Abstract
Under the acceleration of climate variability of Sudan, food storage should be undertaken seriously the moisture content and temperature which significantly affected the product quality. The objective of this study was to determine the adsorption and desorption equilibrium moisture content for Roselle Calyx. The study was carried out at the Faculty of Agriculture, University of Khartoum, Shambat, Sudan. Three adsorption isotherms (10?øC, 30?øC and 50?øC) and two desorption (30?øC and 50?øC) were used to determine equilibrium moistures content (EMC) of whole and broken Roselle calyx. Regression technique showed that no difference between adsorption and desorption equilibrium moisture content values for both whole and broken Roselle calyx. As relative humidity (RH%) increases up to 85% equilibrium moisture content will be increased, while Above 85% of relative humidity no equilibrium moisture content values were detected due to the growth of mould on the tested sample. On the other hand, temperature was found to have negative relationship with equilibrium moisture content. No hysteresis effects between adsorption and desorption equilibrium moisture content. The study recommended that whole or broken Roselle calyx could be stored safety at 10?øC – 50?øC air temperature and at a relative humidity below 85% to avoid mould growth on food stored.
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