Effect of high-pressure processing (HPP) on phenolics and their antioxidant activities of Atlantic sea cucumber (Cucumaria frondosa)

• Main Author: Hossain, Abul
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2021
• Subjects: Cucumaria frondosa; North Atlantic; Orange-footed sea cucumber
• Online Access: https://research.library.mun.ca/15455/; https://research.library.mun.ca/15455/1/thesis.pdf

Sea cucumber belongs to the phylum Echinodermata and Holothuroidea class, which contains numerous bioactive compounds, including phenolics. In particular, body wall, aquapharyngeal bulb/ flower, and internal organs/ viscera are rich sources of phenolics. Sea cucumber is harvested mainly for its body wall and muscle bands. However, during sea cucumber processing, several visceral by-products are produced, including gonad, respiratory tract, and intestine, which are ultimately discarded as waste. These visceral by-products represent up to 50% of the sea cucumber biomass and are a rich source of bioactive compounds, mainly phenolics. The most common sea cucumber found in the North Atlantic region is the orange-footed sea cucumber (Cucumaria frondosa, Gunnerus, 1767). However, this species is under-explored for its bioactive compounds, especially its polyphenolic composition. Hence, this study investigated the free, esterified, and insoluble-bound phenolics from different commercial body parts (tentacles and body wall) and processing discards of sea cucumber (C. frondosa), as affected by high-pressure processing (HPP) pre-treatment. For that, sea cucumber was subjected to high-pressure (2000, 4000, and 6000 bar for 5, 10, and 15 min), followed by separation into the three aforementioned fractions. The contents of total phenolics and flavonoids were determined, and antioxidant activity reflected in scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), and hydroxyl radicals was monitored. The metal chelating ability of various phenolic fractions was also evaluated. Moreover, bioactivities such as inhibition of peroxyl and hydroxyl radical-induced supercoiled DNA strand scission, LDL-cholesterol oxidation inhibition, antiglycation activity, and α-glucosidase activity were examined. Furthermore, thiobarbituric acid (TBA) assay in a fish-model system was performed. Compared to untreated samples, those treated with HPP exhibited significantly higher total ...