IMPROVING TOMATO FRUIT QUALITY USING BIOSCIENCE

Tomatoes are used by consumers either as fresh tomato fruit or as processed products. The quality of tomatoes is of paramount importance to guarantee consumer satisfactions. Fruit quality parameters are different from fresh and processing tomatoes. We have studied tomato fruit ripening at the biochemical and molecular level in order to identify genes which make major contributions to fruit quality parameters. This approach has allowed us to isolate and characterise genes which control the rate of ripening, texture, colour and flavour.

These genes have been used to generate genetically modified tomatoes in which processing characteristics have been improved. Bostwick viscosity is greatly increased when the cell wall modifying enzyme, polygalacturonase, is inhibited. Serum viscosity is improved through the inhibition of pectinesterase. Inhibiting both enzymes leads additionally to an increase in Brix. Thus, the major quality parameters of the tomato processing industry can now be improved using these directed methods.