Abstract:
Accelerated ageing is an artificial technique that induces ageing effect in fresh paddy
within a short period of time while reducing the holding costs for millers. Thus, the
aim of the study was to check the suitability of dry and steam heat treatments
separately, as two accelerated aging approaches to mitigate the stickiness of freshly
harvested paddy with preserved physicochemical and cooking properties. Freshly
harvested cleaned Bg352 paddy variety was subjected to dry heat treatments using a
hot air dryer at different combinations of temperatures and drying times (60, 80 and
100 °C for 2, 4 and 6 hours) and steam heat treatments using mini boiler at different
combinations of steam pressures (SP) and exposure times (SP; 0.5, 1.0 and 1.5 Kg/cm2
for 5, 7.5 and 10 minutes). The samples were milled to study milling, physico-chemical,
cooking and textural characteristics of rice. Rice stickiness of freshly harvested paddy
was 3.23 ± 0.03. In dry heat treatment method, exposing of freshly harvested paddy
to 100 °C for 0.5 hours has shown the significantly highest reduction in rice stickiness
from 3.23 ± 0.03 to 0.71±0.03. The results revealed that the yield %, Water Uptake
Ratio, Elongation Ratio, Solid Loss, Cooking Time and Whiteness Index were not
significantly different (p >0.05) between naturally aged and treated paddy under 100
°C for 0.5 hours but, were significantly different (p <0.05) for broken rice%. In steam
heat treatment method, freshly harvested paddy subjected to 1.5 Kg/cm2 for 10
minutes has shown the significantly highest reduction in rice stickiness from 3.23 ±
0.03 to 0.67±0.03 while it has preserved the favourable parameters than the dry heat
treatment. In conclusion, both dry and steam heat treatments accelerate the artificial
aging of fresh paddy while steam heat treatment preserve the quality at significantly
highest levels.
