- 作者： 嚴仲陽; 林仁混
- 作者服務機構： 國立臺灣大學醫學院生化學研究所暨行政院國科會癌症研究推動小組環境致癌物研究工作組
- 中文摘要：
在本研究中我們選取黃金白菜、清江白菜、油菜、芥菜及空心菜來進行實驗。該五種蔬菜硝
酸鹽含量隨栽培時間增長而增加，亞硝酸鹽含量則呈一定而微量存在。蔬菜種子平均硝酸鹽含量
150 ppm ，土壤栽培成長後則升高為 1,710-7,400 ppm，其鹽類的獲得大都來自土壤，而
硝酸鹽還原?活性高低，並不能影響硝酸鹽的吸收。生長期間亞硝酸鹽還原?活性與硝酸鹽還原
?相近，因此亞硝酸鹽不能在蔬菜造成累積。
新鮮蔬菜貯存實驗發現冰箱冷藏部貯存的蔬菜比夏季室溫下的蔬菜遲緩 3～4 天發生硝酸鹽
還原現象，貯存溫度高或貯存時間久均可使硝酸鹽還原成亞硝酸鹽現象發生。壤 - 英文摘要： In the previous report (Lin & Lue, 1979),we estimated the levels of nitrite and nitratein 57 kinds of edible vegetables. Among them,15 vegetables contained 84 ppm or higher ofnitrite and 10 vegetables contained 226 ppm orhigher of nitrate. It seemed that the contentsof nitrate and nitrite in various vegetables werechangeable as the time and temperature ofstorage varied. In the present study, a furtherpursuit on the factors affecting on the levelsof nitrate, nitrite, nitrate reductase and nitritereuctase was attempted. The nitrate and nitrite levels of short-petioled cabbage, long-footed cabbage, field mus-tard, broad-leaf mustard and water convolvuluswere determined in their germinating seeds andgrowing vegetables. These seeds contain 94.2-189.6 ppm of nitrate and 1.5-4.0 ppm of nitrite.The nitrate concentrations of these growingvegetables are varied between 1,710 to 6,940 ppmdepending on which of the five species wasstudied; meanwhile their nitrite contents arearound 1.6-4.4 ppm. The nitrogen fertilizer ureaseemed to induce remarkable nitrate accumul-ation in the growing vegetables. The influence of storage at different tem-peratures on the nitrate and nitrite contents offresh and homogenized vegetables were studied.Not much changes in nitrate and nitrite werefound if these samples were stored at －10 or2°C; when the samples were stored at 26 or32°C, the nitrite increased rapidly as nitratedecreased. Nitrate reductase and nitrite reductasein these vegetables at different growing stageswere estimated and no significant change intheir activity was observed. The total intakes of nitrate and nitrite inChinese inhabitants were calculated on the basisof available data. The effect of dietary nitrateon the formation of salivary nitrite and endoge-nous carcinogenic N-nitroso compounds wasdiscussed and emphasized.
- 中文關鍵字： --
- 英文關鍵字： --
