2.2.5. Cyclic temperature stress test
The cyclic temperature stress test is often used to predict long term emulsion stability. The following protocol for one cycle was used: (1) the samples were put in a refrigerator at–10 °C for 24 h; (2) the samples were allowed to thaw at room temperature (22 ± 2 °C) for 24 h; (3) the samples were put in a thermostatic chamber (INB 500, Memmert, Germany) at +40 °C for 24 h; (4) the samples were allowed to equilibrate at room temperature for 24 h. Six freeze–thaw cycles were performed. One sample was stored isothermally at room temperature, one isothermally at +4 °C and one isothermally at +40 °C during the cycling time. These samples were used for comparison.pH, conductivity and rheological measurements were performed after the 3rd and 6th cycle and compared with the results obtained for the control samples.