Glycaemic responses of some varieties of cocoyam in Nigeria using normo-glycaemic subjects

Abstract

Background: Cocoyam is part of the meal in dietary management of type 2 diabetes. However, information on glycaemic responses of normo-glycaemic subjects to some cocoyam varieties are limited.

Objective: The study determined the postprandial glycaemic responses of normo-glycaemic subjects to four different varieties of cocoyam.

Methods: The cocoyam varieties used were Xanthosoma sagittifolium, Xanthosoma atrovirens, Colocasia esculenta, and Colocasia spp. The samples were prepared and cooked, with salt, until softened and proximate composition then determined. The glycaemic index (GI) of each sample was determined. The amounts that would deliver 50g glycaemic carbohydrates and glucose solution (50g in 300ml potable water 25⁰C, 1:6w/v) were served to 9 normo-glycaemic subjects after an over-night fast. Their glycaemic responses were checked at 0 (base-line), 30, 60, 90 and 120 minute. Analysis of variance was used to separate the mean.

Results: The total carbohydrate of ede uhie (73.10g100^-g) and ede okoriko (72.76g100^-g) were significantly (p < 0.05) different from cocondia (63.51g100^-g) and ede anambe (61.80g 100^-g); edeanambe (5.46g100^-g) had significantly different crude fibre from the other samples. Ede uhie had the highest energy value (349.53 Kcal); whereas cocondia had the highest (7.96g 100^-g) protein. Mean glucose responses of the subjects ranged from 70.8-92.2mg^–dl (baseline) to 65-85.2mg^–dl. The GI was intermediate (45-55) for ede uhie (47) and cocondia (52) whereas ede anambe (21) and ede okoriko (22) had very low GI (21-22).

Conclusion: Ede anambe had the least GI. It should form a greater part of the meal used in the dietary management of type 2 diabetes.

Keywords: Cocoyam varieties, glycaemic index, postprandial glucose