Effect of polishing on glycemic index and antioxidant properties of red and white basmati rice

- Fat, ash, fiber and antioxidant activity are higher in red basmati than white basmati.
- Rice polishing levels do not affect the rate of blood glucose release.
- Red basmati varieties show lower GI values than white basmati varieties.
- Ash, fiber and antioxidant activity negatively correlate with GI.
- The degree of rice polishing has no direct effect on the GI.

Four different pigmented dark-red (red) and non-pigmented white basmati rice varieties were tested for their nutrient composition, glycemic index (GI), total phenolic content (TPC), total anthocyanin content (TAC) and antioxidant activity (AOA) at 10% and 100% polished levels. The red basmati had higher content of ash, protein, fat, TPC, TAC and AOA than white basmati. Red and white basmati varieties can be classified as low GI and medium GI rice, respectively. The degree of polishing had no effect on the GI. However, there was a significant negative correlation (r > −0.81; P < 0.01) between GI value with amylose, crude fiber, crude fat, crude protein, ash, AOA, TPC and TAC contents of basmati. Relatively higher levels of TPC, TAC and AOA were found in red basmati than white basmati varieties. Therefore, red basmati varieties can serve as low GI sources of functional food.