2.8. Determination of solubility of starch
Solubility (%) of starch was determined according to the methods
described by Leach, McCowen, and Schoch (1959) with a slight
modification. Rice samples (0.5 g) were suspended in 30 ml of distilled
water in 50 ml-falcon tubes and heated in a thermostatically
controlled water bath for 30 min at different temperature ranging
from 50 to 90 C at 10 C intervals. The tubes were rapidly cooled
to room temperature before centrifuging at 1500g for 30 min.
Supernatant solution (soluble starch) was poured into an aluminum
dish and dried at 120 C for 4 h. The solubility of starch was
calculated by dividing the mass of dried supernatant by the mass
of starch.