In addition, it appears that some seaweeds have also served ceremonial and religious purposes (O'Connor, 2017; Pérez-Lloréns et al., 2020).

The most celebrated example of possible prehistoric human use of seaweeds as food or medicine stems from an archaeological excavation site in Monte Verde in southern Chile (Dillehay et al., 2008). Finds at this site dating 14,000 years ago date back to the late Pleistocene Era and included the remains of 20 different marine seaweed species, from, e.g., the genera Pyropia, Gracilaria, Sargassum, Macrocystis, and Durvillaea. It is remarkable that some of the same species are still used for medicinal purposes by people in the area today.

Traces of seaweeds found on stone tools suggested that the seaweeds were processed in some way, possibly by chopping them into pieces or grinding them, for medicinal purposes. It is impossible to tell if the seaweeds were used as a food source or as medicine. However, it is unlikely that it has been used as firewood. Monte Verde is a settlement located inland, several kilometers from the coastline, and the use of these specific seaweeds indicated that the inhabitants must have had a tradition for venturing to the sea and collecting seaweeds for their needs. This tradition has been linked to the prevailing theory of the peopling of South America along the so-called ‘kelp highway’ (Erlandson et al., 2007). According to this theory, the first humans arrived in North America from Asia via the Beringia land bridge at least 14,000 years ago and from there moved south along the west coast of North America and then further south along the west coast of South America. The finding of a wide range of different seaweed species in Monte Verde suggested that the migrating people had developed rather advanced uses of a range of seaweeds along their extended migration route and maintained the tradition of collecting seaweeds throughout the seasons of the year after settling inland in the southern parts of Chile (Fig. 1.2).

Although we have no historical record to document this, it is likely, simply due to the abundance and availability of a great variety of seaweeds, that coastal dwellers around the world have included at least some of them as sustenance and supplementation to their land-based diets. Although the most early written records mentioning human uses of seaweed pertain to medicinal purposes, we find it highly likely that seaweeds, in one way or another, found their way into the ancient culinary cultures. As we shall see below, some of these cultures have a continuous and proud tradition of using seaweeds as foods up to modern days (Mouritsen, 2013; Mouritsen et al., 2021; O'Connor, 2017; Pérez-Lloréns et al., 2018, 2020).

Historical and traditional uses of seaweeds as food

The general history of human interaction with seaweeds, including some uses as food during famine and the current quest for sustainable food production, was recently reviewed in the context of selected seaweeds being a savior of human activities and welfare in times of need (Mouritsen et al., 2021). It was pointed out that under critical conditions, such as famine, diseases, environmental disasters, wars, and the climate crisis, humans have often turned to seaweeds and created new opportunities for their use to mitigate disasters. Another recent review testified how seaweeds featured at large in mythology, folklore, poetry, and human daily life, not least as food (Pérez-Lloréns et al., 2020).

Below we provide a short overview of the historical and traditional uses of seaweeds, which can be documented around the world. A more comprehensive review, including world seaweed cuisine and gastronomy, i.e., phycogastronomy, can be found in Mouritsen et al. (2018). It would appear that in Asia, particularly in Japan, Korea, and China, and in some places in Polynesia, especially Hawaii, there is a living and strong culinary tradition for using a variety of seaweeds in the daily diet. This can be contrasted to the Americas and Europe, where only some pockets of food cultures have maintained a continuous tradition of use and others who apparently abandoned the uses of seaweeds in current times, yet have a strong recollection of their uses in past eras.

The consumption of seaweeds is very different in the various regions of the world, as shown in Table 1.1. Almost all the seaweeds used for human food are consumed in Southeast Asia. The table also shows that whereas the people of Japan and Korea consume over 90% of the total amount of harvested seaweeds, seaweed production in China is equally shared between human consumption and industrial applications (mostly for gums and gels). One caveat is that the data in the table is subject to some uncertainty due to the import and export of certain seaweeds and the reliability of reporting methods.

Some seaweeds for human food are still harvested from wild populations, including some of the giant kelps. However, most of the seaweeds (i.e., more than 95%) used in the world for human consumption come from aquaculture (i.e., large-scale, open-water seaweed cultivation or phyconomic activities), mostly in Southeast Asia. There is still very little cultivation of seaweeds outside Asia, although recent years have witnessed a number of mostly experimental initiatives within Europe and the Americas. These activities are likely to be enhanced as part of a green transition in the global food production systems.

