Question

Cellophane is being used to keep food moist at 38oC. (2 Points) Calculate the maximum loss of water vapor in g/day at steady state for a wrapping 0.10 mm thick and an area of 0.2 m2 when the vapor pressure of water vapor inside is 10 mm Hg and the air outside contains water vapor at a pressure of 5 mm Hg. The density of Hg is 13.56 g/cm. (1 Point) Under these conditions, if the package holds 30 g of product at 25% (wb) moisture, what would be the moisture of the product after 7 days of storage. Consider that the food does not offer any “resistance” to water loss, so all the water that could permeate through the package would be lost. Hint: Find permeability value of H2O in cellophane from Additional Resources.

Answer 1