Savouring the sea: Production and consumption of future seaweed foods
Author
Summary, in English
Current food systems pose one of the greatest health and environmental challenges of the
21st century. A systemic shift in the food sector can be accelerated by technologies and innovations,
such as seaweed food applications. However, introducing and expanding seaweed as a food resource
into Western markets comes with several challenges.
These challenges include its microbial, chemical, and sensory quality, which constitute the main focus
areas of this thesis. Microbial stability was assessed by two alternative methods: fermentation and high-
pressure processing. It was found that fermentation of seaweed by means of lactic acid bacteria is
possible and can exert a promising preservation effect that is able to decrease the pH to out-conquer
spoiling bacteria. The effect of treatment with high pressure was more difficult to evaluate but showed
that the algal texture was altered by up to an 87.7% reduction in hardness and a 60.0% reduction in
compression (chewiness). Processing can enhance the chemical and sensory characteristics, which is
important for increasing food safety and consumer acceptance.
It was further found that the chemical composition of seaweed differs depending on species and harvest
site, and between its different parts. This was observed for both nutrients and potentially toxic elements.
Our studies further showed that while treatment with scalable methods was able to decrease the levels
of total arsenic by 61.1%, inorganic arsenic by 92.4%, lead by 49.4%, and iodine by 72.8%, some
elements, such as mercury and cadmium, were difficult to remove. Considering current regulations,
iodine and cadmium exert the greatest challenges for chemical seaweed quality. Therefore, the species
and cultivation sites should be selected carefully to produce seaweed that is safe for consumption.
To evaluate consumers’ perceptions, descriptive and hedonic analyses were performed. In the
descriptive study, the sensory profiles of four common northern European seaweed species were
mapped. Generally, they had high levels of saltiness, medium umami, low bitterness and sourness, and
no perceived sweetness. Variations between the species’ sensory attributes were moreover observed,
with green and red seaweed associated with grassiness and the sea, respectively. Brown kelps did not
stand out considerably and were similar overall. In the hedonic study, 53.1–77.6% of the respondents
gave positive scores for seaweed bread and 50.0–67.3% liked the seaweed spread. Inclusion of
seaweed into familiar food products could be a successful strategy for increasing its consumption.
However, the sensory attributes of different species should be considered. Nutritional and sensory
profiles of seaweeds can serve as indicators for how to use seaweeds in everyday life.
Overall, the findings in the thesis can be useful as knowledge for the development and improvement of
future seaweed products and their availability, by industrial stakeholders, the academic community
and/or indirectly by consumers.
21st century. A systemic shift in the food sector can be accelerated by technologies and innovations,
such as seaweed food applications. However, introducing and expanding seaweed as a food resource
into Western markets comes with several challenges.
These challenges include its microbial, chemical, and sensory quality, which constitute the main focus
areas of this thesis. Microbial stability was assessed by two alternative methods: fermentation and high-
pressure processing. It was found that fermentation of seaweed by means of lactic acid bacteria is
possible and can exert a promising preservation effect that is able to decrease the pH to out-conquer
spoiling bacteria. The effect of treatment with high pressure was more difficult to evaluate but showed
that the algal texture was altered by up to an 87.7% reduction in hardness and a 60.0% reduction in
compression (chewiness). Processing can enhance the chemical and sensory characteristics, which is
important for increasing food safety and consumer acceptance.
It was further found that the chemical composition of seaweed differs depending on species and harvest
site, and between its different parts. This was observed for both nutrients and potentially toxic elements.
Our studies further showed that while treatment with scalable methods was able to decrease the levels
of total arsenic by 61.1%, inorganic arsenic by 92.4%, lead by 49.4%, and iodine by 72.8%, some
elements, such as mercury and cadmium, were difficult to remove. Considering current regulations,
iodine and cadmium exert the greatest challenges for chemical seaweed quality. Therefore, the species
and cultivation sites should be selected carefully to produce seaweed that is safe for consumption.
To evaluate consumers’ perceptions, descriptive and hedonic analyses were performed. In the
descriptive study, the sensory profiles of four common northern European seaweed species were
mapped. Generally, they had high levels of saltiness, medium umami, low bitterness and sourness, and
no perceived sweetness. Variations between the species’ sensory attributes were moreover observed,
with green and red seaweed associated with grassiness and the sea, respectively. Brown kelps did not
stand out considerably and were similar overall. In the hedonic study, 53.1–77.6% of the respondents
gave positive scores for seaweed bread and 50.0–67.3% liked the seaweed spread. Inclusion of
seaweed into familiar food products could be a successful strategy for increasing its consumption.
However, the sensory attributes of different species should be considered. Nutritional and sensory
profiles of seaweeds can serve as indicators for how to use seaweeds in everyday life.
Overall, the findings in the thesis can be useful as knowledge for the development and improvement of
future seaweed products and their availability, by industrial stakeholders, the academic community
and/or indirectly by consumers.
Department/s
Publishing year
2024-03-18
Language
English
Full text
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Document type
Dissertation
Publisher
Biotechnology, Lund University
Topic
- Food Science
Keywords
- Saccharina latissima
- Alaria esculenta
- Palmaria palmata
- Ulva spp.
- Microbial stability
- Chemical safety
- Sensory analysis
Status
Published
ISBN/ISSN/Other
- ISBN: 978-91-8096-026-7
- ISBN: 978-91-8096-027-4
Defence date
19 April 2024
Defence time
10:00
Defence place
Lecture Hall KC:A, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund
Opponent
- Claus Heiner Bang-Berthelsen (Senior Scient.)