Effect of processing on resistant starch content of Indian rice varieties (Sona Masuri and Mogra) and its impact on postprandial blood glucose levels

Introduction: Resistant starch has elicited new possibilities around the globe due to its plausible health benefits and functional properties. This research aimed to evaluate the effect of processing on the resistant starch content in selected Indian rice varieties and its effect on postprandial blood glucose levels. Methods: Two Indian rice varieties (Sona Masuri and Mogra) were evaluated for resistant starch in raw form, after boiling, steaming, and refrigeration. Thereafter, the increment in resistance starch content by different processing methods was validated by oral glucose tolerance test (OGTT) on ten healthy participants. Results: Among the two rice varieties, raw Sona Masuri had a higher resistance starch content (10.86%). After processing, resistant starch was observed to be high in steamed Mogra variety (3.52%). In the boiling process, Sona Masuri developed a higher resistant starch content (2.44%) as compared to Mogra variety (1.05%). The assessment done after refrigeration revealed a slight increase in resistant starch content in both rice varieties. Mogra variety had higher resistant starch (3.68%) than the other rice variety (2.56%) after refrigeration. Validation of increase in resistant starch content and its effect on blood glucose responses done through OGTT revealed that Mogra rice (test food) did not cause a swift spike in blood glucose level compared to glucose (reference food). Differences in blood glucose responses by test and reference food at 0, 30, 60, 90, and 120 minutes were statistically significant. Conclusion: Steamed and refrigerated Mogra rice did not cause significant increase in blood glucose.