Glycemic Index of Selected Traditional Rice Varieties of Tamil Nadu, India

Abstract

Traditional rice varieties are receiving increasing attention because of their nutritional composition and potential relevance in dietary glycaemic management. This study evaluated the glycaemic index, selected nutritional components and consumer acceptability of two traditional rice varieties of Tamil Nadu, Red Kavuni and Kattuyanam, in comparison with the fine-grain rice variety TKM 13. Rice samples collected from Tiruvallur District, Tamil Nadu, were cleaned, dehusked and processed into rice flakes. The carbohydrate and crude fibre contents of TKM 13, Red Kavuni and Kattuyanam were 85.60 g/100 g and 1.50 g/100 g, 76.00 g/100 g and 2.90 g/100 g, and 72.50 g/100 g and 2.80 g/100 g, respectively. Total phenolic and flavonoid contents were higher in Red Kavuni and Kattuyanam than in TKM 13. Glycaemic response was assessed in healthy adult volunteers after overnight fasting, using glucose as the reference food. Blood glucose was measured at fasting and at 15, 30, 45, 60, 90 and 120 minutes after food intake, and the incremental area under the curve was used to calculate glycaemic index. Glycaemic index values were 68 for TKM 13, 55 for Red Kavuni and 57 for Kattuyanam. Consumer acceptability was highest for TKM 13, while Red Kavuni showed the highest recovery percentage and benefit-cost ratio. These findings indicate that Red Kavuni and Kattuyanam rice flakes produced lower glycaemic responses than TKM 13 under the conditions of this study.