Abstract:
Arabica coffee belongs to the family Rubiaceae and to the genus Coffea. It is also the
backbone of Ethiopia’s economy, contributing the highest of all exports revenues. The
quality of coffee is influenced by several factors of which post-harvest handling is one.
Coffee in Ethiopia is processed in two different methods on different drying materials
including bare soil uniformly across locations. However, lack of information on the effects
of post harvest processing and drying on quality necessitates a comprehensive study.
Thus, the objectives of this experiment was to evaluate the influence of processing methods
and drying materials on the physical and organoleptic quality attributes of known coffee
varieties under Gera and Jimma conditions, and to estimate the economic advantages of
coffee processing and drying practices under each agro-ecology. Accordingly, the
experiment was conducted at Jimma agricultural research center and Gera agricultural
research sub center from October 2009 up to June 2010 using a 2×6×3 factorial
experiment arranged in split-split plot, using randomized complete block design (RCBD)
with three replications. Days to drying, physical and cup quality parameters were
recorded and analyzed using SAS version 9.2 computer package. As a result, variation
among the varieties were highly significant (P<0.01) for bean size and hundred bean
weight at both sites. Body and bean size showed significant variation (P<0.05) at Gera
and highly significant variation (P<0.01) at Jimma for body and shape and make due to
the processing methods. The maximum value for odor (10) was obtained from drying
material mesh wire, bamboo, palm leaves mat and jute mesh at Gera while at Jimma the
maximum value was obtained only from mesh wire. With regard to aromatic quality,
drying material bamboo demonstrated significantly the highest value (3.31) at Jimma. Wet
processing significantly (P<0.01) increased the value for body from 2.88 to 3.74 at Gera
and 3.25 to 3.89 at Jimma. A highly significant (P<0.01) interaction was also noticed
between drying material and variety on acidity wherein 74110 dried on mesh wire resulted
in the highest (3.39) at Jimma. As to flavor, mesh wire recorded the highest 2.90 at Jimma.
Thus from the study the wet processed coffee dried on bamboo, mesh wire, palm leaves
mat, and jute mesh had good cup quality. With reference to days to drying, at both
locations and using both processing methods, the use of bamboo resulted in earlier drying
as compared to the other coffee drying materials. Differently, either wet or dry processed
coffee dried on soil was found to be strongly discouraging because of its bad quality. Thus
from the study the variety 74110 processed with wet processing method is superior in
terms of most of the Quality parameters considered in this study and can be recommended
for Jimma Zone specially for Melko. 7440 and 75227 processed with wet processing
method had acceptable physical and cup quality at JARC and best at Gera; consequently,
can be recommended for Gera. However further researches including biochemical
analysis and environmental factors should be conducted to give concrete
recommendations
