MSc

Tuber crops are known as poor man’s crop as it provides food of high
calorific value and quality starch. Queensland arrowroot (Canna edulis L.)
belonging to the family Cannaceae, is a perennial herb grown in many countries
for its edible starchy rhizome. It is an outstandingly versatile and one of the
underutilized crops of tropics. The present study entitled ‘Value addition and
quality evaluation of Queensland arrowroot (Canna edulis L)’ was undertaken to
evaluate the nutritional, antinutritional and organoleptic qualities of Queensland
arrowroot rhizomes. The study also aimed to assess the quality aspects of the flour
and starch powder prepared from the rhizomes. Organoleptic and shelf life
qualities of the products developed with the flour and starch powder were also
assessed.
Nutritional and chemical constituents like moisture, protein, starch, total
carbohydrate, fibre, calcium, iron, phosphorus, sodium, potassium, vitamin C,
carotene, total phenols and oxalates were estimated. Fresh rhizome was rich in
various nutrients especially carbohydrate, starch and mineral constituents. Total
carbohydrate and starch content of fresh rhizome were 59.8 and 25.8 per cent
respectively. Organoleptic qualities of cooked rhizomes obtained a mean score
above 7.00 for all parameters.
Flour and starch powder prepared from rhizomes were evaluated for
various physical, microbial and sensory qualities initially and after three months
of storage. The bulk density of rhizome flour and starch powder was found to be
0.74g per cc and 0.69g per cc respectively. Water absorption index (WAI) of
rhizome flour and starch powder was 17.59 and 19.64 respectively. Oil absorption
capacity (OAC) of rhizome flour was 0.84 g per g. In the case of starch powder it
was 0.49 g per g. A decrease in the physical qualities was observed during storage
for both flour and starch powder. A gradual increase in the microbial count was
observed during storage. Insect infestation was not detected in both flour and
starch powder throughout the storage period. High mean scores were obtained for
sensory qualities like colour, flavour and texture of rhizome flour and starch
powder.
Two products namely vattal and murukku were prepared from rhizome
flour and ready to use custard powder was standardized using rhizome starch.
Vattal and murukku were prepared incorporating rhizome flour and rice flour in
different proportions. Ready to use custard powder was also prepared using
rhizome starch and corn flour in varying proportions. These products were
evaluated organoleptically for different quality attributes using score card. Vattal
prepared with 80 per cent rhizome flour and 20 per cent rice flour obtained higher
mean scores for different quality attributes. The organoleptic scores obtained for
all treatments were above 7 for murukku and the treatment with 30 per cent
rhizome flour and 70 per cent rice flour obtained maximum scores for all quality
attributes. Different treatments tried for custard powder also recorded high mean
scores of above 8 for all quality parameters. Custard prepared exclusively with
rhizome starch powder was selected as the most acceptable treatment.
The selected products were packed and stored under ambient conditions
for a period of three months. Decrease in mean scores of organoleptic parameters
and gradual increase in the microbial count was observed during storage. Presence
of insects and storage pests were not detected throughout the period of storage.
The present study found that Canna rhizomes are rich in various nutrients
especially starch, carbohydrate, and mineral constituents like sodium, phosphorus,
calcium and potassium. Rhizome flour and starch powder were of good sensory
qualities and can be used to prepare acceptable products like vattal, murukku and
custard powder. The physiochemical properties of Canna tubers are very much
suited for various food applications.