Page 46 - FoodFocusThailand No.157 April 2019

STRATEGIC R & D

Seaweeds-derived

Potential Functional

Food Ingredients

for Gut Health Benefits

Seaweed Bioactive Compounds and their Potential to commercial interest in the isolation and development of
as Functional Foods polysaccharides and other compounds with gut health potential from
Seaweeds are a large and diverse group of photosynthetic macro- novel sources.
algae found across the world’s oceans. They can be categorized into
different taxonomic groups based on their pigments, including red Prebiotic Effects of Seaweeds
seaweed (Rhodophyceae), green seaweed (Chlorophyceae), and Most seaweed polysaccharides such as alginates, fucoidans,
brown seaweed (Phaeophyceae). The cultivation of seaweeds has laminarins, ulvans, agars, and carrageenans may be regarded as
been growing rapidly and is now practiced in about 50 countries, and dietary fibre, as they resist the digestion by enzymes present in the
28.5 million tonnes of seaweed and other algae were harvested in human gastrointestinal tract, selectively stimulate the growth of
2014 to be used for direct consumption, or as a starting material for beneficial gut bacteria, inhibit pathogen adhesion and evasion, and
the production of food, hydrocolloids, fertilizers, and other purposes modulate intestinal metabolism including fermentation (O’Sullivan
(FAO, 2016). et al., 2010). The digestibility of seaweed components can be
Recently, the annual global production of seaweed hydrocolloids determined in vitro to verify whether they are decomposed by human
for various applications across the food, pharmaceutical, and digestive enzymes, and thus their likelihood of reaching the large
biotechnology industries has reached 100,000 tonnes and a gross bowel and its resident microbiota. Neoagaro-oligosaccharides from
market value just above USD 1.1 billion (Rhein-Knudsen et al., 2015). red seaweeds, for instance, have shown that they were not digestible
There is a growing recognition that seaweeds are important sources by enzymes typically present in the small intestine (Hu et al., 2006).
of bioactive compounds with a variety of biological activities which The fermentation of seaweed components by beneficial bacteria
are not produced by terrestrial plants. They are rich in carbohydrates, has also been shown to generate beneficial metabolites such as
proteins, polyunsaturated fatty acids (PUFAs) including omega-3 fatty short chain fatty acids (SCFAs), particularly butyric, acetic, and
acids, and minerals as well as polyphenols, pigments (chlorophylls, propionic acids (de Jesus Raposo et al., 2016). Butyric acid is the
fucoxanthins, phycobilins), and mycosporine-like amino acids (MAAs). primary energy source of cells lining the colon, and helps maintain
These compounds possess various biological functions including colonic tissue integrity through stimulation of apoptosis in cells with
antioxidant, anti-HIV, anticancer, antidiabetic, antimicrobial, high levels of DNA damage. Acetic acid can inhibit the growth of
anticoagulant, antivirus, anti-tumor, anti-inflammatory, enteropathogenic bacteria, and propionic acid produced in the gut
immunomodulatory, prebiotic and cholesterol lowering effects (Holdt may influence hepatic cholesterol synthesis (Raman et al. 2016).
and Kraan, 2011). The beneficial effects of SCFAs on host health include protection
from obesity, chronic respiratory disease or asthma, cancer, and
Overview of Prebiotics inflammatory bowel, as well as modulation of immunity, glucose
Interest in prebiotics as functional foods has increased due to their homeostasis, lipid metabolism, and appetite regulation (Koh et al.,
recognized health benefits. The term ‘prebiotic’ was introduced and 2016; Morrison and Preston, 2016).
defined as substrates that (1) are resistant to gastrointestinal digestion Beneficial changes in gut microbes in response to prebiotics is
and absorption, (2) can be fermented by the microbes in the large well documented, and this has been demonstrated for seaweed-
intestine, and (3) selectively stimulate the growth and/or activity of derived prebiotics in several studies. For instance, Charoensiddhi
the intestinal microbes leading to health benefits of the host. The et al. (2016) demonstrated that extracts from the brown seaweed
global prebiotics market size was over USD 3.34 billion in 2016, and Ecklonia radiata stimulated the growth of beneficial microbes such
continued growth is expected due to increasing consumer awareness as Bifidobacterium and Lactobacillus which are the most commonly
of gut health issues (Grand View Research, 2019). Prebiotics recognized bacterial markers of prebiosis. Kuda et al. (2015)
commonly used in the current market include inulin, demonstrated that sodium alginate and laminaran from brown
fructooligosaccharides, galactooligosaccharides, and lactulose. A seaweeds inhibited the adhesion and invasion of pathogens
growing consumer awareness of the benefits of prebiotics is leading (Salmonella Typhimurium, Listeria monocytogenes, and Vibrio

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