Chemical Properties, in vitro Starch Digestibility and the Estimated Glycemic Index of Water Yam, Cocoyam, Sweet Potato and Cassava

• O.A. Afolabi

  Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

  Author

• P.M. Osamudiamen

  Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

  Author

• O.F. Osundahunsi

  Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

  Author

This study characterised the most cultivated and consumed roots and tubers (cocoyam, sweet potato and cassava-TMS 0581, except water yam) in Nigeria, based on their chemical composition, in vitro starch digestibility and the estimated glycemic index. Samples were analysed for proximate composition, resistant starch, amylose content, in vitro starch digestibility and the estimated glycemic index using standard analytical methods. The result showed that the moisture content of the samples ranged from 11.67 to 12.63% dry matter; ash content (3.20-3.98%); fat content (1.14-2.65%); crude fibre (1.03-2.34%); protein content (1.56-4.75%); carbohydrate content (86.28-92.99%); energy value (387.97-390.66 Kcal/ 100 g); amylose (21.30-32.67%) and resistant starch (4.73-15.23 g/ 100 g). The in vitro starch digestibility ranged from 1.34 mg/ g to 3.19 mg/ g and the estimated glycemic index from 53.57 to 63.79%. Water yam with the least values of in vitro starch digestibility and the estimated glycemic index can be used as a suitable and reliable low glycemic index food for diabetic patients because of its potential to undergo a slower but gradual release of glucose into the blood stream.

1. O.A. Afolabi, Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

   Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

2. P.M. Osamudiamen, Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

   Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

3. O.F. Osundahunsi, Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

   Department of Food Science and Technology, Federal University of Technology, PMB 704, Akure, Nigeria

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