Question

Estimate thermal conductivity of a potato at 20Celsius. the potato gas water content of 79.8% wb and based on the total mass it contains 2.1% of protein, 17.1% carbohydrates, 0.9% ash and 0.1% fat.

Answer 1

Potato composition : by wt basis.

water content, x1 = 0.798

Protein, x2 = 0.021

Carbohydrates, x3 = 0.171

Ash, x4 = 0.009

Fat, x5 = 0.001

By table,

Thermal conductivity of different components, at 20C

water , k1 = 0.6 W/m.k

Protein, k2 = 0.1 W/m.k

Carbohydrates, k3 = 0.25 W/m.k

Ash, k4 = 0.46 W/m.k

Fat, k5 = 0.209 W/m.k

As we know that for this type of question overall thermal conductivity of potato,

k = x1*k1 + x2*k2 + x3*k3 + x4*k4 + x5*k5

k = 0.798*0.6 + 0.021*0.1 + 0.171*0.25 + 0.009*0.46 +0.001*0.209

k = 0.52779 W/m.k

thermal conductivity of potato given composition,

k = 0.52779 W/m.k