Paprika is utilized for its strong colour and has very little pungency. The
quality of ground paprika is mainly determined by its seasoning power i.e.
, capsaicin content its natural colour i.e., carotenoid content, its partic
le size and water content. Selection of proper drying conditions is necessa
ry for minimizing thermal stress, over-drying and maintenance of relevant c
ompounds which determine the quality of the product. Loss of red colour is
caused by autoxidation of the carotenoids. It is reported that the stabilit
y of the quality of paprika, during storage is dependent on drying conditio
ns and the degradation rate of quality increases as the drying temperature
increases. In view of the importance of this spice product standardization
of processing protocol is necessary.
Transport properties in terms of interphase mass and heat transfer along wi
th the diffusion coefficient were determined for paprika from drying experi
ments. The analysis includes the comprehensive process including the form o
f the product like whole fruit or pericarp, various preprocessing steps lik
e cutting, separating, steam blanching and drying. Drying was carried out u
sing both a conventional pilot scale convective dryer and a laboratory drye
r with the additional facility of drying under inert atmosphere. For proces
sing under inert gas, the pre- and post-drying steps of cutting, separating
and grinding the product before storage were also carried out under inert
conditions The influence of these pre-processing steps on the drying behavi
our was characterized by determining the transport properties. Additionally
, the product was also analyzed for its red colour intensity (ASTA) value,
tocopherol, carotenoids and vitamin C content, to evaluate the best possibl
e processing protocol to obtain a good quality product. (C) 2001 Elsevier S
cience Ltd. All rights reserved.