Abstract:
Six high amylose rice varieties with nearly similar amylose content (30%)
and gelatinization temperature (77 ⁰C), but differing in size (length/width)
were cooked under the same cooking conditions and their physicochemical
properties, digestibility and expected glycemic index were investigated and
compared. Resistant starch content ranged from 0.48 to 1.6. Expected in
Vitro glycemic index was nearly 116 for all tested varieties. The results
showed that the size (length/width) and resistant starch content have
apparently no impact on the glycemic index of tested six rice varieties. It
appears that the dominant factors that determine the glycemic index of
tested rice varieties were amylose content and the gelatinization
temperature. Except for pasting temperature, other pasting properties
obtained by RVA (Rapid Visco-Analyzer) test significantly varied among
the tested six rice varieties. Pasting temperature corresponds to the
gelatinization temperature. Thus, pasting properties, except for pasting
temperature are not good predictors for the glycemic index of high amylose
rice.
