Abstract

Geographical Indication (GI) tagged traditional rice of Kerala namely the red pigmented Palakkadan Matta and non-pigmented aromatic rice – Wayanadan Gandhakasala and Wayanadan Jeerakasala are well known for their cooking and eating quality, but are underutilized for their nutritional significance. The objective of this study was to classify these varieties based on their starch digestibility, biochemical composition and cooking characteristics. Results indicated significant (p <0.05) variation among rice varieties for all the parameters evaluated. In vitro starch digestibility studies found significantly low glycemic index (< 68) but higher RS content for Wayanadan Gandhakasala and Chettadi. Aromatic varieties had lower cooking time (< 25 min) than Palakkadan Matta varieties. High water uptake ratio and elongation ratio was also noted for Wayanadan Gandhakasala. Total phenolic content correlated positively to total flavonoid content. Over all, Palakkadan Matta varieties had significantly higher free phenolic, free flavonoid and total flavonoid content than nonpigmented varieties. The study indicates that these GI tagged traditional rice varieties can thus be utilised in the functional food industry based on their intermediate glycemic index, desirable cooking qualities and the presence of beneficial bioactive components.