Hydrocolloids as Functional Food Ingredients for Gut Health

Seaweeds are a natural source of nutrients, and dependent on the variety, are rich in dietary fibre, proteins, essential vitamins and minerals. However this resource is highly underexploited. Countries such as Japan, China, North and South Korea are large consumers of edible seaweed while exposure in Western countries is much lower and mainly as industrially extracted seaweed derivatives, a common additive in many food and healthcare products. Seaweeds have been associated with a number of human gut promoting health benefits such as decreasing faecal transit time through the gastrointestinal tract thus preventing constipation and resulting in a reduced exposure to harmful substances (decreasing colon cancer risk). These health benefits can be attributed to seaweeds high dietary fibre content. Interestingly, the food and healthcare industry already utilize seaweed-extracted fibre in the manufacturing process thus steering the way forward towards the development of novel functional food products. These seaweed-extracted fibres are high molecular weight polysaccharides known as hydrocolloids and are non-digestible by humans, hence classified as dietary fibre. Traditionally, seaweed derived polysaccharides (hydrocolloids) have been used to provide thickening and gelling functionality to food stuffs and other industrial applications however there is emerging evidence to show that lower molecular weight polysaccharides and oligosaccharides derived from these hydrocolloids can also act as a source of soluble fibre and may have prebiotic activity. Recent developments in Japan and Korea have lead to the commercial availability of products containing low molecular weight seaweed derived fibre. There is also some evidence for the beneficial effects of seaweed derived fibre in other key health areas such as cardiovascular health, cancer, diabetes and obesity. However, relatively little is known about the chemical, physio-chemical and fermentation characteristics of seaweed fib