In this study the model systems between strawberry anthocyanins as pigment and rose polyphenols as copigment was investigated. The solutions were prepared from 1:2 to 1:10 pigment:copigment. The addition of increasing concentrations of rose petal polyphenols resulted in a gradual increase of hyperchromic effect. The absorption was determined at heating system from 20 to 50 ^oC and following cooling the same system from 50 to 20 ^oC. All calculated thermodynamic parameters were negative. The copigmentation reaction was determined as spontaneous, exothermic and thermally reversible.

The effect of temperature and concentrations on the stability of anthocyanin extract from aronia as pigment and sinapic acid as copigment was evaluated. Different temperatures and copigment concentrations were used for the investigation pigment:copigment interaction. Equilibrium constant of copigmentation process was determined. Thermodynamic parameters Gibbs free energy (ΔG), enthalpy (ΔH), entropy (ΔS) and kinetic parameters activation energy (Ea) and z – factor were calculated. At high temperatures, around 80 °C destruction was observed and after that at 25 °C, restoration of the complex was observed again according the calculations. This was conformation for reversibility of copigmentation process.

Different percent pumpkin oil was used to prepare food O/W emulsions. A stabilizer added soybean protein isolate. The thermodynamic properties of food emulsions were determined by spectroscopic measurements. pH determinations were applied in all emulsions and the values were found between 5.8 – 6.3 according application in foods. Thermodynamic parameters Gibbs free energy, enthalpy, and entropy were calculated after experiment. All parameters exhibit negative values. Some highest values of Gibbs free energy was seen in emulsions prepared with high pumpkin oil percent and determined this food emulsions as more stable.