Effect of Freeze-Drying Conditions on the Quality of Spaghetti with Meat Sauce

摘要

The effects of freeze drying pressure, platen temperature, storage temperature, and storage time on appearance of product out of the dryer, rehydration ratio, and oxygen uptake of freeze-dried spaghetti with meat sauce were studied. It was found that high dryer pressure (1.5 - 2.5 mm of mercury) appeared to cause vacuum drying and that high platen temperatures (175 - 200 F.) caused browning. Low pressure (0.5 mm of mercury) resulted in the best rehydration ratio, whereas low and high plate temperatures gave the best rehydration. While platen temperature and dryer pressure had statistically significant effects on oxygen uptake, their contribution to the total variance observed was small. (Author)