- 期刊
粗竹醋液之精製與性質分析
Refining and Properties Analysis of Crude Bamboo Vinegar
摘要
本研究之目的係將不同來源土窯及機械窯產粗竹醋液，分別在70mmHg與50、70、90℃下行減壓蒸餾及靜置6個月行精製作業，分析粗竹醋液與蒸餾竹醋液基本性質及組成分之變化。試驗結果顯示，粗竹醋液之酸鹼值介於3.1-3.7之間，比重介於1.000-1.032，有機酸含量為3.31-9.24%，溶解焦油含量為0.01-0.62%，顏色為黃褐色且具有煙燒烏梅味；將粗竹醋液減壓蒸餾後，所得之蒸餾竹醋液之酸鹼值、比重、有機酸含量皆有下降的趨勢，溶解焦油可完全去除，顏色變為清澈透明。不同來源之粗竹醋液的有機成分均以酸性物質之醋酸含量最多，酚類物質主要為酚(phenol)、2,6二甲氧基酚(2,6-dimethoxy phenol)及2-甲氧基酚(2-methylphenol)，醇類物質為乙醇，中性物質則以糠醛(2-furancarboxaldehyde)為主。蒸餾竹醋液組成分仍以醋酸含量最高，但分子量較大的化合物，如香草酸(4-hydroxy-3-methoxy-benzoic acid)、2,6-二甲氧基酚、1,2,3-三甲氧基苯(1,2,3-trimethoxy-benzene)、安息香酸乙酯(1-methyl-2-pyrrolecarboxaldehyde)及2-硫基苯並噻唑(2(3H)-benzothiazolethione)等含量明顯減少，甚至去除，顯示減壓蒸餾法確實能將竹醋液精製，使性質與成分更為均一。將粗竹醋液及蒸餾竹醋液靜置6個月後，粗竹醋液pH值無明顯變化，均介於2.6-3.6之間，但顏色加深，比重、有機酸及溶解焦油含量均降低，而蒸餾竹醋液的酸鹼值趨於一致均為2.6-2.8，有機酸含量減少，顏色稍呈淡黃色，焦油含量些微增加，有機成分仍以醋酸為主。
並列摘要
The aim of this study was to analyze the fundamental properties and organic components of crude bamboo vinegars and distilled bamboo vinegars which made from earth kiln and steel kiln. The refining processes of crude bamboo vinegars were under a reduced pressure of 70 mmHg at 50, 70 and 90℃, respectively as well as by setting for six months. The results indicated that the pH 3.1-3.7, specific gravity 1.000-1.032, organic acid content 3.31-9.24% and soluble tar content 0.01-0.62% of crude bamboo vinegars were observed. The color of crude bamboo vinegar was yellowish-brown and has a smoked plums flavor. The main organic component in acidic components of crude bamboo vinegar was acetic acid, followed by the phenol, 2-methoxy-phenol and 2,6-dimethoxy-phenol in phenolic components, ethanol in alcoholic components and 2-furancarboxaldehyde in neutral components. After distillation under a reduced pressure, the pH, specific gravity, organic acid content and soluble tar content of distilled bamboo vinegars were lower than those of crude bamboo vinegars. The colors of distilled bamboo vinegars were clear and transparent. Besides, acetic acid was still the main components of the total organic components, and high molecular weight components such as 4-hydroxy-3-methoxy-benzoic acid, 2,6-dimethoxyphenol, 1,2,3-trimethoxy-benzene, 1-methyl-2-pyrrolecarboxaldehyde and 2 (3H)-benzothiazolethione were removed. After setting for six months, the pH values were 2.6-3.6 of bamboo vinegars and kept at a constant value for each specimen. In addition, the color values, specific gravity, organic acid contents and soluble tar contents of bamboo vinegars were lower than those of crude bamboo vinegars. The distilled bamboo vinegars setting for six months later had the pH of 2.6-2.8, the lower organic acid contents, the slightly more soluble tar contents than unsetting distilled bamboo vinegars and they had light yellow color and also contained the main organic components of acetic acid.