Abstract:
Five existing and newly developed rice varieties (Super kernel, Purple queen, Rathu
suduru, Red fragrant, and White slender (parboiled)) were tested for glycaemic index
(GI) and glycaemic load (GL). Sixteen healthy volunteers were recruited. After overnight
fasting, each of them was given a 50 g available carbohydrate portion of glucose (reference
food) or different varieties of cooked rice (test foods) on separate occasions.
At each occasion, the fasting and post-prandial capillary blood glucose responses were
determined over 2 h, and the incremental area under the curve (IAUC) was calculated.
The GI value was calculated as the IAUC of the test food / IAUC of the reference food
Ö 100. The GI values of Super kernel (40 ± 5.5%) and Rathu suduru (61 ± 5.5%) were
found to be significantly different (P < 0.05) and GI values for Purple queen (47 ±
4.9%), Red fragrant (54 ± 3.8%) and White slender (parboiled) (49 ± 3.8%) were found
to be not significantly different (P > 0.05). GI values of Red fragrant at 40% and 100%
polishing levels were 54 ± 5.7% and 53 ± 5.5%, respectively and they were found to be
not significantly different (P > 0.05). The GL values of Rathu suduru (12 ± 1.1%) and
Super kernel (8 ± 1.0%) were found to be significantly different (P¡0.05) while that of
Purple queen (9 ± 0.9%), Red fragrant (10 ± 0.7%) and White slender (parboiled) (9
± 0.7%) were found to be not significantly different (P > 0.05). All the rice varieties
tested could be classified as low GI and low GL except Rathu suduru (Medium GI and
GL). Therefore, the low GI and GL rice varieties may confer potential benefits in terms
of glycaemic control and as a guide to food selection among people with diabetes.
