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

Abstract

Kinetics of lycopene degradation during heating of tomato pulp at 100 °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 °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 °C), lycopene content was not affected by heating temperature ( P > 0.05).