Grain Colour and Type as Determinants of Glycemic Response in Medicinal and Aromatic Rice Varieties of Kerala

This study aimed to estimate the Glycemic Index (GI) of medicinal and aromatic rice varieties from Kerala and compare them with Uma, a high-yielding, non-medicinal cultivar.Medicinal varieties exhibited relatively higher resistant starch (RS) content; however, cooking significantly reduced RS across all samples.The varieties represented diverse grain colours (brown, red, and white), yet grain colour alone was not a reliable predictor of GI.Notably, the released rice variety Uma (red) showed the highest GI, exceeding that of the white aromatic types, whereas the Njavara Black variety consistently exhibited the lowest GI.These findings highlight that biochemical attributes, particularly amylose and RS content, play a more decisive role in modulating glycemic response than visual traits such as grain colour.The estimated glycemic index values obtained from the in vitro digestion model provide preliminary estimates of glycemic potential and should not be considered direct evidence of clinical glycemic responses or as a basis for specific dietary recommendations for individuals with diabetes.Further validation using broader rice germplasm, diverse cooking and processing conditions, and controlled in vivo and human postprandial studies is warranted.The study underscores the importance of selecting rice based on functional and nutritional properties for potential dietary and therapeutic applications.Integrating traditional knowledge with scientific evaluation can facilitate the identification of rice varieties with potentially favourable health benefits.