우유(牛乳)와 유제품(乳製品)의 Riboflavin 함량(含量) 및 일광(日光) 노출시의 파괴율에 관한 연구

Riboflavin in milk and milk products and the destructive effect of sunlight

국내(國內)에서 생산(生産)되는 시유(市乳)와 유제품(乳製品)의 riboflavin함량(含量)을 분석(分析)하고 병우유와 폴리팩우유, 흰우유와 초코렛색의 우유를 대비(對比)시켜 일광(日光)에 예민한 riboflavin의 함량변화(含量變化)를 추적한 결과(結果)를 요약(要約)하면 다음과 같다. (1) Riboflavin의 함량(含量)은 시료 100g당 병우유 흰것 $62.4{\mu}g$, 폴리팩우유 $62.4{\mu}g$, 초코렛우유 $61.5{\mu}g$, 커피우유 $62.5{\mu}g$, 바나나우유 $87.7{\mu}g$, 딸기우유 $89.3{\mu}g$, 발효유 $36.2{\mu}g$, Hard ice cream bar $130.4{\mu}g$, vanilla soft ice cream $195.9{\mu}g$이었다. (2) 한시간 일광(日光)노출후 병우유 72.4%, 폴리팩우유 77,7%, 두시간 경과후 병우유가 92.0%, 폴리팩우유가 91.4%로서 폴리팩우유가 riboflavin이 약간 빨리 파괴되는 경향(傾向)을 보였으나, 두시간 경과후의 파괴율은 서로 비슷하였다. (3) 1시간 일광(日光)노출후 초코렛색 우유는 36.1%, 흰우유는 72.4%, 두시간 후에는 초코렛색 우유 46.3%, 흰우유는 92.0%의 riboflavin의 파괴율을 보여 초코렛우유가 훨씬 파괴율이 적었다. 이상의 결과(結果)로 미루어 특히 여름철의 일광(日光) 노출은 riboflavin의 막대한 손실이 올 수 있음을 알 수 있었고 초콜렛색의 우유가 흰우유 보다 일광(日光)노출에 대한 riboflavin의 보존(保存)에 효과적이었다.

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 $62.4{\mu}g$ riboflavin per 100g of homogenized milk to $195.9{\mu}g$ 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 period. 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 were about equally affected by the sunlight.