Modeling quality changes in tomato paste containing microencapsulated olive leaf extract by accelerated shelf life testing

• Arrhenius and shelf life equations were used to predict tomato paste color and pH.
• The lowest activation energy, Ea was related to un-encapsulated olive leaf extract.
• Samples with encapsulated olive leaf extract had the closest Q10 for color and pH.

In this research, Arrhenius equation accelerated shelf life testing (ASLT) were applied to predict color and pH indices of bulk tomato paste containing microencapsulated and non-encapsulated olive leaf extract. Seven samples of tomato paste containing 500 and 1000 ppm non-encapsulated olive leaf extract (NC 500 and NC 1000), 500 and 1000 ppm microencapsulated olive leaf extract (C 500 and C 1000), and 500 and 1000 ppm sodium benzoate (B 500 and B 1000) along with control sample were prepared and investigated at three temperatures of 30, 40 and 50 (°C). Control and B 1000 samples, respectively yielded the highest (0.022 day−1) and lowest (0.003 day−1) rate constants for both color and pH change. In the case of pH and among different treatments, the lowest and highest activation energies, Ea were related to NC 500 and B 1000 samples, respectively; interestingly pH rate constants of encapsulated samples were higher than non-encapsulated ones and even higher than benzoate sample (only at the level of 500 ppm). Also, ASLT procedure could estimate changes in color of C 500 and pH of C 1000 samples better than other samples (during storage time).