Effects of Temperature and Variety on Rehydration Parameters and Solute Loss during Soaking of Omakwa and Abrohemaa Maize Varieties

Abstract

This study was carried out to investigate the effects of soaking temperature and variety on the rehydration parameters and solute loss (essential minerals and vitamin C) of two maize varieties. Sun-dried kernels of the maize varieties (Omakwa and Abrohemaa) were soaked at four different water temperatures of 30oC, 40oC, 50oC and 60oC in a thermostatic water bath and the rehydration parameters determined. Temperature and variety were the two principal factors found to influence water uptake by the kernels. The highest rehydration ratio of 13.28 and 14.65 for Omakwa and Abrohemaa respectively occurred at the highest soaking temperature of 60oC. The quantitative analysis of solute loss (phosphorus, sodium, potassium and vitamin C) carried out reveals that large amounts of Potassium and vitamin C leached into the soaking water at higher water temperatures while residual amount of sodium saw an initial increase before decreasing to a low value as the temperature increases. For phosphorus, larger residual amounts were obtained at low to moderate soaking temperatures while a further increase in soaking temperature beyond 50oC resulted in a decrease. Soaking at temperatures of 40oC and 50oC were found to retain more nutrients hence moderate temperature of 40oC ≤X≤ 50oC may be considered for soaking of Omakwa and Abrohemaa maize varieties.