동결건조 쌀죽의 재수화 특성에 미치는 동결온도의 영향

To study the effect of freezing rate on the quality of freeze-dried rice porridge, freeze-dried rice porridge products were prepared with rice porridge pre-frozen at three different temperatures of ?20, ?,40, and ?70℃. The porridge properties such as microstructure, mechanical properties, textural properties, and rehydration rate were determined. Scanning electron microscopy images indicated that fewer air cells were obtained with a larger size of freeze-dried rice porridge frozen at ?20℃ compared with that frozen at ?40 and ? 70℃. In contrast, quick frozen products at ?70℃ had more dense texture with higher mechanical strength, whereas slow frozen products exhibited higher rehydration rates than those of quick frozen products. In conclusion, the proper choice of pre-freezing temperature plays a decisive role when preparing freeze-dried rice porridge with optimum quality and convenience.