Figure 1.2  Left: Microscopic view of remains of the brown alga Sargassum sp. found on the floor of a hut at Monte Verde in southern Chile, dating from about 12,000 BCE. Right: Stone tool from Monte Verde with remnants of seaweed along its edge. From Dillehay, T. D., Ramírez, C., Pino, M., Collins, M. B., Rossen, J., & Pino-Navarro, J. D. (2008). Monte Verde: Seaweed, food, medicine, and the peopling of South America. Science, 320, 784–786.

Table 1.1

Modified from McHugh, D. J. (2003). A guide to the seaweed industry. FAO, Fisheries Technical Paper, Vol. 441, 73–90.

Southeast Asia

China

Seaweeds (or hǎicǎo) were consumed in China as early as 2700 BCE and were afforded great reverence (Porterfield, 1922). During the Sung Dynasty (960–1279) nori (Porphyra/Neopyropia spp.) was presented yearly as a precious gift to the Emperor (Tseng, 1984). At least 74 seaweed species have been used as human food or medicine in China, most notably wakame, konbu, and nori (Xia & Abbot, 1987). Traditionally, the Chinese preferred seaweeds in a hot dish or soup. In recent centuries, konbu has been used as a kind of sea vegetable that is served along with pork meat and soy sauce. Contemporary uses of seaweeds in Chinese cooking include Cantonese seaweed soup with nori and various seaweeds in fish and vegetable dishes or mixed as filling in dumplings. Nori sheets are also used to wrap various ingredients, such as shrimp. In Shanghai, a popular dish is seaweed fried rice and the cold appetizer ‘Hot and sour seaweed,’ with chopped seaweed in a soy sauce, vinegar, chili oil, and garlic mixture. Strips of softened agar (extracted from specific red seaweeds, e.g., Gracilaria spp.) appear in salads or along with other dishes, e.g., with chicken (Simoons, 1991).

Japan

The Ainu (which means ‘human’ in their own language) are the original inhabitants of the island of Hokkaidō in northern Japan. Ainu are animists and feel a deep reverence for nature. It appears that the word konbu (or kombu) comes from kompu, a word these people used to refer to things that grow on the rocks of the seabed. Ainu activities included the harvesting and use of seaweeds, mainly konbu, to make their traditional tasty ohaw soup, a kelp stock flavored with fish or animal bones (Pérez-Lloréns et al., 2018) (Fig. 1.3).

Similar to the transfer of many other elements of culture, art, and crafts between China and Japan, it appears that the Chinese at some point in time demonstrated both medicinal and culinary uses of seaweeds to the Japanese, who then incorporated them into their food culture and raised their uses to new gastronomical heights. However, the Japanese, may have used seaweeds at least as early as the Chinese. In Japan, remains of some seaweeds (or kaisō) mixed with fish bones and shell fragments were found in human settlements from the Jōmon Era (i.e., 10,500–300 BCE) and the Yayoi Era (i.e., 200 BCE–200 CE) (Nisizawa et al., 1987). Judging from the archaeological finds, the seaweeds utilized were cooked in clay pots, a kind of early nabemono, which to this day remains the most eaten type of hot-pot dish in Japan. Mention of the use of nori from Pyropia/Porphyra is found in a written document, the Tahio Law Codes from 701 BCE. This document described 30 types of marine crops, including seaweeds, for which a yearly tax had to be paid to the Emperor (Tseng, 1984). Nori was associated with the highest value and veneration (O'Connor, 2013). The same is the case in today's Japan (Fig. 1.4).

Figure 1.3  A native Ainu from the island of Hokkaidō drying Saccharina japonica (konbu) and baling it for use over the winter. From Landor, A. H. S. (1893). Alone with the hairy Ainu. Or, 3,800 milles on a pack saddle in Yezo and a cruise to the Kurile Islands. London: John Murray.

Figure 1.4  N ori (Porphyra spp.) harvesting in Japan in ancient and modern times. Left: Woodblock print by Katsukawa Shunsen (1762-ca. 1830). Right: Harvesting nori mechanically by boat at the Ariake Sea. Photo courtesy by Ole G. Mouritsen.

