|Scott, John - UNIVERSITY OF FLORIDA|
|Shewfelt, Robert - UNIVERSITY OF GEORGIA|
Submitted to: Tomato Quality Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 10, 1996
Publication Date: N/A
Interpretive Summary: Consumers are often dissatisfied with the flavor quality of tomatoes. Tomatoes must be harvested green to survive shipment and ripen on route to market. In an attempt to improve this situation tomatoes have been genetically manipulated to ripen more slowly so that they can be harvested at a more mature stage (with some red color) and still endure long distance eshipping without incurring undue losses. It is assumed that tomatoes harvested with red color will result in a superior quality product than those harvested green. However, in this study some genetically altered fruit were found to have lower levels of important flavor volatiles and were rated lower by a sensory panel than high quality normal tomatoes.
Technical Abstract: One goal of genetic manipulation of tomatoes is to slow softening or delay ripening in order to harvest fruit at a more mature state without incurring undue losses during shipping and handling. In theory, later harvest maturity should indirectly improve the flavor of tomatoes. In this study, tomato mutant hybrids (normal tomatoes crossed with naturally occurring non-ripening mutants) and transgenic tomatoes with down-regulated polygalacturonase (an enzyme thought to induce softening) were compared to normal tomatoes harvested at different maturity stages for soluble solids, titratable acidity, flavor volatiles, firmness, and shelf life. Results showed that the mutant hybrids were often lower in important flavor volatiles. A consumer sensory panel rated a normal cultigen over 2 mutant hybrids for overall flavor quality although soluble solids, sugar levels and titratable acidity were similar in these cultigens. The difference was deduced to be a result of flavor volatiles.