IODINE CONTENT OF MILK AND OTHER FOODS

Excess dietary I intake has been identified as an issue of public health concern. The recommended dietary allowance for I is 100-150 .mu.g for adults 70-120 .mu.g per day for children. A 1978 Food and Drug Administration survey found that milk and dairy products contributed more than 50% of the total food I intake for most age groups. A wide variety of dairy and food products were analyzed for I content. Red breakfast cereals and red candy (that contain FD and C Red No. 3), dairy products, eggs, milk, marine fish and iodized salt contained the most significant quantities of I. I content of individual raw milk samples from approximately 2500 farms in New York State was measured. Approximately 62% of all farms had milk I levels less than 200 .mu.g/l, 28% between 200 and 499 .mu.g/l, 7% between 500 and 1000 .mu.g/l and 3% had greater than 1000 .mu.g/l. The I content of all types of retail milk averaged 394.1 .mu.g/l, cheese and cheese products averaged 15.2 .mu.g/100 g. Most of the I partitions into the whey during cheese processing. For dairy powders (including whey), the average I content was 471.8 .mu.g/100 g. Use of these powders as ingredients in other dairy and non-dairy products can contribute to high I content of other food proucts. In particular, the I content of ice cream was extremely variable, ranging from 18 to 359 .mu.g/100 g. Generally, ice creams and ice milks that contained high proportions of whey and non-fat milk powders had higher levels of I in the finished product. Addition of FD and C Red No. 3 to foods substantially increases their total I content. However, the measured free I content of 4 brands of red breakfast cereal was higher than would be expected. Food and Drug Administration specifications for certified lots of FD and C Red No. 3 allows up to 0.4% NaI as a contaminant from manufacture. The 4 brands of red breakfast cereal averaged 6% of their total I as free I (366 .mu.g/30 g serving). This may indicate that free I may be released from FD and C Red No. 3 during processing.