Biochemical composition of the Australasian sea cucumber, Australostichopus mollis, from a nutritional point of view

Background: Sea cucumbers are highly prized seafood in Asia, where the demand for them has increased dramatically in recent years. However, nutritional information is only available for only a few of the commercially traded species. Methods: In this study, the biochemical composition of the sea cucumber Australostichopus mollis was evaluated in terms of the major functional components: collagen, amino acid and fatty acid content using standard analytical procedures. Results: The collagen, mostly type I, formed a homogeneously clustered network constituting 1.4% of the wet weight of adult A. mollis which is lower than for some other species of sea cucumber. The collagen consisted of α1 and α2 chains (around 116 kDa), α chain dimers, β chains (around 212 kDa), and small amounts of γ components. The most abundant amino acids were glycine, alanine, threonine, serine and proline (lysine/arginine ratio of 0.1). Threonine was the most abundant essential amino acid, followed by methionine and valine, while glycine was the dominant non-essential amino acid. The sea cucumbers had a low lipid content (0.2 and 0.1% of wet weight for the viscera and body wall, respectively) which is below the range reported for most other species of sea cucumber. The lipid contained high levels of PUFA (54%) compared to MUFA (23%) and SFA (24%). The dominant PUFA was arachidonic acid in both the body wall and viscera, followed by eicosapentaenoic acid. Conclusions: Overall, the Australasian sea cucumber has strong potential as a functional food due to its high levels of PUFA and essential amino acids, comparing favourably with the most commercially valuable sea cucumbers.