Seaweeds were, until modern times, harvested in the wild and sold at open markets, and the higher qualities, in particular nori, were mostly a luxury good in the Heian Era (794–1185). The demand for seaweeds increased along with the spread of Buddhism and vegan cuisine in the Kamakura Era (1185–1333). In the Edo Era (1603–1867), nori became popular as a wrap for vegetables and various seafoods, most well-known from maki-sushi, which remains very popular right up to this day and has now entered the realm of global cuisines. Processing of the large brown seaweed konbu (i.e., Saccharina japonica and S. longissima) for culinary purposes stems from about 1730 (Smith, 1905). The seaweeds were harvested on the northern island of Hokkaidō and transported in dried form along the so-called ‘konbu-route’ to Kyoto and Sakai, where they were stored and matured in cellars and then manufactured, including with the use of soy sauce and vinegar into several products (Fig. 1.5).

Konbu still has a special place in Japanese cuisine since it is the main ingredient in the famous Japanese soup stock, dashi, around which the whole traditional Japanese cuisine revolves, not least of all the vegan cuisine, shojin ryori (Mouritsen & Styrbæk, 2014). Aqueous extracts of konbu are the mother lode of the basal umami taste or flavor that we now know is elicited by high amounts of free glutamate (Ikeda, 2002(1909)). Konbu comes in many different varieties and qualities and the highest of which served as precious gifts. Processed konbu in the form of various condiments has been used to impart umami to bland steamed rice dishes, e.g., so-called konbu-tsukudani that is konbu simmered in soy sauce, areal umami bomb.

Other seaweed species traditionally used in Japan, along with nori and konbu include wakame (Undaria pinnatifida), hijiki (Sargassum fusiforme), arame (Ecklonia bicyclis , E. arborea), as well a range of small and decorative red seaweed species used in salads, e.g., the red and crispy seaweeds funori (Gloiopeltis spp.), ogonori (Gracilaria spp.), and tosaka-nori (Meristotheca papulosa).

Nori is produced as a kind of seaweed paper from Pyropia/Porphyra species, and despite great demand and many efforts made over the centuries to farm this seaweed, this was only made practically feasible after the discovery in 1949 of the peculiar life cycle of Porphyra umbilicalis (purple laver) by the British seaweed researcher Kathleen Mary Drew-Baker (1901–51) (Mouritsen, 2013). It is, therefore, not without reason that Drew Baker in Japan is known as ‘The Mother of the Sea.’ Every year, on the 14th of April, the nori fishermen gather on a hill overlooking the Ariake Sea in southern Japan to honor Drew Baker, whose work was absolutely crucial in laying the foundation of domestication for the seaweeds for cultivation and the now very prosperous Japanese nori industry. As already mentioned, nori is used as a wrap in sushi or simply around a ball of steamed rice (onigiri), which is popular street food. It is also used in small strips as a condiment with steamed rice. Other traditional uses of the Pyropia/Porphyra come in the form of nori-tsukudani, which is seaweed simmered in soy sauce, or simply as dried fronds on seafood dishes.

Figure 1.5  Collection and harvesting of konbu (Saccharina japonica) in Japan in ancient and modern times. Left: Matsumae-konbu gathering in the Edo Era (1603–1867), an illustration from the book Nihon sankaimeibutsu-zue (1797). Right: Harvesting of farmed konbu on the island Hokkaidō in Japan. Photo courtesy S. Kawashima.

In a report carried out in 1905 by the United States Department of Commerce and Fishing on the Japanese seaweed industries, it was remarked that: "At railway stations, at street stands, and in the push carts of vendors, as well as in private families, a common seaweed article in all parts of Japan takes the place of a sandwich in America and is called sushi. On a sheet of amanori [nori], boiled rice is spread, and on the rice, strips of meat or fish are placed; the whole is then made into a roll and cut into transverse slices."

Wakame has been cultivated widely around the Japanese coastlines at least back to the Nara Era (710–794), and it is used both raw, dried, blanched, boiled, and salted. It was, and still is, an omnipresent ingredient in Japanese soups, such as miso soup, and in green salads. In particular, the sporophylls (mekabu) of wakame are highly appreciated for their rich and nutty flavor and cartilaginous texture (Koreans call them ‘ears of wakame’ not only because of their appearance but also because of their cartilaginous (and soft) mouthfeel).

