Question

Raw whole apples with a moisture content of 87% (wet basis) are peeled and cored before being sliced and dried to 7.5% moisture content (wet basis). 18% of the raw apples mass is lost due to peeling and coring. Assume the peels and cores have the same moisture content of the rest of the apple.

1.) How many kilograms of 87% (wet basis) apple slices (already peeled and cored) are needed to make 30 kg of fried apple slices at 7.5% moisture (wet basis)

2.) How much water needs to be removed during drying?

3.) How many kg of whole raw apples (not peeled or cored) are required to make the 30 kg of the dried product?

Answer 1

Pulp and non-water content of apple is 13% as 87% is water.

18% of apple is lost in the process means 82 is left to dry.

Lets Total amount of apple required is = m.

amount of apple left after peeling and coreing is = 0.82m

Non-water and pulp content = 0.82m*.13 = 0.1066m

Non- water and pulp content remains constant

Moisture content after drying is 7.5% = .82m*(7.5/100) = 0.0615m

So, total mass left after drying = 0.1066m+ 0.0615m = 0.1681m

As given in the question, final amount is 30 Kg, So.

So, total apple required to get 30kg of dried apple is 178.5 kg (answer of part c)

Apple left after coreing and peeling = (answer of part a)

Water to be dried = 146.37 - 30 = 116.37 kg (answer of part b)