Arrhenius equation modeling for the shelf life prediction of tomato paste containing a natural preservative

The shelf life of tomato paste with microencapsulated olive leaf extract was compared with that of samples containing a commercial preservative by accelerated shelf life testing. Based on previous studies showing that olive leaf extract as a rich source of phenolic compounds can have antimicrobial properties, application of its encapsulated form to improve the storage stability of tomato paste is proposed here.

Regarding total soluble solids, the control and the sample containing 1000 µg g^-1 sodium benzoate had the lowest (Q₁₀  = 1.63) and highest (Q₁₀  = 1.88) sensitivity to temperature changes respectively; also, the microencapsulated sample containing 1000 µg g^-1 encapsulated olive leaf extract (Q₁₀  = 1.83) followed the sample containing 1000 µg g^-1 sodium benzoate in terms of the highest kinetic rates. In the case of consistency, the lowest and highest activation energies (E_a ) corresponded to samples containing 1000 µg g^-1 non-encapsulated olive leaf extract and 1000 µg g^-1 microencapsulated olive leaf extract respectively.

Interestingly, samples containing microencapsulated olive leaf extract could maintain the original quality of the tomato paste very well, while those with non-encapsulated olive leaf extract rated the worst performance (among all specimens) in terms of maintaining their quality indices for a long time period. Overall, the shelf life equation was able to predict the consistency index of all tomato paste samples during long-time storage with high precision. © 2017 Society of Chemical Industry.