Dehydration of cabbage:In dehydration technology the main principle involved is under controlled conditions removing the moisture from produce by application of heat, temperature, humidity and the air-flow. In this process after blanching shredded vegetables are spread over the tray in single layer. The initial temperature in dryer is adjusted to 60-65?c for 4-5 hrs and then after the temperature is reduced to 50-55?c for complete drying of vegetables. In dried vegetables drying method also improves the aesthetic quality and rehydration quality. In India, cabbage shreds are blanched and soaked in 3 % salt plus 6% sucrose for 12-16 hrs at a temperature of 4?c to reduce shrinkage, improve rehydration without affecting quality and to extend shelf life of produce.
In Philippines, dehydrated cabbage is prepared by removing the outer wrapper damaged or discolored leaves (De leon et al., 1988). Remove the core, and then head is cut into small pieces.
Small pieces are shredded to ¼ inch thickness, blanched and steamed for 4 minutes. The blanched shreds are spread on trays, then dried in a cabinet drier at a temperature of 60-70?c until moisture reaches upto 5-6% followed by cooling and packed in suitable polypropylene bags.In Myanmar, the cabbage heads are washed with clean water and cut into small pieces (about 4mm) (kyi, 2007). Before drying, pieces are blanched by dipping in boiling warer for 3 minutes or steaming for 5 seconds.
Sodium bicarbonate (10g per liter of water) is added to the boiling water. The optimum temperature maintained for dring is 55?c till the final moisture in the produce reaches to 4%. The drying ratio is 1:18. When the leaves become hard and brittle that is the end point of drying.