Stable carbon isotopic characterization of rice vinegar protein as an intrinsic reference for discriminating the authenticity of brewed rice vinegar
Journal
Journal of Food and Drug Analysis
Journal Volume
30
Journal Issue
1
Pages
38-45
Date Issued
2022
Author(s)
Abstract
Rice vinegar plays an important role in daily life. However, some unscrupulous manufacturers may deliberately add synthetic acetic acid in vinegar products to reduce fermentation time and save production costs. To protect the rights and health of consumers, vinegar authenticity must be controlled. The rice vinegar protein was used as an intrinsic reference and its stable carbon isotope ratio (d13Cprotein) was analyzed by elemental analyzer-isotope ratio mass spectrometry. The stable carbon isotope ratio difference between the acetic acid and the rice vinegar protein (Dd13Cacetic acid-protein) was calculated to evaluate vinegar authenticity. Sixteen rice vinegar samples were analyzed and a stable carbon isotopic pattern of rice vinegar was established by the 95% confidence interval for Dd13Cacetic acid-protein (0.27‰e2.10‰). An acetic acid adulteration curve of Dd13Cacetic acid-protein was also assumed according to the data from rice vinegar samples, and its validity was confirmed by rice vinegar deliberately blended with acetic acid at different ratios (25, 50, and 75%). The Dd13Cacetic acid-protein values of the adulterated vinegars decreased with increasing amounts blended acetic acid, but the d13Cprotein values did not, showing that rice vinegar protein could be used as an intrinsic reference for identifying the adulterated rice vinegar. The rice vinegar adulterated with acetic acid at higher than approximately 10% could be detected. © 2022 Taiwan Food and Drug Administration.
Subjects
Authenticity; EA-IRMS; Protein; Stable isotope ratio; Vinegar
Other Subjects
acetic acid; carbon; stable isotope; vinegar; acetic acid; Article; brewing; controlled study; mass spectrometry; rice; stable isotope labeling; fermentation; metabolism; Oryza; Acetic Acid; Carbon; Carbon Isotopes; Fermentation; Oryza
Type
journal article