The brown seaweeds arame and hijiki have also enjoyed a long-time use in Japanese cuisine. Arame has a rather mild taste and is often included in soups and salads. Hijiki has a nutty flavor and a firm texture and is typically used as a soy sauce-simmered condiment along with a breakfast serving and as a topping on steamed rice.

A special preparation of the red seaweed tengusa (Gelidium amansii) comes in the form of kanten (agar), which technically is a hydrogel well suited to form gels. Kanten enjoys a long history in Japanese food culture (Nisizawa, 2002) both as a soaked, soft, and somewhat crispy element of a salad or as a gelling agent in sweet desserts (yōkan and mitsuname), often prepared with sweet azuki beans (Fig. 1.6).

Figure 1.6  Yōkan, seaweed jelly with red azuki beans made with agar (kanten) from red seaweeds (Gelidium amansii). Photo courtesy Jonas Drotner Mouritsen.

Korea

Like Japan and China, Korea has a long tradition of using seaweeds (or jolyu) as food, and they are part of the local culture and folklore, not least of all as wakame in soups (Pettid, 2008). The traditional example is miyukkuk, a soup cooked with wakame and clams. This soup is often consumed when celebrating childbirth and birthdays. In the second half of the 20th century, after the advent of rational farming of Pyropia/Porphyra in aquaculture, Koreans adopted Japanese-style uses of nori (O'Connor, 2017), called kim or jim in Korean, for example for maki-sushi (gimbap). The Koreans often prefer their nori seasoned with sesame and perilla oils.

Thailand

In Thailand, seaweeds have been consumed fresh or blanched as salad vegetables, mixed with other ingredients, or used in soup preparations (Lewmanomont, 1978).

Polynesia and South Pacific

The peoples of the many islands of Polynesia, in particular Hawaii, have a grand tradition more than three millennia old for eating seaweeds and considering them a delicacy suited for the gods (O'Connor, 2017; Ostraff, 2003). In Hawaii, seaweeds (limu) were grown in special marine gardens installed by chefs, using such species as Asparagopsis taxiformis, Grateloupia filicina, Gracilaria coronopifolia, Laurencia nidifica, Codium spp., and Ulva spp. Preparations of limu used a mixture of seaweeds mashed or chopped along with chilis and salt and were eaten as a relish with poi (a traditional Polynesian stable dish made from starchy vegetables, e.g., breadfruit, plantain, or taro). In Hawaii, limu is traditionally served at celebrations, like birthdays and anniversaries, and can nowadays also be presented as a gift (Abbot, 1978). Another traditional dish is ake limu, which brings together the seaweed Grateloupia filicina with raw liver.

Aku-po-ke is a dish of chunks of raw fish, seaweed, and other condiments. The modern-day popular poke salad is a manifestation of the globalization of this type of Polynesian food.

Limu was a vital part of the diet in the Kingdom of Tonga before the arrival of the Europeans in 1820, and it served as a rescue during times of famine. It is said that when Captain Cook visited Tonga in 1777, the islanders offered him limu to restore his strength and energy.

The seaweeds would be crushed, boiled, baked, dried, or pounded and eaten fresh and sometimes pickled. Today, unfortunately, limu is no longer an important part of the diet in Tonga (Ostraff, 2003) (Fig. 1.7).

European seafarers reported as early as 1292 seaweed uses around Indonesia where they were used as a kind of sea vegetable (Zaneveld, 1955). Although not part of peoples' diet except along the coastline, Indonesian inhabitants used seaweeds raw as salads, boiled as vegetables, pickled, cooked with coconut milk, or as a thickening agent in soups puddings and jellies (Soegiarto & Sulustijo, 1990).

