Changes in the Cadmium and Lead Contents of Rice and Wheat Flour during their Cooking and Processing

쌀과 밀가루의 조리가공(調理加工)중 카드뮴 및 납 함량(含量)의 변화

This study was undertaken to investigate the removal efficiency of heavy metals (Cd, Pb) in rice and wheat flour by cooking and processing. After four times washing of rice grains with water, the removal ratios of cadmium and lead from artificially-contaminated samples were 39.271 and 34.9%, respectively. In cookingof rice grains washed three-times with water, the residue levels of cadmium and lead decreased to 85.7%, 83.0% in electric rice cooker and 74.51%, 72.6% in pressure rice cooker, respectively. No significant difference was observed in the removal of the metals between naturally-contaminated and artificially contaminated rice samples, and between the electric and pressure rice cookers. In baking of artificially-contaminated wheat flour into cookie and loaf bread, the removal ratios of cadmium and lead were negligible as expected. When knife-cut noodle was made from artificially-contaminated wheat flour and boiled in water, 75% of the metals were found in the noodle solids and only 25% of them were removed into the broth.

식품원료의 조리(調理) 및 가공(加工)중 오염된 중금속(重金屬)의 함량변화를 규명하기 위해 쌀과 밀가루를 시료로 수세(水洗), 취반(炊飯)과정 그리고 쿠키, 국수, 빵으로의 가공(加工)중 카드뮴(Cd) 및 납(Pb) 함량의 변화를 측정하였다. 중금속을 인위적으로 오염시킨 쌀을 4희 수세하였을때 Cd는 39.2%, Pb는 34.9%제거되었다. 쌀을 3회 수세후 취반하였을 때 전기밥솥의 경우 Cd는 14.3%, Pb는 17.0% 제거되었으며 압력밥솥의 경우 Cd는 25.5%, Pb는 27.4%가 제거되었다. 취반시 Cd와 Pb의 제거효율을 자연적으로 오염된 쌀과 인위적으로 오염시킨 쌀 간에 또는 전기밥솥과 압력밥솥 간에 유의적인 차이가 없었다. 중금속으로 오염된 밀가루로 쿠키를 구울 때와 제빵시 Cd와 Pb의 제거효과는 기대할 수 없었다. 밀가루로 칼국수를 만들고 이것을 삶았을 때 Cd 및 Pb 함량은 국수 고형물에 75%. 국물에 25%가 이 동하였다.