Radiation sensitivity of an extract of roselle (Hibiscus sabdariffa L.)

Abstract

True roselle is Hibiscus sabdariffa L. (family Malvacea) which is cultivated for its jute-like fiber in India, the East Indies, Nigeria and to some extent in tropical America. More recently started a commercial production in Sao Paulo State, Brazil. An aqueous extract (1:4 w/v) of roselle was prepared and gamma-irradiated in a 60Co Gammacell 220 with doses of 0.5, 1.0, 2.0, 5.0 and 10.0 kGy. The radiation effect on color stability was followed spectrophotometrically. Viscosity changes were registered. The viscosity of roselle preparation appears to be quite stable against radiation oxidative shock. Meanwhile, the absorbance at 500nm declined sharply with the increment of dose.