Simultaneous Quantification of Major Phenolic Compounds in Sake Using High-Performance Liquid Chromatography with Ultraviolet and Fluorescence Detectors

Abstract

　Phenolic compounds significantly affect sake quality as bitter taste or smoke odor. To effectively manage sake quality, a simultaneous quantification method was developed for eight major phenolic compounds found in sake using high-performance liquid chromatography with ultraviolet and fluorescence detectors. This method was realized under the temperature condition that the quantified content value of volatile phenols did not increase through phenolic acid decomposition compared with the real content value and that preprocessing was not required. Good response linearities were obtained for all phenolic compounds, with the determination coefficients (r²) of the calibration curves ranging from 0.9999 to 1.0000. The precision values of the peak area and retention time as relative standard deviations (%) of each compound were below 3% and 0.1%. In addition, the limit of quantification (LOQ) was the threshold level in the sensory test, and the LOQs of guaiacol, 4-vinylphenol, 4-vinylguaiacol, ethyl ferulate, tyrosol, vanillic acid, p-coumaric acid, and ferulic acid, were 14 μg/ℓ, 1.6 μg/ℓ, 2.6 μg/ℓ, 0.039 mg/ℓ, 8.9 mg/ℓ, 0.47 mg/ℓ, 0.18 mg/ℓ and 0.14 mg/ℓ, respectively, using the proposed method. These results showed that a simple, sensitive, and reliable quantification method was achieved.