ABSTRACT
The defects that drying in concrete yards impose on coffee beans and the search for gourmet coffee production have prompted the emergence of new drying technologies. This work verified the technical and economic feasibility of drying coffee with dehumidified air with a refrigerating capacity of 422,908.7 J s-1, compatible with static capacity dryers equal to 75 m3. Considering the sale price of coffee, the cost of electric energy acquisition, the monthly interest rate and maintenance time, expenses that are equivalent to the depreciation of the concrete yard, a central compound rotational design was considered with 28 tests for the feasibility analysis, including the internal rate of return, net present value and the return on investment. The results showed that in the electric drying units, the dried coffee presents fewer broken and defective beans and has higher retention in a No. 17 sieve. With a higher beverage quality and a price 12.11% higher, drying with dehydrated air showed a PBD of 2.27 years and a return of US$ 2.49 million. The optimisation results were 98.98% desirable. It was concluded that it is economically feasible to dry coffee with dehydrated air and without using a concrete yard.
artificial drying; Coffea Arabica L; electric dryers; quality of the drink; postharvest losses
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Source: Adapted from 
Notes: X1: Sale price of a 60 kg bag of coffee dried in the concrete yard in Reais, X2: Cost of electric energy acquisition in US$ kWh-1, X3: Annual percentage rate of interest, and X4: Maintenance period in the concrete yard with an amount equivalent to its depreciation in years. The two most striking variables on each response were used in the horizontal axes.