Control of Browning of Yam (Dioscorea rotundata) and Sweet potato (Ipomoea batatas) using African Cardamon (Aframomum danielli), Turmeric (Curcuma longa) and Clove (Syzygiumnn aromaticum)

Abstract

This study was carried out to evaluate the effect of using the aqueous extracts of Aframomum danielli, Turmeric and Clove at different concentrations of 5%, 10% and 15% as pretreatments in controlling browning of yam (Dioscorea rotundata) and sweet potato (Ipomoea batatas). Colour measurements were carried out on the untreated (control) and pretreated yam and sweet potato slices, using reflectance spectroscopy. The L* and a* values obtained for the control samples were compared with those of the pretreated yam and sweet potato samples. The inhibition of enzymatic browning in the samples was indicated by an increase in the “L*” values which ranged from 81.60 to 62.66 for yam samples and from 81.52 to 62.03 for sweet potato samples; browning was also associated to a decrease in the “a*” values for all the samples, which ranged from 4.29 to -1.86 for yam samples and 4.02 to -2.46 for sweet potato samples. Aqueous extracts of Aframomum danielli at minimum concentrations of 5% and 10% were found to be effective in controlling browning reactions in the pretreated yam slices and sweet potato slices respectively.