Determination of 2, 6-Dimethoxyphenol, Guaiacol and 4-Methylguaiacol in Dried Skipjack (Katsuobushi) by High Perfomance Liquid Chromatography

Abstract

Phenolic compounds in Katsuobushi was determined by a high-performance liquid chromatography (HPLC). An assay solution was prepared as follows; 5g of Katsuobushi powder were extracted with 60ml of 40 (v/v) ethyl alcohol for 15min at room temperature. The extract was filled up to 100ml with 40%(v/v) ethyl alcohol and was filtrated with 0.2μm filter. Determination was performed using Shimadzu LC-6A under the following conditions; A column pipe (4mmφ×15cm)was packed with ODSH (Shimadzu Techno-Research)and eluted with methanol-water (adjusted to pH 2.1 with phosphoric acid)[15:85, v/v]at a flow rate of 0.8ml/min. Column temperature was 55°C. Column effluents were monitored at 268nm. This method will ensure the determination of phenolic compounds in Katsuobushi with 2-3% of coefficients of varience and 96-99% of recovery. 2, 6-Dimethoxyphenol was the most predominant among 3 kinds of phenolic compounds, and the concentration of the phenol was 50μg/g. The phenolic compounds gradually increased in number as well as in amount with the advance of the smoking process, and reached saturation at the middle of smoking process.