Table 4. Changes of free organic acids and free sugars contents during acetic acid fermentation of MV1) (unit: ppm)
| | Fermentation time (day) |
| 0 | 9 |
| Free organic acid | Oxalic acid | 438.55±2.192) | 934.25±118.71**4) |
| Formic acid | ND3) | ND |
| Malic acid | 1,093.01±18.85 | ND |
| Acetic acid | ND | 33,804.27±1,788.64*** |
| Citric acid | 1,216.37±35.43 | 3,623.77±140.14*** |
| Succinic acid | 499.95±40.02 | ND |
| Free sugar | Fructose | 104.57±0.63 | 40.79±2.98 |
| Glucose | 41.43±0.49 | ND |
| Sucrose | ND | ND |
| Maltose | ND | ND |
Mulberry vinegar through yeast and acetic acid bacteria fermentation.
Values are mean±SD (n=3).
ND, not detected.
Significant differences were compared with the before fermentation at **p<0.01 and ***p<0.001 in the same row by Levene’s t-test.