Method for the isolation of citric acid and malic acid in Japanese apricot liqueur for carbon stable isotope analysis.
A method for detecting the undeclared addition of acidic ingredients is required to control the authenticity of Japanese apricot liqueur. We developed an analytical procedure that minimizes carbon isotope discrimination for measurement of the δ(13)C values of citric and malic acid isolated from Japanese apricot liqueur. Our results demonstrated that freeze-drying is preferable to nitrogen spray-drying, because it does not significantly affect the δ(13)C values of citric acid and results in smaller isotope discrimination for malic acid. Both 0.1% formic acid and 0.2% phosphoric acid are acceptable HPLC mobile phases for the isolation of citric and malic acid, although the δ(13)C values of malic acid exhibited relatively large variation compared with citric acid following isolation using either mobile phase. The developed procedure allows precise δ(13)C measurements of citric and malic acid isolated from Japanese apricot liqueur.
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan. Electronic address: akamatsu99@gmail.com.
Fumikazu
F
Akamatsu
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
Tomokazu
T
Hashiguchi
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
Yuri
Y
Hisatsune
Agriculture, Forestry and Fisheries Department, Wakayama Prefecture, 1-1 Komatsubara-dori, Wakayama, Wakayama 640-8585, Japan.
Takaaki
T
Oe
Agriculture, Forestry and Fisheries Department, Wakayama Prefecture, 1-1 Komatsubara-dori, Wakayama, Wakayama 640-8585, Japan.
Takafumi
T
Kawao
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
Tsutomu
T
Fujii
D000434:Alcoholic Beverages; D002247:Carbon Isotopes / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D019343:Citric Acid / Q000302:isolation & purification*; D003890:Desiccation; D008293:Malates / Q000302:isolation & purification*; D000068219:Prunus armeniaca / Q000737:chemistry
D002247:Carbon Isotopes; D008293:Malates; D019343:Citric Acid; C030298:malic acid
Acidulants; Carbon stable isotope ratio; Citric acid; Japanese apricot liqueur; Malic acid