Measurement of the Isotope Ratio of Acetic Acid in Vinegar by HS-SPME-GC-TC/C-IRMS

Abstract

Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.

The Genome Characteristics and Predicted Function of Methyl-Group Oxidation Pathway in the Obligate Aceticlastic Methanogens, Methanosaeta spp

“…Methane and acetate were determined by gas chromatograph GC-14B (Shimadzu) and CO 2 was determined by gas chromatograph GC-14C (Shimadzu) [8], [40]. The stable isotope composition was determined by Trace GC/IsoLink/Delta V Advantage GC/IRMS (Thermo Fisher Scientific, Bremen, Germany) [41], [42].…”

Characterization and Comparison of Commercial Chinese Cereal and European Grape Vinegars Using 1H NMR Spectroscopy Combined with Multivariate Analysis

“…Values of R 2 X and Q 2 are 0.944 and 0.984, respectively. The loading plot ( Figure 3C) shows that glucose (25,26), fructose (22), alanine (12), citrate (34), HMF (31) and formate (35) are the main compounds that contribute to the discrimination of BVM with high correlation coefficients (|r|＞0.5). The loading plot ( Figure 3C) shows that glucose (25,26), fructose (22), alanine (12), citrate (34), HMF (31) and formate (35) are the main compounds that contribute to the discrimination of BVM with high correlation coefficients (|r|＞0.5).…”

“…The validity of the model is confirmed by CV-ANOVA results (p＜0.05) and permutation test ( Figure S10). Especially glucose (25,26) and fructose (22), they exhibit the highest correlation coefficients (|r|＞0.8). Especially glucose (25,26) and fructose (22), they exhibit the highest correlation coefficients (|r|＞0.8).…”

“…Main component contributing to the negative loadings is caramel, because those variables are spread across the line loading plots with broad line width. One the other hand, resonances with high positive PC2 values are ethanol (7), ethyl acetate (8), succinate (18), malate (17), citrate (34), fructose (22), β-glucose (25) and α-glucose (26). One the other hand, resonances with high positive PC2 values are ethanol (7), ethyl acetate (8), succinate (18), malate (17), citrate (34), fructose (22), β-glucose (25) and α-glucose (26).…”

“…Wine vinegar is a type of grape vinegar made from red or white grape wine using submerged liquid fermentation method. [18][19][20][21][22][23][24][25] Most of the analytical techniques mentioned above involve sample pretreatment and they are complicated, time consuming and sometimes not reproducible to obtain an overall characterization. In China, commercial vinegars are mainly made from cereal using solid-state fermentation method.…”