Solar Drying: Fundamentals,Applications and Innovations - National ...

Aware and Thorat - Solar Drying of Fruits and Vegetables
Figure 2.9. Different pretreated solar dried fenugreek leaves
Various analysis is carried out after dehydration like chlorophyll, carotene and saponins
determination, color analysis, drying kinetics etc. During the drying there is a
loss of color. The pretreatments help in retention of greenish color of fenugreek leaves.
In solar drying of fenugreek sample C is greener than that of other samples. The sample
C which is treated with 0.1% Sodium bicarbonate gives better retention of color as
shown in Figure 2.9.
2.7. CONCLUDING REMARKS AND FUTURE SCENARIO
From the work carried out to date on solar drying of fruits and vegetables, it is concluded
that the solar dryers can be used to a great extent. Farmers should use solar
dryers for drying their own agro produce and the use of solar dryers should be promoted
by the respective Government authorities in the particular country. If we think of
raisins production in India, still the 95% of the raisins are produced by the traditional
open sun drying and shed drying, this inferior quality produce can be overtaken by superior
quality produce by solar dryers. But to happen so, some steps should be taken to
aware the farmers about the use solar dryers for their own fruits and vegetables produce.
One of the most important potential applications of solar energy is the solar drying
of agricultural products. It has been established that solar drying of fruits and vegetables
is technically feasible and economically viable. Losses of fruits and vegetables
during their drying in developing countries are estimated to be 30–40% of production.
The postharvest losses of agricultural products in the rural areas of the developing
countries can be reduced drastically by using well-designed solar drying systems. Drying
time can be further reduced using the same system with heat storage material. Economically
sound farmers capable of moderate investments can choose solar dryers according
to their individual requirements. In order to encourage small and marginal farmers
to use solar dryers, it is necessary to develop a simple, effective and economical
natural convection solar dryer. A multipurpose solar dryer capable of drying a variety of
Drying of Foods, Vegetables and Fruits 67