豆渣為製造豆漿與豆腐等黃豆加工製品之廢棄物，其含水量高易腐敗，為豆漿、豆腐工廠迄待解決之廢棄物問題。本實驗以黃豆豆渣為原料，探討添加木糖或蔗糖（0~4%）、酵母萃取物或黃豆分離蛋白（0~10%）、無機氮源（0~2%）、氯化鈉鉀或鈣（0~1.5%）與綜合維生素（0~1.5%），對豆渣狀納豆之納豆激酶活性之影響。研究結果發現納豆激酶活性：隨著木糖或蔗糖（碳源）添加濃度上升而降低；酵母萃取物與黃豆分離蛋白（氮源）隨著濃度上升而上升；1.5%綜合維生素添加量顯著增加；其餘添加物變化較不明顯。
Okara is a byproduct of soymilk and tofu manufacturing, the high water content make okara spoiled easily and the waste treatment always is a problem of such manufacturer. The purpose of this experiment was to increasing the nattokinase activity of the okara natto by adding different concentrations of xylose or sucrose (0~4%), yeast extract or soy protein isolate (0~10%), sodium chloride, potassium chloride or calcium chloride (0~1.5%) and vitamins mixture (0~1.5%). The results found the nattokinase activity of okara-natto decreased when the concentrations of xylose and sucrose increased. Nattokinase activity of okara-natto increased when the concentrations of yeast extract and soy protein isolate increased. When 1.5% vitamins mixture was added, nattokinase activity of okara-natto increased significantly. The other additives effect had no significantly different effects.
