Question

Raw potatoes are composed of about 18%–20% starch and approximately 75% water. Before frying, raw

potatoes are peeled and then washed. Assume that 8% by weight of the raw potatoes is lost in the peeling.
Potatoes are then dried to 7% total water content. What is the mass of dried potatoes produced from
each 100 kg of raw potatoes?

Answer 1

You start with 100 kg raw potatoes.

8% of mass is lost by peeling:

100 - ( 8 / 100) × 100 = 92 kg of peeled raw potatoes

By drying the water contents is reduces from 75% to 7%, that means a 68% loss by weight:

92 - ( 68 / 100) × 92 = 92 - 62.56 = 29.44 kg of dried potatoes