A novel HPLC-based method employing molar absorption coefficient ratios to 4-hydroxybenzoic acid 4HBA was developed for the determination of quassin and neoquassin in Jamaica quassia extract, which is used as a food additive in Japan. Based on comparisons of quantitative NMR qNMR spectra and HPLC chromatograms of an artificial mixture of quassin, neoquassin, and 4HBA, the molar absorption coefficient ratios of quassin and neoquassin to 4HBA were determined as 0.84 and 0.85, respectively. Quassin and neoquassin were quantified in food additives by qNMR and HPLC based on molar absorption coefficient ratios using 1,4-bis trimethylsilyl benzene-d 4 and 4HBA as internal standards, respectively. The differences in quantitation values between qNMR and HPLC analyses were below 1.2 . Our proposed novel HPLC-based quantitation method employing the molar absorption coefficient ratios is a reliable tool for determining levels of quassin and neoquassin in food additives and processed foods.

To identify the major mutagen in pyroligneous acid (PA), 10 wood and 10 bamboo pyroligneous acids were examined using the Ames test in Salmonella typhimurium strains TA100 and TA98. Subsequently, the mutagenic dicarbonyl compounds (DCs), glyoxal, methylglyoxal (MG), and diacetyl in PA were quantified using high-performance liquid chromatography, and the mutagenic contribution ratios for each DC were calculated relative to the mutagenicity of PA. Eighteen samples were positive for mutagens and showed the strongest mutagenicity in TA100 in the absence of S9 mix. MG had the highest mutagenic contribution ratio, and its presence was strongly correlated with the specific mutagenicity of PA. These data indicate that MG is the major mutagen in PA.

A simple and rapid method was developed to identify the source species of pufferfish products. Randomly amplified polymorphic DNA RAPD analysis was applied to identify 8 species of pufferfish. Commercial kits were used for DNA extraction and amplification. Simultaneous identification was possible by polyacrylamide gel electrophoresis of PCR products. Two primers were chosen based on the result of pre-examination with 40 primers, and the PCR conditions were optimized. Characteristic RAPD patterns were obtained for each pufferfish species. The developed method was applied to identify the source species of 26 pufferfish products. The results suggest that the developed method would be useful for verification of the labeled species of pufferfish products.