Effect of edible coating on the aromatic attributes of roasted coffee beans.

Coffee is known throughout the world for its distinct
aroma and flavour which results from a number of volatile
compounds present in it. It is very difficult to arrest the
aromatic compounds once the roasting process is complete
and it becomes even more challenging to store the beans for
a longer time with the retained volatiles as these compounds
are easily lost during industrialized processing such as the
grinding of roasted coffee beans and storage of ground coffee.
Thus, an attempt was made to minimise the loss of volatile
from roasted coffee beans by coating with Carboxymethyl
cellulose (CMC), Hydroxypropylmethyl cellulose (HPMC)
and Whey protein concentrate. Coffee volatiles were analysed
by Gas chromatography and 14 major compounds were identified
and compared in this study. Results showed an increase
in the relative area of major volatile compounds in coated
roasted coffee beans when compared with unroasted coffee
beans for consecutive two months. Moreover, effect of coating
on textural properties and non-volatiles were also analysed.
The results have indicated that edible coatings preserve the
sensory properties of roasted coffee beans for a longer shelf
life and cellulose derivatives, as an edible coating, exhibited
the best protecting effect on roasted coffee beans.