Extraction of bioactive compounds from black-footed abalone (Haliotis iris) using subcritical water extraction

Background: Owing to their biodiversity, many valuable natural compounds have been extracted from marine resources and used in the development of pharmaceutical, nutraceutical and cosmeceutical products. The New Zealand black-footed abalone (Haliotis iris) is known to host a variety of bioactive compounds in its flesh.

Results: Water-soluble bioactive compounds were extracted from H. iris by subcritical water extraction technique, and the effect of subcritical water temperature (110–280 °C) on the extraction performance was studied. The highest antioxidant activity and subsequently glycogen and phenolic content, as well as concentration of bioactives, were found at temperatures between 220 and 250 °C. The carbohydrate content of the extracts peaked at 110 °C, which was then degraded at higher temperatures. Protein and amino acid contents of H. iris extracts were also decreased as the temperature increased above 160 °C. Furthermore, the H. iris extracts were found to be non-toxic.

Conclusion: The results indicate that extraction temperature has a significant impact on the bioactivity of H. iris extracts. Subcritical water extraction can be used in place of more traditional techniques to create high-quality abalone extracts.

Keywords: Bioactive compounds; Antioxidant; Subcritical water extraction; Haliotis iris; Phenolic compounds; Glycogen content