以芥菜榨汁及加入乳酸菌(Lactobacillus plantarum CCRC 12942)進行乳酸發酵，並測定發酵過程中芥菜汁之各項生化變化。凡接菌者，其pH值降低，且有較高之可滴定酸度及較大之糖分變化。對照組中之抗壞血酸含量改變最大，而殺菁組之含量變化最小。殺菁組中之總酚量變化最小，且無PPO及POD酵素活性。對照組中有最大之PPO及POD酵素活性，而發酵末期之總酚含量則最低。由各試驗組之L, a及b值測定及上述各項生化變化結果，推測芥菜汁進行乳酸發酵過程中之色澤變化，乃與酵素性或抗壞血酸分解參與之褐變反應有關。 Mustard juices prepared from mustard vegetables were inoculated vvith the culture of LactobaciUus plonfarum CCRC 12942 and various biochemical changes in mustard juice were determined during lactic acid fermentation. I`he pH dropped down, higher titratable acidity and signizicant cnanges of sugar content were ound in all the inoculated trials. The content of ascorbic acid in the control trials changed significantly. However, the least changes of the contents of ascorbic acid and total phenolics were couna, ana activities of PPO and POD were not detected in the blanched trials. The study of mustard brine fennentation by lactic acid bacteria indicated that the color changes of the juice was directly related to enzymatic browning and the degradation of ascorbic acid might also contribute partially to the browning reaction.