Comparative analysis of organic acids and volatile organic compounds of ginseng vinegars fermented by Acetobacter ghanensis and Acetobacter pasteurianus

Abstract

To develop a ginseng vinegar in a short production time, the liquid fermentation of 9 days was carried out with the bacteria Acetobacter pasteurianus and Acetobacter ghanensis and the carbon source ethanol. The ginseng vinegar fermented with A. pasteurianus (AAB-hn) exhibited higher total flavonoid and polyphenol contents than ginseng vinegar fermented by A. ghanensis (AAB-jc), which reached 265.51 mg/L and 26.21 mg/L, respectively. 8 organic acids including oxalic acid, tartaric acid, malic acid, lactic acid, acetic acid, citric acid, succinic acid and fumaric acid were quantified by HPLC. Acetic acid was found to be the predominant organic acid in both samples. 108 volatile organic compounds (VOCs) were identified by GC-MS and GC-IMS. 28 differentially metabolites(VIP>1)including esters and acids were screened by OPLS-DA analysis. 10 key-VOCs were further confirmed by GC-O and odor activity values (OAVs ≥ 1). Nonanal, 2-methoxy-4-vinylphenol, and 2(3H)-furanone, dihydro-5-pentyl- were aroma factors unique to the two ginseng vinegars. Linalool and 1-octen-3-ol with floral and mushroom aromas were only detected in the AAB-hn, while α-terpineol and β-damascenone with anise and rose-like aromas were only discovered in the AAB-jc. E-nose and principal component analysis (PCA) can effectively differentiate different samples. AAB-jc had the highest overall score of 82.83 in the sensory evaluation. This study provided key insights into optimizing ginseng vinegar production by exploiting strain-specific metabolic capabilities for the development of functional vinegars with tailored health benefits and sensory profiles.