Abstract:Using microwave vacuum freeze-drying technology to dehydrate fresh sauerkraut, study the influence of microwave power, vacuum degree and layer thickness on the drying characteristics and rehydration ratio of sauerkraut, determine the best drying conditions, and the low-field nuclear magnetic resonance technology (LF-NMR) was used to study the moisture state of dried pickled cabbage products during rehydration. The results showed that the drying rate of sauerkraut increased with higher microwave power, lower vacuum degree, and smaller thickness of the material layer, and the drying time was shortened. the optimal drying process conditions were found to include microwave power of 320 W, vacuum of 200 Pa, 2 mm of the thickness of the pavement layer, and the rehydration ratio of sauerkraut was 9.14 g/g. The LF-NMR showed that the difficult-to-flow water was the main form of water in the sauerkraut after rehydration, and few changes were found in the combined water and free water.