Determination of blood glucose response and glycaemic index among healthy young adults after consuming taro (Colocassia esculenta) and tannia (Xanthosoma sagittifolium)

Abstract

This randomized cross-over study was carried out to determine the blood glucose response and to determine the glycemic index value of tannia and taro. There are 12 healthy young adults aged between 21 to 23 years old comprising 6 male and 6 female participated in this study. Subjects were required to fast 10-I 2 hours and they were required to consume each test meals (tannia and taro) and glucose reference at different time within 15 minutes. Finger-prick capillary blood samples were taken at 0, 15, 30, 45, 90 and 120 min after consumption of the test meals. Area under the curve (iAUC) was calculated geometrically and the GI value was determined according to the standardized methodology. Mean aged and BMI of subjects are 2 I .25 ± 0.5 years and 21.5 ± 1.3 kg/m2. This study shows the peak value of blood glucose response of tannia and glucose reference were at 30 minutes while taro at 45 minutes. This study shows that tannia had the lowest blood glucose response (1.8 ± I.I mmol/L) compared to taro (2.1 ± 1.0 mmol/L) and glucose reference (2.7 ± 0.5 mmol/L). This study also shows that peak blood glucose response for male subjects (2.3 ± 1.2 mmol/L) and glucose reference (2.7 ± 0.5 mmol/L) were at time interval 30 minutes while the peak blood glucose response for female subjects (2.3 ± 1.1 mmol/L) was at time interval 45 minute after taro being consumed while peak blood glucose response after tannia being consumed were (2.5 ± 0.8 mmol/L) for male, (I. I ± 1.0 mmol/L) for female and ( 2.7 ± 0.5 mmol/L) for glucose reference with respective blood glucose response at 30 minute. This study showed that tannia could be categorized as having intermediate GI (59 ± 0.3) while taro considered as high GI food (7.8 ± 9.5) and glucose reference with GI (100 ± 0). There was a significant different between GI values of tannia and glucose reference (p<0.05) while there was no significant difference between between GI value of taro and glucose reference (p>0.05). This study also shows there was no significant correlation between amount of fiber, fat and water with GI value of both test meals. Therefore, this study may provide useful information for dietitian and nutritionist to determine whether tannia and taro suitable or not for the diet of diabetics.