Abstract:
Alocasia macrorrhiza is an edible corm native to Sri Lanka. Despite its nutritional and
medicinal benefits, it is not consumed in Sri Lanka due to its acridity and is regarded
an underutilized corm. These corms can be processed into flour after applying thermal
processing which can alter the properties of flour. The present study aimed to evaluate
functional properties and antioxidant properties of flours after milling raw, boiled
and roasted corm into flour. The water and oil absorption capacities (166.61±14.43
and 132.58±5.34% respectively) of raw corn flour was significantly similar to that of
commercial wheat flour (116.67±15.28 and 160.00±5.00% respectively). Moreover, the
flour showed better solubility characteristics than wheat flour. The swelling power of
the flours ranged between 3.01±0.01 and 7.34±0.13 g/g and these values were lower
than swelling power of commercial wheat flour. The gelatinization temperatures of
flour samples were in the range of 72.67±2.08 to 89.67±0.58°C which was higher than
commercial wheat flour. Higher bulk densities showed by all samples while the highest
bulk density (0.71±0.02 g/cm3) and tapped density (0.89±0.00 g/cm3) were shown by
roasted corm flour. The processed corm flour showed moderate flowability while raw
corm flour showed poor flowability. Total phenolic contents of raw, roasted, and boiled
corm flours were 50.01±1.36, 77.42±1.67, and 49.39±1.75 mg GAE/ 100 g, respectively.
However, total flavonoid contents were not significantly different among flour samples.
The roasted corm flour showed the highest radical scavenging activities with a minimum
IC50 value (66.70±2.52 mg/ml) for DPPH assay and reducing power (155.7±20.6 mg
TE/100 g) compared to raw and boiled corm flour. The boiled corm flour showed the
highest radical scavenging activities with a minimum IC50 value (9.96±1.23 mg/ml) for
ABTS assay. In concluding, thermally processed corm flours showed higher functional
and antioxidant properties than raw corm flour.
