Effect of heating and exposure to light on the stability of lycopene in tomato puree

Lycopene is a powerful natural antioxidant. Epidemiological studies have associated its consumption with numerous health benefits. The effects of heating and exposure to light on lycopene were investigated by exposing tomato puree to different temperature treatments (60, 80, 100, and 120 degrees C, 1-6 h) and exposure to light (light intensity similar to normal indoor condition, 1-6 days). The results showed that 60 and 80 degrees C heating favoured the isomerization of lycopene. Heating treatment at 120 degrees C and long time heating treatment at 100 degrees C improved the extraction of lycopene from puree matrix. Color change of tomato puree was inconsistent because the measured value was affected by the different extractability of lycopene in puree matrix. Exposure to light caused no significant change to total and all-trans lycopene, although significant loss of cis-isomer lycopene was observed. Crown Copyright (c) 2007 Published by Elsevier Ltd. All rights reserved.