Tomato powder has good potential as substitute of
tomato paste and other tomato products. In order to protect
physicochemical properties and nutritional quality of tomato during
dehydration process, investigation was carried out using different
drying methods and pretreatments. Solar drier and continuous
conveyor (tunnel) drier were used for dehydration where as calcium
chloride (CaCl2), potassium metabisulphite (KMS), calcium chloride
and potassium metabisulphite (CaCl2 +KMS), and sodium chloride
(NaCl) selected for treatment.. lycopene content, dehydration ratio,
rehydration ratio and non-enzymatic browning in addition to
moisture, sugar and titrable acidity were studied. Results show that
pre-treatment with CaCl2 and NaCl increased water removal and
moisture mobility in tomato slices during drying of tomatoes. Where
CaCl2 used along with KMS the NEB was recorded the least
compared to other treatments and the best results were obtained
while using the two chemicals in combination form. Storage studies
in LDPE polymeric and metalized polyesters films showed less
changes in the products packed in metallized polyester pouches and
even after 6 months lycopene content did not decrease more than
20% as compared to the control sample and provide extension
of shelf life in acceptable condition for 6 months. In most of the
quality characteristics tunnel drier samples presented better values in
comparison to solar drier.