Antioxidant Potential and Emulsifying Properties of Neem (Azadirachitaindica, Family Meliaceae) Gum Polysaccharide

Abstract

Neem Gum (NG) is exudates of plant. Crude NG was purified using water as solvent and ethyl alcohol as precipitating agent. Effect of temperature and concentration on the surface tension of neem gum was determined. Emulsifying properties of gum was evaluated using sunflower as oil phase and purified water as continuous phase further prepared emulsions were evaluated in terms of globular size, flow rate, emulsion capacity and emulsion stability, foam capacity and foam stability and creaming (%). Free radical scavenging properties of polymer was also studied using ascorbic acid as standard against DPPH and H2O2 as initiator. At higher concentration of NG better emulsifying and foaming properties were observed due to reduction in rate of coalescence and creaming. Globular size of prepared emulsions does not changed significantly after 45 days. The effective concentration (EC50) sufficient to scavenge 50% of free radical generated using DPPH was found to be 4.55 μg/ml ± 0.98 and 29 μg/ml ± 1.21 for ascorbic acid and NG respectively. The effective concentration (EC50) sufficient to scavenge 50% of hydroxyl ions generated using H2O2 was calculated and found to be 55.27 μg/ml ± 0.67 and 71.36 μg/ml ± 0.87 for ascorbic acid and NG respectively. So it can be concluded from the findings of the results that Ng can be used as emulsifying agents in food, cosmetic and pharmaceutical industry with significant antioxidant potential.