대두유를 튀김유로 사용하여 french fried potato를 $185^{circ}C$에서 제조하면서, 1일 7시간씩 총 56시간동안 가열 및 튀김후 composited powder (citric acid, 물, rhyolite 혼합물)를 처리한 대두유와 처리하지 않은 대두유의 기능성, 발연점, 기포성 및 점도와 물리화학적 성질을 비교 분석하였다. Composited powder를 처리하면 극성지질의 생성을 억제하고, 불포화 지방산의 가열산패를 억제시켜, 튀김유의 수명을 약 50% 증가시켰음을 확인하였다. 그러나 산가증가의 억제 및 발연점 저하의 효과가 없었다.
The useful life of frying oil was increased by treating the frying oil with a composited powder comprising water, citric acid and porous rhyolite carrier. The color darkening and foaming tendency of the oil during frying operation was apparently retarded. Increase rates of polar lipid components, dielectric constant and formation of the conjugated dienes and trienes of the used frying oil were reduced to two thirds of the oil without treatment during 84 hr frying operation. Iodine value and polyenoic index was also much less decreased by treatment. The treatment, however, have no significant effect to inhibit the decrease of smoke point and the increase of viscosity.
