The emulsifying properties of Persian gum (Amygdalus scoparia Spach) as compared with gum Arabic

The current study compares the emulsifying properties of Persian gum (PG) and gum Arabic (GA) in emulsions. The effects of concentration (0.5-3% w/v PG, 2.5-15% w/v PG), pH (2-7), ionic strength [NaCl, CaCl2 (0-300mM)], and temperature (40-90 degrees C) were investigated. The surface-volume mean diameter (D-32) of the emulsions showed that the minimum values were 9.89 +/- 0.68 and 4.52 +/- 0.03 mu m for emulsions containing 1.5% w/v PG and 15% w/v GA, respectively. In addition, the zeta potential of PG and GA emulsion changed from -23.5 to -39.5 and -30.5 to -46.0mV, respectively. The interfacial tensions of PG and GA emulsions were varied in the ranges of 34.0-15.0 and 29.0-9.0mN/m, respectively. Changes in the D-32 value of GA emulsions showed were not significantly different (p>0.05) with respect to the effects of pH, NaCl, CaCl2, and temperature. The NaCl concentration had no significant effect on D-32; but its value decreased from 13.11 to 5.70 mu m as the CaCl2 concentration increased. The interfacial tension of PG significantly increased with decreasing pH 7-2 and increasing 0-300mM salts. After heating (25-90 degrees C), the D-32 values of PG and GA emulsions changed to 11.04-14.54 and 4.21-4.21m, respectively. The results of this study can be useful for the application of PG as an emulsifier in beverage emulsions. [GRAPHICS]