A study on thermal stability of lycopene in tomato in water and oil food systems using response surface methodology

P>Thermal processed tomato-food products rich in Z-lycopene isomers have demonstrated higher bioactivity compared to fresh products which contain mainly all-E-lycopene isomer. The objectives of this study were to optimise processing conditions for production of tomato products rich in Z-lycopene isomers in water and oil systems. The results showed that the optimal conditions for water and oil systems were temperature 120 degrees C, heating time 2.14 h, and the percentage of Z-lycopene isomers content was 51 +/- 1% and 57 +/- 2%, respectively. The ratio of tomato extract to oil/water had no influence on the Z-lycopene formation. Therefore, from these results it can be concluded that the combination of high temperature and relatively short heat treatment time could improve formation of Z-lycopene isomers or degradation of Z-isomers is lower during tomato processing .These research results could be useful in assisting the industry to improve processing technology, nutritional value and health-benefits of tomato-based foods.