This study was conducted to investigate the quality and organoleptic properties of dehydrated onions with steaming and heating. Sliced onions were treated as follows: steaming time (X1, 5∼25 min); drying temperature (X2, 55∼70℃) and drying time (X3, 4∼20 hr). All the variables were modelled and analyzed using a central composite design and response surface methodology (RSM). The coefficients (R2) of the water content and water activity model induced from RSM were 0.9514 (p〈0.01) and 0.9455 (p〈0.01), respectively. The water content and water activity were affected by the drying temperature and time. The R2 on the models of Hunter's L, a, b values were 0.9419 (p〈0.05), 0.8818 (p〈0.01) and 0.9360 (p〈0.01), respectively. Hunter's L, a, b values were affected by the drying temperature and time, but Hunter's b value was not affected by the steaming time. In addition, the R2 on the models of overall palatability was 0.8867 (p〈0.05). The maximum palatability response was 5.92 when the steaming time was 13.14 min, the drying temperature was 63.11℃ and the drying time was 14.49 hr.
동결건조 양파분말을 첨가하여 기능성 두부를 제조하고 품질특성 변화를 조사하였다. 두부의 수분함량은 양파건조 분말의 첨가량이 증가할수록 그 값이 다소 증가하는 현상을 나타내었다. 색도 변화에 있어 백색도(L값)는 양파건조분말 0.1%를 첨가했을 때 83.06으로 가장 높게 나타났다. 적색도(a값)는 대조구나 양파건조분말 첨가구에서 로 거의 변화가 없었다. 황색도(b값)의 경우 양파건조분말 첨가구는 으로 비슷하게 나타났다. Sucrose함량은 0.2