Antioxidative Activity of Broiled-Dryed Skipjack (Katuobushi) Extracts

Abstract

The change of antioxidative activity of extracts of Katuobushi during smoking process was investigated. The antioxidative subsutances in the extracts was examined. Results obtained were as follows: (1) The antioxidative activity of the extracts gradually increased and reached maximum in the half period of smoking process. (2) The extracts of Arabusi (Skipjack meat after smoking process) was fractionated by dialysis. The antioxidative activity was mainly recoginized in the dialyzable fraction. The dialyzable fraction was fractionated on ODSmini-column (YMC-DispoC18, Yamamura Co. Ltd) by eluting with mixtures of water-acetonitorile, increasing the ratio of acetonitorile in steps. The fractionation of antioxidative substances eluted with water was applied to HPLC. A number of peaks which appeared in the chromatogram of extracts of Arabushi compared with that of Namaribushi (Skipjack meat is boiled and smoked once for about an hour were seemed to be responsible for antioxidative reinforcement of extracts of Katuobushi. The main antioxidant peak which remarkably increased during smoking gave serine, proline, glycine, aranine and isoleucine after complete hydrolysis. (3) The extracts of Katuobushi showed an antioxidative activity against a minced sardine.