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

Abstract

ABSTRACTThe 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 (0–300 mM)], and temperature (40–90°C) were investigated. The surface–volume mean diameter (D32) of the emulsions showed that the minimum values were 9.89 ± 0.68 and 4.52 ± 0.03 µm 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 −46.0 mV, respectively. The interfacial tensions of PG and GA emulsions were varied in the ranges of 34.0–15.0 and 29.0–9.0 mN/m, respectively. Changes in the D32 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 D32; but its value decreased from 13.11 to 5.70 µm as the CaCl2 concentration increased. The interfacial tension of PG significantly increased with decreasing pH 7–2 and increasing 0–300 mM salts. After heating (25–90°C), the D32 values of PG and GA emulsions changed to 11.04–14.54 and 4.21–4.21 μm, respectively. The results of this study can be useful for the application of PG as an emulsifier in beverage emulsions.