Glycemic Index and Insulin Index of Palmyrah Based Edible Products Commonly Consumed in Jaffna

The objective of this study was to determine the insulin index and glucose index to isoenergetic (1000-kJ) portions of palmyrah based foods commonly consumed in Jaffna and their correlations between nutrient and phytochemical contents. Subjects were selected those having fasting blood sugar less than 100 mg/dl. Glucose (reference food) and four test foods such as pinnatu, Jaggery, odiyalpittu and pullukodiyal flour snak were administrated to four groups of 24 subjects and serving weight were calculated based on the energy content. Subjects were fasted for12h before the administration of foods then venous blood samples were collected at 0 time and every 30 min for two hours after either feeding with glucose and test foods. An insulin score and glycemic score were calculated from the area under the insulin/glucose response curve for each food with the use of reference food. Among the test foods pinattu has low glycemic (52.9%) and low insulin index (36.47%).Carbohydrate, ash and Total Dietary Fiber (TDF) present in the those products were negatively correlated with glycemic index. Insulin index was negatively correlated with TDF, protein and ash contents. Not only the nutrient contents but also the phytochemicals such as total phenols and flavonoids showed negative correlation. All the tested products showed less plasma insulin, although high plasma insulin causes coronary heart disease. Therefore palmyrah products could be used in order to develop new value added foods, which could have more beneficial health properties regarding glucose and insulin metabolism.