Physico-chemical characteristics of non-irradiated and γ-irradiated yams cultivars (Dioscorea rotundata, Dioscorea alata) and sweet potato (Ipomoea batatas (L) Lam)

Abstract

Physico-chemical (pasting) properties of non-irradiated (fresh) and γ-irradiated yam cultivars and sweet potato were determined using Rapid Visco Analyser (RVA). Generally, pasting characteristics of the commodities decreased significantly with increased γ-irradiation dose. Non-irradiated sweet potato showed significantly higher peak (45.79), trough (35.25), breakdown (10.54), final (75.21) and setback (39.96) viscosities (in RVU) than γ-irradiated samples. Also, peak time (6.97min) and pasting temperature (50.18 RVU) significantly reduced with increased γ-irradiation dose of tubers. The pasting properties of non-irradiated and γ-irradiated sweet potato showed similar but clearer trend compared with yam flours. Also, non-irradiated and γ-irradiated Dioscorea rotundata and Dioscorea alata showed significantly higher values of each of the pasting characteristics than values noted in sweet potato. Aside from the TDr 03/00196, peak time did not vary significantly with γ-irradiation dose. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.