ZETA POTENTIALS OF TRISTEAROYLGLYCEROL CRYSTALS IN OLIVE OIL

The zeta potential of tristcaroylglycerol crystals suspended in olive oil was determined by means of electrophoretic light scattering at high field strengths. The effects of various additives (electrolytes, fatty acids, monoacylglycerols, phospholipids) to the oil phase were investigated. The zeta potentials were generally found to be positive and were strongly influenced by the presence of contaminants or additives. Their values appear to be determined by the presence of native or adsorbed proton acceptor groups on the crystal surface. Phosphatidylcholine proved to be the most effective additive: addition of 0.045% (w/w) to the oil raised the zeta potential from about 10 to 60 mV.