Saturday, August 4, 2012


Tomato is one of the most consumed vegetables in the world and most consumers associate its quality with color and taste. Of course texture also counts to some extent when tomato is eaten as a part of a salad. But the processing industry wants, above all, a firm texture that will enable shipping over long distances with minimum damage. With the advent of modern biotechnology, it is possible to impart any desirable characteristics to a plant as desired by the consumer or the processor. Modern day retailing system involves hauling food materials over long distance through road, rail, ship and air and naturally such long distance haulage can inflict heavy damage during transportation. During development of firm textured tomato varieties some genetic changes are brought about by the plant breeders to get a uniform color and texture and it appears such genetic tinkering  while imparting the color and texture sought after, also caused flavor changes making modern tomato practically a flavorless vegetable. The good old heirloom tomato with its characteristic juiciness and flavor has been relegated to oblivion and here is the sad story of such a transformation. 

It looks like 70 years of breeding for better color in unripe fruit has inadvertently helped create the wet-paper towel flavor of the modern tomato.  Growers care about the green of unripe tomatoes, explains biochemist Ann L. Thomas Powell of the University of California, Davis. Ripening globes that are each uniformly green let growers easily judge when a field will be ready for harvest. Over decades breeders have selected for this uniform green coloring instead of for tomatoes that turn a deeper shade around the stem end, Powell says. The problem is, getting rid of that dark green zone, called green shoulders, turns out to have sabotaged a gene called SlGLK2 that boosts sugar and other sources of flavor in the ripe tomato, Powell and her colleagues report in the June 29 Science. "It is a good illustration of unintended consequences," says molecular biologist Harry Klee of the University of Florida in Gainesville, who studies tomato flavor. For years, Powell says, breeders assumed that a ripe red tomato got all of its sugars from the little photosynthetic engines known as chloroplasts in the plant leaves. It turns out, however, that a green-shouldered tomato gets about 20 percent of its sugars from its own chloroplasts. Without a functional SlGLK2 gene, the ripening tomato forms fewer and punier chloroplasts that don't deliver, Powell and her colleagues have found.

The million dollar question is whether such gross changes in the original nature of a vegetable like Tomato is accepted readily by the consumer and is there still a yearning for the good old tomato? Probably the modern generation of consumers who were not acquainted with the original Tomato may not be too much bothered by the flavorless characteristics of the product available to day having had no chance to see and experience eating the real Tomato and therefore industry can get away with such brazen attempts to ignore flavor in preference to texture and color. Probably a time may come when there might be a renascence of old Tomato and consumers willing to pay a premium price as it has happened with organic foods.  


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