title: High-performance liquid chromatography analysis of naturally occurring D-amino acids in sake.
abstract: We measured all of the D- and L-amino acids in 141 bottles of sakes using HPLC. We used two precolumn derivatization methods of amino acid enantiomer detection with o-phthalaldehyde and N-acetyl-L-cysteine, as well as (+)-1-(9-fluorenyl)ethyl chloroformate/1-aminoadamantane and one postcolumn derivatization method with o-phthalaldehyde and N-acetyl-L-cysteine. We found that the sakes contained the D-amino acids forms of Ala, Asn, Asp, Arg, Glu, Gln, His, Ile, Leu, Lys, Ser, Tyr, Val, Phe, and Pro. We were not able to detect D-Met, D-Thr D-Trp in any of the sakes analyzed. The most abundant D-Ala, D-Asp, and D-Glu ranged from 66.9 to 524.3 μM corresponding to relative 34.4, 12.0, and 14.6% D-enantiomer. The basic parameters that generally determine the taste of sake such as the sake meter value (SMV; "Nihonshudo"), acidity ("Sando"), amino acid value ("Aminosando"), alcohol content by volume, and rice species of raw material show no significant relationship to the D-amino acid content of sake. The brewing water ("Shikomimizu") and brewing process had effects on the D-amino acid content of the sakes: the D-amino acid contents of the sakes brewed with deep-sea water "Kaiyoushinosousui", "Kimoto yeast starter", "Yamahaimoto", and the long aging process "Choukijukusei" are high compared with those of other sakes analyzed. Additionally, the D-amino acid content of sakes that were brewed with the adenine auxotroph of sake yeast ("Sekishoku seishu kobo", Saccharomyces cerevisiae) without pasteurization ("Hiire") increased after storage at 25 °C for three months.
authors.affiliation: Department of Life Science and Biotechnology, Faculty of Chemistry, Materials, and Bioengineering, Kansai University, Suita, Osaka-Fu 564-8680, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Gogami
authors.forename: Kaori
authors.initials: K
authors.lastname: Okada
authors.forename: Tadao
authors.initials: T
authors.lastname: Oikawa
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005285:Fermentation; D007564:Japan; D012623:Seawater; D013237:Stereoisomerism; D015003:Yeasts
chemical_list: D000596:Amino Acids