Dehydration is the process of removing moisture from the food under controlled conditions of temperature, relative humidity and airflow. This process is performed in a dehydrator using hot air as an energy source. Alternatively, the product may be sun-dried. In general, the raw material is prepared in the same manner as for cooking. It is spread on trays that are placed in the dehydrator or in the sun.
Instruments
- Rotary Washer
- Abrasive Peeler
- Sharp Knife
- Multipurpose Machine
- Steam Blancher
- Dehydrator
- Cellophane Pouches
- Sealer
Procedure
- Weigh about 5 kg selected, graded potatoes.
- Wash in a rotary washer and peel in an abrasion peeler.
- Trim to remove green portions and eyes.
- Weigh the peeled and trimmed potatoes.
- Record trimming and peeling losses.
- Cut potatoes into 3/8″ square strips or slice into-1/4″ slices.
- Steam blanch for 5-8 minutes at 100 °C.
- Wash in the rotary washer to remove starch.
- Spread potatoes evenly on the trays, 0.25 kg per sq. ft.
- Dry according to the following schedule:
- a. 82 °C, relative humidity 24-30% until 80% water is evaporated.
- b. Finish at 71 °C.
- c. Record weight hourly.
- d. Record relative humidity hourly.
- Compute drying ratio and yield.
- Pack dried potatoes in cellophane pouches.
- Seal and store in a cool, dry place.
