African Star Apple (Chrysophyllum Africanum) Gum and Its Oxidized Derivatives as Stabilizer for Water Melon Juice (Published)
The gum obtained from the pulp of Chrysophyllum africanum is highly insoluble. Chemical oxidation through hydrogen peroxide was used to degrade the gum. Physicochemical properties of the native and oxidized gums were determined while Fourier transform Infrared spectroscopy was used to study functional group changes. The amount of recovered gum reduced as the degree of oxidation increased and there was increase in the carboxyl content to a maximum of 57.06 %. Lower moisture content and high ash content were recorded for the oxidized gums. The oxidized gums were more soluble than the native gum. Viscosity reduced as the degree of oxidation increased. The maximum viscosity of the oxidized gum at 1% concentration was 2.385 mP.a.s. Maximum juice clarity and viscosity at 1% gum concentration were 81.56% and 2.974 mPa.s respectively. Oxidation improved the stability of water mellon juice over the storage period and therefore the potentials of the gum as stabilizer in drinks.
Keywords: African Star apple, Chrysophyllum africanum, Gums, Oxidation, physicochemical properties