Effect of atmospheric humidity on drying of papads.

Blackgram (Phaseolus mungo) papads were dried in the open under widely varying conditions of RH (38-82%) and at 24-25 degree C and also in a cabinet drier at 64-66% RH and 31 degree C for 6 h. At 38-43% RH, papads were over-dried, warped and brittle within 4 h; drying at 78-82% RH for 6 h resulted in incompletely dried products, susceptible to fungal spoilage. Drying for 6 h at 66-70% RH at 25 degree C in open air gave a pliable product with the desired moisture content of 14.5%. Drying in a cabinet dryer at 64-66% RH and 31 degree C for 5 h also gave a pliable product with optimum moisture content. It is suggested that artificial drying of papads be adopted, maintaining temp. at 25-31 degree C with electric heaters and RH at 64-70% by spraying water in the room.