Cooking of the rice was conducted with an automatic rice cooker
. 800 g rice was soaked in a pot for 30 min with
1040 ml of tap water. After the rice cooked for 20 min, the thermostat
coupled with micro-switch automatically switched off the
cooker. The cooked rice samples were held in the rice cooker for an
additional 15 min. Finally, about 1300 g cooked rice was removed
from the rice cooker to a stainless steel tray (300 300 20, mm)
for freezing to the centre temperature of cooked rice piles to less
than 18 C. To avoid the difference of freezing, the cooked rice in
the centre layer of the tray was taken out, packaged in polyethylene
bags and sealed for experiments.