Abstract:Phenolic substances are important bioactive components in strawberries, which are unstable and easy to degrade. In order to explore the changing trend of the phenolic substances in dried strawberries during storage, the degradation kinetics of these compounds in the dried strawberries stored in different packages at 4, 20and 37 ℃ were examined. The results showed that the phenolic substances in dried strawberry were unstable to heat and light. With the increase of storage temperature, the degradation rate increased and the half-life decreased. At the same storage temperature, the degradation rate of the strawberries in vacuum light-proof packaging was the lowest, followed by those with vacuum light-transmitting packaging, non-vacuum light-proof packaging and non-vacuum light-transmitting packaging. The degradation of phenolic substances in the dried strawberries packaged with the four packagings all conformed to the first-order kinetic model, with their reaction activation energies as 22.45, 17.75, 18.91 and 17.42 kJ/mol, respectively. The correlation coefficients between the validated values of the strawberries in the four packaging materials obtained from the prediction model and the measured values, R2, were higher than 0.99, indicating the effectiveness of the model. The model can be used to predict the contents of phenolic substances stored at any temperature and the shelf life of dried strawberries. At the same time, the values of the thermodynamic parameters for the phenolic substances in the dried strawberries were calculated and analyzed, which provide a basis for explaining the degradation mechanism of phenolics.
