Production Practices and Quality Assessment of Food Crops. Vol. 1

and Micheli, 1979a; Sampathu et al., 1984; Green, 1995). Larger yields are expected
from the third and fourth year plants. This stage is very crucial for the overall quality
of the final product. Frequently, sudden rainfall during blooming is the reason for
the collection of dirty stigmas and very wet material which remaining for many hours
in the baskets deteriorates. Therefore, the quantity of plant material per basket should
not be great and it is urgent to remove petals, clean and dry the product as soon
as possible after collection.
5. THE EFFECT OF PROCESSING ON QUALITY
Losses of desirable compounds, such as volatile constituents, are related to the drying
method used for herbs and spices. Literature concerning a great number of them
(thyme, sage, dill, marjoram, oregano, parsley sweet basil, etc) is useful to those
that intend to adopt a drying system or technology in another case of an aromatic
plant. Air drying (in shade or solar), freeze-drying, hot air drying, fluidised bed
drying, microwave hot air drying, drying by means of convection, etc. (Cohen and
Yang, 1995; Venskutonis, 1997) are some of the procedures used in practice by individual
producers or in industrial scale. All means are not suitable for every plant
material. Not to forget is the fact that smallholders, mainly in developing countries,
are those who grow herbs and spices. In such cases, due to the lack of
information and the absence of hygiene rules implementation, rather primitive and
sometimes inappropriate drying methods for the product are employed. Moreover,
pets and other ‘visitors’ cannot be excluded from the area where drying takes place
whereas long storage period before drying or slow drying encourages the growth
of microorganisms. A common process flow chart for a herb or spice involves
after harvesting drying, sorting, washing or winnowing, cutting, finish drying, further
cleaning, packing and storage till distribution.
5.1. Drying
Saffron Quality 241
Drying brings about the physical, biochemical and chemical changes necessary
for imparting the desired attributes to saffron. Drying saffron is a difficult task
because its principle characteristics, the crocins, are water-soluble and consequently
washing is prohibited though foreign matter (dust, mud, parts of insects, etc)
is not rare. On the other hand, crocins, as all carotenoids, are light sensitive so
that exposure to light throughout processing should be the minimum. Picrocrocin,
the bitter constituent decreases during the first drying and the subsequent treatment
steps whereas safranal absent before drying and the period just after that
starts to develop in the first period of storage.
The various saffron drying versions as briefly presented by Basker (1999b)
show that little has been published to this direction. The practice of growers differs
from country to country as a result of experience gained through trial and error.
Moreover, each one of saffron growing regions or countries has devised a procedure
that takes into account the available resources. Still, variations are found
even among the producers of the neighbouring plots of land in the same region.