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

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 purée to different temperature treatments (60, 80, 100, and 120 °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 °C heating favoured the isomerization of lycopene. Heating treatment at 120 °C and long time heating treatment at 100 °C improved the extraction of lycopene from purée matrix. Color change of tomato purée was inconsistent because the measured value was affected by the different extractability of lycopene in purée matrix. Exposure to light caused no significant change to total and all-trans lycopene, although significant loss of cis-isomer lycopene was observed.