Lycopene isomerization during processing

Shi and Le Maguer (2000) recently showed that the main causes of tomato lycopene degradation during processing are isomerization and oxidation. Thermal processing generally causes some loss of lycopene in tomato-based foods. In general, dehydrated and powdered tomatoes have poor lycopene... 

The present volume also addresses the issue of processing and its effects on the bioavailability of bioactives. It shows that processing of a functional food may have profound effects on specific health benefits it claims to deliver. As illustrated in Chapter 4, the physiological effects of lycopene are altered significantly during processing, primarily due to its isomerization and oxidation. Worth noting, however,... 

Bioactivity potency of lycopene is dependent on the extent of degradation due to isomerization and oxidation. The main causes of lycopene degradation during food processing are oxidation and isomerization. Determination of the extent of lycopene isomerization would provide better insights into the potential health benefits of processed food products. In processed foods, oxidation is a complex process and depends upon many factors, such as processing conditions, moisture, temperature, and the presence of pro- or antioxidants and of lipids. The characterization and quantification of isomers would be desirable to more accurately assess the bioactivity than just the total lycopene content with no knowledge of its isomeric composition. 

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