Investigation and Determination of Iodine Content in Table Salts and Dairy Products

• Main Authors: Teh Tong Lan, 鄭東蘭
• Other Authors: Yih-Fong Liew
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/42091068429085404431

碩士 === 輔仁大學 === 營養科學系碩士班 === 102 === Iodine is an essential trace element, which is critical for the synthesis of thyroid hormone and plays a role in development of the brain. Therefore, insufficient of iodine intake can lead to iodine deficiency disorders (IDDs) including goiter, cretinism, reduced of intelligence, mental retardation etc. The types of commercialized salt had been increased since the privatization of salt plant from 2004 and repealed the regulation of salt policy in Taiwan. However, the food labeling of salt iodine content is ambiguous, so that consumers cannot be clearly informed of salt iodine content. In addition to iodized salt, certain foods also contain a lot of iodine, such as dairy products. However, there is limited information of the iodine content in dairy products. Therefore, the purpose of this study is to investigate the iodine content of salts anddairy products by using iodometric titration method and As3+-Ce4+ catalytic spectrophotometry method.In 29 commercial salt products in Taiwan, there is 27.6% iodized salt have clearly labeled iodine content. Iodine contents of iodized salt are between 3.01 and 16.45 ppm by new titration method, which match with their labeled values. Iodine contents in other without labeling salts were not detectable which mean iodine content < 0.53 ppm. In Asia-Pacific region, the highest iodine content of salt is in China. However, the salts of Japan and South Korea are almost cannot determine the iodine content. In addition, salt iodization is not mandatory in Malaysia and Singapore except Thailand. Investigation and determination on the iodine content of dairy products: such as fresh milk (whole, low-fat and skim milk), flavored milk, fortified milk and extended shelf life milk. Using As3+-Ce4+ catalytic spectrophotometry method to determine iodine content in fresh milk, flavored milk, fortified milk and extended shelf life milk were 52－125, 8－67, 36－118 and 7－96 μg/L, respectively. In summary, there are only about 1/4 of commercial salt products had clearly labeled as iodized salt. Among dairy products, fresh milk had the highest iodine content, while flavored milks had the lowest iodine level. These data provide the valuable information to help the consumers identify salts that contain added iodine and choose the dairy products, and this information can be supplied by the government in the prevention and treatment strategies of iodine nutrition status ofpeople and monitor the policy of salt iodization.