There are examples of the use of seaweeds as food in the Philippines, where a popular red species, Eucheuma spinosum (now E. denticulatum), was prepared in the so-called kinilaw-style, involving short-time blanching and then marinating in vinegar, tomato, ginger, onion, and chili. Whereas Australia does not have a long-documented use of seaweeds as food (Winberg, 2017), a specific Australian coastal chef cuisine has come on the scene in recent years, flourishing on the richness of seaweeds, in particular on the south coast and around Tasmania (Tinellis, 2014). In contrast, the Maori people of New Zealand paid some attention to sea vegetables, specifically Caulerpa spp. (sea grapes). The traditional Maori diet included several seaweed species, both as foods and medicines, such as greens (Ulva spp.), browns (Durvillaea antarctica (called rimuroa) and Hormosira banksii), and reds (Pyropia/Porphyra spp. (called karengo) and Gigartina spp. (called rehia)). Karengo was considered a real, traditional delicacy (Smith et al., 2010).

The Americas

Seaweeds are known to have been used as foods by coastal tribes of Native Americans, including Inuit, in both South and North America, as also alluded to above when describing the peopling of the two continents along the ‘kelp highway.’ Along the northwest coast of Canada, it was particularly red laver (Pyropia/Porphyra), and the Kwakwaka'wakw and Haida tribes dried the seaweeds, packing them together sometimes with fats from fish, and let them ferment for days. The resulting product was a kind of cake that was then chopped or shredded and subsequently boiled in soups or stews. Often, the freshly picked laver was simply dried in the sun on rocks. This is very much in the same way laver is processed nowadays in coastal areas of North America, also on the east coast in Maine and the Canadian Maritime provinces.

Figure 1.7  Green katoni (Eucheuma cottonii) farming at Nusa Lembongan, Bali. Photo courtesy Jean-Marie Hullot.

Dried laver was then used either as a snack or cooked in a variety of dishes, traditionally along with heads of halibut, clams, or salmon (Kuhnlein & Turner, 1991). European traditions (see the section below) with using various seaweeds were, in the mid-19th century, brought along with Irish and Scottish immigrants to coastal areas in both West and East North America (California, British Columbia, Nova Scotia, and New England) and became part of the culinary traditions, particularly in the Canadian Maritime provinces. The delectable red seaweed, dulse (Palmaria palmata), was the preferred seaweed, a preference that has survived in modern-day snacks in the area.

Turning to South America, as mentioned earlier, uses of seaweeds as food go at least 14,000 years back in Chile. There has been a continuous tradition of using seaweeds, as food during times of hunger. Macocho (Gigartina spp.) is typical of Peru, and luche (Pyropia columbina) and cochayuyo (Durvillaea antarctica) have been consumed in Chile since pre-Columbian times (Fig. 1.8). The Mapuche used cochayuyo at the time when the Spanish first arrived, and it was incorporated into the diet by the colonizers themselves (Pereira, 1977). Luche has been consumed by the Mapuche and Mestizo both as filling in empanadas, sauteed, as well as in soups, stews, and salads. A typical meal is lamb cazuela with luche. Like the Europeans imported their traditions for using seaweeds as food to New England, a wave of Japanese immigrants brought Japanese culinary traditions into Brazil and Peru in the late 1900s (Masterson & Funada-Classen, 2004), over time leading to a kind of fusion cuisine. The best-known example is Nikkei-style Japanese-Peruvian fusion food, which is now being globalized. It is nori (luche) which is the key seaweed here in various kinds of wrapped sushi (e.g., temaki), that in addition to local seafood can include tropical fruits and dressings with lime.

Figure 1.8  Cochayuyo (Durvillaea antarctica) seller at a Chilean market. Photo courtesy Javier Ignacio Acuña Ditzel.

Europe

Uses of seaweeds as food in Europe may go as far back as 9000 years to the Mesolithic Era (9000–4000 BCE), although, as mentioned before, seaweeds do not leave traces in the many middens with remains of fish and shellfish found in coastal areas around Europe. In Ireland, the Brehon Laws from the 5th century mention seaweed, duileasc (dulse, Palmaria palmata), as a condiment to serve with bread, milk, and butter.

In North European countries, seaweeds were rather common as food in coastal areas, particularly in Scotland and Ireland, where a common preparation would be a soup with shellfish, seaweeds, vegetables, and herbs allowed to extensively simmer (Sexton, 1998). There is a 1400-year-old written record of monks in Western Scotland collecting dulse and handing it out to poor people. Camden's Brittania from 1607 described a seaweed-based food called lhavan (black butter) (Newton, 1951). Generally, consumption of seaweeds in both Scotland and Ireland was often associated with poor times and famine (e.g., the Great Famine in Ireland, 1845–52), a striking contrast to the celebration of seaweeds in Southeast Asia. Other historical uses of seaweeds in Ireland include dried carraigin (carrageen, Chondrus crispus) and duileasc (Palmaria palmata) (Fig. 1.9).

