Degradation kinetics of lycopene, β-carotene and ascorbic acid in tomatoes during hot air drying

Degradation kinetics of lycopene, β-carotene and ascorbic acid in tomato quarters of Rio Grande variety were determined during hot air drying. Tomato quarters were dried at five different temperatures (60, 70, 80, 90 and 100 °C) in a cabinet drier at an airflow rate of 0.2 m/s and 20% relative humidity. Degradation kinetics of lycopene, β-carotene and ascorbic acid in tomato quarters during hot air drying followed a first-order reaction. Drying temperature had a significant influence on the loss of lycopene, β-carotene and ascorbic acid in tomato quarters. The range of the reaction rate constants for lycopene, β-carotene and ascorbic acid losses were 0.078-0.448, 0.084-0.38, and 0.076-0.472 h−1, respectively. Activation energy calculated for lycopene and ascorbic acid was about 47 kJ/mol, and 40 kJ/mol for β-carotene. The most effective temperature change in tomatoes was from 70 to 80 °C for lycopene and β-carotene degradation, while it was from 60 to 70 °C for ascorbic acid degradation.

► Lycopene, β-carotene and ascorbic acid degradation follow a first-order reaction. ► Activation energy values range from 40 to 47 kJ/mol ► Reaction rate constants for lycopene and β-carotene are similar. ► Ascorbic acid is more susceptible to changes in drying temperature than others.