Different carbon stable isotopic compositions of CO2 in sparkling sake using natural and exogenous carbonation methods

• Published in: Journal of food composition and analysis 2022-06, Vol.109, p.104474, Article 104474
• Main Authors: Akamatsu, Fumikazu, Fujii, Tsutomu, Igi, Yukari, Fujita, Akiko, Yamada, Osamu, Isogai, Atsuko
• Format: Article
• Language: English
• Subjects: Carbon isotope discrimination; Carbon stable isotope; Carbonation; CO2; Ethanol; Glucose; Sparkling sake
• ISSN: 0889-1575; 1096-0481
• DOI: 10.1016/j.jfca.2022.104474

•δ13C measurements identified two carbonation methods in sparkling sake manufacture.•CO2δ13C values from natural carbonation were higher than from exogenous carbonation.•Glucose δ13C values did not differ significantly between the two carbonation methods.•Ethanol δ13C values did not differ significantly between the two methods.•δ13C measurements will help identify carbonation methods used in sparkling sake. Sparkling sake has recently become a popular alcoholic beverage and is manufactured using one of two types of carbonation method. In this study, we determined the carbon stable isotopic composition (expressed as δ13C) of CO2 bubbles derived from rice (natural carbonation) or petroleum (exogenous carbonation) in sparkling sake to address authenticity. Our results showed that the CO2δ13C values (−25.8 ± 0.5‰) in sparkling sake manufactured using natural carbonation increased by 0.4 ± 1.2‰ relative to glucose δ13C values (−26.2 ± 1.0‰), while the ethanol δ13C values (−28.2 ± 0.3‰) decreased by 2.0 ± 1.0‰ relative to glucose δ13C values. The CO2δ13C values of sparkling sake manufactured using natural carbonation were significantly higher than those manufactured using exogenous carbonation (−31.3 ± 3.4‰). However, there were no significant differences in the δ13C values of glucose and ethanol in sparkling sake manufactured using either natural or exogenous carbon methods. Carbon stable isotope analysis of CO2 bubbles in sparkling sake will help determine the carbon source of CO2 and contribute to the authenticity of sparkling sake.