发酵温度对辣白菜理化特性的影响

Influence of Fermentation Temperature on the Quality of Kimchi

为了研究较低温度下发酵的辣白菜品质特性，以大白菜为主要原料，采用朝鲜族传统工艺制造辣白菜，分别在-4℃、4℃、15℃下对发酵过程中pH值、总酸、氨基酸态氮、还原糖、Vc、亚硝酸盐等理化指标进行测定与分析。结果表明：-40C、4℃下发酵45d时其酸度和pH值分别为0．64％和0．77％，4．87和4．74，与15℃发酵辣白菜第10d的pH值和酸度接近。15℃发酵辣白菜第5d氨基酸态氮和还原糖含量为0．11g／100mL和3．66％，而-4℃和4℃下发酵辣白菜到第45d也未能达到此水平。15℃发酵辣白菜的v。含量到第45d为1．11mg／g，而较低温度下发酵的辣白菜中Vc含量仅为0．66mg／g和0．63mg／g。在15℃发酵辣白菜亚硝酸盐峰值达到77．92mg／100g，明显低于低温发酵的两种辣白菜。因此低温不仅能延缓辣白菜的发酵，还可以较长时间维持较好品质，但Vc损失严重，亚硝酸盐含量较高。

The Kimchi was prepared by Korean traditional method, and was stored at -4℃, 4℃, 15℃. The variance of pH, total acid, amino-acid nitrogen, reducing sugar, Vc and nitrite were measured and analyzed. The results showed that when Kimchi was fermented at 15 ℃, titratable acidity was 0.854% and pH was about 4.27 on the 10 th day, and it was nearly to the level of fermentation for 45 days at 4℃ and -4℃. On the 5 th day, the quantity of amino acid was 0.109 g/100 mL, and it was nearly to the content of the 45th day for fermenting at lower temperture. After 45 days, Kimchi was fermented at 15℃, the content of Vc was 1.11 mg/g, however, when Kimchi was fermented at lower temperature, the content of Vc was only 0.66 mg/g and 0.63 mg/g. The quantity of reducing sugar was 2.64% fermented at 4℃ and was 4.26% fermented at -4℃, and it was nearly to the content of reducing sugar of the 10 th and 15th day fermented at 15℃. In the process of fermentation, Kimchi was fermented at 15℃, which maximum nitrate was 77.92 mg/100 g, and it was significantly lower than the other two Kimchi fermented at lower temperature. Fermentation was promoted at higher temperature, but reducing sugar and amino acid was reduced badly. It＇s beneficial for storing at lower temperature during fermentation, but Vc was reduced badly, and the variance of nitrite was higher which was bad for health.