The Irish seaweed cuisine has enjoyed increased attention both in Ireland and abroad due to the writings of Prannie Rhatigan, M.D., who revived and renewed this traditional cuisine in her books (Rhatigan, 2009, 2018). She describes the customary uses of a wide range of seaweeds found along the Atlantic and Irish coasts and how they can find a place in modern households.

Examples include dulse (Palmaria palmata), laver (Pyropia/Porphyra), carrageen (Chondrus crispus), oarweed (Laminaria digitata), sugar kelp (Saccharina latissima), pepper dulse (Osmundea pinnatifida), bladderwrack (Fucus vesiculosus), and sea lettuce (Ulva spp.). Dulse champ is still a traditional favorite in Northern Ireland, potatoes mashed with milk and butter, and sprinkled with cooked and chopped dulse. Sleabhac (laver, Pyropia spp.) was harvested right after the first heavy frost of the season in early January. Traditionally, it was simmered for up to 4 h, then seasoned with a little salt and pepper and mixed with very finely diced onion. It was eaten on its own or with potatoes or bread. In her most recent book, Rhatigan (2018) takes the seaweed traditions into a range of Christmas dishes.

Figure 1.9  Many Irish people survived the great famine (1845–52) thanks to eating seaweeds. An etching published in The Christian Herald and Signs of Our Times (1886). From The Christian Herald and Signs of Our Times (1886).

Bara lawr or laverbread is a traditional Welsh preparation of laver (Pyropia/Porphyra). Laverbread (that has nothing to do with bread) is typically eaten for breakfast with oatmeal, bacon, and cockles. It bears some resemblance to the Japanese nori-tsukudani mentioned above. Laverbread is made by a laborious process involving rinsing the freshly picked seaweed, followed by boiling for at least 6 h until it becomes a brown and mucilaginous sludgy mass with a full marine flavor (O'Connor, 2013). Laver has also been used to make a sauce to go with a dish of roasted salt marsh lambs from Wales (O'Connor, 2017) (Fig. 1.10).

Although Brittany and France mostly have a long tradition of using seaweeds for feed and industrial purposes, there is a traditional dish, bara mor (‘the bread of the sea’) where dulse and kelp seaweeds are minced in butter (beurre des algues) and used for cooking fish or spreading on bread. However, in recent years, several Breton companies have built a business supplying the European market with a variety of dried and salted seaweeds from the waters around Brittany.

Figure 1.10  Laverbread, a traditional Welsh preparation of Porphyra spp. Photo courtesy Jonas Drotner Mouritsen.

In several Nordic countries, seaweeds have been exploited as human food or as feed for livestock for at least the last 1000 years, although the tradition remains only in a few places, particularly in Iceland, Greenland, and the Faroe Islands. The use of dulse (called søl in old Norse) goes, according to old Icelandic laws, at least back to 931 (Hallsson, 1964). The value assigned to dry dulse was signaled in its use as a currency. For preparation as food, the fresh dulse was washed, dried, and packed in barrels, where it was kept dry and compressed, sometimes for months before eating. Dulse was often consumed daily with dried fish and butter or with milk and bread. Today, dulse is eaten in Iceland as a snack or in salads (Fig. 1.11). When promoting and marketing seaweeds, the Icelanders refer to the old tradition of using seaweeds, e.g., by attaching the word Viking to some of the products. In addition to dulse, winged kelp (Alaria esculenta) was considered as a delectable seaweed by the old Icelanders, at least over the last couple of centuries. The freshly harvested winged kelp was kept for a couple of days in fresh water and then chopped and cooked with water or milk and flour. The resulting dish was eaten as a thick pudding with milk or cream as described by Pratt (1850), who remarked: "This sea-weed has when first tasted a pleasant flavor; but that it leaves upon the tongue and mouth a disagreeable crust of greenish mucus. The midrib is eaten in its raw state, but it would not easily be digested by any but persons who can take robust exercise, for it is as hard as the raw carrot or turnip of our fields, and to many its fishy,