Grape vinegar(A) and grape onion vinegar(B) added (3% of onion juice) were produced through two stages of fermentation(alcohol fermentation and acetic acid fermentation) to increase the grape's use. Grape wine which contained 5.6% alcohol was produced...
Grape vinegar(A) and grape onion vinegar(B) added (3% of onion juice) were produced through two stages of fermentation(alcohol fermentation and acetic acid fermentation) to increase the grape's use. Grape wine which contained 5.6% alcohol was produced on the 3rd day of first stage. Then through the second stages, grape vinegar, of which total acidity was 5.37% was produced. The quality of (A) and (B) which was produced through the two stages of fermentation was compared with the traditional grape vinegar(C,D) in the market. The content of sugar in (D) was a little higher such as 5.4 °Brix than others. That of (A) and (B) was 5.13, 4.98 °Brix respectively. The content of remaining alcohol in (C) was high such as 0.23% comparatively, But there was no remaining alcohol in (A) and (B). The content of acetic acid was 4.3~5.3% as a major organic acid of vinegars. The content of tartaric acid was 340.0 in (A), 316.7 in (B), 322.6 in (C) and 391.7㎎% in (D). The content of lactic acid was distinctly high such as 277.4㎎% in (D). There were differences such as 9.2~15.5㎎% in the content of total free amino acids among grape vinegars. (D) contained 15.5㎎% of total free amino acid and (B) also highly such as 12.0㎎%. Potassium was high in grape vinegars. The content of potassium, sodium and copper was higher in (A) than (B).