Extraction and and characterization of collagen from sea cucumber (Holothuria cinerascens) and its potential application in moisturizing cosmetics

To increase the utilization of sea cucumbers and focus on the development and screening of natural raw materials for moisturizing cosmetics, we used the body wall of sea cucumber Holothuria cinerascens as raw materials for extracting pepsin-solubilized collagen. We compared the collagen with that from the skin of tilapia and pig. SDS-PAGE profiles revealed that, the collagen from the three species were type I. Sea cucumber had the smallest molecular weight (80-90 kDa). Maximum peak at 230 nm on UV-visible spectroscopy profiles revealed that the three collagens contained amino acids with C = O, COOH, and CONH 2 groups. FTIR spectroscopy showed the three collagens with amide A, I, II, III peaks generated by the main functional groups in the proteins. The dominant amino acids of the three collagens were glycine (31%), proline (9-12%) and alanine (10-12%). The three collagens exhibited better moisture-retention and moisture-absorption capacity than glycerol, so the collagen molecules are rich in hydrophilic groups, which has potential application in cosmetic formulations. Further studies are needed to retain the properties of extracted collagen during processing or other applications because the commercial value of the industrial by-products of sea cucumber could be increase and thus reduce the environmental impact caused by the disposal of this material.