Quantitative analysis of D- and L-amino acids in black vinegar (Kurozu) and rice vinegar (Komezu)

Abstract

We used high-performance liquid chromatography to measure the concentration of d- and l-amino acids in 7 bottles of black vinegar produced by traditional field fermentation with an Aman pot in Fukuyama-Cho, Kagoshima, Japan. The data for the traditional black vinegar were compared with the data for bottles of black vinegar and rice vinegar produced by a modern fermentation method in a plant as well as black vinegar #001 that had been used to pickle 9 different fruits, such as blueberries, mandarin oranges, and apples, Japanese plums, green umes, persimmons, strawberries, acerolas, and pineapples. We found that d-Asn, d-Thr, d-Arg, d-Met, d-Trp, d-Ile, d-Lys, and L-Gln were specifically contained in black vinegar. The d- and L-amino acid concentrations in black vinegar were generally higher than the concentrations in rice vinegar. The d-amino acids with the highest concentrations in the analyzed traditional black vinegar samples produced by Fukuyama Kurozu Co. Ltd. were Glu, Ser, His, Ala, Val, and Pro. The use of black vinegar to pickle fruits generally increased the concentrations of d-amino acids of the vinegar, with Japanese plums providing the largest effect.