Effect of Irradiation on Sprouting of Water Yam (Dioscorea Alata) Using Different Doses of Gamma Radiation

James Imeh,S A Jonah,M Y Onimisi

doi:10.5923/j.chemistry.20120203.07

James Imeh, S A Jonah + Show 1 more

Open Access

https://doi.org/10.5923/j.chemistry.20120203.07

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Abstract

Water yam (Dioscorea Alata) tuber samples from Abuja, Nigeria were irradiated with gamma radiation of doses 60, 80, 100, 120 and 140 gray respectively at an average dose rate of 3 gray/min and some un-irradiated used as control. All were monitored during storage for 7 months. Results indicated that all the un-irradiated water yams sprouted by the end of the 3rd month of storage. 90% of the irradiated water yams at 60 gray, 30% of the irradiated water yams at 80 gray and only 10% of the irradiated water yam at 100 gray sprouted within the storage period. None of the irradiated water yams at 120 and 140 gray sprouted. The results suggest that gamma radiation dose range of 100 - 140 gray could effectively inhibit sprouting in water yams for 7 months. 80% of the un-irradiated water yams rotted while none of the irradiated water yams rotted within the storage period. The percentage weight loss (64.79±13.45%) in the un-irradiated was significantly (p ≤ 0.05) higher than the irradiated tubers. There were no significant differences (p ≤ 0.05) in the average values of the lipid, protein and carbo- hydrate content of the irradiated and un-irradiated water yam tubers. The results suggest that radiation processing preserved the quality of water yam tubers through sprout inhibition, reduction of weight loss, preservation of macronutrients such as protein, lipid, and carbohydrate content.

Highlights

Yam is the second most important tuber crop in Africa next to cassava
The irradiated yams at 120 Gy and 140 Gy did not sprout. This shows that a dose range of 100 Gy – 140 Gy will completely inhibit sprouting in water yam
This study clearly demonstrates that gamma radiation at the dose of 100-140 Gy will effectively inhibit sprouting in water yam (Dioscorea alata) tubers

Summary

Introduction

Yam is the second most important tuber crop in Africa next to cassava. Nigeria is the main producer of yam globally with 71% of world production[1]. Yams are annual or perennial tuber-bearing and climbing plants with over 600 species in which only few are cultivated for food and medicine[2]. The most cultivated species in Nigeria are the white yam (D. rotundata), yellow yam (D. cayenensis), water yam (D. alata) and trifoliate yam (D. dumetorum)[3]. The crop is of major importance in the diet and economic life of people in West Africa, the Caribbean islands, parts of Asia, and Oceania[4]. Yam is an elite crop, preferred over other root and tuber crops of West Africa and a choice during ceremonies and festivities[5]

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