Inadequacy of riboflavin intake among Koreans had been pointed out repeatedly in most dietary and nutritional surveys in Korea. The consumption rate of dairy products has been increasing markedly in recent years. Milk and milk products are known to be a good source of the vitamin which can easily be destroyed by the sunlight. Total riboflavin content of the pasteurized and homogenized milk, both plain and flavored, and the milk products were measured by the Lumiflavin method. It ranged from 62.4,ug riboflavin per 100g of homogenized milk to 195.9,ug for vanilla flavored ice cream. In general milk products in the form of cream contained about three times as much riboflavin as plain milk.
The rates of destruction of riboflavin in chocolate milk and white milk in clear glass bottle and in polyethylene pack were different when measured in 30 min intervals after exposure to bright sunlight for two hours. In the case of the plain milk, the riboflavin content decreased rapidly and remained only about a quarter of the initial value within an hour of the exposure pariod. The destruction rate slowed down after the first hour of the exposure and resulted about 90% destruction of riboflavin in two hours. The chocolate milk however exhibited a protective effects of the riboflavin from the sunlight. It retained 65% of the initial riboflavin after an hour of the exposure to sun and 55% ofter two hours.
Two most widely used milk containers, clear glass bottle and polyethylene pack ,vere about equally affected by the sunlight.
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