Effects of morphometric and biochemical parameters on collagen and pepsin-solubilized collagen yields of Holothuria tubulosa (Gmelin, 1790) and Holothuria (Roweothuria) poli (Delle Chiaje, 1823)

Due to their unique biochemical composition, sea cucumbers are highly prized marine echinoderm species. One of their most important properties is that they contain a high amount of collagen in their body wall. In this study, the relationship between collagen and pepsin-solubilized collagen yields from Holothuria tubulosa and Holothuria poli and morphometric and biochemical parameters were investigated. Collagen yields were in the range of 10.63–16.04% for H. tubulosa and 7.12–13.10% for H. poli. It was determined that they may be related to length, body wall weight, and biochemical composition at different length frequencies. Moreover, maturity may have a direct effect on the yield, as mature specimens were found to have lower content of collagen, whereas immature small specimens contained a higher percentage of collagen. It was found that with increasing pepsin concentration, the PSC yield increased to 1.83–1.89% in H. tubulosa and H. poli, respectively. It was determined that collagen from smaller individuals, which contained more moisture and ash, was likely more susceptible to pepsin hydrolyzation.
This is the first published study demonstrating that collagen yield of sea cucumbers can vary with length, weight, maturity, and biochemical composition, in addition to species-specific differences.

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