Effect of Drying Temperature on Quality of Spirogyra sp.

Abstract

Desorption isotherm of Spirogyra sp. was studied at the water activity range of 0.2 - 0.8. The data were fitted to 3 desorption isotherm models which were GAB, Halsey and Oswin models. GAB model was the best model to describe desorption isotherm of Spirogyra sp. The temperature of hot air drying process was studied in the range of 50 – 70^oC. The result showed drying temperature at 60^oC was the suitable condition to process dried Spirogyra sp. The texture and -carotene content of the dried sample at 60^oC were not significantly different from the dried sample at 50^oC but the drying time at 60^oC was shorter. Moreover, the dried sample at 60^oC showed the lowest color difference from the fresh sample and had significantly higher -carotene content than the dried sample at 70^oC.