대두의 영양 저해인자로 알려진 phytic acid를 pH를 조절하는 각기 다른 방법으로 제거할 low-phytate soy protein isolate(SPI)와 high-phytate SPI를 얻어 이들 분리 대두단백의 용해도와 소화율에 미치는 phytic acid 함량의 영향을 조사하였다. 분리 대두단백의 phytic acid 함량은 high-phytate SPI에서 2.48%이었고, low-phytate SPI에서는 0.72%이었다. 분리 대두단백의 용해도는 모든 pH에서 low-phytate SPI가 high-phytate SPI 보다 높았으며 phytic acid의 첨가량이 많을수록 용해도가 떨어져 침전되었다. 분리 대두단백의 소화율에 미치는 phytic acid의 저해적 영향은 phytic acid 첨가량이 증가할수록 더 컸으며, low-phytate SPI 보다 high-phytate SPI에서 그 저해효과가 약간 크게 나타났다.
Phytic acid known as an antinutritional facfor was studied for its effect on the solubility and digestibility of high-phytate and low-phytate soy protein isolates (SPI) obtained by two different methods of pH adjustment. Phytic acid content was 2.48% in high-phytate SPI and 0.72% in low-phytate SPI. Solubility of soy proteins was higher in low-phytate SPI than in high-phytate SPI at all pH values tested and it was lowered by adding more phytic acid to result in precipitation of the proteins. The inhibitory effect of phytic acid toward pepsin digestion of SPI increased by the increasing amount of phytic acid added and its effect was slightly higher in high-phytate SPI than in low-phytate SPI.
