Abstract:
Carrots are a root vegetable also known as Daucus carota, a member of the Umbelliferae
family and thus related to parsley, dill and celery.The aim of this study was to study the
retention of β-carotene at solar and cabinet drying conditions and storage of dehydrated
carrot. The fresh carrot (Daucus carota) of 8 weeks after sowing was taken and washed
with clean water and cubed into uniform thickness of 1 cm × 1cm × 1cm. The cubes were
blanched at 98°C water for 0, 30, 60, 90, 120, 150, 180 and 210 s to optimize the blanching
time by peroxidase test. Then the carrot cubes were dried at cabinet drier at 60±5°C for 8 h
and solar drier until equilibrium moisture content was obtained. Similar drying was done
for unblanched carrot cubes. After drying the drying condition was optimized according to
the retention of β-carotene content. Then the rehydration of dried carrot was done to study
rehydration properties. And, the optimized sample was powdered and powdered samples
(250 g) were stored in Low-Density Polyethylene (LDPE) of 40μ and High-Density
Polyethylene (HDPE) of 50μ packaging at 27ºC and β-carotene retention was studied at
interval of 10 days for 60 days.
The optimized blanching condition was found to be at 98°C water for 3.5 min. The
higher β-carotene retention of 30.21 mg/100 g was found for blanched carrot sample dried
at cabinet dryer at 60°C for 8- h. The desorption rate was higher for the blanched cabinet
dried sample. The rehydration properties of all the samples (solor and cabinet dried carrot)
were not found to be significantly difference. During storage of carrot powder in LDPE
packaging material and HDPE packaging for 60 days, β-carotene destruction was high for
LDPE packaging (26.06 mg/ 100 g to 8.88 mg/ 100 g) than that of HDPE packaging (26.06
mg/ 100 g to 15.89 mg/ 100 g). So, it can be concluded that β-carotene can be retained
more by drying blanched carrot in cabinet dryer at 60±5°C for 8 h.
Description:
A dissertation submitted to the Department of Food Technology, Central Campus of
Technology, Tribhuvan University, in partial fulfillment for the degree of B.Tech. in
Food Technology
