Roasting Effects on Radical Scavenging Activity of an Edible Brown Alga, Hijikia Fusiformis (Hijiki)

Higashi-Okai K, Takenouchi A, Tanaka Y and Akram M

Published on: 2023-12-20

Abstract

An edible brown alga, Hijikia fusiformis (Hijiki) has been used as a traditional healthy food in Asian countries such as Japan, Korea and China. Although the weak radical scavenging activity was observed in the water extract of unheated Hijiki, the strong radical scavenging activity of Hijiki extract was generated by high temperature roasting conditions (180ºC and 200ºC), which was analyzed by (i) a stable radical compound, diphenylpicrylhydrazyl (DPPH), (ii) hydroperoxide radical generating system of linoleic acid peroxidation and (iii) opsonized zymosan (Opz)-induced oxygen radical generating system in human blood neutrophils. The enhancing effects of the roasting treatment on the radical scavenging activities in the Hijiki extracts were associated? with the roasting-induced increase in the concentrations of polyphenol, tannin and saccharide in the extracts. As a specific active component for the enhancing effect on the radical scavenging activity in the roasted Hijiki, the role of polysaccharide fraction of Hijiki was analyzed. The significance of the roasting effect on the radical scavenging activity in Hijiki is discussed from the viewpoint of medical food science.