台灣市售牛奶及奶粉硝酸鹽及亞硝酸鹽檢測   全文下載

Investigation of the Nitrate and Nitrite Contents in Milk and Milk Powder in Taiwan

由於嬰幼兒除了母乳以外主要的食物營養來源為牛奶及嬰兒副食品，因此牛奶中硝酸鹽及亞硝酸鹽含量的檢測，對於維持嬰幼兒的健康有其重要性。傳統比色方法檢測食品的硝酸鹽與亞硝酸鹽步驟繁雜，本研究針對 100件台灣市售牛奶及奶粉檢測，採用離子層析法同時量測硝酸鹽與亞硝酸鹽的濃度，而不需繁複的處理步驟。硝酸鹽的偵測極限為 0.33 ppm，亞硝酸鹽偵測極限為 0.07 ppm。檢測結果硝酸鹽濃度 0.3 - 417.7 ppm，平均值為 92.7 ppm，而亞硝酸鹽皆低於偵測極限。含初乳蛋白的奶粉硝酸鹽平均值為 14.1 - 136 ppm。含乳清蛋白的奶粉硝酸鹽平均值為 42.6 - 242.8 ppm。一般奶粉硝酸鹽平均值為 57.9 - 157.6 ppm。以量測到的硝酸鹽濃度對不同年齡層計算攝取量都低於 WHO 建議的 ADI 值 3.7 mg /kg body weight /day。最後並探討攝取包含硝酸鹽與亞硝酸鹽的食物有對人類健康的影響。

Cow milk is one of the most important nutrition sources besides breast milk for infants and babies; therefore the detection of nitrate and nitrite in milk is of great importance to the health of infants and babies. Traditional colorimetric method for the determination of the nitrate and nitrite concentrations in food is very tedious. In the present study, 100 samples of milk and milk powder were analyzed by ion chromatography to detect nitrate and nitrite simultaneously without tedious preparation steps. The limit of detection (LOD) for nitrate is 0.33 ppm and the LOD for nitrite 0.07 ppm. The measured nitrate concentration in milk ranged from 0.3 - 417.7 ppm with an average concentration of 92.7 ppm. The nitrite concentration in all milk samples were below the detection limit. The survey information was as the following: (1) the average nitrate concentration of colostrums fortified milk ranged from 14.1 to 136 ppm. (2) the average nitrate concentra-tion of whey fortified milk ranged from 42.6 to 242.8 ppm. (3) the average nitrate concentration of ordinary milk ranged from 57.9 to 157.6 ppm. The dietary intake of nitrate from milk and milk products in Taiwanese adults and children were estimated. All the nitrate exposure levels calculated with the measured results for the different age groups were less than the acceptable daily intake (ADI) of 3.7 mg/ kg body weight per day suggested by WHO. Finally the health effect of nitrate and nitrite in foods was discussed.