Kinetics of lycopene degradation in tomato pulp solids under different processing and storage conditions

Kinetics of lycopene degradation during heating of tomato pulp at 100 degrees C under different conditions followed a pseudo first order reaction. When concentrating tomato pulp during heating, the rate of lycopene degradation was higher (K = 0.0023 min(-1)) compared with when heating was done without concentration (K = 0.0017 min(-1)). In another case, when water insoluble tomato pulp solids were heated in distilled water without concentration, rate of lycopene degradation was lowest (K = 0.0011 min(-1)), indicating that acids and sugars contributed towards loss of lycopene. When the fibre-rich fractions of tomato pulp were stored at -20, 5 and 25 degrees C under different storage conditions, the activation energy and Q(10) values of lycopene loss ranged from 19.87 to 27.74 kJ/mole and 1.35 to 1.52, respectively. When these fractions were freeze-dried and oven-dried (at 25-75 degrees C), lycopene content was not affected by heating temperature (P > 0.05). Copyright (C) 1996 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd